oracular (3) create_trans_table.3alleg4.gz

Provided by: allegro4-doc_4.4.3.1-5_all bug

NAME
       create_trans_table  -  Fills  a  color  mapping  table for translucency effects. Allegro game programming
       library.


SYNOPSIS
       #include <allegro.h>

       void create_trans_table(COLOR_MAP *table, const PALETTE pal, int r, g, b, void (*callback)(int pos));


DESCRIPTION
       Fills the specified color mapping table  with  lookup  data  for  doing  translucency  effects  with  the
       specified  palette.  When  combining  the  colors  c1  and c2 with this table, the result will be a color
       somewhere between the two. The r, g, and b parameters specify  the  solidity  of  each  color  component,
       ranging from 0 (totally transparent) to 255 (totally solid). For 50% solidity, pass 128.

       This function treats source color #0 as a special case, leaving the destination unchanged whenever a zero
       source pixel is encountered, so that  masked  sprites  will  draw  correctly.  This  function  will  take
       advantage  of  the global rgb_map variable to speed up color conversions. If the callback function is not
       NULL, it will be called 256 times during the calculation, allowing you to display a  progress  indicator.
       Example:

          COLOR_MAP trans_table;
          ...
          /* Build a color lookup table for translucent drawing. */
          create_trans_table(&trans_table, pal, 128, 128, 128, NULL);


SEE ALSO
       color_map(3alleg4),               create_light_table(3alleg4),               create_color_table(3alleg4),
       create_blender_table(3alleg4),           draw_trans_sprite(3alleg4),            draw_lit_sprite(3alleg4),
       draw_gouraud_sprite(3alleg4), rgb_map(3alleg4), ex3d(3alleg4), extrans(3alleg4)