v7 man page for extrans

extrans(3alleg4)						  Allegro manual						  extrans(3alleg4)

NAME

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

SYNOPSIS

       #include <allegro.h>

       Example extrans

DESCRIPTION

       This program demonstrates how to use the lighting and translucency functions. The first part of the example will show a dark screen illumi-
       nated 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.

SEE ALSO

       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_bit-
       map(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 4.4.2						  extrans(3alleg4)