utility to generate blended pixel values

This commit is contained in:
Jorj Bauer 2022-02-10 16:10:56 -05:00
parent 70e28fa438
commit 26a0a2abd5
1 changed files with 211 additions and 0 deletions

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util/gen-palette.cpp Normal file
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#include <stdio.h>
#include <stdint.h>
#include <math.h>
#ifndef min
#define min(a,b) (((a) < (b)) ? (a) : (b))
#endif
#ifndef max
#define max(a,b) (((a) > (b)) ? (a) : (b))
#endif
#define _565To332(c) ((((c) & 0xe000) >> 8) | (((c) & 0x700) >> 6) | (((c) & 0x18) >> 3))
static void rgb_to_hsv(double r, double g, double b, double *h, double *s, double *v)
{
// Range for these equations is [0..1] not [0..255]
r = r / 255.0;
g = g / 255.0;
b = b / 255.0;
// h, s, v = hue, saturation, value
double cmax = max(r, max(g, b)); // maximum of r, g, b
double cmin = min(r, min(g, b)); // minimum of r, g, b
double diff = cmax - cmin; // diff of cmax and cmin.
// if cmax and cmax are equal then h = 0
if (cmax == cmin)
*h = 0;
// if cmax equal r then compute h
else if (cmax == r)
*h = (int)(60 * ((g - b) / diff) + 360) % 360;
// if cmax equal g then compute h
else if (cmax == g)
*h = (int)(60 * ((b - r) / diff) + 120) % 360;
// if cmax equal b then compute h
else if (cmax == b)
*h = (int)(60 * ((r - g) / diff) + 240) % 360;
// if cmax equal zero
if (cmax == 0)
*s = 0;
else
*s = (diff / cmax) * 100;
// compute v
*v = cmax * 100;
}
static void hsv_to_rgb(double H, double S, double V, uint8_t *R, uint8_t *G, uint8_t *B)
{
float s = S/100;
float v = V/100;
float C = s*v;
float X = C*(1-fabs(fmod(H/60.0, 2)-1));
float m = v-C;
float r,g,b;
if(H >= 0 && H < 60){
r = C,g = X,b = 0;
}
else if(H >= 60 && H < 120){
r = X,g = C,b = 0;
}
else if(H >= 120 && H < 180){
r = 0,g = C,b = X;
}
else if(H >= 180 && H < 240){
r = 0,g = X,b = C;
}
else if(H >= 240 && H < 300){
r = X,g = 0,b = C;
}
else{
r = C,g = 0,b = X;
}
*R = (r+m)*255;
*G = (g+m)*255;
*B = (b+m)*255;
}
// blend two 24-bit packed colors
uint32_t blendColors(uint32_t a, uint32_t b)
{
uint8_t r1, r2, g1, g2, b1, b2;
r1 = (a & 0xFF0000) >> 16;
g1 = (a & 0x00FF00) >> 8;
b1 = (a & 0x0000FF);
r2 = (b & 0xFF0000) >> 16;
g2 = (b & 0x00FF00) >> 8;
b2 = (b & 0x0000FF);
double h1, s1, v1, h2, s2, v2;
rgb_to_hsv(r1, g1, b1, &h1, &s1, &v1);
rgb_to_hsv(r2, g2, b2, &h2, &s2, &v2);
hsv_to_rgb((h1+h2)/2, (s1+s2)/2, (v1+v2)/2, &r1, &g1, &b1);
uint32_t ret = (r1 << 16) | (g1 << 8) | (b1);
return ret;
}
// RGB map of each of the lowres colors
const uint8_t loresPixelColors[16][3] = { { 0, 0, 0 }, // black
{ 0xAC, 0x12, 0x4C }, // magenta
{ 0x00, 0x07, 0x83 }, // dark blue
{ 0xAA, 0x1A, 0xD1 }, // purple
{ 0x00, 0x83, 0x2F }, // dark green
{ 0x9F, 0x97, 0x7E }, // drak grey
{ 0x00, 0x8A, 0xB5 }, // medium blue
{ 0x9F, 0x9E, 0xFF }, // light blue
{ 0x7A, 0x5F, 0x00 }, // brown
{ 0xFF, 0x72, 0x47 }, // orange
{ 0x78, 0x68, 0x7F }, // light gray
{ 0xFF, 0x7A, 0xCF }, // pink
{ 0x6F, 0xE6, 0x2C }, // green
{ 0xFF, 0xF6, 0x7B }, // yellow
{ 0x6C, 0xEE, 0xB2 }, // aqua
{ 0xFF, 0xFF, 0xFF } // white
};
static const uint16_t palette16[16] = {
0x0000, // 0 black
0xC006, // 1 magenta
0x0010, // 2 dark blue
0xA1B5, // 3 purple
0x0480, // 4 dark green
0x6B4D, // 5 dark grey
0x1B9F, // 6 med blue
0x0DFD, // 7 light blue
0x92A5, // 8 brown
0xF8C5, // 9 orange
0x9555, // 10 light gray
0xFCF2, // 11 pink
0x07E0, // 12 green
0xFFE0, // 13 yellow
0x87F0, // 14 aqua
0xFFFF // 15 white
};
#define color16To32(x) ( (((x) & 0xF800) << 8) | (((x) & 0x07E0) << 5) | (((x) & 0x001F)<<3) )
#define packColor32(x) ( (x[0] << 16) | (x[1] << 8) | (x[2]) )
#define unpackRed(x) ( ((x) & 0xFF0000) >> 16 )
#define unpackGreen(x) ( ((x) & 0xFF00) >> 8 )
#define unpackBlue(x) ( ((x) & 0xFF) )
// FIXME this blend could be optimized - and it's a dumb blend that
// just averages RGB values individually, rather than trying to find a
// sane blend of 2 pixels. Needs thought.
#define luminanceFromRGB(r,g,b) ( ((r)*0.2126) + ((g)*0.7152) + ((b)*0.0722) )
int main(int argc, char *argv[])
{
for (int i=0; i<16; i++) {
printf("color %d: 32-bit 0x%.8X 16-bit 0x%.4X 8-bit 0x%.2X\n",
i,
packColor32(loresPixelColors[i]),
palette16[i],
_565To332(palette16[i]));
}
uint32_t mix32[16][16];
uint16_t mix16[16][16];
uint8_t mix8[16][16];
for (int a=0; a<16; a++) {
for (int b=0; b<16; b++) {
uint32_t v = blendColors(packColor32(loresPixelColors[a]),
packColor32(loresPixelColors[b]));
uint16_t v16 = ((unpackRed(v) & 0xF8) << 8) |
((unpackGreen(v) & 0xFC) << 3) |
((unpackBlue(v) & 0xF8) >> 3);
uint8_t v8 = _565To332(v16);
mix32[a][b] = v;
mix16[a][b] = v16;
mix8[a][b] = v8;
}
}
printf("uint8_t mix8[16][16] = {\n");
for (int a=0; a<16; a++) {
for (int b=0; b<16; b++) {
printf("0x%.2X, ", mix8[a][b]);
}
printf("\n");
}
printf("};\n\n");
printf("uint16_t mix16[16][16] = {\n");
for (int a=0; a<16; a++) {
for (int b=0; b<16; b++) {
printf("0x%.4X, ", mix16[a][b]);
}
printf("\n");
}
printf("};\n\n");
printf("uint32_t mix32[16][16] = {\n");
for (int a=0; a<16; a++) {
for (int b=0; b<16; b++) {
printf("0x%.8X, ", mix32[a][b]);
}
printf("\n");
}
printf("};\n\n");
return 0;
}