draw_trans_sprite(3alleg4)       Allegro manual       draw_trans_sprite(3alleg4)

       draw_trans_sprite - Draws a sprite blending it with the destination.
       Allegro game programming library.

       #include <allegro.h>

       void draw_trans_sprite(BITMAP *bmp, BITMAP *sprite, int x, int y);

       Uses the global color_map table or truecolor blender functions to overlay
       the sprite on top of the existing image. This must only be used after you
       have set up the color mapping table (for 256-color modes) or blender
       functions (for truecolor modes). Because it involves reading as well as
       writing the bitmap memory, translucent drawing is very slow if you draw
       directly to video RAM, so wherever possible you should use a memory
       bitmap instead. Example:

          /* Some one time initialisation code. */
          COLOR_MAP global_trans_table;
          create_trans_table(&global_trans_table, my_palette,
                             128, 128, 128, NULL);
          if (get_color_depth() == 8)
             color_map = &global_trans_table;
             set_trans_blender(128, 128, 128, 128);

          draw_trans_sprite(buffer, ghost_sprite, x, y);

       The bitmap and sprite must normally be in the same color depth, but as a
       special case you can draw 32 bit RGBA format sprites onto any hicolor or
       truecolor bitmap, as long as you call set_alpha_blender() first, and you
       can draw 8-bit alpha images onto a 32-bit RGBA destination, as long as
       you call set_write_alpha_blender() first. As draw_sprite() this function
       skips transparent pixels, except if the source sprite is an 8-bit image;
       if this is the case, you should pay attention to properly set up your
       color map table for index 0.

       draw_sprite(3alleg4), draw_lit_sprite(3alleg4),
       draw_trans_rle_sprite(3alleg4), color_map(3alleg4),
       set_trans_blender(3alleg4), set_alpha_blender(3alleg4),
       set_write_alpha_blender(3alleg4), bitmap_mask_color(3alleg4),
       exalpha(3alleg4), exblend(3alleg4), exlights(3alleg4), exrotscl(3alleg4),
       extrans(3alleg4), exxfade(3alleg4)

Allegro                           version 4.4.3       draw_trans_sprite(3alleg4)