1 /* 2 * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved. 3 * Copyright (C) 2007 Alp Toker <alp (at) atoker.com> 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include "config.h" 28 #include "Gradient.h" 29 30 #include "Color.h" 31 #include "FloatRect.h" 32 #include <wtf/UnusedParam.h> 33 34 namespace WebCore { 35 36 Gradient::Gradient(const FloatPoint& p0, const FloatPoint& p1) 37 : m_radial(false) 38 , m_p0(p0) 39 , m_p1(p1) 40 , m_r0(0) 41 , m_r1(0) 42 , m_stopsSorted(false) 43 , m_lastStop(0) 44 , m_spreadMethod(SpreadMethodPad) 45 { 46 platformInit(); 47 } 48 49 Gradient::Gradient(const FloatPoint& p0, float r0, const FloatPoint& p1, float r1) 50 : m_radial(true) 51 , m_p0(p0) 52 , m_p1(p1) 53 , m_r0(r0) 54 , m_r1(r1) 55 , m_stopsSorted(false) 56 , m_lastStop(0) 57 , m_spreadMethod(SpreadMethodPad) 58 { 59 platformInit(); 60 } 61 62 Gradient::~Gradient() 63 { 64 platformDestroy(); 65 } 66 67 void Gradient::adjustParametersForTiledDrawing(IntSize& size, FloatRect& srcRect) 68 { 69 if (m_radial) 70 return; 71 72 if (srcRect.isEmpty()) 73 return; 74 75 if (m_p0.x() == m_p1.x()) { 76 size.setWidth(1); 77 srcRect.setWidth(1); 78 srcRect.setX(0); 79 return; 80 } 81 if (m_p0.y() != m_p1.y()) 82 return; 83 84 size.setHeight(1); 85 srcRect.setHeight(1); 86 srcRect.setY(0); 87 } 88 89 void Gradient::addColorStop(float value, const Color& color) 90 { 91 float r; 92 float g; 93 float b; 94 float a; 95 color.getRGBA(r, g, b, a); 96 m_stops.append(ColorStop(value, r, g, b, a)); 97 98 m_stopsSorted = false; 99 100 platformDestroy(); 101 } 102 103 static inline bool compareStops(const Gradient::ColorStop& a, const Gradient::ColorStop& b) 104 { 105 return a.stop < b.stop; 106 } 107 108 void Gradient::sortStopsIfNecessary() 109 { 110 if (m_stopsSorted) 111 return; 112 113 if (m_stops.size()) 114 std::stable_sort(m_stops.begin(), m_stops.end(), compareStops); 115 m_stopsSorted = true; 116 } 117 118 void Gradient::getColor(float value, float* r, float* g, float* b, float* a) const 119 { 120 ASSERT(value >= 0); 121 ASSERT(value <= 1); 122 123 if (m_stops.isEmpty()) { 124 *r = 0; 125 *g = 0; 126 *b = 0; 127 *a = 0; 128 return; 129 } 130 if (!m_stopsSorted) { 131 if (m_stops.size()) 132 std::stable_sort(m_stops.begin(), m_stops.end(), compareStops); 133 m_stopsSorted = true; 134 } 135 if (value <= 0 || value <= m_stops.first().stop) { 136 *r = m_stops.first().red; 137 *g = m_stops.first().green; 138 *b = m_stops.first().blue; 139 *a = m_stops.first().alpha; 140 return; 141 } 142 if (value >= 1 || value >= m_stops.last().stop) { 143 *r = m_stops.last().red; 144 *g = m_stops.last().green; 145 *b = m_stops.last().blue; 146 *a = m_stops.last().alpha; 147 return; 148 } 149 150 // Find stop before and stop after and interpolate. 151 int stop = findStop(value); 152 const ColorStop& lastStop = m_stops[stop]; 153 const ColorStop& nextStop = m_stops[stop + 1]; 154 float stopFraction = (value - lastStop.stop) / (nextStop.stop - lastStop.stop); 155 *r = lastStop.red + (nextStop.red - lastStop.red) * stopFraction; 156 *g = lastStop.green + (nextStop.green - lastStop.green) * stopFraction; 157 *b = lastStop.blue + (nextStop.blue - lastStop.blue) * stopFraction; 158 *a = lastStop.alpha + (nextStop.alpha - lastStop.alpha) * stopFraction; 159 } 160 161 int Gradient::findStop(float value) const 162 { 163 ASSERT(value >= 0); 164 ASSERT(value <= 1); 165 ASSERT(m_stopsSorted); 166 167 int numStops = m_stops.size(); 168 ASSERT(numStops >= 2); 169 ASSERT(m_lastStop < numStops - 1); 170 171 int i = m_lastStop; 172 if (value < m_stops[i].stop) 173 i = 1; 174 else 175 i = m_lastStop + 1; 176 177 for (; i < numStops - 1; ++i) 178 if (value < m_stops[i].stop) 179 break; 180 181 m_lastStop = i - 1; 182 return m_lastStop; 183 } 184 185 void Gradient::setSpreadMethod(GradientSpreadMethod spreadMethod) 186 { 187 // FIXME: Should it become necessary, allow calls to this method after m_gradient has been set. 188 ASSERT(m_gradient == 0); 189 m_spreadMethod = spreadMethod; 190 } 191 192 void Gradient::setGradientSpaceTransform(const AffineTransform& gradientSpaceTransformation) 193 { 194 m_gradientSpaceTransformation = gradientSpaceTransformation; 195 setPlatformGradientSpaceTransform(gradientSpaceTransformation); 196 } 197 198 #if !(PLATFORM(SKIA) && !PLATFORM(ANDROID)) 199 void Gradient::setPlatformGradientSpaceTransform(const AffineTransform&) 200 { 201 } 202 #endif 203 204 205 } //namespace 206