The Tor Browser: layout/base/nsCSSColorUtils.cpp@b8a032363ba2 (annotated)

layout/base/nsCSSColorUtils.cpp@b8a032363ba2 (annotated)

layout/base/nsCSSColorUtils.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

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

The Tor Browser / annotate

layout/base/nsCSSColorUtils.cpp@b8a032363ba2 (annotated)

layout/base/nsCSSColorUtils.cpp