color.c

#include "dreaming.h"

/*
 * Note to self: more color spaces to explore below:
 *
 * http://bids.github.io/colormap/
 * HSV space
 * HLV space
 * CIECAM02 space
 * http://warp.povusers.org/Mandelbrot/
 */


struct _rgb uf_colors[16] = {{66, 30, 15},
			     {25, 7, 26},
			     {9, 1, 47},
			     {4, 4, 73},
			     {0, 7, 100},
			     {12, 44, 138},
			     {24, 82, 177},
			     {57, 125, 209},
			     {134, 181, 229},
			     {211, 236, 248},
			     {241, 233, 191},
			     {248, 201, 95},
			     {255, 170, 0},
			     {204, 128, 0},
			     {153, 87, 0},
			     {106, 52, 3}};

palette_t ultra_fractal = {16, uf_colors};

inline palette_t *uf_rgb_palette() {
  return &ultra_fractal;
}


/*
 * build RGB cyclic colormap
 *
 * Red -> Yellow -> Green -> Cyan -> Blue -> Magenta -> Red
 */
struct _rgb *build_RGB_colormap() {
  int i, total = 0;

  struct _rgb *rgb_map = malloc(sizeof(struct _rgb) * 6 * 256);

  /* red -> yellow interpolation */
  for (i = 0; i < 256; i++) {
    rgb_map[i].r = 255;
    rgb_map[i].g = i;
    rgb_map[i].b = 0;
  }

  total += i - 1;

  /* yellow -> green */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = (255 - i);
    rgb_map[total + i].g = 255;
    rgb_map[total + i].b = 0;
  }

  total += i - 1;

  /* green -> cyan */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = 0;
    rgb_map[total + i].g = 255;
    rgb_map[total + i].b = i;
  }

  total += i - 1;

  /* cyan -> blue */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = 0;
    rgb_map[total + i].g = (255 - i);
    rgb_map[total + i].b = 255;
  }

  total += i - 1;

  /* blue -> magenta */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = i;
    rgb_map[total + i].g = 0;
    rgb_map[total + i].b = 255;
  }

  total += i - 1;

  /* magenta -> red */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = 255;
    rgb_map[total + i].g = 0;
    rgb_map[total + i].b = (255 - i);
  }

  return rgb_map;
}

/*
 * build RGB cyclic colormap cycling from blue -> red
 *
 */
struct _rgb *build_RGB_colormap_reverse() {
  int i, total = 0;

  struct _rgb *rgb_map = malloc(sizeof(struct _rgb) * 6 * 256);

  /* blue -> magenta interpolation */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = i;
    rgb_map[total + i].g = 0;
    rgb_map[total + i].b = 255;
  }

  total += i - 1;

  /* magenta -> red */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = 255;
    rgb_map[total + i].g = 0;
    rgb_map[total + i].b = (255 - i);
  }

  total += i - 1;

  /* red -> yellow interpolation */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = 255;
    rgb_map[total + i].g = i;
    rgb_map[total + i].b = 0;
  }

  total += i - 1;

  /* yellow -> green */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = (255 - i);
    rgb_map[total + i].g = 255;
    rgb_map[total + i].b = 0;
  }

  total += i - 1;

  /* green -> cyan */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = 0;
    rgb_map[total + i].g = 255;
    rgb_map[total + i].b = i;
  }

  total += i - 1;

  /* cyan -> blue */
  for (i = 0; i < 256; i++) {
    rgb_map[total + i].r = 0;
    rgb_map[total + i].g = (255 - i);
    rgb_map[total + i].b = 255;
  }

  total += i - 1;

  return rgb_map;
}


/*
 * build RGB grayscale
 *
 * R = G = B is "shades of gray" in RGB colorspace
 */
palette_t *grayscale_RGB_palette() {
  int i;
  palette_t *p = malloc(sizeof(*p));

  p->size = 256;
  p->colors = malloc(sizeof(struct _rgb) * 256);

  for (i = 0; i < 256; i++) {
    p->colors[i].r = i;
    p->colors[i].g = i;
    p->colors[i].b = i;
  }

  return p;
}