exalpha − Creating and using 32 bit RGBA sprites. Allegro game programming library.
#include <allegro.h>
Example exalpha
This program demonstrates how to use the 32 bit RGBA translucency functions to store an alpha channel along with a bitmap graphic. Two images are loaded from disk. One will be used for the background and the other as a sprite. The example generates an alpha channel for the sprite image, composing the 32 bit RGBA bitmap during runtime, and draws it at the position of the mouse cursor.
BITMAP(3), END_OF_MAIN(3), SCREEN_H(3), SCREEN_W(3), allegro_error(3), allegro_init(3), allegro_message(3), blit(3), clear_keybuf(3), create_bitmap(3), destroy_bitmap(3), draw_trans_sprite(3), drawing_mode(3), font(3), getb(3), getg(3), getpixel(3), getr(3), install_keyboard(3), install_mouse(3), install_timer(3), keypressed(3), load_bitmap(3), makecol(3), mouse_x(3), mouse_y(3), putpixel(3), rectfill(3), replace_filename(3), screen(3), set_alpha_blender(3), set_color_conversion(3), set_color_depth(3), set_gfx_mode(3), set_multiply_blender(3), set_write_alpha_blender(3), solid_mode(3), stretch_blit(3), textprintf_ex(3)