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Gold Medal Software 3
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Gold Medal Software - Volume 3 (Gold Medal) (1994).iso
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INITPAL.C
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1992-04-03
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/* Sets up the palette in mode X, to a 2-2-2 general R-G-B organization, with
64 separate levels each of pure red, green, and blue. This is very good
for pure colors, but mediocre at best for mixes.
-------------------------
|0 0 | Red|Green| Blue |
-------------------------
7 6 5 4 3 2 1 0
-------------------------
|0 1 | Red |
-------------------------
7 6 5 4 3 2 1 0
-------------------------
|1 0 | Green |
-------------------------
7 6 5 4 3 2 1 0
-------------------------
|1 1 | Blue |
-------------------------
7 6 5 4 3 2 1 0
Colors are gamma corrected for a gamma of 2.3 to provide approximately
even intensity steps on the screen.
*/
#include <dos.h>
#include "polygon.h"
static unsigned char Gamma4Levels[] = { 0, 39, 53, 63 };
static unsigned char Gamma64Levels[] = {
0, 10, 14, 17, 19, 21, 23, 24, 26, 27, 28, 29, 31, 32, 33, 34,
35, 36, 37, 37, 38, 39, 40, 41, 41, 42, 43, 44, 44, 45, 46, 46,
47, 48, 48, 49, 49, 50, 51, 51, 52, 52, 53, 53, 54, 54, 55, 55,
56, 56, 57, 57, 58, 58, 59, 59, 60, 60, 61, 61, 62, 62, 63, 63,
};
static unsigned char PaletteBlock[256][3]; /* 256 RGB entries */
void InitializePalette()
{
int Red, Green, Blue, Index;
union REGS regset;
struct SREGS sregset;
for (Red=0; Red<4; Red++) {
for (Green=0; Green<4; Green++) {
for (Blue=0; Blue<4; Blue++) {
Index = (Red<<4)+(Green<<2)+Blue;
PaletteBlock[Index][0] = Gamma4Levels[Red];
PaletteBlock[Index][1] = Gamma4Levels[Green];
PaletteBlock[Index][2] = Gamma4Levels[Blue];
}
}
}
for (Red=0; Red<64; Red++) {
PaletteBlock[64+Red][0] = Gamma64Levels[Red];
PaletteBlock[64+Red][1] = 0;
PaletteBlock[64+Red][2] = 0;
}
for (Green=0; Green<64; Green++) {
PaletteBlock[128+Green][0] = 0;
PaletteBlock[128+Green][1] = Gamma64Levels[Green];
PaletteBlock[128+Green][2] = 0;
}
for (Blue=0; Blue<64; Blue++) {
PaletteBlock[192+Blue][0] = 0;
PaletteBlock[192+Blue][1] = 0;
PaletteBlock[192+Blue][2] = Gamma64Levels[Blue];
}
/* Now set up the palette */
regset.x.ax = 0x1012; /* set block of DAC registers function */
regset.x.bx = 0; /* first DAC location to load */
regset.x.cx = 256; /* # of DAC locations to load */
regset.x.dx = (unsigned int)PaletteBlock; /* offset of array from which
to load RGB settings */
sregset.es = _DS; /* segment of array from which to load settings */
int86x(0x10, ®set, ®set, &sregset); /* load the palette block */
}