quantum/color.c

   1 /* Copyright 2017 Jason Williams
   2  *
   3  * This program is free software: you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation, either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16
  17 #include "color.h"
  18 #include "led_tables.h"
  19 #include "progmem.h"
  20
  21 RGB hsv_to_rgb(HSV hsv) {
  22     RGB      rgb;
  23     uint8_t  region, remainder, p, q, t;
  24     uint16_t h, s, v;
  25
  26     if (hsv.s == 0) {
  27 #ifdef USE_CIE1931_CURVE
  28         rgb.r = rgb.g = rgb.b = pgm_read_byte(&CIE1931_CURVE[hsv.v]);
  29 #else
  30         rgb.r = hsv.v;
  31         rgb.g = hsv.v;
  32         rgb.b = hsv.v;
  33 #endif
  34         return rgb;
  35     }
  36
  37     h = hsv.h;
  38     s = hsv.s;
  39 #ifdef USE_CIE1931_CURVE
  40     v = pgm_read_byte(&CIE1931_CURVE[hsv.v]);
  41 #else
  42     v = hsv.v;
  43 #endif
  44
  45     region    = h * 6 / 255;
  46     remainder = (h * 2 - region * 85) * 3;
  47
  48     p = (v * (255 - s)) >> 8;
  49     q = (v * (255 - ((s * remainder) >> 8))) >> 8;
  50     t = (v * (255 - ((s * (255 - remainder)) >> 8))) >> 8;
  51
  52     switch (region) {
  53         case 6:
  54         case 0:
  55             rgb.r = v;
  56             rgb.g = t;
  57             rgb.b = p;
  58             break;
  59         case 1:
  60             rgb.r = q;
  61             rgb.g = v;
  62             rgb.b = p;
  63             break;
  64         case 2:
  65             rgb.r = p;
  66             rgb.g = v;
  67             rgb.b = t;
  68             break;
  69         case 3:
  70             rgb.r = p;
  71             rgb.g = q;
  72             rgb.b = v;
  73             break;
  74         case 4:
  75             rgb.r = t;
  76             rgb.g = p;
  77             rgb.b = v;
  78             break;
  79         default:
  80             rgb.r = v;
  81             rgb.g = p;
  82             rgb.b = q;
  83             break;
  84     }
  85
  86     return rgb;
  87 }
  88
  89 #ifdef RGBW
  90 #    ifndef MIN
  91 #        define MIN(a, b) ((a) < (b) ? (a) : (b))
  92 #    endif
  93 void convert_rgb_to_rgbw(LED_TYPE *led) {
  94     // Determine lowest value in all three colors, put that into
  95     // the white channel and then shift all colors by that amount
  96     led->w = MIN(led->r, MIN(led->g, led->b));
  97     led->r -= led->w;
  98     led->g -= led->w;
  99     led->b -= led->w;
 100 }
 101 #endif