package org.oscim.utils;
import static org.oscim.backend.canvas.Color.b;
import static org.oscim.backend.canvas.Color.g;
import static org.oscim.backend.canvas.Color.r;
import static org.oscim.utils.FastMath.clamp;
import org.oscim.backend.canvas.Color;
import org.oscim.utils.math.Vec3;
public class ColorUtil {
private final static Vec3 TMP_VEC = new Vec3();
public static synchronized int desaturate(int color) {
Vec3 hsl = TMP_VEC;
rgbToHsl(r(color), g(color), b(color), hsl);
return hslToRgb(hsl.x, 0, hsl.z);
}
public static synchronized int saturate(int color, double saturation) {
Vec3 hsl = TMP_VEC;
rgbToHsv(r(color), g(color), b(color), hsl);
return hsvToRgb(hsl.x, saturation, hsl.z);
}
public static synchronized int setHue(int color, double hue) {
Vec3 hsl = TMP_VEC;
rgbToHsv(r(color), g(color), b(color), hsl);
return hsvToRgb(hue, hsl.y, hsl.z, null);
}
public static synchronized int shiftHue(int color, double hue) {
Vec3 hsv = TMP_VEC;
rgbToHsv(r(color), g(color), b(color), hsv);
hsv.x += hue;
hsv.x -= Math.floor(hsv.x);
return hsvToRgb(clamp(hsv.x, 0, 1), hsv.y, hsv.z, null);
}
public static synchronized int saturate(int color, double saturation, boolean relative) {
Vec3 hsl = TMP_VEC;
rgbToHsv(r(color), g(color), b(color), hsl);
return hsvToRgb(hsl.x, clamp(saturation * hsl.y, 0, 1), hsl.z);
}
public static synchronized int modHsv(int color, double hue, double saturation, double value,
boolean relative) {
Vec3 hsl = TMP_VEC;
rgbToHsv(r(color), g(color), b(color), hsl);
return hsvToRgb(clamp(hue * hsl.x, 0, 1),
clamp(saturation * hsl.y, 0, 1),
clamp(value * hsl.z, 0, 1));
}
// functions ported from http://axonflux.com/handy-rgb-to-hsl-and-rgb-to-hsv-color-model-c
/**
* Converts an RGB color value to HSL. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes r, g, and b are contained in the set [0, 255] and
* returns h, s, and l in the set [0, 1].
*
* @param Number r The red color value
* @param Number g The green color value
* @param Number b The blue color value
* @return Array The HSL representation
*/
public static Vec3 rgbToHsl(double r, double g, double b, Vec3 out) {
r /= 255d;
g /= 255d;
b /= 255d;
double max = Math.max(r, Math.max(g, b));
double min = Math.min(r, Math.min(g, b));
double h = 0, s = 0, l = (max + min) / 2;
if (max != min) {
double d = max - min;
s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
if (max == r)
h = (g - b) / d + (g < b ? 6 : 0);
else if (max == g)
h = (b - r) / d + 2;
else
h = (r - g) / d + 4;
h /= 6;
}
out.set(h, s, l);
return out;
}
public static Vec3 rgbToHsl(double r, double g, double b) {
return rgbToHsl(r, g, b, new Vec3());
}
/**
* Converts an HSL color value to RGB. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes h, s, and l are contained in the set [0, 1] and
* returns r, g, and b in the set [0, 255].
*
* @param Number h The hue
* @param Number s The saturation
* @param Number l The lightness
* @return Array The RGB representation
*/
public static int hslToRgb(double h, double s, double l, Vec3 out) {
double r, g, b;
if (s == 0) {
r = g = b = l; // achromatic
} else {
double q = l < 0.5 ? l * (1 + s) : l + s - l * s;
double p = 2 * l - q;
r = hue2rgb(p, q, h + 1 / 3);
g = hue2rgb(p, q, h);
b = hue2rgb(p, q, h - 1 / 3);
}
if (out != null)
out.set(r, g, b);
return Color.get(r, g, b);
}
static double hue2rgb(double p, double q, double t) {
if (t < 0)
t += 1;
if (t > 1)
t -= 1;
if (t < 1 / 6)
return p + (q - p) * 6 * t;
if (t < 1 / 2)
return q;
if (t < 2 / 3)
return p + (q - p) * (2 / 3 - t) * 6;
return p;
}
/**
* Converts an RGB color value to HSV. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSV_color_space.
* Assumes r, g, and b are contained in the set [0, 255] and
* returns h, s, and v in the set [0, 1].
*
* @param Number r The red color value
* @param Number g The green color value
* @param Number b The blue color value
* @return Array The HSV representation
*/
public static Vec3 rgbToHsv(double r, double g, double b, Vec3 out) {
r /= 255d;
g /= 255d;
b /= 255d;
double max = Math.max(r, Math.max(g, b));
double min = Math.min(r, Math.min(g, b));
double h = 0, s, v = max;
double d = max - min;
s = max == 0 ? 0 : d / max;
if (max != min) {
if (max == r)
h = (g - b) / d + (g < b ? 6 : 0);
else if (max == g)
h = (b - r) / d + 2;
else if (max == b)
h = (r - g) / d + 4;
h /= 6;
}
out.set(h, s, v);
return out;
}
public static Vec3 rgbToHsv(double r, double g, double b) {
return rgbToHsv(r, g, b, new Vec3());
}
/**
* Converts an HSV color value to RGB. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSV_color_space.
* Assumes h, s, and v are contained in the set [0, 1] and
* returns r, g, and b in the set [0, 255].
*
* @param h The hue
* @param s The saturation
* @param v The value
* @param out result rgb, may be ommited
* @return Array The RGB representation
*/
public static int hsvToRgb(double h, double s, double v, Vec3 out) {
double r = 0, g = 0, b = 0;
int i = (int) Math.floor(h * 6);
double f = h * 6 - i;
double p = v * (1 - s);
double q = v * (1 - f * s);
double t = v * (1 - (1 - f) * s);
switch (i % 6) {
case 0:
r = v;
g = t;
b = p;
break;
case 1:
r = q;
g = v;
b = p;
break;
case 2:
r = p;
g = v;
b = t;
break;
case 3:
r = p;
g = q;
b = v;
break;
case 4:
r = t;
g = p;
b = v;
break;
case 5:
r = v;
g = p;
b = q;
break;
}
if (out != null)
out.set(r, g, b);
return Color.get(r, g, b);
}
public static int hsvToRgb(double h, double s, double v) {
return hsvToRgb(h, s, v, null);
}
public static int hslToRgb(double h, double s, double l) {
return hslToRgb(h, s, l, null);
}
}