api_rh_set_conversion_colour_map
List of: Functions
Subjects: Image Output
Contents: Rendering Base

Action: Sets the color map for conversion.

Prototype: outcome api_rh_set_conversion_colour_map (


LwInt32 r_max, // red color map index


LwInt32 g_max, // green color map index


LwInt32 b_max, // blue color map index


LwInt32 r_mult, // red color multiplier


LwInt32 g_mult, // green color multiplier


LwInt32 b_mult, // blue color multiplier


LwInt32 base_index // base index


);

Includes: #include "kernel/acis.hxx"

#include "kernel/kernapi/api/api.hxx"

#include "rnd_husk/api/rnd_api.hxx"

#include "rnd_husk/include/rh_types.h"

Description: This function describes the color map of the output device, and it takes the form of an RGB cube. An RGB cube is a 3D array containing an ordered spectrum of colors. The subscripts of an RGB cube are values representing the respective amounts of each red, green, and blue color component of a particular color.


Images are displayed on a display device using a color-map containing the spectrum of colors described by the RGB cube.


Display devices' color-maps are normally 1D arrays, with the subscript being a color-map index. r_mult, g_mult, and b_mult are the multipliers for the respective RGB cube subscripts used to build a color-map index. The color-map index of a color within the RGB cube, with RGB cube subscript levels of r, g, and b are base_index + r x r_mult + g x g_mult + b x b_mult.


When LwConvertRGBScanline or LwConvertRGBFloatScanline is called, the pixels' colors are converted into color-map indexes within the RGB cube.


This function's parameters describe the layout of a 3D array representing the RGB cube. Set r_max, g_max, and b_max to the maximum number of different shades of each primary color in the RGB cube. Set r_mult, g_mult, and b_mult to the multipliers for the respective components within the RGB cube when converting RGB levels into color-map indexes. Set base_index to the start index of the RGB cube within the color-map. For a standard 8-bit display device, the values are typically: r_max = 5, g_max = 5, b_max = 5, r_mult = 36, g_mult = 6, b_mult = 1, describing a 216-color cube with six levels of each color component. Set base_index to the index of the first entry of the cube in the map.


For the grey-scale conversion method only r_max, r_mult, and base_index are significant.


For the monochrome conversion method, only base_index is significant.


Set the conversion color-map for an image before calling LwConvertImageStart. This function is ignored if it is called between calls to LwConvertImageStart and LwConvertImageEnd.


The default conversion color-map set by LwInitialiseImageUtilities is a 6 x 6 x 6 RGB cube with parameters of r_max = 5, g_max = 5, b_max = 5, r_mult = 36, g_mult = 6, b_mult = 1, and base_index = 0.

Library: rnd_husk

Filename: rbase/rnd_husk/api/rnd_api.hxx

Effect: System routine
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