/*
 * Copyright © 2019 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <string.h>
#include <stdlib.h>
#include <assert.h>

#include <vulkan/vulkan.h>
#include <vulkan/vk_layer.h>

#include "git_sha1.h"

#include "imgui.h"

#include "overlay_params.h"

#include "util/debug.h"
#include "util/hash_table.h"
#include "util/list.h"
#include "util/ralloc.h"
#include "util/os_time.h"
#include "util/os_socket.h"
#include "util/simple_mtx.h"

#include "vk_enum_to_str.h"
#include "vk_util.h"

/* Mapped from VkInstace/VkPhysicalDevice */
struct instance_data {
   struct vk_instance_dispatch_table vtable;
   VkInstance instance;

   struct overlay_params params;
   bool pipeline_statistics_enabled;

   bool first_line_printed;

   int control_client;

   /* Dumping of frame stats to a file has been enabled. */
   bool capture_enabled;

   /* Dumping of frame stats to a file has been enabled and started. */
   bool capture_started;
};

struct frame_stat {
   uint64_t stats[OVERLAY_PARAM_ENABLED_MAX];
};

/* Mapped from VkDevice */
struct queue_data;
struct device_data {
   struct instance_data *instance;

   PFN_vkSetDeviceLoaderData set_device_loader_data;

   struct vk_device_dispatch_table vtable;
   VkPhysicalDevice physical_device;
   VkDevice device;

   VkPhysicalDeviceProperties properties;

   struct queue_data *graphic_queue;

   struct queue_data **queues;
   uint32_t n_queues;

   /* For a single frame */
   struct frame_stat frame_stats;
};

/* Mapped from VkCommandBuffer */
struct command_buffer_data {
   struct device_data *device;

   VkCommandBufferLevel level;

   VkCommandBuffer cmd_buffer;
   VkQueryPool pipeline_query_pool;
   VkQueryPool timestamp_query_pool;
   uint32_t query_index;

   struct frame_stat stats;

   struct list_head link; /* link into queue_data::running_command_buffer */
};

/* Mapped from VkQueue */
struct queue_data {
   struct device_data *device;

   VkQueue queue;
   VkQueueFlags flags;
   uint32_t family_index;
   uint64_t timestamp_mask;

   VkFence queries_fence;

   struct list_head running_command_buffer;
};

struct overlay_draw {
   struct list_head link;

   VkCommandBuffer command_buffer;

   VkSemaphore semaphore;
   VkFence fence;

   VkBuffer vertex_buffer;
   VkDeviceMemory vertex_buffer_mem;
   VkDeviceSize vertex_buffer_size;

   VkBuffer index_buffer;
   VkDeviceMemory index_buffer_mem;
   VkDeviceSize index_buffer_size;
};

/* Mapped from VkSwapchainKHR */
struct swapchain_data {
   struct device_data *device;

   VkSwapchainKHR swapchain;
   unsigned width, height;
   VkFormat format;

   uint32_t n_images;
   VkImage *images;
   VkImageView *image_views;
   VkFramebuffer *framebuffers;

   VkRenderPass render_pass;

   VkDescriptorPool descriptor_pool;
   VkDescriptorSetLayout descriptor_layout;
   VkDescriptorSet descriptor_set;

   VkSampler font_sampler;

   VkPipelineLayout pipeline_layout;
   VkPipeline pipeline;

   VkCommandPool command_pool;

   struct list_head draws; /* List of struct overlay_draw */

   bool font_uploaded;
   VkImage font_image;
   VkImageView font_image_view;
   VkDeviceMemory font_mem;
   VkBuffer upload_font_buffer;
   VkDeviceMemory upload_font_buffer_mem;

   /**/
   ImGuiContext* imgui_context;
   ImVec2 window_size;

   /**/
   uint64_t n_frames;
   uint64_t last_present_time;

   unsigned n_frames_since_update;
   uint64_t last_fps_update;
   double fps;

   enum overlay_param_enabled stat_selector;
   double time_dividor;
   struct frame_stat stats_min, stats_max;
   struct frame_stat frames_stats[200];

   /* Over a single frame */
   struct frame_stat frame_stats;

   /* Over fps_sampling_period */
   struct frame_stat accumulated_stats;
};

static const VkQueryPipelineStatisticFlags overlay_query_flags =
   VK_QUERY_PIPELINE_STATISTIC_INPUT_ASSEMBLY_VERTICES_BIT |
   VK_QUERY_PIPELINE_STATISTIC_INPUT_ASSEMBLY_PRIMITIVES_BIT |
   VK_QUERY_PIPELINE_STATISTIC_VERTEX_SHADER_INVOCATIONS_BIT |
   VK_QUERY_PIPELINE_STATISTIC_GEOMETRY_SHADER_INVOCATIONS_BIT |
   VK_QUERY_PIPELINE_STATISTIC_GEOMETRY_SHADER_PRIMITIVES_BIT |
   VK_QUERY_PIPELINE_STATISTIC_CLIPPING_INVOCATIONS_BIT |
   VK_QUERY_PIPELINE_STATISTIC_CLIPPING_PRIMITIVES_BIT |
   VK_QUERY_PIPELINE_STATISTIC_FRAGMENT_SHADER_INVOCATIONS_BIT |
   VK_QUERY_PIPELINE_STATISTIC_TESSELLATION_CONTROL_SHADER_PATCHES_BIT |
   VK_QUERY_PIPELINE_STATISTIC_TESSELLATION_EVALUATION_SHADER_INVOCATIONS_BIT |
   VK_QUERY_PIPELINE_STATISTIC_COMPUTE_SHADER_INVOCATIONS_BIT;
#define OVERLAY_QUERY_COUNT (11)

static struct hash_table_u64 *vk_object_to_data = NULL;
static simple_mtx_t vk_object_to_data_mutex = _SIMPLE_MTX_INITIALIZER_NP;

thread_local ImGuiContext* __MesaImGui;

static inline void ensure_vk_object_map(void)
{
   if (!vk_object_to_data)
      vk_object_to_data = _mesa_hash_table_u64_create(NULL);
}

#define HKEY(obj) ((uint64_t)(obj))
#define FIND(type, obj) ((type *)find_object_data(HKEY(obj)))

static void *find_object_data(uint64_t obj)
{
   simple_mtx_lock(&vk_object_to_data_mutex);
   ensure_vk_object_map();
   void *data = _mesa_hash_table_u64_search(vk_object_to_data, obj);
   simple_mtx_unlock(&vk_object_to_data_mutex);
   return data;
}

static void map_object(uint64_t obj, void *data)
{
   simple_mtx_lock(&vk_object_to_data_mutex);
   ensure_vk_object_map();
   _mesa_hash_table_u64_insert(vk_object_to_data, obj, data);
   simple_mtx_unlock(&vk_object_to_data_mutex);
}

static void unmap_object(uint64_t obj)
{
   simple_mtx_lock(&vk_object_to_data_mutex);
   _mesa_hash_table_u64_remove(vk_object_to_data, obj);
   simple_mtx_unlock(&vk_object_to_data_mutex);
}

/**/

#define VK_CHECK(expr) \
   do { \
      VkResult __result = (expr); \
      if (__result != VK_SUCCESS) { \
         fprintf(stderr, "'%s' line %i failed with %s\n", \
                 #expr, __LINE__, vk_Result_to_str(__result)); \
      } \
   } while (0)

/**/

static VkLayerInstanceCreateInfo *get_instance_chain_info(const VkInstanceCreateInfo *pCreateInfo,
                                                          VkLayerFunction func)
{
   vk_foreach_struct(item, pCreateInfo->pNext) {
      if (item->sType == VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO &&
          ((VkLayerInstanceCreateInfo *) item)->function == func)
         return (VkLayerInstanceCreateInfo *) item;
   }
   unreachable("instance chain info not found");
   return NULL;
}

static VkLayerDeviceCreateInfo *get_device_chain_info(const VkDeviceCreateInfo *pCreateInfo,
                                                      VkLayerFunction func)
{
   vk_foreach_struct(item, pCreateInfo->pNext) {
      if (item->sType == VK_STRUCTURE_TYPE_LOADER_DEVICE_CREATE_INFO &&
          ((VkLayerDeviceCreateInfo *) item)->function == func)
         return (VkLayerDeviceCreateInfo *)item;
   }
   unreachable("device chain info not found");
   return NULL;
}

static struct VkBaseOutStructure *
clone_chain(const struct VkBaseInStructure *chain)
{
   struct VkBaseOutStructure *head = NULL, *tail = NULL;

   vk_foreach_struct_const(item, chain) {
      size_t item_size = vk_structure_type_size(item);
      struct VkBaseOutStructure *new_item =
         (struct VkBaseOutStructure *)malloc(item_size);;

      memcpy(new_item, item, item_size);

      if (!head)
         head = new_item;
      if (tail)
         tail->pNext = new_item;
      tail = new_item;
   }

   return head;
}

static void
free_chain(struct VkBaseOutStructure *chain)
{
   while (chain) {
      void *node = chain;
      chain = chain->pNext;
      free(node);
   }
}

/**/

static struct instance_data *new_instance_data(VkInstance instance)
{
   struct instance_data *data = rzalloc(NULL, struct instance_data);
   data->instance = instance;
   data->control_client = -1;
   map_object(HKEY(data->instance), data);
   return data;
}

static void destroy_instance_data(struct instance_data *data)
{
   if (data->params.output_file)
      fclose(data->params.output_file);
   if (data->params.control >= 0)
      os_socket_close(data->params.control);
   unmap_object(HKEY(data->instance));
   ralloc_free(data);
}

static void instance_data_map_physical_devices(struct instance_data *instance_data,
                                               bool map)
{
   uint32_t physicalDeviceCount = 0;
   instance_data->vtable.EnumeratePhysicalDevices(instance_data->instance,
                                                  &physicalDeviceCount,
                                                  NULL);

   VkPhysicalDevice *physicalDevices = (VkPhysicalDevice *) malloc(sizeof(VkPhysicalDevice) * physicalDeviceCount);
   instance_data->vtable.EnumeratePhysicalDevices(instance_data->instance,
                                                  &physicalDeviceCount,
                                                  physicalDevices);

   for (uint32_t i = 0; i < physicalDeviceCount; i++) {
      if (map)
         map_object(HKEY(physicalDevices[i]), instance_data);
      else
         unmap_object(HKEY(physicalDevices[i]));
   }

   free(physicalDevices);
}

/**/
static struct device_data *new_device_data(VkDevice device, struct instance_data *instance)
{
   struct device_data *data = rzalloc(NULL, struct device_data);
   data->instance = instance;
   data->device = device;
   map_object(HKEY(data->device), data);
   return data;
}

static struct queue_data *new_queue_data(VkQueue queue,
                                         const VkQueueFamilyProperties *family_props,
                                         uint32_t family_index,
                                         struct device_data *device_data)
{
   struct queue_data *data = rzalloc(device_data, struct queue_data);
   data->device = device_data;
   data->queue = queue;
   data->flags = family_props->queueFlags;
   data->timestamp_mask = (1ull << family_props->timestampValidBits) - 1;
   data->family_index = family_index;
   list_inithead(&data->running_command_buffer);
   map_object(HKEY(data->queue), data);

   /* Fence synchronizing access to queries on that queue. */
   VkFenceCreateInfo fence_info = {};
   fence_info.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
   fence_info.flags = VK_FENCE_CREATE_SIGNALED_BIT;
   VK_CHECK(device_data->vtable.CreateFence(device_data->device,
                                            &fence_info,
                                            NULL,
                                            &data->queries_fence));

   if (data->flags & VK_QUEUE_GRAPHICS_BIT)
      device_data->graphic_queue = data;

   return data;
}

static void destroy_queue(struct queue_data *data)
{
   struct device_data *device_data = data->device;
   device_data->vtable.DestroyFence(device_data->device, data->queries_fence, NULL);
   unmap_object(HKEY(data->queue));
   ralloc_free(data);
}

static void device_map_queues(struct device_data *data,
                              const VkDeviceCreateInfo *pCreateInfo)
{
   for (uint32_t i = 0; i < pCreateInfo->queueCreateInfoCount; i++)
      data->n_queues += pCreateInfo->pQueueCreateInfos[i].queueCount;
   data->queues = ralloc_array(data, struct queue_data *, data->n_queues);

   struct instance_data *instance_data = data->instance;
   uint32_t n_family_props;
   instance_data->vtable.GetPhysicalDeviceQueueFamilyProperties(data->physical_device,
                                                                &n_family_props,
                                                                NULL);
   VkQueueFamilyProperties *family_props =
      (VkQueueFamilyProperties *)malloc(sizeof(VkQueueFamilyProperties) * n_family_props);
   instance_data->vtable.GetPhysicalDeviceQueueFamilyProperties(data->physical_device,
                                                                &n_family_props,
                                                                family_props);

   uint32_t queue_index = 0;
   for (uint32_t i = 0; i < pCreateInfo->queueCreateInfoCount; i++) {
      for (uint32_t j = 0; j < pCreateInfo->pQueueCreateInfos[i].queueCount; j++) {
         VkQueue queue;
         data->vtable.GetDeviceQueue(data->device,
                                     pCreateInfo->pQueueCreateInfos[i].queueFamilyIndex,
                                     j, &queue);

         VK_CHECK(data->set_device_loader_data(data->device, queue));

         data->queues[queue_index++] =
            new_queue_data(queue, &family_props[pCreateInfo->pQueueCreateInfos[i].queueFamilyIndex],
                           pCreateInfo->pQueueCreateInfos[i].queueFamilyIndex, data);
      }
   }

   free(family_props);
}

static void device_unmap_queues(struct device_data *data)
{
   for (uint32_t i = 0; i < data->n_queues; i++)
      destroy_queue(data->queues[i]);
}

static void destroy_device_data(struct device_data *data)
{
   unmap_object(HKEY(data->device));
   ralloc_free(data);
}

/**/
static struct command_buffer_data *new_command_buffer_data(VkCommandBuffer cmd_buffer,
                                                           VkCommandBufferLevel level,
                                                           VkQueryPool pipeline_query_pool,
                                                           VkQueryPool timestamp_query_pool,
                                                           uint32_t query_index,
                                                           struct device_data *device_data)
{
   struct command_buffer_data *data = rzalloc(NULL, struct command_buffer_data);
   data->device = device_data;
   data->cmd_buffer = cmd_buffer;
   data->level = level;
   data->pipeline_query_pool = pipeline_query_pool;
   data->timestamp_query_pool = timestamp_query_pool;
   data->query_index = query_index;
   list_inithead(&data->link);
   map_object(HKEY(data->cmd_buffer), data);
   return data;
}

static void destroy_command_buffer_data(struct command_buffer_data *data)
{
   unmap_object(HKEY(data->cmd_buffer));
   list_delinit(&data->link);
   ralloc_free(data);
}

/**/
static struct swapchain_data *new_swapchain_data(VkSwapchainKHR swapchain,
                                                 struct device_data *device_data)
{
   struct instance_data *instance_data = device_data->instance;
   struct swapchain_data *data = rzalloc(NULL, struct swapchain_data);
   data->device = device_data;
   data->swapchain = swapchain;
   data->window_size = ImVec2(instance_data->params.width, instance_data->params.height);
   list_inithead(&data->draws);
   map_object(HKEY(data->swapchain), data);
   return data;
}

static void destroy_swapchain_data(struct swapchain_data *data)
{
   unmap_object(HKEY(data->swapchain));
   ralloc_free(data);
}

struct overlay_draw *get_overlay_draw(struct swapchain_data *data)
{
   struct device_data *device_data = data->device;
   struct overlay_draw *draw = list_is_empty(&data->draws) ?
      NULL : list_first_entry(&data->draws, struct overlay_draw, link);

   VkSemaphoreCreateInfo sem_info = {};
   sem_info.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;

   if (draw && device_data->vtable.GetFenceStatus(device_data->device, draw->fence) == VK_SUCCESS) {
      list_del(&draw->link);
      VK_CHECK(device_data->vtable.ResetFences(device_data->device,
                                               1, &draw->fence));
      list_addtail(&draw->link, &data->draws);
      return draw;
   }

   draw = rzalloc(data, struct overlay_draw);

   VkCommandBufferAllocateInfo cmd_buffer_info = {};
   cmd_buffer_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
   cmd_buffer_info.commandPool = data->command_pool;
   cmd_buffer_info.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
   cmd_buffer_info.commandBufferCount = 1;
   VK_CHECK(device_data->vtable.AllocateCommandBuffers(device_data->device,
                                                       &cmd_buffer_info,
                                                       &draw->command_buffer));
   VK_CHECK(device_data->set_device_loader_data(device_data->device,
                                                draw->command_buffer));


   VkFenceCreateInfo fence_info = {};
   fence_info.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
   VK_CHECK(device_data->vtable.CreateFence(device_data->device,
                                            &fence_info,
                                            NULL,
                                            &draw->fence));

   VK_CHECK(device_data->vtable.CreateSemaphore(device_data->device, &sem_info,
                                                NULL, &draw->semaphore));

   list_addtail(&draw->link, &data->draws);

   return draw;
}

static const char *param_unit(enum overlay_param_enabled param)
{
   switch (param) {
   case OVERLAY_PARAM_ENABLED_frame_timing:
   case OVERLAY_PARAM_ENABLED_acquire_timing:
   case OVERLAY_PARAM_ENABLED_present_timing:
      return "(us)";
   case OVERLAY_PARAM_ENABLED_gpu_timing:
      return "(ns)";
   default:
      return "";
   }
}

static void parse_command(struct instance_data *instance_data,
                          const char *cmd, unsigned cmdlen,
                          const char *param, unsigned paramlen)
{
   if (!strncmp(cmd, "capture", cmdlen)) {
      int value = atoi(param);
      bool enabled = value > 0;

      if (enabled) {
         instance_data->capture_enabled = true;
      } else {
         instance_data->capture_enabled = false;
         instance_data->capture_started = false;
      }
   }
}

#define BUFSIZE 4096

/**
 * This function will process commands through the control file.
 *
 * A command starts with a colon, followed by the command, and followed by an
 * option '=' and a parameter.  It has to end with a semi-colon. A full command
 * + parameter looks like:
 *
 *    :cmd=param;
 */
static void process_char(struct instance_data *instance_data, char c)
{
   static char cmd[BUFSIZE];
   static char param[BUFSIZE];

   static unsigned cmdpos = 0;
   static unsigned parampos = 0;
   static bool reading_cmd = false;
   static bool reading_param = false;

   switch (c) {
   case ':':
      cmdpos = 0;
      parampos = 0;
      reading_cmd = true;
      reading_param = false;
      break;
   case ';':
      if (!reading_cmd)
         break;
      cmd[cmdpos++] = '\0';
      param[parampos++] = '\0';
      parse_command(instance_data, cmd, cmdpos, param, parampos);
      reading_cmd = false;
      reading_param = false;
      break;
   case '=':
      if (!reading_cmd)
         break;
      reading_param = true;
      break;
   default:
      if (!reading_cmd)
         break;

      if (reading_param) {
         /* overflow means an invalid parameter */
         if (parampos >= BUFSIZE - 1) {
            reading_cmd = false;
            reading_param = false;
            break;
         }

         param[parampos++] = c;
      } else {
         /* overflow means an invalid command */
         if (cmdpos >= BUFSIZE - 1) {
            reading_cmd = false;
            break;
         }

         cmd[cmdpos++] = c;
      }
   }
}

static void control_send(struct instance_data *instance_data,
                         const char *cmd, unsigned cmdlen,
                         const char *param, unsigned paramlen)
{
   unsigned msglen = 0;
   char buffer[BUFSIZE];

   assert(cmdlen + paramlen + 3 < BUFSIZE);

   buffer[msglen++] = ':';

   memcpy(&buffer[msglen], cmd, cmdlen);
   msglen += cmdlen;

   if (paramlen > 0) {
      buffer[msglen++] = '=';
      memcpy(&buffer[msglen], param, paramlen);
      msglen += paramlen;
      buffer[msglen++] = ';';
   }

   os_socket_send(instance_data->control_client, buffer, msglen, 0);
}

static void control_send_connection_string(struct device_data *device_data)
{
   struct instance_data *instance_data = device_data->instance;

   const char *controlVersionCmd = "MesaOverlayControlVersion";
   const char *controlVersionString = "1";

   control_send(instance_data, controlVersionCmd, strlen(controlVersionCmd),
                controlVersionString, strlen(controlVersionString));

   const char *deviceCmd = "DeviceName";
   const char *deviceName = device_data->properties.deviceName;

   control_send(instance_data, deviceCmd, strlen(deviceCmd),
                deviceName, strlen(deviceName));

   const char *mesaVersionCmd = "MesaVersion";
   const char *mesaVersionString = "Mesa " PACKAGE_VERSION MESA_GIT_SHA1;

   control_send(instance_data, mesaVersionCmd, strlen(mesaVersionCmd),
                mesaVersionString, strlen(mesaVersionString));
}

static void control_client_check(struct device_data *device_data)
{
   struct instance_data *instance_data = device_data->instance;

   /* Already connected, just return. */
   if (instance_data->control_client >= 0)
      return;

   int socket = os_socket_accept(instance_data->params.control);
   if (socket == -1) {
      if (errno != EAGAIN && errno != EWOULDBLOCK && errno != ECONNABORTED)
         fprintf(stderr, "ERROR on socket: %s\n", strerror(errno));
      return;
   }

   if (socket >= 0) {
      os_socket_block(socket, false);
      instance_data->control_client = socket;
      control_send_connection_string(device_data);
   }
}

static void control_client_disconnected(struct instance_data *instance_data)
{
   os_socket_close(instance_data->control_client);
   instance_data->control_client = -1;
}

static void process_control_socket(struct instance_data *instance_data)
{
   const int client = instance_data->control_client;
   if (client >= 0) {
      char buf[BUFSIZE];

      while (true) {
         ssize_t n = os_socket_recv(client, buf, BUFSIZE, 0);

         if (n == -1) {
            if (errno == EAGAIN || errno == EWOULDBLOCK) {
               /* nothing to read, try again later */
               break;
            }

            if (errno != ECONNRESET)
               fprintf(stderr, "ERROR on connection: %s\n", strerror(errno));

            control_client_disconnected(instance_data);
         } else if (n == 0) {
            /* recv() returns 0 when the client disconnects */
            control_client_disconnected(instance_data);
         }

         for (ssize_t i = 0; i < n; i++) {
            process_char(instance_data, buf[i]);
         }

         /* If we try to read BUFSIZE and receive BUFSIZE bytes from the
          * socket, there's a good chance that there's still more data to be
          * read, so we will try again. Otherwise, simply be done for this
          * iteration and try again on the next frame.
          */
         if (n < BUFSIZE)
            break;
      }
   }
}

static void snapshot_swapchain_frame(struct swapchain_data *data)
{
   struct device_data *device_data = data->device;
   struct instance_data *instance_data = device_data->instance;
   uint32_t f_idx = data->n_frames % ARRAY_SIZE(data->frames_stats);
   uint64_t now = os_time_get(); /* us */

   if (instance_data->params.control >= 0) {
      control_client_check(device_data);
      process_control_socket(instance_data);
   }

   if (data->last_present_time) {
      data->frame_stats.stats[OVERLAY_PARAM_ENABLED_frame_timing] =
         now - data->last_present_time;
   }

   memset(&data->frames_stats[f_idx], 0, sizeof(data->frames_stats[f_idx]));
   for (int s = 0; s < OVERLAY_PARAM_ENABLED_MAX; s++) {
      data->frames_stats[f_idx].stats[s] += device_data->frame_stats.stats[s] + data->frame_stats.stats[s];
      data->accumulated_stats.stats[s] += device_data->frame_stats.stats[s] + data->frame_stats.stats[s];
   }

   /* If capture has been enabled but it hasn't started yet, it means we are on
    * the first snapshot after it has been enabled. At this point we want to
    * use the stats captured so far to update the display, but we don't want
    * this data to cause noise to the stats that we want to capture from now
    * on.
    *
    * capture_begin == true will trigger an update of the fps on display, and a
    * flush of the data, but no stats will be written to the output file. This
    * way, we will have only stats from after the capture has been enabled
    * written to the output_file.
    */
   const bool capture_begin =
      instance_data->capture_enabled && !instance_data->capture_started;

   if (data->last_fps_update) {
      double elapsed = (double)(now - data->last_fps_update); /* us */
      if (capture_begin ||
          elapsed >= instance_data->params.fps_sampling_period) {
         data->fps = 1000000.0f * data->n_frames_since_update / elapsed;
         if (instance_data->capture_started) {
            if (!instance_data->first_line_printed) {
               bool first_column = true;

               instance_data->first_line_printed = true;

#define OVERLAY_PARAM_BOOL(name) \
               if (instance_data->params.enabled[OVERLAY_PARAM_ENABLED_##name]) { \
                  fprintf(instance_data->params.output_file, \
                          "%s%s%s", first_column ? "" : ", ", #name, \
                          param_unit(OVERLAY_PARAM_ENABLED_##name)); \
                  first_column = false; \
               }
#define OVERLAY_PARAM_CUSTOM(name)
               OVERLAY_PARAMS
#undef OVERLAY_PARAM_BOOL
#undef OVERLAY_PARAM_CUSTOM
               fprintf(instance_data->params.output_file, "\n");
            }

            for (int s = 0; s < OVERLAY_PARAM_ENABLED_MAX; s++) {
               if (!instance_data->params.enabled[s])
                  continue;
               if (s == OVERLAY_PARAM_ENABLED_fps) {
                  fprintf(instance_data->params.output_file,
                          "%s%.2f", s == 0 ? "" : ", ", data->fps);
               } else {
                  fprintf(instance_data->params.output_file,
                          "%s%" PRIu64, s == 0 ? "" : ", ",
                          data->accumulated_stats.stats[s]);
               }
            }
            fprintf(instance_data->params.output_file, "\n");
            fflush(instance_data->params.output_file);
         }

         memset(&data->accumulated_stats, 0, sizeof(data->accumulated_stats));
         data->n_frames_since_update = 0;
         data->last_fps_update = now;

         if (capture_begin)
            instance_data->capture_started = true;
      }
   } else {
      data->last_fps_update = now;
   }

   memset(&device_data->frame_stats, 0, sizeof(device_data->frame_stats));
   memset(&data->frame_stats, 0, sizeof(device_data->frame_stats));

   data->last_present_time = now;
   data->n_frames++;
   data->n_frames_since_update++;
}

static float get_time_stat(void *_data, int _idx)
{
   struct swapchain_data *data = (struct swapchain_data *) _data;
   if ((ARRAY_SIZE(data->frames_stats) - _idx) > data->n_frames)
      return 0.0f;
   int idx = ARRAY_SIZE(data->frames_stats) +
      data->n_frames < ARRAY_SIZE(data->frames_stats) ?
      _idx - data->n_frames :
      _idx + data->n_frames;
   idx %= ARRAY_SIZE(data->frames_stats);
   /* Time stats are in us. */
   return data->frames_stats[idx].stats[data->stat_selector] / data->time_dividor;
}

static float get_stat(void *_data, int _idx)
{
   struct swapchain_data *data = (struct swapchain_data *) _data;
   if ((ARRAY_SIZE(data->frames_stats) - _idx) > data->n_frames)
      return 0.0f;
   int idx = ARRAY_SIZE(data->frames_stats) +
      data->n_frames < ARRAY_SIZE(data->frames_stats) ?
      _idx - data->n_frames :
      _idx + data->n_frames;
   idx %= ARRAY_SIZE(data->frames_stats);
   return data->frames_stats[idx].stats[data->stat_selector];
}

static void position_layer(struct swapchain_data *data)

{
   struct device_data *device_data = data->device;
   struct instance_data *instance_data = device_data->instance;
   const float margin = 10.0f;

   ImGui::SetNextWindowBgAlpha(0.5);
   ImGui::SetNextWindowSize(data->window_size, ImGuiCond_Always);
   switch (instance_data->params.position) {
   case LAYER_POSITION_TOP_LEFT:
      ImGui::SetNextWindowPos(ImVec2(margin, margin), ImGuiCond_Always);
      break;
   case LAYER_POSITION_TOP_RIGHT:
      ImGui::SetNextWindowPos(ImVec2(data->width - data->window_size.x - margin, margin),
                              ImGuiCond_Always);
      break;
   case LAYER_POSITION_BOTTOM_LEFT:
      ImGui::SetNextWindowPos(ImVec2(margin, data->height - data->window_size.y - margin),
                              ImGuiCond_Always);
      break;
   case LAYER_POSITION_BOTTOM_RIGHT:
      ImGui::SetNextWindowPos(ImVec2(data->width - data->window_size.x - margin,
                                     data->height - data->window_size.y - margin),
                              ImGuiCond_Always);
      break;
   }
}

static void compute_swapchain_display(struct swapchain_data *data)
{
   struct device_data *device_data = data->device;
   struct instance_data *instance_data = device_data->instance;

   ImGui::SetCurrentContext(data->imgui_context);
   ImGui::NewFrame();
   position_layer(data);
   ImGui::Begin("Mesa overlay");
   ImGui::Text("Device: %s", device_data->properties.deviceName);

   const char *format_name = vk_Format_to_str(data->format);
   format_name = format_name ? (format_name + strlen("VK_FORMAT_")) : "unknown";
   ImGui::Text("Swapchain format: %s", format_name);
   ImGui::Text("Frames: %" PRIu64, data->n_frames);
   if (instance_data->params.enabled[OVERLAY_PARAM_ENABLED_fps])
      ImGui::Text("FPS: %.2f" , data->fps);

   /* Recompute min/max */
   for (uint32_t s = 0; s < OVERLAY_PARAM_ENABLED_MAX; s++) {
      data->stats_min.stats[s] = UINT64_MAX;
      data->stats_max.stats[s] = 0;
   }
   for (uint32_t f = 0; f < MIN2(data->n_frames, ARRAY_SIZE(data->frames_stats)); f++) {
      for (uint32_t s = 0; s < OVERLAY_PARAM_ENABLED_MAX; s++) {
         data->stats_min.stats[s] = MIN2(data->frames_stats[f].stats[s],
                                         data->stats_min.stats[s]);
         data->stats_max.stats[s] = MAX2(data->frames_stats[f].stats[s],
                                         data->stats_max.stats[s]);
      }
   }
   for (uint32_t s = 0; s < OVERLAY_PARAM_ENABLED_MAX; s++) {
      assert(data->stats_min.stats[s] != UINT64_MAX);
   }

   for (uint32_t s = 0; s < OVERLAY_PARAM_ENABLED_MAX; s++) {
      if (!instance_data->params.enabled[s] ||
          s == OVERLAY_PARAM_ENABLED_fps ||
          s == OVERLAY_PARAM_ENABLED_frame)
         continue;

      char hash[40];
      snprintf(hash, sizeof(hash), "##%s", overlay_param_names[s]);
      data->stat_selector = (enum overlay_param_enabled) s;
      data->time_dividor = 1000.0f;
      if (s == OVERLAY_PARAM_ENABLED_gpu_timing)
         data->time_dividor = 1000000.0f;

      if (s == OVERLAY_PARAM_ENABLED_frame_timing ||
          s == OVERLAY_PARAM_ENABLED_acquire_timing ||
          s == OVERLAY_PARAM_ENABLED_present_timing ||
          s == OVERLAY_PARAM_ENABLED_gpu_timing) {
         double min_time = data->stats_min.stats[s] / data->time_dividor;
         double max_time = data->stats_max.stats[s] / data->time_dividor;
         ImGui::PlotHistogram(hash, get_time_stat, data,
                              ARRAY_SIZE(data->frames_stats), 0,
                              NULL, min_time, max_time,
                              ImVec2(ImGui::GetContentRegionAvailWidth(), 30));
         ImGui::Text("%s: %.3fms [%.3f, %.3f]", overlay_param_names[s],
                     get_time_stat(data, ARRAY_SIZE(data->frames_stats) - 1),
                     min_time, max_time);
      } else {
         ImGui::PlotHistogram(hash, get_stat, data,
                              ARRAY_SIZE(data->frames_stats), 0,
                              NULL,
                              data->stats_min.stats[s],
                              data->stats_max.stats[s],
                              ImVec2(ImGui::GetContentRegionAvailWidth(), 30));
         ImGui::Text("%s: %.0f [%" PRIu64 ", %" PRIu64 "]", overlay_param_names[s],
                     get_stat(data, ARRAY_SIZE(data->frames_stats) - 1),
                     data->stats_min.stats[s], data->stats_max.stats[s]);
      }
   }
   data->window_size = ImVec2(data->window_size.x, ImGui::GetCursorPosY() + 10.0f);
   ImGui::End();
   ImGui::EndFrame();
   ImGui::Render();
}

static uint32_t vk_memory_type(struct device_data *data,
                               VkMemoryPropertyFlags properties,
                               uint32_t type_bits)
{
    VkPhysicalDeviceMemoryProperties prop;
    data->instance->vtable.GetPhysicalDeviceMemoryProperties(data->physical_device, &prop);
    for (uint32_t i = 0; i < prop.memoryTypeCount; i++)
        if ((prop.memoryTypes[i].propertyFlags & properties) == properties && type_bits & (1<<i))
            return i;
    return 0xFFFFFFFF; // Unable to find memoryType
}

static void ensure_swapchain_fonts(struct swapchain_data *data,
                                   VkCommandBuffer command_buffer)
{
   if (data->font_uploaded)
      return;

   data->font_uploaded = true;

   struct device_data *device_data = data->device;
   ImGuiIO& io = ImGui::GetIO();
   unsigned char* pixels;
   int width, height;
   io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
   size_t upload_size = width * height * 4 * sizeof(char);

   /* Upload buffer */
   VkBufferCreateInfo buffer_info = {};
   buffer_info.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
   buffer_info.size = upload_size;
   buffer_info.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
   buffer_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
   VK_CHECK(device_data->vtable.CreateBuffer(device_data->device, &buffer_info,
                                             NULL, &data->upload_font_buffer));
   VkMemoryRequirements upload_buffer_req;
   device_data->vtable.GetBufferMemoryRequirements(device_data->device,
                                                   data->upload_font_buffer,
                                                   &upload_buffer_req);
   VkMemoryAllocateInfo upload_alloc_info = {};
   upload_alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
   upload_alloc_info.allocationSize = upload_buffer_req.size;
   upload_alloc_info.memoryTypeIndex = vk_memory_type(device_data,
                                                      VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
                                                      upload_buffer_req.memoryTypeBits);
   VK_CHECK(device_data->vtable.AllocateMemory(device_data->device,
                                               &upload_alloc_info,
                                               NULL,
                                               &data->upload_font_buffer_mem));
   VK_CHECK(device_data->vtable.BindBufferMemory(device_data->device,
                                                 data->upload_font_buffer,
                                                 data->upload_font_buffer_mem, 0));

   /* Upload to Buffer */
   char* map = NULL;
   VK_CHECK(device_data->vtable.MapMemory(device_data->device,
                                          data->upload_font_buffer_mem,
                                          0, upload_size, 0, (void**)(&map)));
   memcpy(map, pixels, upload_size);
   VkMappedMemoryRange range[1] = {};
   range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
   range[0].memory = data->upload_font_buffer_mem;
   range[0].size = upload_size;
   VK_CHECK(device_data->vtable.FlushMappedMemoryRanges(device_data->device, 1, range));
   device_data->vtable.UnmapMemory(device_data->device,
                                   data->upload_font_buffer_mem);

   /* Copy buffer to image */
   VkImageMemoryBarrier copy_barrier[1] = {};
   copy_barrier[0].sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
   copy_barrier[0].dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
   copy_barrier[0].oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
   copy_barrier[0].newLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
   copy_barrier[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
   copy_barrier[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
   copy_barrier[0].image = data->font_image;
   copy_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
   copy_barrier[0].subresourceRange.levelCount = 1;
   copy_barrier[0].subresourceRange.layerCount = 1;
   device_data->vtable.CmdPipelineBarrier(command_buffer,
                                          VK_PIPELINE_STAGE_HOST_BIT,
                                          VK_PIPELINE_STAGE_TRANSFER_BIT,
                                          0, 0, NULL, 0, NULL,
                                          1, copy_barrier);

   VkBufferImageCopy region = {};
   region.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
   region.imageSubresource.layerCount = 1;
   region.imageExtent.width = width;
   region.imageExtent.height = height;
   region.imageExtent.depth = 1;
   device_data->vtable.CmdCopyBufferToImage(command_buffer,
                                            data->upload_font_buffer,
                                            data->font_image,
                                            VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
                                            1, &region);

   VkImageMemoryBarrier use_barrier[1] = {};
   use_barrier[0].sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
   use_barrier[0].srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
   use_barrier[0].dstAccessMask = VK_ACCESS_SHADER_READ_BIT;
   use_barrier[0].oldLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
   use_barrier[0].newLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
   use_barrier[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
   use_barrier[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
   use_barrier[0].image = data->font_image;
   use_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
   use_barrier[0].subresourceRange.levelCount = 1;
   use_barrier[0].subresourceRange.layerCount = 1;
   device_data->vtable.CmdPipelineBarrier(command_buffer,
                                          VK_PIPELINE_STAGE_TRANSFER_BIT,
                                          VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT,
                                          0,
                                          0, NULL,
                                          0, NULL,
                                          1, use_barrier);

   /* Store our identifier */
   io.Fonts->TexID = (ImTextureID)(intptr_t)data->font_image;
}

static void CreateOrResizeBuffer(struct device_data *data,
                                 VkBuffer *buffer,
                                 VkDeviceMemory *buffer_memory,
                                 VkDeviceSize *buffer_size,
                                 size_t new_size, VkBufferUsageFlagBits usage)
{
    if (*buffer != VK_NULL_HANDLE)
        data->vtable.DestroyBuffer(data->device, *buffer, NULL);
    if (*buffer_memory)
        data->vtable.FreeMemory(data->device, *buffer_memory, NULL);

    VkBufferCreateInfo buffer_info = {};
    buffer_info.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
    buffer_info.size = new_size;
    buffer_info.usage = usage;
    buffer_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
    VK_CHECK(data->vtable.CreateBuffer(data->device, &buffer_info, NULL, buffer));

    VkMemoryRequirements req;
    data->vtable.GetBufferMemoryRequirements(data->device, *buffer, &req);
    VkMemoryAllocateInfo alloc_info = {};
    alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
    alloc_info.allocationSize = req.size;
    alloc_info.memoryTypeIndex =
       vk_memory_type(data, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT, req.memoryTypeBits);
    VK_CHECK(data->vtable.AllocateMemory(data->device, &alloc_info, NULL, buffer_memory));

    VK_CHECK(data->vtable.BindBufferMemory(data->device, *buffer, *buffer_memory, 0));
    *buffer_size = new_size;
}

static struct overlay_draw *render_swapchain_display(struct swapchain_data *data,
                                                     struct queue_data *present_queue,
                                                     const VkSemaphore *wait_semaphores,
                                                     unsigned n_wait_semaphores,
                                                     unsigned image_index)
{
   ImDrawData* draw_data = ImGui::GetDrawData();
   if (draw_data->TotalVtxCount == 0)
      return NULL;

   struct device_data *device_data = data->device;
   struct overlay_draw *draw = get_overlay_draw(data);

   device_data->vtable.ResetCommandBuffer(draw->command_buffer, 0);

   VkRenderPassBeginInfo render_pass_info = {};
   render_pass_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
   render_pass_info.renderPass = data->render_pass;
   render_pass_info.framebuffer = data->framebuffers[image_index];
   render_pass_info.renderArea.extent.width = data->width;
   render_pass_info.renderArea.extent.height = data->height;

   VkCommandBufferBeginInfo buffer_begin_info = {};
   buffer_begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;

   device_data->vtable.BeginCommandBuffer(draw->command_buffer, &buffer_begin_info);

   ensure_swapchain_fonts(data, draw->command_buffer);

   /* Bounce the image to display back to color attachment layout for
    * rendering on top of it.
    */
   VkImageMemoryBarrier imb;
   imb.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
   imb.pNext = nullptr;
   imb.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
   imb.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
   imb.oldLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
   imb.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
   imb.image = data->images[image_index];
   imb.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
   imb.subresourceRange.baseMipLevel = 0;
   imb.subresourceRange.levelCount = 1;
   imb.subresourceRange.baseArrayLayer = 0;
   imb.subresourceRange.layerCount = 1;
   imb.srcQueueFamilyIndex = present_queue->family_index;
   imb.dstQueueFamilyIndex = device_data->graphic_queue->family_index;
   device_data->vtable.CmdPipelineBarrier(draw->command_buffer,
                                          VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT,
                                          VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT,
                                          0,          /* dependency flags */
                                          0, nullptr, /* memory barriers */
                                          0, nullptr, /* buffer memory barriers */
                                          1, &imb);   /* image memory barriers */

   device_data->vtable.CmdBeginRenderPass(draw->command_buffer, &render_pass_info,
                                          VK_SUBPASS_CONTENTS_INLINE);

   /* Create/Resize vertex & index buffers */
   size_t vertex_size = draw_data->TotalVtxCount * sizeof(ImDrawVert);
   size_t index_size = draw_data->TotalIdxCount * sizeof(ImDrawIdx);
   if (draw->vertex_buffer_size < vertex_size) {
      CreateOrResizeBuffer(device_data,
                           &draw->vertex_buffer,
                           &draw->vertex_buffer_mem,
                           &draw->vertex_buffer_size,
                           vertex_size, VK_BUFFER_USAGE_VERTEX_BUFFER_BIT);
   }
   if (draw->index_buffer_size < index_size) {
      CreateOrResizeBuffer(device_data,
                           &draw->index_buffer,
                           &draw->index_buffer_mem,
                           &draw->index_buffer_size,
                           index_size, VK_BUFFER_USAGE_INDEX_BUFFER_BIT);
   }

    /* Upload vertex & index data */
    ImDrawVert* vtx_dst = NULL;
    ImDrawIdx* idx_dst = NULL;
    VK_CHECK(device_data->vtable.MapMemory(device_data->device, draw->vertex_buffer_mem,
                                           0, vertex_size, 0, (void**)(&vtx_dst)));
    VK_CHECK(device_data->vtable.MapMemory(device_data->device, draw->index_buffer_mem,
                                           0, index_size, 0, (void**)(&idx_dst)));
    for (int n = 0; n < draw_data->CmdListsCount; n++)
        {
           const ImDrawList* cmd_list = draw_data->CmdLists[n];
           memcpy(vtx_dst, cmd_list->VtxBuffer.Data, cmd_list->VtxBuffer.Size * sizeof(ImDrawVert));
           memcpy(idx_dst, cmd_list->IdxBuffer.Data, cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx));
           vtx_dst += cmd_list->VtxBuffer.Size;
           idx_dst += cmd_list->IdxBuffer.Size;
        }
    VkMappedMemoryRange range[2] = {};
    range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
    range[0].memory = draw->vertex_buffer_mem;
    range[0].size = VK_WHOLE_SIZE;
    range[1].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
    range[1].memory = draw->index_buffer_mem;
    range[1].size = VK_WHOLE_SIZE;
    VK_CHECK(device_data->vtable.FlushMappedMemoryRanges(device_data->device, 2, range));
    device_data->vtable.UnmapMemory(device_data->device, draw->vertex_buffer_mem);
    device_data->vtable.UnmapMemory(device_data->device, draw->index_buffer_mem);

    /* Bind pipeline and descriptor sets */
    device_data->vtable.CmdBindPipeline(draw->command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS, data->pipeline);
    VkDescriptorSet desc_set[1] = { data->descriptor_set };
    device_data->vtable.CmdBindDescriptorSets(draw->command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
                                              data->pipeline_layout, 0, 1, desc_set, 0, NULL);

    /* Bind vertex & index buffers */
    VkBuffer vertex_buffers[1] = { draw->vertex_buffer };
    VkDeviceSize vertex_offset[1] = { 0 };
    device_data->vtable.CmdBindVertexBuffers(draw->command_buffer, 0, 1, vertex_buffers, vertex_offset);
    device_data->vtable.CmdBindIndexBuffer(draw->command_buffer, draw->index_buffer, 0, VK_INDEX_TYPE_UINT16);

    /* Setup viewport */
    VkViewport viewport;
    viewport.x = 0;
    viewport.y = 0;
    viewport.width = draw_data->DisplaySize.x;
    viewport.height = draw_data->DisplaySize.y;
    viewport.minDepth = 0.0f;
    viewport.maxDepth = 1.0f;
    device_data->vtable.CmdSetViewport(draw->command_buffer, 0, 1, &viewport);


    /* Setup scale and translation through push constants :
     *
     * Our visible imgui space lies from draw_data->DisplayPos (top left) to
     * draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayMin
     * is typically (0,0) for single viewport apps.
     */
    float scale[2];
    scale[0] = 2.0f / draw_data->DisplaySize.x;
    scale[1] = 2.0f / draw_data->DisplaySize.y;
    float translate[2];
    translate[0] = -1.0f - draw_data->DisplayPos.x * scale[0];
    translate[1] = -1.0f - draw_data->DisplayPos.y * scale[1];
    device_data->vtable.CmdPushConstants(draw->command_buffer, data->pipeline_layout,
                                         VK_SHADER_STAGE_VERTEX_BIT,
                                         sizeof(float) * 0, sizeof(float) * 2, scale);
    device_data->vtable.CmdPushConstants(draw->command_buffer, data->pipeline_layout,
                                         VK_SHADER_STAGE_VERTEX_BIT,
                                         sizeof(float) * 2, sizeof(float) * 2, translate);

    // Render the command lists:
    int vtx_offset = 0;
    int idx_offset = 0;
    ImVec2 display_pos = draw_data->DisplayPos;
    for (int n = 0; n < draw_data->CmdListsCount; n++)
    {
        const ImDrawList* cmd_list = draw_data->CmdLists[n];
        for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
        {
            const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
            // Apply scissor/clipping rectangle
            // FIXME: We could clamp width/height based on clamped min/max values.
            VkRect2D scissor;
            scissor.offset.x = (int32_t)(pcmd->ClipRect.x - display_pos.x) > 0 ? (int32_t)(pcmd->ClipRect.x - display_pos.x) : 0;
            scissor.offset.y = (int32_t)(pcmd->ClipRect.y - display_pos.y) > 0 ? (int32_t)(pcmd->ClipRect.y - display_pos.y) : 0;
            scissor.extent.width = (uint32_t)(pcmd->ClipRect.z - pcmd->ClipRect.x);
            scissor.extent.height = (uint32_t)(pcmd->ClipRect.w - pcmd->ClipRect.y + 1); // FIXME: Why +1 here?
            device_data->vtable.CmdSetScissor(draw->command_buffer, 0, 1, &scissor);

            // Draw
            device_data->vtable.CmdDrawIndexed(draw->command_buffer, pcmd->ElemCount, 1, idx_offset, vtx_offset, 0);

            idx_offset += pcmd->ElemCount;
        }
        vtx_offset += cmd_list->VtxBuffer.Size;
    }

   device_data->vtable.CmdEndRenderPass(draw->command_buffer);

   if (device_data->graphic_queue->family_index != present_queue->family_index)
   {
      /* Transfer the image back to the present queue family
       * image layout was already changed to present by the render pass 
       */
      imb.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
      imb.pNext = nullptr;
      imb.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
      imb.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
      imb.oldLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
      imb.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
      imb.image = data->images[image_index];
      imb.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
      imb.subresourceRange.baseMipLevel = 0;
      imb.subresourceRange.levelCount = 1;
      imb.subresourceRange.baseArrayLayer = 0;
      imb.subresourceRange.layerCount = 1;
      imb.srcQueueFamilyIndex = device_data->graphic_queue->family_index;
      imb.dstQueueFamilyIndex = present_queue->family_index;
      device_data->vtable.CmdPipelineBarrier(draw->command_buffer,
                                             VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT,
                                             VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT,
                                             0,          /* dependency flags */
                                             0, nullptr, /* memory barriers */
                                             0, nullptr, /* buffer memory barriers */
                                             1, &imb);   /* image memory barriers */
   }

   device_data->vtable.EndCommandBuffer(draw->command_buffer);

   VkPipelineStageFlags *stages_wait = (VkPipelineStageFlags*) malloc(sizeof(VkPipelineStageFlags) * n_wait_semaphores);
   for (unsigned i = 0; i < n_wait_semaphores; i++)
   {
      // wait in the fragment stage until the swapchain image is ready
      stages_wait[i] = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
   }
   
   VkSubmitInfo submit_info = {};
   submit_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
   submit_info.commandBufferCount = 1;
   submit_info.pCommandBuffers = &draw->command_buffer;
   submit_info.pWaitDstStageMask = stages_wait;
   submit_info.waitSemaphoreCount = n_wait_semaphores;
   submit_info.pWaitSemaphores = wait_semaphores;
   submit_info.signalSemaphoreCount = 1;
   submit_info.pSignalSemaphores = &draw->semaphore;

   device_data->vtable.QueueSubmit(device_data->graphic_queue->queue, 1, &submit_info, draw->fence);
   
   free(stages_wait);

   return draw;
}

static const uint32_t overlay_vert_spv[] = {
#include "overlay.vert.spv.h"
};
static const uint32_t overlay_frag_spv[] = {
#include "overlay.frag.spv.h"
};

static void setup_swapchain_data_pipeline(struct swapchain_data *data)
{
   struct device_data *device_data = data->device;
   VkShaderModule vert_module, frag_module;

   /* Create shader modules */
   VkShaderModuleCreateInfo vert_info = {};
   vert_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
   vert_info.codeSize = sizeof(overlay_vert_spv);
   vert_info.pCode = overlay_vert_spv;
   VK_CHECK(device_data->vtable.CreateShaderModule(device_data->device,
                                                   &vert_info, NULL, &vert_module));
   VkShaderModuleCreateInfo frag_info = {};
   frag_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
   frag_info.codeSize = sizeof(overlay_frag_spv);
   frag_info.pCode = (uint32_t*)overlay_frag_spv;
   VK_CHECK(device_data->vtable.CreateShaderModule(device_data->device,
                                                   &frag_info, NULL, &frag_module));

   /* Font sampler */
   VkSamplerCreateInfo sampler_info = {};
   sampler_info.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
   sampler_info.magFilter = VK_FILTER_LINEAR;
   sampler_info.minFilter = VK_FILTER_LINEAR;
   sampler_info.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
   sampler_info.addressModeU = VK_SAMPLER_ADDRESS_MODE_REPEAT;
   sampler_info.addressModeV = VK_SAMPLER_ADDRESS_MODE_REPEAT;
   sampler_info.addressModeW = VK_SAMPLER_ADDRESS_MODE_REPEAT;
   sampler_info.minLod = -1000;
   sampler_info.maxLod = 1000;
   sampler_info.maxAnisotropy = 1.0f;
   VK_CHECK(device_data->vtable.CreateSampler(device_data->device, &sampler_info,
                                              NULL, &data->font_sampler));

   /* Descriptor pool */
   VkDescriptorPoolSize sampler_pool_size = {};
   sampler_pool_size.type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
   sampler_pool_size.descriptorCount = 1;
   VkDescriptorPoolCreateInfo desc_pool_info = {};
   desc_pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
   desc_pool_info.maxSets = 1;
   desc_pool_info.poolSizeCount = 1;
   desc_pool_info.pPoolSizes = &sampler_pool_size;
   VK_CHECK(device_data->vtable.CreateDescriptorPool(device_data->device,
                                                     &desc_pool_info,
                                                     NULL, &data->descriptor_pool));

   /* Descriptor layout */
   VkSampler sampler[1] = { data->font_sampler };
   VkDescriptorSetLayoutBinding binding[1] = {};
   binding[0].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
   binding[0].descriptorCount = 1;
   binding[0].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
   binding[0].pImmutableSamplers = sampler;
   VkDescriptorSetLayoutCreateInfo set_layout_info = {};
   set_layout_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
   set_layout_info.bindingCount = 1;
   set_layout_info.pBindings = binding;
   VK_CHECK(device_data->vtable.CreateDescriptorSetLayout(device_data->device,
                                                          &set_layout_info,
                                                          NULL, &data->descriptor_layout));

   /* Descriptor set */
   VkDescriptorSetAllocateInfo alloc_info = {};
   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
   alloc_info.descriptorPool = data->descriptor_pool;
   alloc_info.descriptorSetCount = 1;
   alloc_info.pSetLayouts = &data->descriptor_layout;
   VK_CHECK(device_data->vtable.AllocateDescriptorSets(device_data->device,
                                                       &alloc_info,
                                                       &data->descriptor_set));

   /* Constants: we are using 'vec2 offset' and 'vec2 scale' instead of a full
    * 3d projection matrix
    */
   VkPushConstantRange push_constants[1] = {};
   push_constants[0].stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
   push_constants[0].offset = sizeof(float) * 0;
   push_constants[0].size = sizeof(float) * 4;
   VkPipelineLayoutCreateInfo layout_info = {};
   layout_info.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
   layout_info.setLayoutCount = 1;
   layout_info.pSetLayouts = &data->descriptor_layout;
   layout_info.pushConstantRangeCount = 1;
   layout_info.pPushConstantRanges = push_constants;
   VK_CHECK(device_data->vtable.CreatePipelineLayout(device_data->device,
                                                     &layout_info,
                                                     NULL, &data->pipeline_layout));

   VkPipelineShaderStageCreateInfo stage[2] = {};
   stage[0].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
   stage[0].stage = VK_SHADER_STAGE_VERTEX_BIT;
   stage[0].module = vert_module;
   stage[0].pName = "main";
   stage[1].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
   stage[1].stage = VK_SHADER_STAGE_FRAGMENT_BIT;
   stage[1].module = frag_module;
   stage[1].pName = "main";

   VkVertexInputBindingDescription binding_desc[1] = {};
   binding_desc[0].stride = sizeof(ImDrawVert);
   binding_desc[0].inputRate = VK_VERTEX_INPUT_RATE_VERTEX;

   VkVertexInputAttributeDescription attribute_desc[3] = {};
   attribute_desc[0].location = 0;
   attribute_desc[0].binding = binding_desc[0].binding;
   attribute_desc[0].format = VK_FORMAT_R32G32_SFLOAT;
   attribute_desc[0].offset = IM_OFFSETOF(ImDrawVert, pos);
   attribute_desc[1].location = 1;
   attribute_desc[1].binding = binding_desc[0].binding;
   attribute_desc[1].format = VK_FORMAT_R32G32_SFLOAT;
   attribute_desc[1].offset = IM_OFFSETOF(ImDrawVert, uv);
   attribute_desc[2].location = 2;
   attribute_desc[2].binding = binding_desc[0].binding;
   attribute_desc[2].format = VK_FORMAT_R8G8B8A8_UNORM;
   attribute_desc[2].offset = IM_OFFSETOF(ImDrawVert, col);

   VkPipelineVertexInputStateCreateInfo vertex_info = {};
   vertex_info.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
   vertex_info.vertexBindingDescriptionCount = 1;
   vertex_info.pVertexBindingDescriptions = binding_desc;
   vertex_info.vertexAttributeDescriptionCount = 3;
   vertex_info.pVertexAttributeDescriptions = attribute_desc;

   VkPipelineInputAssemblyStateCreateInfo ia_info = {};
   ia_info.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
   ia_info.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;

   VkPipelineViewportStateCreateInfo viewport_info = {};
   viewport_info.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
   viewport_info.viewportCount = 1;
   viewport_info.scissorCount = 1;

   VkPipelineRasterizationStateCreateInfo raster_info = {};
   raster_info.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
   raster_info.polygonMode = VK_POLYGON_MODE_FILL;
   raster_info.cullMode = VK_CULL_MODE_NONE;
   raster_info.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
   raster_info.lineWidth = 1.0f;

   VkPipelineMultisampleStateCreateInfo ms_info = {};
   ms_info.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
   ms_info.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;

   VkPipelineColorBlendAttachmentState color_attachment[1] = {};
   color_attachment[0].blendEnable = VK_TRUE;
   color_attachment[0].srcColorBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;
   color_attachment[0].dstColorBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
   color_attachment[0].colorBlendOp = VK_BLEND_OP_ADD;
   color_attachment[0].srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
   color_attachment[0].dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
   color_attachment[0].alphaBlendOp = VK_BLEND_OP_ADD;
   color_attachment[0].colorWriteMask = VK_COLOR_COMPONENT_R_BIT |
      VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;

   VkPipelineDepthStencilStateCreateInfo depth_info = {};
   depth_info.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;

   VkPipelineColorBlendStateCreateInfo blend_info = {};
   blend_info.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
   blend_info.attachmentCount = 1;
   blend_info.pAttachments = color_attachment;

   VkDynamicState dynamic_states[2] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
   VkPipelineDynamicStateCreateInfo dynamic_state = {};
   dynamic_state.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
   dynamic_state.dynamicStateCount = (uint32_t)IM_ARRAYSIZE(dynamic_states);
   dynamic_state.pDynamicStates = dynamic_states;

   VkGraphicsPipelineCreateInfo info = {};
   info.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
   info.flags = 0;
   info.stageCount = 2;
   info.pStages = stage;
   info.pVertexInputState = &vertex_info;
   info.pInputAssemblyState = &ia_info;
   info.pViewportState = &viewport_info;
   info.pRasterizationState = &raster_info;
   info.pMultisampleState = &ms_info;
   info.pDepthStencilState = &depth_info;
   info.pColorBlendState = &blend_info;
   info.pDynamicState = &dynamic_state;
   info.layout = data->pipeline_layout;
   info.renderPass = data->render_pass;
   VK_CHECK(
      device_data->vtable.CreateGraphicsPipelines(device_data->device, VK_NULL_HANDLE,
                                                  1, &info,
                                                  NULL, &data->pipeline));

   device_data->vtable.DestroyShaderModule(device_data->device, vert_module, NULL);
   device_data->vtable.DestroyShaderModule(device_data->device, frag_module, NULL);

   ImGuiIO& io = ImGui::GetIO();
   unsigned char* pixels;
   int width, height;
   io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);

   /* Font image */
   VkImageCreateInfo image_info = {};
   image_info.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
   image_info.imageType = VK_IMAGE_TYPE_2D;
   image_info.format = VK_FORMAT_R8G8B8A8_UNORM;
   image_info.extent.width = width;
   image_info.extent.height = height;
   image_info.extent.depth = 1;
   image_info.mipLevels = 1;
   image_info.arrayLayers = 1;
   image_info.samples = VK_SAMPLE_COUNT_1_BIT;
   image_info.tiling = VK_IMAGE_TILING_OPTIMAL;
   image_info.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT;
   image_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
   image_info.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
   VK_CHECK(device_data->vtable.CreateImage(device_data->device, &image_info,
                                            NULL, &data->font_image));
   VkMemoryRequirements font_image_req;
   device_data->vtable.GetImageMemoryRequirements(device_data->device,
                                                  data->font_image, &font_image_req);
   VkMemoryAllocateInfo image_alloc_info = {};
   image_alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
   image_alloc_info.allocationSize = font_image_req.size;
   image_alloc_info.memoryTypeIndex = vk_memory_type(device_data,
                                                     VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT,
                                                     font_image_req.memoryTypeBits);
   VK_CHECK(device_data->vtable.AllocateMemory(device_data->device, &image_alloc_info,
                                               NULL, &data->font_mem));
   VK_CHECK(device_data->vtable.BindImageMemory(device_data->device,
                                                data->font_image,
                                                data->font_mem, 0));

   /* Font image view */
   VkImageViewCreateInfo view_info = {};
   view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
   view_info.image = data->font_image;
   view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
   view_info.format = VK_FORMAT_R8G8B8A8_UNORM;
   view_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
   view_info.subresourceRange.levelCount = 1;
   view_info.subresourceRange.layerCount = 1;
   VK_CHECK(device_data->vtable.CreateImageView(device_data->device, &view_info,
                                                NULL, &data->font_image_view));

   /* Descriptor set */
   VkDescriptorImageInfo desc_image[1] = {};
   desc_image[0].sampler = data->font_sampler;
   desc_image[0].imageView = data->font_image_view;
   desc_image[0].imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
   VkWriteDescriptorSet write_desc[1] = {};
   write_desc[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
   write_desc[0].dstSet = data->descriptor_set;
   write_desc[0].descriptorCount = 1;
   write_desc[0].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
   write_desc[0].pImageInfo = desc_image;
   device_data->vtable.UpdateDescriptorSets(device_data->device, 1, write_desc, 0, NULL);
}

static void setup_swapchain_data(struct swapchain_data *data,
                                 const VkSwapchainCreateInfoKHR *pCreateInfo)
{
   data->width = pCreateInfo->imageExtent.width;
   data->height = pCreateInfo->imageExtent.height;
   data->format = pCreateInfo->imageFormat;

   data->imgui_context = ImGui::CreateContext();
   ImGui::SetCurrentContext(data->imgui_context);

   ImGui::GetIO().IniFilename = NULL;
   ImGui::GetIO().DisplaySize = ImVec2((float)data->width, (float)data->height);

   struct device_data *device_data = data->device;

   /* Render pass */
   VkAttachmentDescription attachment_desc = {};
   attachment_desc.format = pCreateInfo->imageFormat;
   attachment_desc.samples = VK_SAMPLE_COUNT_1_BIT;
   attachment_desc.loadOp = VK_ATTACHMENT_LOAD_OP_LOAD;
   attachment_desc.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
   attachment_desc.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
   attachment_desc.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
   attachment_desc.initialLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
   attachment_desc.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
   VkAttachmentReference color_attachment = {};
   color_attachment.attachment = 0;
   color_attachment.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
   VkSubpassDescription subpass = {};
   subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
   subpass.colorAttachmentCount = 1;
   subpass.pColorAttachments = &color_attachment;
   VkSubpassDependency dependency = {};
   dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
   dependency.dstSubpass = 0;
   dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
   dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
   dependency.srcAccessMask = 0;
   dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
   VkRenderPassCreateInfo render_pass_info = {};
   render_pass_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
   render_pass_info.attachmentCount = 1;
   render_pass_info.pAttachments = &attachment_desc;
   render_pass_info.subpassCount = 1;
   render_pass_info.pSubpasses = &subpass;
   render_pass_info.dependencyCount = 1;
   render_pass_info.pDependencies = &dependency;
   VK_CHECK(device_data->vtable.CreateRenderPass(device_data->device,
                                                 &render_pass_info,
                                                 NULL, &data->render_pass));

   setup_swapchain_data_pipeline(data);

   VK_CHECK(device_data->vtable.GetSwapchainImagesKHR(device_data->device,
                                                      data->swapchain,
                                                      &data->n_images,
                                                      NULL));

   data->images = ralloc_array(data, VkImage, data->n_images);
   data->image_views = ralloc_array(data, VkImageView, data->n_images);
   data->framebuffers = ralloc_array(data, VkFramebuffer, data->n_images);

   VK_CHECK(device_data->vtable.GetSwapchainImagesKHR(device_data->device,
                                                      data->swapchain,
                                                      &data->n_images,
                                                      data->images));

   /* Image views */
   VkImageViewCreateInfo view_info = {};
   view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
   view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
   view_info.format = pCreateInfo->imageFormat;
   view_info.components.r = VK_COMPONENT_SWIZZLE_R;
   view_info.components.g = VK_COMPONENT_SWIZZLE_G;
   view_info.components.b = VK_COMPONENT_SWIZZLE_B;
   view_info.components.a = VK_COMPONENT_SWIZZLE_A;
   view_info.subresourceRange = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 };
   for (uint32_t i = 0; i < data->n_images; i++) {
      view_info.image = data->images[i];
      VK_CHECK(device_data->vtable.CreateImageView(device_data->device,
                                                   &view_info, NULL,
                                                   &data->image_views[i]));
   }

   /* Framebuffers */
   VkImageView attachment[1];
   VkFramebufferCreateInfo fb_info = {};
   fb_info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
   fb_info.renderPass = data->render_pass;
   fb_info.attachmentCount = 1;
   fb_info.pAttachments = attachment;
   fb_info.width = data->width;
   fb_info.height = data->height;
   fb_info.layers = 1;
   for (uint32_t i = 0; i < data->n_images; i++) {
      attachment[0] = data->image_views[i];
      VK_CHECK(device_data->vtable.CreateFramebuffer(device_data->device, &fb_info,
                                                     NULL, &data->framebuffers[i]));
   }

   /* Command buffer pool */
   VkCommandPoolCreateInfo cmd_buffer_pool_info = {};
   cmd_buffer_pool_info.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
   cmd_buffer_pool_info.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT;
   cmd_buffer_pool_info.queueFamilyIndex = device_data->graphic_queue->family_index;
   VK_CHECK(device_data->vtable.CreateCommandPool(device_data->device,
                                                  &cmd_buffer_pool_info,
                                                  NULL, &data->command_pool));
}

static void shutdown_swapchain_data(struct swapchain_data *data)
{
   struct device_data *device_data = data->device;

   list_for_each_entry_safe(struct overlay_draw, draw, &data->draws, link) {
      device_data->vtable.DestroySemaphore(device_data->device, draw->semaphore, NULL);
      device_data->vtable.DestroyFence(device_data->device, draw->fence, NULL);
      device_data->vtable.DestroyBuffer(device_data->device, draw->vertex_buffer, NULL);
      device_data->vtable.DestroyBuffer(device_data->device, draw->index_buffer, NULL);
      device_data->vtable.FreeMemory(device_data->device, draw->vertex_buffer_mem, NULL);
      device_data->vtable.FreeMemory(device_data->device, draw->index_buffer_mem, NULL);
   }

   for (uint32_t i = 0; i < data->n_images; i++) {
      device_data->vtable.DestroyImageView(device_data->device, data->image_views[i], NULL);
      device_data->vtable.DestroyFramebuffer(device_data->device, data->framebuffers[i], NULL);
   }

   device_data->vtable.DestroyRenderPass(device_data->device, data->render_pass, NULL);

   device_data->vtable.DestroyCommandPool(device_data->device, data->command_pool, NULL);

   device_data->vtable.DestroyPipeline(device_data->device, data->pipeline, NULL);
   device_data->vtable.DestroyPipelineLayout(device_data->device, data->pipeline_layout, NULL);

   device_data->vtable.DestroyDescriptorPool(device_data->device,
                                             data->descriptor_pool, NULL);
   device_data->vtable.DestroyDescriptorSetLayout(device_data->device,
                                                  data->descriptor_layout, NULL);

   device_data->vtable.DestroySampler(device_data->device, data->font_sampler, NULL);
   device_data->vtable.DestroyImageView(device_data->device, data->font_image_view, NULL);
   device_data->vtable.DestroyImage(device_data->device, data->font_image, NULL);
   device_data->vtable.FreeMemory(device_data->device, data->font_mem, NULL);

   device_data->vtable.DestroyBuffer(device_data->device, data->upload_font_buffer, NULL);
   device_data->vtable.FreeMemory(device_data->device, data->upload_font_buffer_mem, NULL);

   ImGui::DestroyContext(data->imgui_context);
}

static struct overlay_draw *before_present(struct swapchain_data *swapchain_data,
                                           struct queue_data *present_queue,
                                           const VkSemaphore *wait_semaphores,
                                           unsigned n_wait_semaphores,
                                           unsigned imageIndex)
{
   struct instance_data *instance_data = swapchain_data->device->instance;
   struct overlay_draw *draw = NULL;

   snapshot_swapchain_frame(swapchain_data);

   if (!instance_data->params.no_display && swapchain_data->n_frames > 0) {
      compute_swapchain_display(swapchain_data);
      draw = render_swapchain_display(swapchain_data, present_queue,
                                      wait_semaphores, n_wait_semaphores,
                                      imageIndex);
   }

   return draw;
}

static VkResult overlay_CreateSwapchainKHR(
    VkDevice                                    device,
    const VkSwapchainCreateInfoKHR*             pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkSwapchainKHR*                             pSwapchain)
{
   struct device_data *device_data = FIND(struct device_data, device);
   VkResult result = device_data->vtable.CreateSwapchainKHR(device, pCreateInfo, pAllocator, pSwapchain);
   if (result != VK_SUCCESS) return result;

   struct swapchain_data *swapchain_data = new_swapchain_data(*pSwapchain, device_data);
   setup_swapchain_data(swapchain_data, pCreateInfo);
   return result;
}

static void overlay_DestroySwapchainKHR(
    VkDevice                                    device,
    VkSwapchainKHR                              swapchain,
    const VkAllocationCallbacks*                pAllocator)
{
   struct swapchain_data *swapchain_data =
      FIND(struct swapchain_data, swapchain);

   shutdown_swapchain_data(swapchain_data);
   swapchain_data->device->vtable.DestroySwapchainKHR(device, swapchain, pAllocator);
   destroy_swapchain_data(swapchain_data);
}

static VkResult overlay_QueuePresentKHR(
    VkQueue                                     queue,
    const VkPresentInfoKHR*                     pPresentInfo)
{
   struct queue_data *queue_data = FIND(struct queue_data, queue);
   struct device_data *device_data = queue_data->device;
   struct instance_data *instance_data = device_data->instance;
   uint32_t query_results[OVERLAY_QUERY_COUNT];

   device_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_frame]++;

   if (list_length(&queue_data->running_command_buffer) > 0) {
      /* Before getting the query results, make sure the operations have
       * completed.
       */
      VK_CHECK(device_data->vtable.ResetFences(device_data->device,
                                               1, &queue_data->queries_fence));
      VK_CHECK(device_data->vtable.QueueSubmit(queue, 0, NULL, queue_data->queries_fence));
      VK_CHECK(device_data->vtable.WaitForFences(device_data->device,
                                                 1, &queue_data->queries_fence,
                                                 VK_FALSE, UINT64_MAX));

      /* Now get the results. */
      list_for_each_entry_safe(struct command_buffer_data, cmd_buffer_data,
                               &queue_data->running_command_buffer, link) {
         list_delinit(&cmd_buffer_data->link);

         if (cmd_buffer_data->pipeline_query_pool) {
            memset(query_results, 0, sizeof(query_results));
            VK_CHECK(device_data->vtable.GetQueryPoolResults(device_data->device,
                                                             cmd_buffer_data->pipeline_query_pool,
                                                             cmd_buffer_data->query_index, 1,
                                                             sizeof(uint32_t) * OVERLAY_QUERY_COUNT,
                                                             query_results, 0, VK_QUERY_RESULT_WAIT_BIT));

            for (uint32_t i = OVERLAY_PARAM_ENABLED_vertices;
                 i <= OVERLAY_PARAM_ENABLED_compute_invocations; i++) {
               device_data->frame_stats.stats[i] += query_results[i - OVERLAY_PARAM_ENABLED_vertices];
            }
         }
         if (cmd_buffer_data->timestamp_query_pool) {
            uint64_t gpu_timestamps[2] = { 0 };
            VK_CHECK(device_data->vtable.GetQueryPoolResults(device_data->device,
                                                             cmd_buffer_data->timestamp_query_pool,
                                                             cmd_buffer_data->query_index * 2, 2,
                                                             2 * sizeof(uint64_t), gpu_timestamps, sizeof(uint64_t),
                                                             VK_QUERY_RESULT_WAIT_BIT | VK_QUERY_RESULT_64_BIT));

            gpu_timestamps[0] &= queue_data->timestamp_mask;
            gpu_timestamps[1] &= queue_data->timestamp_mask;
            device_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_gpu_timing] +=
               (gpu_timestamps[1] - gpu_timestamps[0]) *
               device_data->properties.limits.timestampPeriod;
         }
      }
   }

   /* Otherwise we need to add our overlay drawing semaphore to the list of
    * semaphores to wait on. If we don't do that the presented picture might
    * be have incomplete overlay drawings.
    */
   VkResult result = VK_SUCCESS;
   if (instance_data->params.no_display) {
      for (uint32_t i = 0; i < pPresentInfo->swapchainCount; i++) {
         VkSwapchainKHR swapchain = pPresentInfo->pSwapchains[i];
         struct swapchain_data *swapchain_data =
            FIND(struct swapchain_data, swapchain);

         uint32_t image_index = pPresentInfo->pImageIndices[i];

         before_present(swapchain_data,
                        queue_data,
                        pPresentInfo->pWaitSemaphores,
                        pPresentInfo->waitSemaphoreCount,
                        image_index);

         VkPresentInfoKHR present_info = *pPresentInfo;
         present_info.swapchainCount = 1;
         present_info.pSwapchains = &swapchain;
         present_info.pImageIndices = &image_index;

         uint64_t ts0 = os_time_get();
         result = queue_data->device->vtable.QueuePresentKHR(queue, &present_info);
         uint64_t ts1 = os_time_get();
         swapchain_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_present_timing] += ts1 - ts0;
      }
   } else {
      for (uint32_t i = 0; i < pPresentInfo->swapchainCount; i++) {
         VkSwapchainKHR swapchain = pPresentInfo->pSwapchains[i];
         struct swapchain_data *swapchain_data =
            FIND(struct swapchain_data, swapchain);

         uint32_t image_index = pPresentInfo->pImageIndices[i];

         VkPresentInfoKHR present_info = *pPresentInfo;
         present_info.swapchainCount = 1;
         present_info.pSwapchains = &swapchain;
         present_info.pImageIndices = &image_index;

         struct overlay_draw *draw = before_present(swapchain_data,
                                                    queue_data,
                                                    pPresentInfo->pWaitSemaphores,
                                                    pPresentInfo->waitSemaphoreCount,
                                                    image_index);

         /* Because the submission of the overlay draw waits on the semaphores
          * handed for present, we don't need to have this present operation
          * wait on them as well, we can just wait on the overlay submission
          * semaphore.
          */
         present_info.pWaitSemaphores = &draw->semaphore;
         present_info.waitSemaphoreCount = 1;

         uint64_t ts0 = os_time_get();
         VkResult chain_result = queue_data->device->vtable.QueuePresentKHR(queue, &present_info);
         uint64_t ts1 = os_time_get();
         swapchain_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_present_timing] += ts1 - ts0;
         if (pPresentInfo->pResults)
            pPresentInfo->pResults[i] = chain_result;
         if (chain_result != VK_SUCCESS && result == VK_SUCCESS)
            result = chain_result;
      }
   }
   return result;
}

static VkResult overlay_AcquireNextImageKHR(
    VkDevice                                    device,
    VkSwapchainKHR                              swapchain,
    uint64_t                                    timeout,
    VkSemaphore                                 semaphore,
    VkFence                                     fence,
    uint32_t*                                   pImageIndex)
{
   struct swapchain_data *swapchain_data =
      FIND(struct swapchain_data, swapchain);
   struct device_data *device_data = swapchain_data->device;

   uint64_t ts0 = os_time_get();
   VkResult result = device_data->vtable.AcquireNextImageKHR(device, swapchain, timeout,
                                                             semaphore, fence, pImageIndex);
   uint64_t ts1 = os_time_get();

   swapchain_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_acquire_timing] += ts1 - ts0;
   swapchain_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_acquire]++;

   return result;
}

static VkResult overlay_AcquireNextImage2KHR(
    VkDevice                                    device,
    const VkAcquireNextImageInfoKHR*            pAcquireInfo,
    uint32_t*                                   pImageIndex)
{
   struct swapchain_data *swapchain_data =
      FIND(struct swapchain_data, pAcquireInfo->swapchain);
   struct device_data *device_data = swapchain_data->device;

   uint64_t ts0 = os_time_get();
   VkResult result = device_data->vtable.AcquireNextImage2KHR(device, pAcquireInfo, pImageIndex);
   uint64_t ts1 = os_time_get();

   swapchain_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_acquire_timing] += ts1 - ts0;
   swapchain_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_acquire]++;

   return result;
}

static void overlay_CmdDraw(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    vertexCount,
    uint32_t                                    instanceCount,
    uint32_t                                    firstVertex,
    uint32_t                                    firstInstance)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_draw]++;
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdDraw(commandBuffer, vertexCount, instanceCount,
                               firstVertex, firstInstance);
}

static void overlay_CmdDrawIndexed(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    indexCount,
    uint32_t                                    instanceCount,
    uint32_t                                    firstIndex,
    int32_t                                     vertexOffset,
    uint32_t                                    firstInstance)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_draw_indexed]++;
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdDrawIndexed(commandBuffer, indexCount, instanceCount,
                                      firstIndex, vertexOffset, firstInstance);
}

static void overlay_CmdDrawIndirect(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    uint32_t                                    drawCount,
    uint32_t                                    stride)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_draw_indirect]++;
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdDrawIndirect(commandBuffer, buffer, offset, drawCount, stride);
}

static void overlay_CmdDrawIndexedIndirect(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    uint32_t                                    drawCount,
    uint32_t                                    stride)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_draw_indexed_indirect]++;
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdDrawIndexedIndirect(commandBuffer, buffer, offset, drawCount, stride);
}

static void overlay_CmdDrawIndirectCount(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    VkBuffer                                    countBuffer,
    VkDeviceSize                                countBufferOffset,
    uint32_t                                    maxDrawCount,
    uint32_t                                    stride)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_draw_indirect_count]++;
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdDrawIndirectCount(commandBuffer, buffer, offset,
                                            countBuffer, countBufferOffset,
                                            maxDrawCount, stride);
}

static void overlay_CmdDrawIndexedIndirectCount(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    VkBuffer                                    countBuffer,
    VkDeviceSize                                countBufferOffset,
    uint32_t                                    maxDrawCount,
    uint32_t                                    stride)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_draw_indexed_indirect_count]++;
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdDrawIndexedIndirectCount(commandBuffer, buffer, offset,
                                                   countBuffer, countBufferOffset,
                                                   maxDrawCount, stride);
}

static void overlay_CmdDispatch(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    groupCountX,
    uint32_t                                    groupCountY,
    uint32_t                                    groupCountZ)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_dispatch]++;
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdDispatch(commandBuffer, groupCountX, groupCountY, groupCountZ);
}

static void overlay_CmdDispatchIndirect(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_dispatch_indirect]++;
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdDispatchIndirect(commandBuffer, buffer, offset);
}

static void overlay_CmdBindPipeline(
    VkCommandBuffer                             commandBuffer,
    VkPipelineBindPoint                         pipelineBindPoint,
    VkPipeline                                  pipeline)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   switch (pipelineBindPoint) {
   case VK_PIPELINE_BIND_POINT_GRAPHICS: cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_pipeline_graphics]++; break;
   case VK_PIPELINE_BIND_POINT_COMPUTE: cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_pipeline_compute]++; break;
   case VK_PIPELINE_BIND_POINT_RAY_TRACING_NV: cmd_buffer_data->stats.stats[OVERLAY_PARAM_ENABLED_pipeline_raytracing]++; break;
   default: break;
   }
   struct device_data *device_data = cmd_buffer_data->device;
   device_data->vtable.CmdBindPipeline(commandBuffer, pipelineBindPoint, pipeline);
}

static VkResult overlay_BeginCommandBuffer(
    VkCommandBuffer                             commandBuffer,
    const VkCommandBufferBeginInfo*             pBeginInfo)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   struct device_data *device_data = cmd_buffer_data->device;

   memset(&cmd_buffer_data->stats, 0, sizeof(cmd_buffer_data->stats));

   /* We don't record any query in secondary command buffers, just make sure
    * we have the right inheritance.
    */
   if (cmd_buffer_data->level == VK_COMMAND_BUFFER_LEVEL_SECONDARY) {
      VkCommandBufferBeginInfo *begin_info = (VkCommandBufferBeginInfo *)
         clone_chain((const struct VkBaseInStructure *)pBeginInfo);
      VkCommandBufferInheritanceInfo *parent_inhe_info = (VkCommandBufferInheritanceInfo *)
         vk_find_struct(begin_info, COMMAND_BUFFER_INHERITANCE_INFO);
      VkCommandBufferInheritanceInfo inhe_info = {
         VK_STRUCTURE_TYPE_COMMAND_BUFFER_INHERITANCE_INFO,
         NULL,
         VK_NULL_HANDLE,
         0,
         VK_NULL_HANDLE,
         VK_FALSE,
         0,
         overlay_query_flags,
      };

      if (parent_inhe_info)
         parent_inhe_info->pipelineStatistics = overlay_query_flags;
      else {
         inhe_info.pNext = begin_info->pNext;
         begin_info->pNext = &inhe_info;
      }

      VkResult result = device_data->vtable.BeginCommandBuffer(commandBuffer, pBeginInfo);

      if (!parent_inhe_info)
         begin_info->pNext = inhe_info.pNext;

      free_chain((struct VkBaseOutStructure *)begin_info);

      return result;
   }

   /* Otherwise record a begin query as first command. */
   VkResult result = device_data->vtable.BeginCommandBuffer(commandBuffer, pBeginInfo);

   if (result == VK_SUCCESS) {
      if (cmd_buffer_data->pipeline_query_pool) {
         device_data->vtable.CmdResetQueryPool(commandBuffer,
                                               cmd_buffer_data->pipeline_query_pool,
                                               cmd_buffer_data->query_index, 1);
      }
      if (cmd_buffer_data->timestamp_query_pool) {
         device_data->vtable.CmdResetQueryPool(commandBuffer,
                                               cmd_buffer_data->timestamp_query_pool,
                                               cmd_buffer_data->query_index * 2, 2);
      }
      if (cmd_buffer_data->pipeline_query_pool) {
         device_data->vtable.CmdBeginQuery(commandBuffer,
                                           cmd_buffer_data->pipeline_query_pool,
                                           cmd_buffer_data->query_index, 0);
      }
      if (cmd_buffer_data->timestamp_query_pool) {
         device_data->vtable.CmdWriteTimestamp(commandBuffer,
                                               VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
                                               cmd_buffer_data->timestamp_query_pool,
                                               cmd_buffer_data->query_index * 2);
      }
   }

   return result;
}

static VkResult overlay_EndCommandBuffer(
    VkCommandBuffer                             commandBuffer)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   struct device_data *device_data = cmd_buffer_data->device;

   if (cmd_buffer_data->timestamp_query_pool) {
      device_data->vtable.CmdWriteTimestamp(commandBuffer,
                                            VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
                                            cmd_buffer_data->timestamp_query_pool,
                                            cmd_buffer_data->query_index * 2 + 1);
   }
   if (cmd_buffer_data->pipeline_query_pool) {
      device_data->vtable.CmdEndQuery(commandBuffer,
                                      cmd_buffer_data->pipeline_query_pool,
                                      cmd_buffer_data->query_index);
   }

   return device_data->vtable.EndCommandBuffer(commandBuffer);
}

static VkResult overlay_ResetCommandBuffer(
    VkCommandBuffer                             commandBuffer,
    VkCommandBufferResetFlags                   flags)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   struct device_data *device_data = cmd_buffer_data->device;

   memset(&cmd_buffer_data->stats, 0, sizeof(cmd_buffer_data->stats));

   return device_data->vtable.ResetCommandBuffer(commandBuffer, flags);
}

static void overlay_CmdExecuteCommands(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    commandBufferCount,
    const VkCommandBuffer*                      pCommandBuffers)
{
   struct command_buffer_data *cmd_buffer_data =
      FIND(struct command_buffer_data, commandBuffer);
   struct device_data *device_data = cmd_buffer_data->device;

   /* Add the stats of the executed command buffers to the primary one. */
   for (uint32_t c = 0; c < commandBufferCount; c++) {
      struct command_buffer_data *sec_cmd_buffer_data =
         FIND(struct command_buffer_data, pCommandBuffers[c]);

      for (uint32_t s = 0; s < OVERLAY_PARAM_ENABLED_MAX; s++)
         cmd_buffer_data->stats.stats[s] += sec_cmd_buffer_data->stats.stats[s];
   }

   device_data->vtable.CmdExecuteCommands(commandBuffer, commandBufferCount, pCommandBuffers);
}

static VkResult overlay_AllocateCommandBuffers(
   VkDevice                           device,
   const VkCommandBufferAllocateInfo* pAllocateInfo,
   VkCommandBuffer*                   pCommandBuffers)
{
   struct device_data *device_data = FIND(struct device_data, device);
   VkResult result =
      device_data->vtable.AllocateCommandBuffers(device, pAllocateInfo, pCommandBuffers);
   if (result != VK_SUCCESS)
      return result;

   VkQueryPool pipeline_query_pool = VK_NULL_HANDLE;
   VkQueryPool timestamp_query_pool = VK_NULL_HANDLE;
   if (device_data->instance->pipeline_statistics_enabled &&
       pAllocateInfo->level == VK_COMMAND_BUFFER_LEVEL_PRIMARY) {
      VkQueryPoolCreateInfo pool_info = {
         VK_STRUCTURE_TYPE_QUERY_POOL_CREATE_INFO,
         NULL,
         0,
         VK_QUERY_TYPE_PIPELINE_STATISTICS,
         pAllocateInfo->commandBufferCount,
         overlay_query_flags,
      };
      VK_CHECK(device_data->vtable.CreateQueryPool(device_data->device, &pool_info,
                                                   NULL, &pipeline_query_pool));
   }
   if (device_data->instance->params.enabled[OVERLAY_PARAM_ENABLED_gpu_timing]) {
      VkQueryPoolCreateInfo pool_info = {
         VK_STRUCTURE_TYPE_QUERY_POOL_CREATE_INFO,
         NULL,
         0,
         VK_QUERY_TYPE_TIMESTAMP,
         pAllocateInfo->commandBufferCount * 2,
         0,
      };
      VK_CHECK(device_data->vtable.CreateQueryPool(device_data->device, &pool_info,
                                                   NULL, &timestamp_query_pool));
   }

   for (uint32_t i = 0; i < pAllocateInfo->commandBufferCount; i++) {
      new_command_buffer_data(pCommandBuffers[i], pAllocateInfo->level,
                              pipeline_query_pool, timestamp_query_pool,
                              i, device_data);
   }

   if (pipeline_query_pool)
      map_object(HKEY(pipeline_query_pool), (void *)(uintptr_t) pAllocateInfo->commandBufferCount);
   if (timestamp_query_pool)
      map_object(HKEY(timestamp_query_pool), (void *)(uintptr_t) pAllocateInfo->commandBufferCount);

   return result;
}

static void overlay_FreeCommandBuffers(
   VkDevice               device,
   VkCommandPool          commandPool,
   uint32_t               commandBufferCount,
   const VkCommandBuffer* pCommandBuffers)
{
   struct device_data *device_data = FIND(struct device_data, device);
   for (uint32_t i = 0; i < commandBufferCount; i++) {
      struct command_buffer_data *cmd_buffer_data =
         FIND(struct command_buffer_data, pCommandBuffers[i]);

      /* It is legal to free a NULL command buffer*/
      if (!cmd_buffer_data)
         continue;

      uint64_t count = (uintptr_t)find_object_data(HKEY(cmd_buffer_data->pipeline_query_pool));
      if (count == 1) {
         unmap_object(HKEY(cmd_buffer_data->pipeline_query_pool));
         device_data->vtable.DestroyQueryPool(device_data->device,
                                              cmd_buffer_data->pipeline_query_pool, NULL);
      } else if (count != 0) {
         map_object(HKEY(cmd_buffer_data->pipeline_query_pool), (void *)(uintptr_t)(count - 1));
      }
      count = (uintptr_t)find_object_data(HKEY(cmd_buffer_data->timestamp_query_pool));
      if (count == 1) {
         unmap_object(HKEY(cmd_buffer_data->timestamp_query_pool));
         device_data->vtable.DestroyQueryPool(device_data->device,
                                              cmd_buffer_data->timestamp_query_pool, NULL);
      } else if (count != 0) {
         map_object(HKEY(cmd_buffer_data->timestamp_query_pool), (void *)(uintptr_t)(count - 1));
      }
      destroy_command_buffer_data(cmd_buffer_data);
   }

   device_data->vtable.FreeCommandBuffers(device, commandPool,
                                          commandBufferCount, pCommandBuffers);
}

static VkResult overlay_QueueSubmit(
    VkQueue                                     queue,
    uint32_t                                    submitCount,
    const VkSubmitInfo*                         pSubmits,
    VkFence                                     fence)
{
   struct queue_data *queue_data = FIND(struct queue_data, queue);
   struct device_data *device_data = queue_data->device;

   device_data->frame_stats.stats[OVERLAY_PARAM_ENABLED_submit]++;

   for (uint32_t s = 0; s < submitCount; s++) {
      for (uint32_t c = 0; c < pSubmits[s].commandBufferCount; c++) {
         struct command_buffer_data *cmd_buffer_data =
            FIND(struct command_buffer_data, pSubmits[s].pCommandBuffers[c]);

         /* Merge the submitted command buffer stats into the device. */
         for (uint32_t st = 0; st < OVERLAY_PARAM_ENABLED_MAX; st++)
            device_data->frame_stats.stats[st] += cmd_buffer_data->stats.stats[st];

         /* Attach the command buffer to the queue so we remember to read its
          * pipeline statistics & timestamps at QueuePresent().
          */
         if (!cmd_buffer_data->pipeline_query_pool &&
             !cmd_buffer_data->timestamp_query_pool)
            continue;

         if (list_is_empty(&cmd_buffer_data->link)) {
            list_addtail(&cmd_buffer_data->link,
                         &queue_data->running_command_buffer);
         } else {
            fprintf(stderr, "Command buffer submitted multiple times before present.\n"
                    "This could lead to invalid data.\n");
         }
      }
   }

   return device_data->vtable.QueueSubmit(queue, submitCount, pSubmits, fence);
}

static VkResult overlay_CreateDevice(
    VkPhysicalDevice                            physicalDevice,
    const VkDeviceCreateInfo*                   pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkDevice*                                   pDevice)
{
   struct instance_data *instance_data =
      FIND(struct instance_data, physicalDevice);
   VkLayerDeviceCreateInfo *chain_info =
      get_device_chain_info(pCreateInfo, VK_LAYER_LINK_INFO);

   assert(chain_info->u.pLayerInfo);
   PFN_vkGetInstanceProcAddr fpGetInstanceProcAddr = chain_info->u.pLayerInfo->pfnNextGetInstanceProcAddr;
   PFN_vkGetDeviceProcAddr fpGetDeviceProcAddr = chain_info->u.pLayerInfo->pfnNextGetDeviceProcAddr;
   PFN_vkCreateDevice fpCreateDevice = (PFN_vkCreateDevice)fpGetInstanceProcAddr(NULL, "vkCreateDevice");
   if (fpCreateDevice == NULL) {
      return VK_ERROR_INITIALIZATION_FAILED;
   }

   // Advance the link info for the next element on the chain
   chain_info->u.pLayerInfo = chain_info->u.pLayerInfo->pNext;

   VkPhysicalDeviceFeatures device_features = {};
   VkDeviceCreateInfo device_info = *pCreateInfo;

   if (pCreateInfo->pEnabledFeatures)
      device_features = *(pCreateInfo->pEnabledFeatures);
   if (instance_data->pipeline_statistics_enabled) {
      device_features.inheritedQueries = true;
      device_features.pipelineStatisticsQuery = true;
   }
   device_info.pEnabledFeatures = &device_features;


   VkResult result = fpCreateDevice(physicalDevice, &device_info, pAllocator, pDevice);
   if (result != VK_SUCCESS) return result;

   struct device_data *device_data = new_device_data(*pDevice, instance_data);
   device_data->physical_device = physicalDevice;
   vk_load_device_commands(*pDevice, fpGetDeviceProcAddr, &device_data->vtable);

   instance_data->vtable.GetPhysicalDeviceProperties(device_data->physical_device,
                                                     &device_data->properties);

   VkLayerDeviceCreateInfo *load_data_info =
      get_device_chain_info(pCreateInfo, VK_LOADER_DATA_CALLBACK);
   device_data->set_device_loader_data = load_data_info->u.pfnSetDeviceLoaderData;

   device_map_queues(device_data, pCreateInfo);

   return result;
}

static void overlay_DestroyDevice(
    VkDevice                                    device,
    const VkAllocationCallbacks*                pAllocator)
{
   struct device_data *device_data = FIND(struct device_data, device);
   device_unmap_queues(device_data);
   device_data->vtable.DestroyDevice(device, pAllocator);
   destroy_device_data(device_data);
}

static VkResult overlay_CreateInstance(
    const VkInstanceCreateInfo*                 pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkInstance*                                 pInstance)
{
   VkLayerInstanceCreateInfo *chain_info =
      get_instance_chain_info(pCreateInfo, VK_LAYER_LINK_INFO);

   assert(chain_info->u.pLayerInfo);
   PFN_vkGetInstanceProcAddr fpGetInstanceProcAddr =
      chain_info->u.pLayerInfo->pfnNextGetInstanceProcAddr;
   PFN_vkCreateInstance fpCreateInstance =
      (PFN_vkCreateInstance)fpGetInstanceProcAddr(NULL, "vkCreateInstance");
   if (fpCreateInstance == NULL) {
      return VK_ERROR_INITIALIZATION_FAILED;
   }

   // Advance the link info for the next element on the chain
   chain_info->u.pLayerInfo = chain_info->u.pLayerInfo->pNext;

   VkResult result = fpCreateInstance(pCreateInfo, pAllocator, pInstance);
   if (result != VK_SUCCESS) return result;

   struct instance_data *instance_data = new_instance_data(*pInstance);
   vk_load_instance_commands(instance_data->instance,
                             fpGetInstanceProcAddr,
                             &instance_data->vtable);
   instance_data_map_physical_devices(instance_data, true);

   parse_overlay_env(&instance_data->params, getenv("VK_LAYER_MESA_OVERLAY_CONFIG"));

   /* If there's no control file, and an output_file was specified, start
    * capturing fps data right away.
    */
   instance_data->capture_enabled =
      instance_data->params.output_file && instance_data->params.control < 0;
   instance_data->capture_started = instance_data->capture_enabled;

   for (int i = OVERLAY_PARAM_ENABLED_vertices;
        i <= OVERLAY_PARAM_ENABLED_compute_invocations; i++) {
      if (instance_data->params.enabled[i]) {
         instance_data->pipeline_statistics_enabled = true;
         break;
      }
   }

   return result;
}

static void overlay_DestroyInstance(
    VkInstance                                  instance,
    const VkAllocationCallbacks*                pAllocator)
{
   struct instance_data *instance_data = FIND(struct instance_data, instance);
   instance_data_map_physical_devices(instance_data, false);
   instance_data->vtable.DestroyInstance(instance, pAllocator);
   destroy_instance_data(instance_data);
}

static const struct {
   const char *name;
   void *ptr;
} name_to_funcptr_map[] = {
   { "vkGetDeviceProcAddr", (void *) vkGetDeviceProcAddr },
#define ADD_HOOK(fn) { "vk" # fn, (void *) overlay_ ## fn }
#define ADD_ALIAS_HOOK(alias, fn) { "vk" # alias, (void *) overlay_ ## fn }
   ADD_HOOK(AllocateCommandBuffers),
   ADD_HOOK(FreeCommandBuffers),
   ADD_HOOK(ResetCommandBuffer),
   ADD_HOOK(BeginCommandBuffer),
   ADD_HOOK(EndCommandBuffer),
   ADD_HOOK(CmdExecuteCommands),

   ADD_HOOK(CmdDraw),
   ADD_HOOK(CmdDrawIndexed),
   ADD_HOOK(CmdDrawIndirect),
   ADD_HOOK(CmdDrawIndexedIndirect),
   ADD_HOOK(CmdDispatch),
   ADD_HOOK(CmdDispatchIndirect),
   ADD_HOOK(CmdDrawIndirectCount),
   ADD_ALIAS_HOOK(CmdDrawIndirectCountKHR, CmdDrawIndirectCount),
   ADD_HOOK(CmdDrawIndexedIndirectCount),
   ADD_ALIAS_HOOK(CmdDrawIndexedIndirectCountKHR, CmdDrawIndexedIndirectCount),

   ADD_HOOK(CmdBindPipeline),

   ADD_HOOK(CreateSwapchainKHR),
   ADD_HOOK(QueuePresentKHR),
   ADD_HOOK(DestroySwapchainKHR),
   ADD_HOOK(AcquireNextImageKHR),
   ADD_HOOK(AcquireNextImage2KHR),

   ADD_HOOK(QueueSubmit),

   ADD_HOOK(CreateDevice),
   ADD_HOOK(DestroyDevice),

   ADD_HOOK(CreateInstance),
   ADD_HOOK(DestroyInstance),
#undef ADD_HOOK
};

static void *find_ptr(const char *name)
{
   for (uint32_t i = 0; i < ARRAY_SIZE(name_to_funcptr_map); i++) {
      if (strcmp(name, name_to_funcptr_map[i].name) == 0)
         return name_to_funcptr_map[i].ptr;
   }

   return NULL;
}

VK_LAYER_EXPORT VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL vkGetDeviceProcAddr(VkDevice dev,
                                                                             const char *funcName)
{
   void *ptr = find_ptr(funcName);
   if (ptr) return reinterpret_cast<PFN_vkVoidFunction>(ptr);

   if (dev == NULL) return NULL;

   struct device_data *device_data = FIND(struct device_data, dev);
   if (device_data->vtable.GetDeviceProcAddr == NULL) return NULL;
   return device_data->vtable.GetDeviceProcAddr(dev, funcName);
}

VK_LAYER_EXPORT VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL vkGetInstanceProcAddr(VkInstance instance,
                                                                               const char *funcName)
{
   void *ptr = find_ptr(funcName);
   if (ptr) return reinterpret_cast<PFN_vkVoidFunction>(ptr);

   if (instance == NULL) return NULL;

   struct instance_data *instance_data = FIND(struct instance_data, instance);
   if (instance_data->vtable.GetInstanceProcAddr == NULL) return NULL;
   return instance_data->vtable.GetInstanceProcAddr(instance, funcName);
}
