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: #include "mozilla/ArrayUtils.h"         // for ArrayLength
michael@0: #include "mozilla/mozalloc.h"           // for operator delete, etc
michael@0: 
michael@0: #include "nsColor.h"
michael@0: #include <sys/types.h>                  // for int32_t
michael@0: #include "nsColorNames.h"               // for nsColorNames
michael@0: #include "nsDebug.h"                    // for NS_ASSERTION, etc
michael@0: #include "nsStaticNameTable.h"
michael@0: #include "nsString.h"                   // for nsAutoCString, nsString, etc
michael@0: #include "nscore.h"                     // for nsAString, etc
michael@0: 
michael@0: using namespace mozilla;
michael@0: 
michael@0: // define an array of all color names
michael@0: #define GFX_COLOR(_name, _value) #_name,
michael@0: static const char* const kColorNames[] = {
michael@0: #include "nsColorNameList.h"
michael@0: };
michael@0: #undef GFX_COLOR
michael@0: 
michael@0: // define an array of all color name values
michael@0: #define GFX_COLOR(_name, _value) _value,
michael@0: static const nscolor kColors[] = {
michael@0: #include "nsColorNameList.h"
michael@0: };
michael@0: #undef GFX_COLOR
michael@0: 
michael@0: #define eColorName_COUNT (ArrayLength(kColorNames))
michael@0: #define eColorName_UNKNOWN (-1)
michael@0: 
michael@0: static nsStaticCaseInsensitiveNameTable* gColorTable = nullptr;
michael@0: 
michael@0: void nsColorNames::AddRefTable(void) 
michael@0: {
michael@0:   NS_ASSERTION(!gColorTable, "pre existing array!");
michael@0:   if (!gColorTable) {
michael@0:     gColorTable = new nsStaticCaseInsensitiveNameTable();
michael@0:     if (gColorTable) {
michael@0: #ifdef DEBUG
michael@0:     {
michael@0:       // let's verify the table...
michael@0:       for (uint32_t index = 0; index < eColorName_COUNT; ++index) {
michael@0:         nsAutoCString temp1(kColorNames[index]);
michael@0:         nsAutoCString temp2(kColorNames[index]);
michael@0:         ToLowerCase(temp1);
michael@0:         NS_ASSERTION(temp1.Equals(temp2), "upper case char in table");
michael@0:       }
michael@0:     }
michael@0: #endif      
michael@0:       gColorTable->Init(kColorNames, eColorName_COUNT); 
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: void nsColorNames::ReleaseTable(void)
michael@0: {
michael@0:   if (gColorTable) {
michael@0:     delete gColorTable;
michael@0:     gColorTable = nullptr;
michael@0:   }
michael@0: }
michael@0: 
michael@0: static int ComponentValue(const char16_t* aColorSpec, int aLen, int color, int dpc)
michael@0: {
michael@0:   int component = 0;
michael@0:   int index = (color * dpc);
michael@0:   if (2 < dpc) {
michael@0:     dpc = 2;
michael@0:   }
michael@0:   while (--dpc >= 0) {
michael@0:     char16_t ch = ((index < aLen) ? aColorSpec[index++] : '0');
michael@0:     if (('0' <= ch) && (ch <= '9')) {
michael@0:       component = (component * 16) + (ch - '0');
michael@0:     } else if ((('a' <= ch) && (ch <= 'f')) || 
michael@0:                (('A' <= ch) && (ch <= 'F'))) {
michael@0:       // "ch&7" handles lower and uppercase hex alphabetics
michael@0:       component = (component * 16) + (ch & 7) + 9;
michael@0:     }
michael@0:     else {  // not a hex digit, treat it like 0
michael@0:       component = (component * 16);
michael@0:     }
michael@0:   }
michael@0:   return component;
michael@0: }
michael@0: 
michael@0: NS_GFX_(bool) NS_HexToRGB(const nsAString& aColorSpec,
michael@0:                                        nscolor* aResult)
michael@0: {
michael@0:   const char16_t* buffer = aColorSpec.BeginReading();
michael@0: 
michael@0:   int nameLen = aColorSpec.Length();
michael@0:   if ((nameLen == 3) || (nameLen == 6)) {
michael@0:     // Make sure the digits are legal
michael@0:     for (int i = 0; i < nameLen; i++) {
michael@0:       char16_t ch = buffer[i];
michael@0:       if (((ch >= '0') && (ch <= '9')) ||
michael@0:           ((ch >= 'a') && (ch <= 'f')) ||
michael@0:           ((ch >= 'A') && (ch <= 'F'))) {
michael@0:         // Legal character
michael@0:         continue;
michael@0:       }
michael@0:       // Whoops. Illegal character.
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     // Convert the ascii to binary
michael@0:     int dpc = ((3 == nameLen) ? 1 : 2);
michael@0:     // Translate components from hex to binary
michael@0:     int r = ComponentValue(buffer, nameLen, 0, dpc);
michael@0:     int g = ComponentValue(buffer, nameLen, 1, dpc);
michael@0:     int b = ComponentValue(buffer, nameLen, 2, dpc);
michael@0:     if (dpc == 1) {
michael@0:       // Scale single digit component to an 8 bit value. Replicate the
michael@0:       // single digit to compute the new value.
michael@0:       r = (r << 4) | r;
michael@0:       g = (g << 4) | g;
michael@0:       b = (b << 4) | b;
michael@0:     }
michael@0:     NS_ASSERTION((r >= 0) && (r <= 255), "bad r");
michael@0:     NS_ASSERTION((g >= 0) && (g <= 255), "bad g");
michael@0:     NS_ASSERTION((b >= 0) && (b <= 255), "bad b");
michael@0:     *aResult = NS_RGB(r, g, b);
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // Improperly formatted color value
michael@0:   return false;
michael@0: }
michael@0: 
michael@0: // This implements part of the algorithm for legacy behavior described in
michael@0: // http://www.whatwg.org/specs/web-apps/current-work/complete/common-microsyntaxes.html#rules-for-parsing-a-legacy-color-value
michael@0: NS_GFX_(bool) NS_LooseHexToRGB(const nsString& aColorSpec, nscolor* aResult)
michael@0: {
michael@0:   if (aColorSpec.EqualsLiteral("transparent")) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   int nameLen = aColorSpec.Length();
michael@0:   const char16_t* colorSpec = aColorSpec.get();
michael@0:   if (nameLen > 128) {
michael@0:     nameLen = 128;
michael@0:   }
michael@0: 
michael@0:   if ('#' == colorSpec[0]) {
michael@0:     ++colorSpec;
michael@0:     --nameLen;
michael@0:   }
michael@0: 
michael@0:   // digits per component
michael@0:   int dpc = (nameLen + 2) / 3;
michael@0:   int newdpc = dpc;
michael@0: 
michael@0:   // Use only the rightmost 8 characters of each component.
michael@0:   if (newdpc > 8) {
michael@0:     nameLen -= newdpc - 8;
michael@0:     colorSpec += newdpc - 8;
michael@0:     newdpc = 8;
michael@0:   }
michael@0: 
michael@0:   // And then keep trimming characters at the left until we'd trim one
michael@0:   // that would leave a nonzero value, but not past 2 characters per
michael@0:   // component.
michael@0:   while (newdpc > 2) {
michael@0:     bool haveNonzero = false;
michael@0:     for (int c = 0; c < 3; ++c) {
michael@0:       NS_ABORT_IF_FALSE(c * dpc < nameLen,
michael@0:                         "should not pass end of string while newdpc > 2");
michael@0:       char16_t ch = colorSpec[c * dpc];
michael@0:       if (('1' <= ch && ch <= '9') ||
michael@0:           ('A' <= ch && ch <= 'F') ||
michael@0:           ('a' <= ch && ch <= 'f')) {
michael@0:         haveNonzero = true;
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0:     if (haveNonzero) {
michael@0:       break;
michael@0:     }
michael@0:     --newdpc;
michael@0:     --nameLen;
michael@0:     ++colorSpec;
michael@0:   }
michael@0: 
michael@0:   // Translate components from hex to binary
michael@0:   int r = ComponentValue(colorSpec, nameLen, 0, dpc);
michael@0:   int g = ComponentValue(colorSpec, nameLen, 1, dpc);
michael@0:   int b = ComponentValue(colorSpec, nameLen, 2, dpc);
michael@0:   NS_ASSERTION((r >= 0) && (r <= 255), "bad r");
michael@0:   NS_ASSERTION((g >= 0) && (g <= 255), "bad g");
michael@0:   NS_ASSERTION((b >= 0) && (b <= 255), "bad b");
michael@0: 
michael@0:   *aResult = NS_RGB(r, g, b);
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: NS_GFX_(bool) NS_ColorNameToRGB(const nsAString& aColorName, nscolor* aResult)
michael@0: {
michael@0:   if (!gColorTable) return false;
michael@0: 
michael@0:   int32_t id = gColorTable->Lookup(aColorName);
michael@0:   if (eColorName_UNKNOWN < id) {
michael@0:     NS_ASSERTION(uint32_t(id) < eColorName_COUNT,
michael@0:                  "gColorTable->Lookup messed up");
michael@0:     if (aResult) {
michael@0:       *aResult = kColors[id];
michael@0:     }
michael@0:     return true;
michael@0:   }
michael@0:   return false;
michael@0: }
michael@0: 
michael@0: // Returns kColorNames, an array of all possible color names, and sets
michael@0: // *aSizeArray to the size of that array. Do NOT call free() on this array.
michael@0: NS_GFX_(const char * const *) NS_AllColorNames(size_t *aSizeArray)
michael@0: {
michael@0:   *aSizeArray = ArrayLength(kColorNames);
michael@0:   return kColorNames;
michael@0: }
michael@0: 
michael@0: // Macro to blend two colors
michael@0: //
michael@0: // equivalent to target = (bg*(255-fgalpha) + fg*fgalpha)/255
michael@0: #define MOZ_BLEND(target, bg, fg, fgalpha)       \
michael@0:   FAST_DIVIDE_BY_255(target, (bg)*(255-fgalpha) + (fg)*(fgalpha))
michael@0: 
michael@0: NS_GFX_(nscolor)
michael@0: NS_ComposeColors(nscolor aBG, nscolor aFG)
michael@0: {
michael@0:   // This function uses colors that are non premultiplied alpha.
michael@0:   int r, g, b, a;
michael@0: 
michael@0:   int bgAlpha = NS_GET_A(aBG);
michael@0:   int fgAlpha = NS_GET_A(aFG);
michael@0: 
michael@0:   // Compute the final alpha of the blended color
michael@0:   // a = fgAlpha + bgAlpha*(255 - fgAlpha)/255;
michael@0:   FAST_DIVIDE_BY_255(a, bgAlpha*(255-fgAlpha));
michael@0:   a = fgAlpha + a;
michael@0:   int blendAlpha;
michael@0:   if (a == 0) {
michael@0:     // In this case the blended color is totally trasparent,
michael@0:     // we preserve the color information of the foreground color.
michael@0:     blendAlpha = 255;
michael@0:   } else {
michael@0:     blendAlpha = (fgAlpha*255)/a;
michael@0:   }
michael@0:   MOZ_BLEND(r, NS_GET_R(aBG), NS_GET_R(aFG), blendAlpha);
michael@0:   MOZ_BLEND(g, NS_GET_G(aBG), NS_GET_G(aFG), blendAlpha);
michael@0:   MOZ_BLEND(b, NS_GET_B(aBG), NS_GET_B(aFG), blendAlpha);
michael@0: 
michael@0:   return NS_RGBA(r, g, b, a);
michael@0: }
michael@0: 
michael@0: // Functions to convert from HSL color space to RGB color space.
michael@0: // This is the algorithm described in the CSS3 specification
michael@0: 
michael@0: // helper
michael@0: static float
michael@0: HSL_HueToRGB(float m1, float m2, float h)
michael@0: {
michael@0:   if (h < 0.0f)
michael@0:     h += 1.0f;
michael@0:   if (h > 1.0f)
michael@0:     h -= 1.0f;
michael@0:   if (h < (float)(1.0/6.0))
michael@0:     return m1 + (m2 - m1)*h*6.0f;
michael@0:   if (h < (float)(1.0/2.0))
michael@0:     return m2;
michael@0:   if (h < (float)(2.0/3.0))
michael@0:     return m1 + (m2 - m1)*((float)(2.0/3.0) - h)*6.0f;
michael@0:   return m1;      
michael@0: }
michael@0: 
michael@0: // The float parameters are all expected to be in the range 0-1
michael@0: NS_GFX_(nscolor)
michael@0: NS_HSL2RGB(float h, float s, float l)
michael@0: {
michael@0:   uint8_t r, g, b;
michael@0:   float m1, m2;
michael@0:   if (l <= 0.5f) {
michael@0:     m2 = l*(s+1);
michael@0:   } else {
michael@0:     m2 = l + s - l*s;
michael@0:   }
michael@0:   m1 = l*2 - m2;
michael@0:   r = uint8_t(255 * HSL_HueToRGB(m1, m2, h + 1.0f/3.0f));
michael@0:   g = uint8_t(255 * HSL_HueToRGB(m1, m2, h));
michael@0:   b = uint8_t(255 * HSL_HueToRGB(m1, m2, h - 1.0f/3.0f));
michael@0:   return NS_RGB(r, g, b);  
michael@0: }
michael@0: 
michael@0: NS_GFX_(const char*)
michael@0: NS_RGBToColorName(nscolor aColor)
michael@0: {
michael@0:   for (size_t idx = 0; idx < ArrayLength(kColors); ++idx) {
michael@0:     if (kColors[idx] == aColor) {
michael@0:       return kColorNames[idx];
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   return nullptr;
michael@0: }