120 lines
4.6 KiB
C
120 lines
4.6 KiB
C
/*-*- 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};
|