From fc53809803cd2bc2434e312b19a18fa36776da12 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 12 Jun 2024 05:50:40 +0200 Subject: Adding upstream version 256. Signed-off-by: Daniel Baumann --- src/shared/color-util.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 src/shared/color-util.c (limited to 'src/shared/color-util.c') diff --git a/src/shared/color-util.c b/src/shared/color-util.c new file mode 100644 index 0000000..9d714c0 --- /dev/null +++ b/src/shared/color-util.c @@ -0,0 +1,80 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include + +#include "color-util.h" +#include "macro.h" + +void rgb_to_hsv(double r, double g, double b, + double *ret_h, double *ret_s, double *ret_v) { + + assert(r >= 0 && r <= 1); + assert(g >= 0 && g <= 1); + assert(b >= 0 && b <= 1); + + double max_color = fmax(r, fmax(g, b)); + double min_color = fmin(r, fmin(g, b)); + double delta = max_color - min_color; + + if (ret_v) + *ret_v = max_color * 100.0; + + if (max_color <= 0) { + if (ret_s) + *ret_s = 0; + if (ret_h) + *ret_h = NAN; + return; + } + + if (ret_s) + *ret_s = delta / max_color * 100.0; + + if (ret_h) { + if (delta > 0) { + if (r >= max_color) + *ret_h = 60 * fmod((g - b) / delta, 6); + else if (g >= max_color) + *ret_h = 60 * (((b - r) / delta) + 2); + else if (b >= max_color) + *ret_h = 60 * (((r - g) / delta) + 4); + + *ret_h = fmod(*ret_h, 360); + } else + *ret_h = NAN; + } +} + +void hsv_to_rgb(double h, double s, double v, + uint8_t* ret_r, uint8_t *ret_g, uint8_t *ret_b) { + + double c, x, m, r, g, b; + + assert(s >= 0 && s <= 100); + assert(v >= 0 && v <= 100); + assert(ret_r); + assert(ret_g); + assert(ret_b); + + h = fmod(h, 360); + c = (s / 100.0) * (v / 100.0); + x = c * (1 - fabs(fmod(h / 60.0, 2) - 1)); + m = (v / 100) - c; + + if (h >= 0 && h < 60) + r = c, g = x, b = 0.0; + else if (h >= 60 && h < 120) + r = x, g = c, b = 0.0; + else if (h >= 120 && h < 180) + r = 0.0, g = c, b = x; + else if (h >= 180 && h < 240) + r = 0.0, g = x, b = c; + else if (h >= 240 && h < 300) + r = x, g = 0.0, b = c; + else + r = c, g = 0.0, b = x; + + *ret_r = (uint8_t) ((r + m) * 255); + *ret_g = (uint8_t) ((g + m) * 255); + *ret_b = (uint8_t) ((b + m) * 255); +} -- cgit v1.2.3