extrans - Lighting and translucency effects. Allegro game programming library.

       This  program  demonstrates  how  to  use  the lighting and translucency functions. The first part of the
       example will show a dark screen illuminated by a spotlight you can move with  your  mouse.  After  a  key
       press  the  example  shows  the  full  bitmap  and  the  spotlight changes to be a reduced version of the
       background with 50% of translucency.

       The translucency effect is easy to do in all color depths.   However,  the  lighting  effect  has  to  be
       performed in a different way depending on whether the screen is in 8bit mode or another color depth. This
       is because additive drawing mode uses a different set of routines for truecolor modes.

       extrans - Lighting and translucency effects. Allegro game programming library.

BITMAP(3alleg4),     COLOR_MAP(3alleg4),     END_OF_MAIN(3alleg4),     PALETTE(3alleg4),    RGB(3alleg4),
       RGB_MAP(3alleg4), SCREEN_H(3alleg4),  SCREEN_W(3alleg4),  allegro_error(3alleg4),  allegro_init(3alleg4),
       allegro_message(3alleg4),      bitmap_color_depth(3alleg4),      blit(3alleg4),      circlefill(3alleg4),
       clear_bitmap(3alleg4),      clear_keybuf(3alleg4),      color_map(3alleg4),       create_bitmap(3alleg4),
       create_bitmap_ex(3alleg4),             create_light_table(3alleg4),            create_rgb_table(3alleg4),
       create_trans_table(3alleg4), destroy_bitmap(3alleg4), draw_trans_sprite(3alleg4),  drawing_mode(3alleg4),
       install_keyboard(3alleg4),     install_mouse(3alleg4),    install_timer(3alleg4),    keypressed(3alleg4),
       load_bitmap(3alleg4),   mouse_x(3alleg4),   mouse_y(3alleg4),   poll_mouse(3alleg4),   rectfill(3alleg4),
       replace_filename(3alleg4),  rest(3alleg4), rgb_map(3alleg4), screen(3alleg4), set_alpha_blender(3alleg4),
       set_gfx_mode(3alleg4),                 set_palette(3alleg4),                  set_trans_blender(3alleg4),
       set_write_alpha_blender(3alleg4), stretch_blit(3alleg4)

Allegro                                           version 4.4.3                                 extrans(3alleg4)

#include<allegro.h>Exampleextrans