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)