makecol15_dither man page

makecol15_dither, makecol16_dither — Calculates a dithered 15 or 16-bit RGB value. Allegro game programming library.

Synopsis

#include <allegro.h>

int makecol15_dither(int r, int g, int b, int x, int y);

int makecol16_dither(int r, int g, int b, int x, int y);

Description

Given both a color value and a pixel coordinate, calculate a dithered 15 or 16-bit RGB value. This can produce better results when reducing images from truecolor to hicolor. In addition to calling these functions directly, hicolor dithering can be automatically enabled when loading graphics by calling the set_color_conversion() function, for example set_color_conversion(COLORCONV_REDUCE_TRUE_TO_HI | COLORCONV_DITHER).

Example:

int pixel1, pixel2;

/* The following two color values MAY be different. */
pixel1 = makecol16_dither(255, 192, 64, 0, 0);
pixel2 = makecol16_dither(255, 192, 64, 1, 0);

Return Value

Returns the RGB value dithered for the specified coordinate.

See Also

makecol(3), makecol8(3), set_color_conversion(3)

Referenced By

makecol(3), makecol8(3), makecol_depth(3), set_color_conversion(3).

makecol16_dither(3) is an alias of makecol15_dither(3).

version 4.4.2 Allegro Allegro manual