OpenLayer Offline Manual

OpenLayer | Bitmap | Load Load
bool Load( | const char *filename );
Loads the Bitmap from a bitmap file, which may contain an alpha channel. Returns true in success.
bool Load( | const char *rgbFilename, const char *alphaFilename );
Loads the Bitmap from two separate bitmaps, one bitmap for the color information and one 8-bit bitmap for the transparency information. Returns true in success.
bool Load( | BITMAP *allegroBmp, bool hasAlphaChannel = false, bool convertMagicPink = false );
Loads the bitmap from an Allegro bitmap. If convertMagicPink is true the magic pink pixels in the bitmap will be converted to transparent pixels in the Bitmap. OpenLayer doesn't free the passed BITMAP even if the Bitmap is destroyed.
bool Load( | BITMAP *allegroBmp, int conversionMode );
Same as above but the parameters are given by using a bitwise "or" of the following conversion parameters: HAS_ALPHA_CHANNEL and CONVERT_MAGIC_PINK. The loaded bitmap may be in any format that is supported by Allegro (bmp, pcx, tga) or by any add-on libraries you've installed (Loadpng for pngs or JPGAlleg for JPEGs, for example). Installing Loadpng is recommended as png files may contain an alpha channel to allow for transparent or translucent pixels. Png files also compress better than tga files. The latest OpenLayer's packages contain the loadpng, libpng and libz -libraries which are required to load png images. It's best to check if the loading succeedes or not. The file may not be found or the format may not be supported. OpenLayer logs all loading failures in allegro.log, though, so you can also check the log file to find out if the loading has failed. But instead of letting your program crash it's better to display a message for the end user to let him know what went wrong. You'll get better feedback for your game that way ;) Examples // Remember to call Setup::SetupProgram and Setup::SetupScreen before loading any bitmaps! // // Load myBmp from gfx/Bitmap.png // Bitmap myBmp; myBmp.Load( "gfx/Bitmap.png" ); // It's best to check if the loading succeedes! (Bitmap really exists) // Bitmap myBmp; if( myBmp.Load( "gfx/Bitmap.png" ) == false ) { // Display an error message // allegro_message( "Bitmap couldn't be loaded!" ); // Exit the program // exit(-1); } // If you have BitmapColor.bmp that has the color information // // and an 8-bit BitmapAlpha.bmp that contains the translucency: // Bitmap myBmp; myBmp.Load( "gfx/BitmapColor.bmp", "gfx/BitmapAlpha.bmp" ); Other functions of the class Bitmap
Load | Loads the bitmap
Blit | Draws the Bitmap to the screen
BlitRotated | Draws the Bitmap to the screen rotated along a point
BlitStretched | Draws the Bitmap to the screen stretched to the specified size
BlitTransformed | Draws the Bitmap to the screen rotated and stretched
BlitDistorted | Draws the Bitmap to the screen with the given corner points
Width | Returns the width of the Bitmap
Height | Returns the height of the Bitmap
LoadListOfBitmaps | Loads a list of bitmaps from the disk
GetPixel | Returns the color value of a pixel
Destroy | Destroys the Bitmap
IsValid | Checks if the Bitmap was loaded correctly
Save | Saves the Bitmap to disk with the specified filename
CopyFromScreen | Copies a region of the game window to the Bitmap
GetMemoryBitmap | Returns a memory bitmap copy of (part of) the Bitmap
GetCollisionPoly | Returns the generated collision polygon for the Bitmap
SetDefaultPivot | Sets the default pivot point
GetDefaultPivot | Returns the default pivot point
Advanced functions
GetPixelPacked | Returns the color value of the specified pixel in a packed integer
SendToGPU | Sends the Bitmap to the graphics card
UnloadFromGPU | Unloads the Bitmap from the graphics card
Select | Selects the Bitmap as the active texture of OpenGL
UseAutoDelete | Chooses the Bitmap to be automatically deleted when the program quits
HasAlphaChannel | Checks if the Bitmap has an alpha channel
StartFastBlitting | This function should be called right before using FastBlit
FastBlit | A faster version of Blit
FinishFastBlitting | This function should be called after calling FastBlit
UnloadToMemory | Unloads the Bitmap from the graphics card keeping the image data saved in the Bitmap
TexturedQuad | Outputs a raw textured quad to the video card
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