michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /* functions that manipulate colors */
michael@0: 
michael@0: #include "nsCSSColorUtils.h"
michael@0: #include "nsDebug.h"
michael@0: #include <math.h>
michael@0: 
michael@0: // Weird color computing code stolen from winfe which was stolen
michael@0: // from the xfe which was written originally by Eric Bina. So there.
michael@0: 
michael@0: #define RED_LUMINOSITY        299
michael@0: #define GREEN_LUMINOSITY      587
michael@0: #define BLUE_LUMINOSITY       114
michael@0: #define INTENSITY_FACTOR      25
michael@0: #define LUMINOSITY_FACTOR     75
michael@0: 
michael@0: #define MAX_COLOR             255
michael@0: #define COLOR_DARK_THRESHOLD  51
michael@0: #define COLOR_LIGHT_THRESHOLD 204
michael@0: 
michael@0: #define COLOR_LITE_BS_FACTOR 45
michael@0: #define COLOR_LITE_TS_FACTOR 70
michael@0: 
michael@0: #define COLOR_DARK_BS_FACTOR 30
michael@0: #define COLOR_DARK_TS_FACTOR 50
michael@0: 
michael@0: #define LIGHT_GRAY NS_RGB(192, 192, 192)
michael@0: #define DARK_GRAY  NS_RGB(96, 96, 96)
michael@0: 
michael@0: #define MAX_BRIGHTNESS  254
michael@0: #define MAX_DARKNESS     0
michael@0: 
michael@0: void NS_GetSpecial3DColors(nscolor aResult[2],
michael@0:                            nscolor aBackgroundColor,
michael@0:                            nscolor aBorderColor)
michael@0: {
michael@0: 
michael@0:   uint8_t f0, f1;
michael@0:   uint8_t r, g, b;
michael@0: 
michael@0:   uint8_t rb = NS_GET_R(aBorderColor);
michael@0:   uint8_t gb = NS_GET_G(aBorderColor);
michael@0:   uint8_t bb = NS_GET_B(aBorderColor);
michael@0: 
michael@0:   uint8_t a = NS_GET_A(aBorderColor);
michael@0: 
michael@0:   // This needs to be optimized.
michael@0:   // Calculating background brightness again and again is 
michael@0:   // a waste of time!!!. Just calculate it only once.
michael@0:   // .....somehow!!!
michael@0: 
michael@0:   uint8_t red = NS_GET_R(aBackgroundColor);
michael@0:   uint8_t green = NS_GET_G(aBackgroundColor);
michael@0:   uint8_t blue = NS_GET_B(aBackgroundColor);
michael@0:   
michael@0:   uint8_t elementBrightness = NS_GetBrightness(rb,gb,bb);
michael@0:   uint8_t backgroundBrightness = NS_GetBrightness(red, green, blue);
michael@0: 
michael@0: 
michael@0:   if (backgroundBrightness < COLOR_DARK_THRESHOLD) {
michael@0:     f0 = COLOR_DARK_BS_FACTOR;
michael@0:     f1 = COLOR_DARK_TS_FACTOR;
michael@0: 	if(elementBrightness == MAX_DARKNESS)
michael@0: 	{
michael@0:        rb = NS_GET_R(DARK_GRAY);
michael@0:        gb = NS_GET_G(DARK_GRAY);
michael@0:        bb = NS_GET_B(DARK_GRAY);
michael@0: 	}
michael@0:   }else if (backgroundBrightness > COLOR_LIGHT_THRESHOLD) {
michael@0:     f0 = COLOR_LITE_BS_FACTOR;
michael@0:     f1 = COLOR_LITE_TS_FACTOR;
michael@0: 	if(elementBrightness == MAX_BRIGHTNESS)
michael@0: 	{
michael@0:        rb = NS_GET_R(LIGHT_GRAY);
michael@0:        gb = NS_GET_G(LIGHT_GRAY);
michael@0:        bb = NS_GET_B(LIGHT_GRAY);
michael@0: 	}
michael@0:   }else {
michael@0:     f0 = COLOR_DARK_BS_FACTOR +
michael@0:       (backgroundBrightness *
michael@0:        (COLOR_LITE_BS_FACTOR - COLOR_DARK_BS_FACTOR) / MAX_COLOR);
michael@0:     f1 = COLOR_DARK_TS_FACTOR +
michael@0:       (backgroundBrightness *
michael@0:        (COLOR_LITE_TS_FACTOR - COLOR_DARK_TS_FACTOR) / MAX_COLOR);
michael@0:   }
michael@0:   
michael@0:   
michael@0:   r = rb - (f0 * rb / 100);
michael@0:   g = gb - (f0 * gb / 100);
michael@0:   b = bb - (f0 * bb / 100);
michael@0:   aResult[0] = NS_RGBA(r, g, b, a);
michael@0: 
michael@0:   r = rb + (f1 * (MAX_COLOR - rb) / 100);
michael@0:   g = gb + (f1 * (MAX_COLOR - gb) / 100);
michael@0:   b = bb + (f1 * (MAX_COLOR - bb) / 100);
michael@0:   aResult[1] = NS_RGBA(r, g, b, a);
michael@0: }
michael@0: 
michael@0: int NS_GetBrightness(uint8_t aRed, uint8_t aGreen, uint8_t aBlue)
michael@0: {
michael@0: 
michael@0:   uint8_t intensity = (aRed + aGreen + aBlue) / 3;
michael@0: 
michael@0:   uint8_t luminosity = NS_GetLuminosity(NS_RGB(aRed, aGreen, aBlue)) / 1000;
michael@0:  
michael@0:   return ((intensity * INTENSITY_FACTOR) +
michael@0:           (luminosity * LUMINOSITY_FACTOR)) / 100;
michael@0: }
michael@0: 
michael@0: int32_t NS_GetLuminosity(nscolor aColor)
michael@0: {
michael@0:   // When aColor is not opaque, the perceived luminosity will depend
michael@0:   // on what color(s) aColor is ultimately drawn on top of, which we
michael@0:   // do not know.
michael@0:   NS_ASSERTION(NS_GET_A(aColor) == 255,
michael@0:                "impossible to compute luminosity of a non-opaque color");
michael@0:   
michael@0:   return (NS_GET_R(aColor) * RED_LUMINOSITY +
michael@0:           NS_GET_G(aColor) * GREEN_LUMINOSITY +
michael@0:           NS_GET_B(aColor) * BLUE_LUMINOSITY);
michael@0: }
michael@0: 
michael@0: // Function to convert RGB color space into the HSV colorspace
michael@0: // Hue is the primary color defined from 0 to 359 degrees
michael@0: // Saturation is defined from 0 to 255.  The higher the number.. the deeper
michael@0: // the color Value is the brightness of the color. 0 is black, 255 is white.
michael@0: void NS_RGB2HSV(nscolor aColor, uint16_t &aHue, uint16_t &aSat,
michael@0:                 uint16_t &aValue, uint8_t &aAlpha)
michael@0: {
michael@0:   uint8_t r, g, b;
michael@0:   int16_t delta, min, max, r1, b1, g1;
michael@0:   float   hue;
michael@0: 
michael@0:   r = NS_GET_R(aColor);
michael@0:   g = NS_GET_G(aColor);
michael@0:   b = NS_GET_B(aColor);
michael@0: 
michael@0:   if (r>g) {
michael@0:     max = r;
michael@0:     min = g;
michael@0:   } else {
michael@0:     max = g;
michael@0:     min = r;
michael@0:   }
michael@0: 
michael@0:   if (b>max) {
michael@0:     max = b;
michael@0:   }
michael@0:   if (b<min) {
michael@0:     min = b;
michael@0:   }
michael@0: 
michael@0:   // value or brightness will always be the max of all the colors(RGB)
michael@0:   aValue = max;   
michael@0:   delta = max-min;
michael@0:   aSat = (max!=0)?((delta*255)/max):0;
michael@0:   r1 = r;
michael@0:   b1 = b;
michael@0:   g1 = g;
michael@0: 
michael@0:   if (aSat==0) {
michael@0:     hue = 1000;
michael@0:   } else {
michael@0:     if(r==max){
michael@0:       hue=(float)(g1-b1)/(float)delta;
michael@0:     } else if (g1==max) {
michael@0:       hue= 2.0f+(float)(b1-r1)/(float)delta;
michael@0:     } else { 
michael@0:       hue = 4.0f+(float)(r1-g1)/(float)delta;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   if(hue<999) {
michael@0:     hue*=60;
michael@0:     if(hue<0){
michael@0:       hue+=360;
michael@0:     }
michael@0:   } else {
michael@0:     hue=0;
michael@0:   }
michael@0: 
michael@0:   aHue = (uint16_t)hue;
michael@0: 
michael@0:   aAlpha = NS_GET_A(aColor);
michael@0: }
michael@0: 
michael@0: // Function to convert HSV color space into the RGB colorspace
michael@0: // Hue is the primary color defined from 0 to 359 degrees
michael@0: // Saturation is defined from 0 to 255.  The higher the number.. the deeper
michael@0: // the color Value is the brightness of the color. 0 is black, 255 is white.
michael@0: void NS_HSV2RGB(nscolor &aColor, uint16_t aHue, uint16_t aSat, uint16_t aValue,
michael@0:                 uint8_t aAlpha)
michael@0: {
michael@0:   uint16_t  r = 0, g = 0, b = 0;
michael@0:   uint16_t  i, p, q, t;
michael@0:   double    h, f, percent;
michael@0: 
michael@0:   if ( aSat == 0 ){
michael@0:     // achromatic color, no hue is defined
michael@0:     r = aValue;
michael@0:     g = aValue;
michael@0:     b = aValue;
michael@0:   } else {
michael@0:     // hue in in degrees around the color wheel defined from
michael@0:     // 0 to 360 degrees.  
michael@0:     if (aHue >= 360) {
michael@0:       aHue = 0;
michael@0:     }
michael@0: 
michael@0:     // we break the color wheel into 6 areas.. these
michael@0:     // areas define how the saturation and value define the color.
michael@0:     // reds behave differently than the blues
michael@0:     h = (double)aHue / 60.0;
michael@0:     i = (uint16_t) floor(h);
michael@0:     f = h-(double)i;
michael@0:     percent = ((double)aValue/255.0);   // this needs to be a value from 0 to 1, so a percentage
michael@0:                                         // can be calculated of the saturation.
michael@0:     p = (uint16_t)(percent*(255-aSat));
michael@0:     q = (uint16_t)(percent*(255-(aSat*f)));
michael@0:     t = (uint16_t)(percent*(255-(aSat*(1.0-f))));
michael@0: 
michael@0:     // i is guaranteed to never be larger than 5.
michael@0:     switch(i){
michael@0:       case 0: r = aValue; g = t; b = p;break;
michael@0:       case 1: r = q; g = aValue; b = p;break;
michael@0:       case 2: r = p; g = aValue; b = t;break;
michael@0:       case 3: r = p; g = q; b = aValue;break;
michael@0:       case 4: r = t; g = p; b = aValue;break;
michael@0:       case 5: r = aValue; g = p; b = q;break;
michael@0:     }
michael@0:   }
michael@0:   aColor = NS_RGBA(r, g, b, aAlpha);
michael@0: }
michael@0: 
michael@0: #undef RED_LUMINOSITY
michael@0: #undef GREEN_LUMINOSITY
michael@0: #undef BLUE_LUMINOSITY
michael@0: #undef INTENSITY_FACTOR
michael@0: #undef LUMINOSITY_FACTOR
michael@0: 
michael@0: #undef MAX_COLOR
michael@0: #undef COLOR_DARK_THRESHOLD
michael@0: #undef COLOR_LIGHT_THRESHOLD
michael@0: 
michael@0: #undef COLOR_LITE_BS_FACTOR
michael@0: #undef COLOR_LITE_TS_FACTOR
michael@0: 
michael@0: #undef COLOR_DARK_BS_FACTOR
michael@0: #undef COLOR_DARK_TS_FACTOR
michael@0: 
michael@0: #undef LIGHT_GRAY
michael@0: #undef DARK_GRAY
michael@0: 
michael@0: #undef MAX_BRIGHTNESS
michael@0: #undef MAX_DARKNESS