1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/src/nsColor.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,307 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "mozilla/ArrayUtils.h" // for ArrayLength
1.10 +#include "mozilla/mozalloc.h" // for operator delete, etc
1.11 +
1.12 +#include "nsColor.h"
1.13 +#include <sys/types.h> // for int32_t
1.14 +#include "nsColorNames.h" // for nsColorNames
1.15 +#include "nsDebug.h" // for NS_ASSERTION, etc
1.16 +#include "nsStaticNameTable.h"
1.17 +#include "nsString.h" // for nsAutoCString, nsString, etc
1.18 +#include "nscore.h" // for nsAString, etc
1.19 +
1.20 +using namespace mozilla;
1.21 +
1.22 +// define an array of all color names
1.23 +#define GFX_COLOR(_name, _value) #_name,
1.24 +static const char* const kColorNames[] = {
1.25 +#include "nsColorNameList.h"
1.26 +};
1.27 +#undef GFX_COLOR
1.28 +
1.29 +// define an array of all color name values
1.30 +#define GFX_COLOR(_name, _value) _value,
1.31 +static const nscolor kColors[] = {
1.32 +#include "nsColorNameList.h"
1.33 +};
1.34 +#undef GFX_COLOR
1.35 +
1.36 +#define eColorName_COUNT (ArrayLength(kColorNames))
1.37 +#define eColorName_UNKNOWN (-1)
1.38 +
1.39 +static nsStaticCaseInsensitiveNameTable* gColorTable = nullptr;
1.40 +
1.41 +void nsColorNames::AddRefTable(void)
1.42 +{
1.43 + NS_ASSERTION(!gColorTable, "pre existing array!");
1.44 + if (!gColorTable) {
1.45 + gColorTable = new nsStaticCaseInsensitiveNameTable();
1.46 + if (gColorTable) {
1.47 +#ifdef DEBUG
1.48 + {
1.49 + // let's verify the table...
1.50 + for (uint32_t index = 0; index < eColorName_COUNT; ++index) {
1.51 + nsAutoCString temp1(kColorNames[index]);
1.52 + nsAutoCString temp2(kColorNames[index]);
1.53 + ToLowerCase(temp1);
1.54 + NS_ASSERTION(temp1.Equals(temp2), "upper case char in table");
1.55 + }
1.56 + }
1.57 +#endif
1.58 + gColorTable->Init(kColorNames, eColorName_COUNT);
1.59 + }
1.60 + }
1.61 +}
1.62 +
1.63 +void nsColorNames::ReleaseTable(void)
1.64 +{
1.65 + if (gColorTable) {
1.66 + delete gColorTable;
1.67 + gColorTable = nullptr;
1.68 + }
1.69 +}
1.70 +
1.71 +static int ComponentValue(const char16_t* aColorSpec, int aLen, int color, int dpc)
1.72 +{
1.73 + int component = 0;
1.74 + int index = (color * dpc);
1.75 + if (2 < dpc) {
1.76 + dpc = 2;
1.77 + }
1.78 + while (--dpc >= 0) {
1.79 + char16_t ch = ((index < aLen) ? aColorSpec[index++] : '0');
1.80 + if (('0' <= ch) && (ch <= '9')) {
1.81 + component = (component * 16) + (ch - '0');
1.82 + } else if ((('a' <= ch) && (ch <= 'f')) ||
1.83 + (('A' <= ch) && (ch <= 'F'))) {
1.84 + // "ch&7" handles lower and uppercase hex alphabetics
1.85 + component = (component * 16) + (ch & 7) + 9;
1.86 + }
1.87 + else { // not a hex digit, treat it like 0
1.88 + component = (component * 16);
1.89 + }
1.90 + }
1.91 + return component;
1.92 +}
1.93 +
1.94 +NS_GFX_(bool) NS_HexToRGB(const nsAString& aColorSpec,
1.95 + nscolor* aResult)
1.96 +{
1.97 + const char16_t* buffer = aColorSpec.BeginReading();
1.98 +
1.99 + int nameLen = aColorSpec.Length();
1.100 + if ((nameLen == 3) || (nameLen == 6)) {
1.101 + // Make sure the digits are legal
1.102 + for (int i = 0; i < nameLen; i++) {
1.103 + char16_t ch = buffer[i];
1.104 + if (((ch >= '0') && (ch <= '9')) ||
1.105 + ((ch >= 'a') && (ch <= 'f')) ||
1.106 + ((ch >= 'A') && (ch <= 'F'))) {
1.107 + // Legal character
1.108 + continue;
1.109 + }
1.110 + // Whoops. Illegal character.
1.111 + return false;
1.112 + }
1.113 +
1.114 + // Convert the ascii to binary
1.115 + int dpc = ((3 == nameLen) ? 1 : 2);
1.116 + // Translate components from hex to binary
1.117 + int r = ComponentValue(buffer, nameLen, 0, dpc);
1.118 + int g = ComponentValue(buffer, nameLen, 1, dpc);
1.119 + int b = ComponentValue(buffer, nameLen, 2, dpc);
1.120 + if (dpc == 1) {
1.121 + // Scale single digit component to an 8 bit value. Replicate the
1.122 + // single digit to compute the new value.
1.123 + r = (r << 4) | r;
1.124 + g = (g << 4) | g;
1.125 + b = (b << 4) | b;
1.126 + }
1.127 + NS_ASSERTION((r >= 0) && (r <= 255), "bad r");
1.128 + NS_ASSERTION((g >= 0) && (g <= 255), "bad g");
1.129 + NS_ASSERTION((b >= 0) && (b <= 255), "bad b");
1.130 + *aResult = NS_RGB(r, g, b);
1.131 + return true;
1.132 + }
1.133 +
1.134 + // Improperly formatted color value
1.135 + return false;
1.136 +}
1.137 +
1.138 +// This implements part of the algorithm for legacy behavior described in
1.139 +// http://www.whatwg.org/specs/web-apps/current-work/complete/common-microsyntaxes.html#rules-for-parsing-a-legacy-color-value
1.140 +NS_GFX_(bool) NS_LooseHexToRGB(const nsString& aColorSpec, nscolor* aResult)
1.141 +{
1.142 + if (aColorSpec.EqualsLiteral("transparent")) {
1.143 + return false;
1.144 + }
1.145 +
1.146 + int nameLen = aColorSpec.Length();
1.147 + const char16_t* colorSpec = aColorSpec.get();
1.148 + if (nameLen > 128) {
1.149 + nameLen = 128;
1.150 + }
1.151 +
1.152 + if ('#' == colorSpec[0]) {
1.153 + ++colorSpec;
1.154 + --nameLen;
1.155 + }
1.156 +
1.157 + // digits per component
1.158 + int dpc = (nameLen + 2) / 3;
1.159 + int newdpc = dpc;
1.160 +
1.161 + // Use only the rightmost 8 characters of each component.
1.162 + if (newdpc > 8) {
1.163 + nameLen -= newdpc - 8;
1.164 + colorSpec += newdpc - 8;
1.165 + newdpc = 8;
1.166 + }
1.167 +
1.168 + // And then keep trimming characters at the left until we'd trim one
1.169 + // that would leave a nonzero value, but not past 2 characters per
1.170 + // component.
1.171 + while (newdpc > 2) {
1.172 + bool haveNonzero = false;
1.173 + for (int c = 0; c < 3; ++c) {
1.174 + NS_ABORT_IF_FALSE(c * dpc < nameLen,
1.175 + "should not pass end of string while newdpc > 2");
1.176 + char16_t ch = colorSpec[c * dpc];
1.177 + if (('1' <= ch && ch <= '9') ||
1.178 + ('A' <= ch && ch <= 'F') ||
1.179 + ('a' <= ch && ch <= 'f')) {
1.180 + haveNonzero = true;
1.181 + break;
1.182 + }
1.183 + }
1.184 + if (haveNonzero) {
1.185 + break;
1.186 + }
1.187 + --newdpc;
1.188 + --nameLen;
1.189 + ++colorSpec;
1.190 + }
1.191 +
1.192 + // Translate components from hex to binary
1.193 + int r = ComponentValue(colorSpec, nameLen, 0, dpc);
1.194 + int g = ComponentValue(colorSpec, nameLen, 1, dpc);
1.195 + int b = ComponentValue(colorSpec, nameLen, 2, dpc);
1.196 + NS_ASSERTION((r >= 0) && (r <= 255), "bad r");
1.197 + NS_ASSERTION((g >= 0) && (g <= 255), "bad g");
1.198 + NS_ASSERTION((b >= 0) && (b <= 255), "bad b");
1.199 +
1.200 + *aResult = NS_RGB(r, g, b);
1.201 + return true;
1.202 +}
1.203 +
1.204 +NS_GFX_(bool) NS_ColorNameToRGB(const nsAString& aColorName, nscolor* aResult)
1.205 +{
1.206 + if (!gColorTable) return false;
1.207 +
1.208 + int32_t id = gColorTable->Lookup(aColorName);
1.209 + if (eColorName_UNKNOWN < id) {
1.210 + NS_ASSERTION(uint32_t(id) < eColorName_COUNT,
1.211 + "gColorTable->Lookup messed up");
1.212 + if (aResult) {
1.213 + *aResult = kColors[id];
1.214 + }
1.215 + return true;
1.216 + }
1.217 + return false;
1.218 +}
1.219 +
1.220 +// Returns kColorNames, an array of all possible color names, and sets
1.221 +// *aSizeArray to the size of that array. Do NOT call free() on this array.
1.222 +NS_GFX_(const char * const *) NS_AllColorNames(size_t *aSizeArray)
1.223 +{
1.224 + *aSizeArray = ArrayLength(kColorNames);
1.225 + return kColorNames;
1.226 +}
1.227 +
1.228 +// Macro to blend two colors
1.229 +//
1.230 +// equivalent to target = (bg*(255-fgalpha) + fg*fgalpha)/255
1.231 +#define MOZ_BLEND(target, bg, fg, fgalpha) \
1.232 + FAST_DIVIDE_BY_255(target, (bg)*(255-fgalpha) + (fg)*(fgalpha))
1.233 +
1.234 +NS_GFX_(nscolor)
1.235 +NS_ComposeColors(nscolor aBG, nscolor aFG)
1.236 +{
1.237 + // This function uses colors that are non premultiplied alpha.
1.238 + int r, g, b, a;
1.239 +
1.240 + int bgAlpha = NS_GET_A(aBG);
1.241 + int fgAlpha = NS_GET_A(aFG);
1.242 +
1.243 + // Compute the final alpha of the blended color
1.244 + // a = fgAlpha + bgAlpha*(255 - fgAlpha)/255;
1.245 + FAST_DIVIDE_BY_255(a, bgAlpha*(255-fgAlpha));
1.246 + a = fgAlpha + a;
1.247 + int blendAlpha;
1.248 + if (a == 0) {
1.249 + // In this case the blended color is totally trasparent,
1.250 + // we preserve the color information of the foreground color.
1.251 + blendAlpha = 255;
1.252 + } else {
1.253 + blendAlpha = (fgAlpha*255)/a;
1.254 + }
1.255 + MOZ_BLEND(r, NS_GET_R(aBG), NS_GET_R(aFG), blendAlpha);
1.256 + MOZ_BLEND(g, NS_GET_G(aBG), NS_GET_G(aFG), blendAlpha);
1.257 + MOZ_BLEND(b, NS_GET_B(aBG), NS_GET_B(aFG), blendAlpha);
1.258 +
1.259 + return NS_RGBA(r, g, b, a);
1.260 +}
1.261 +
1.262 +// Functions to convert from HSL color space to RGB color space.
1.263 +// This is the algorithm described in the CSS3 specification
1.264 +
1.265 +// helper
1.266 +static float
1.267 +HSL_HueToRGB(float m1, float m2, float h)
1.268 +{
1.269 + if (h < 0.0f)
1.270 + h += 1.0f;
1.271 + if (h > 1.0f)
1.272 + h -= 1.0f;
1.273 + if (h < (float)(1.0/6.0))
1.274 + return m1 + (m2 - m1)*h*6.0f;
1.275 + if (h < (float)(1.0/2.0))
1.276 + return m2;
1.277 + if (h < (float)(2.0/3.0))
1.278 + return m1 + (m2 - m1)*((float)(2.0/3.0) - h)*6.0f;
1.279 + return m1;
1.280 +}
1.281 +
1.282 +// The float parameters are all expected to be in the range 0-1
1.283 +NS_GFX_(nscolor)
1.284 +NS_HSL2RGB(float h, float s, float l)
1.285 +{
1.286 + uint8_t r, g, b;
1.287 + float m1, m2;
1.288 + if (l <= 0.5f) {
1.289 + m2 = l*(s+1);
1.290 + } else {
1.291 + m2 = l + s - l*s;
1.292 + }
1.293 + m1 = l*2 - m2;
1.294 + r = uint8_t(255 * HSL_HueToRGB(m1, m2, h + 1.0f/3.0f));
1.295 + g = uint8_t(255 * HSL_HueToRGB(m1, m2, h));
1.296 + b = uint8_t(255 * HSL_HueToRGB(m1, m2, h - 1.0f/3.0f));
1.297 + return NS_RGB(r, g, b);
1.298 +}
1.299 +
1.300 +NS_GFX_(const char*)
1.301 +NS_RGBToColorName(nscolor aColor)
1.302 +{
1.303 + for (size_t idx = 0; idx < ArrayLength(kColors); ++idx) {
1.304 + if (kColors[idx] == aColor) {
1.305 + return kColorNames[idx];
1.306 + }
1.307 + }
1.308 +
1.309 + return nullptr;
1.310 +}
