This is a maintenance fork
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

119 lines
4.6 KiB

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "dsp/core/core.h"
#include "dsp/tty/quant.h"
#include "libc/assert.h"
#include "libc/bits/initializer.h"
#include "libc/limits.h"
#include "libc/log/log.h"
#include "libc/macros.h"
#include "libc/math.h"
#include "libc/str/str.h"
#define CUTOFF_VALUE 200
#define DIST(X, Y) ((X) - (Y))
#define SQR(X) ((X) * (X))
#define SUM(X, Y, Z) ((X) + (Y) + (Z))
const uint8_t kXtermCube[6] = {0, 0137, 0207, 0257, 0327, 0377};
struct TtyRgb g_ansi2rgb_[256];
double g_xterm256_gamma;
struct TtyRgb tty2rgb_(struct TtyRgb rgbxt) {
return g_ansi2rgb_[rgbxt.xt];
}
__m128 tty2rgbf_(struct TtyRgb rgbxt) {
rgbxt = g_ansi2rgb_[rgbxt.xt];
return (__m128){(int)rgbxt.r, (int)rgbxt.g, (int)rgbxt.b} / 255;
}
static int rgb2xterm256_(int r, int g, int b) {
int cerr, gerr, ir, ig, ib, gray, grai, cr, cg, cb, gv;
gray = round(r * .299 + g * .587 + b * .114);
grai = gray > 238 ? 23 : (gray - 3) / 10;
ir = r < 48 ? 0 : r < 115 ? 1 : (r - 35) / 40;
ig = g < 48 ? 0 : g < 115 ? 1 : (g - 35) / 40;
ib = b < 48 ? 0 : b < 115 ? 1 : (b - 35) / 40;
cr = kXtermCube[ir];
cg = kXtermCube[ig];
cb = kXtermCube[ib];
gv = 8 + 10 * grai;
cerr = SQR(DIST(cr, r)) + SQR(DIST(cg, g)) + SQR(DIST(cb, b));
gerr = SQR(DIST(gv, r)) + SQR(DIST(gv, g)) + SQR(DIST(gv, b));
if (cerr <= gerr) {
return 16 + 36 * ir + 6 * ig + ib;
} else {
return 232 + grai;
}
}
/**
* Quantizes RGB to ANSI w/ euclidean distance in 3D color space.
*/
struct TtyRgb rgb2ansi_(int r, int g, int b) {
uint32_t d, least;
size_t c, best, min, max;
r = MAX(MIN(r, 255), 0);
g = MAX(MIN(g, 255), 0);
b = MAX(MIN(b, 255), 0);
min = ttyquant()->min;
max = ttyquant()->max;
if (min == 16 && max == 256) {
return (struct TtyRgb){r, g, b, rgb2xterm256_(r, g, b)};
} else {
least = UINT32_MAX;
best = 0;
for (c = min; c < max; c++) {
d = SUM(SQR(DIST(g_ansi2rgb_[c].r, r)), SQR(DIST(g_ansi2rgb_[c].g, g)),
SQR(DIST(g_ansi2rgb_[c].b, b)));
if (d < least) {
least = d;
best = c;
}
}
return (struct TtyRgb){r, g, b, best};
}
}
static int uncube(int x) {
return x < 48 ? 0 : x < 115 ? 1 : (x - 35) / 40;
}
static textstartup void rgb2ansi_init(void) {
uint8_t c, y;
uint32_t i, j;
memcpy(g_ansi2rgb_, &kCgaPalette, sizeof(kCgaPalette));
for (i = 16; i < 232; ++i) {
g_ansi2rgb_[i].r = kXtermCube[((i - 020) / 044) % 06];
g_ansi2rgb_[i].g = kXtermCube[((i - 020) / 06) % 06];
g_ansi2rgb_[i].b = kXtermCube[(i - 020) % 06];
g_ansi2rgb_[i].xt = i;
}
for (i = 232, c = 8; i < 256; i++, c += 10) {
g_ansi2rgb_[i].r = c;
g_ansi2rgb_[i].g = c;
g_ansi2rgb_[i].b = c;
g_ansi2rgb_[i].xt = i;
}
}
const void *const rgb2ansi_init_ctor[] initarray = {rgb2ansi_init};