/* Copyright (c) 2007 Scott Lembcke
 * 
 * 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 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 <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>

#include "chipmunk/chipmunk_private.h"
#include "ChipmunkDemo.h"

static cpBool DrawContacts(cpArbiter *arb, cpSpace *space, void *data){
	cpContactPointSet set = cpArbiterGetContactPointSet(arb);
	
	for(int i=0; i<set.count; i++){
		cpVect p = set.points[i].point;
		ChipmunkDebugDrawDot(6.0, p, RGBAColor(1, 0, 0, 1));
		ChipmunkDebugDrawSegment(p, cpvadd(p, cpvmult(set.points[i].normal, 10.0)), RGBAColor(1, 0, 0, 1));
	}
	
	return cpFalse;
//	return cpTrue;
}

static void
update(cpSpace *space)
{
	int steps = 1;
	cpFloat dt = 1.0f/60.0f/(cpFloat)steps;
	
	for(int i=0; i<steps; i++){
		cpSpaceStep(space, dt);
	}
}

#define MAX(a, b) (a > b ? a : b)
#define MIN(a, b) (a < b ? a : b)

static cpSpace *
init(void)
{
	cpSpace *space = cpSpaceNew();
	cpSpaceSetIterations(space, 5);
	cpSpaceSetDamping(space, 0.1f);
	
	cpSpaceSetDefaultCollisionHandler(space, NULL, DrawContacts, NULL, NULL, NULL);
	
	{
		cpFloat mass = 1.0f;
		cpFloat length = 100.0f;
		cpVect a = cpv(-length/2.0f, 0.0f), b = cpv(length/2.0f, 0.0f);
		
		cpBody *body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForSegment(mass, a, b)));
		cpBodySetPos(body, cpv(-160.0f, 80.0f));
		
		cpSpaceAddShape(space, cpSegmentShapeNew(body, a, b, 30.0f));
	}
	
	{
		cpFloat mass = 1.0f;
		const int NUM_VERTS = 5;
		
		cpVect verts[NUM_VERTS];
		for(int i=0; i<NUM_VERTS; i++){
			cpFloat angle = -2*M_PI*i/((cpFloat) NUM_VERTS);
			verts[i] = cpv(40*cos(angle), 40*sin(angle));
		}
		
		cpBody *body = cpSpaceAddBody(space, cpBodyNew(mass, cpMomentForPoly(mass, NUM_VERTS, verts, cpvzero)));
		cpBodySetPos(body, cpv(-0.0f, 80.0f));
		
		cpSpaceAddShape(space, cpPolyShapeNew(body, NUM_VERTS, verts, cpvzero));
	}
	
	{
		cpFloat mass = 1.0f;
		cpFloat r = 60.0f;
		
		cpBody *body = cpSpaceAddBody(space, cpBodyNew(mass, INFINITY));
		cpBodySetPos(body, cpv(160.0, 80.0f));
		
		cpSpaceAddShape(space, cpCircleShapeNew(body, r, cpvzero));
	}
	
	cpBody *staticBody = cpSpaceGetStaticBody(space);
	
	cpVect terrain[] = {
		cpv(-320, -200),
		cpv(-200, -100),
		cpv(   0, -200),
		cpv( 200, -100),
		cpv( 320, -200),
	};
	int terrainCount = sizeof(terrain)/sizeof(*terrain);
	
	for(int i=1; i<5; i++){
		cpVect v0 = terrain[MAX(i-2, 0)];
		cpVect v1 = terrain[i-1];
		cpVect v2 = terrain[i];
		cpVect v3 = terrain[MIN(i+1, terrainCount - 1)];
		
		cpShape *seg = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, v1, v2, 10.0));
		cpSegmentShapeSetNeighbors(seg, v0, v3);
	}
	
	return space;
}

static void
destroy(cpSpace *space)
{
	ChipmunkDemoFreeSpaceChildren(space);
	cpSpaceFree(space);
}

ChipmunkDemo Smooth = {
	"Smooth",
	1.0f/60.0f,
	init,
	update,
	ChipmunkDemoDefaultDrawImpl,
	destroy,
};
