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extrans(3) Allegro manual extrans(3)
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
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.
SEE ALSO
BITMAP(3), COLOR_MAP(3), END_OF_MAIN(3), PALETTE(3), RGB(3),
RGB_MAP(3), SCREEN_H(3), SCREEN_W(3), allegro_error(3),
allegro_init(3), allegro_message(3), bitmap_color_depth(3), blit(3),
circlefill(3), clear_bitmap(3), clear_keybuf(3), color_map(3),
create_bitmap(3), create_bitmap_ex(3), create_light_table(3),
create_rgb_table(3), create_trans_table(3), destroy_bitmap(3),
draw_trans_sprite(3), drawing_mode(3), install_keyboard(3),
install_mouse(3), install_timer(3), keypressed(3), load_bitmap(3),
mouse_x(3), mouse_y(3), poll_mouse(3), rectfill(3),
replace_filename(3), rest(3), rgb_map(3), screen(3),
set_alpha_blender(3), set_gfx_mode(3), set_palette(3),
set_trans_blender(3), set_write_alpha_blender(3), stretch_blit(3)
Allegro version 4.4.2 extrans(3)