1 /*
2 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
3 * Copyright (C) 2007 Alp Toker <alp@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
32 namespace WebCore {
33
Gradient(const FloatPoint & p0,const FloatPoint & p1)34 Gradient::Gradient(const FloatPoint& p0, const FloatPoint& p1)
35 : m_radial(false)
36 , m_p0(p0)
37 , m_p1(p1)
38 , m_r0(0)
39 , m_r1(0)
40 , m_stopsSorted(false)
41 , m_lastStop(0)
42 , m_spreadMethod(SpreadMethodPad)
43 {
44 platformInit();
45 }
46
Gradient(const FloatPoint & p0,float r0,const FloatPoint & p1,float r1)47 Gradient::Gradient(const FloatPoint& p0, float r0, const FloatPoint& p1, float r1)
48 : m_radial(true)
49 , m_p0(p0)
50 , m_p1(p1)
51 , m_r0(r0)
52 , m_r1(r1)
53 , m_stopsSorted(false)
54 , m_lastStop(0)
55 , m_spreadMethod(SpreadMethodPad)
56 {
57 platformInit();
58 }
59
~Gradient()60 Gradient::~Gradient()
61 {
62 platformDestroy();
63 }
64
addColorStop(float value,const Color & color)65 void Gradient::addColorStop(float value, const Color& color)
66 {
67 float r;
68 float g;
69 float b;
70 float a;
71 color.getRGBA(r, g, b, a);
72 m_stops.append(ColorStop(value, r, g, b, a));
73
74 m_stopsSorted = false;
75
76 platformDestroy();
77 }
78
compareStops(const Gradient::ColorStop & a,const Gradient::ColorStop & b)79 static inline bool compareStops(const Gradient::ColorStop& a, const Gradient::ColorStop& b)
80 {
81 return a.stop < b.stop;
82 }
83
getColor(float value,float * r,float * g,float * b,float * a) const84 void Gradient::getColor(float value, float* r, float* g, float* b, float* a) const
85 {
86 ASSERT(value >= 0);
87 ASSERT(value <= 1);
88
89 if (m_stops.isEmpty()) {
90 *r = 0;
91 *g = 0;
92 *b = 0;
93 *a = 0;
94 return;
95 }
96 if (!m_stopsSorted) {
97 if (m_stops.size())
98 std::stable_sort(m_stops.begin(), m_stops.end(), compareStops);
99 m_stopsSorted = true;
100 }
101 if (value <= 0 || value <= m_stops.first().stop) {
102 *r = m_stops.first().red;
103 *g = m_stops.first().green;
104 *b = m_stops.first().blue;
105 *a = m_stops.first().alpha;
106 return;
107 }
108 if (value >= 1 || value >= m_stops.last().stop) {
109 *r = m_stops.last().red;
110 *g = m_stops.last().green;
111 *b = m_stops.last().blue;
112 *a = m_stops.last().alpha;
113 return;
114 }
115
116 // Find stop before and stop after and interpolate.
117 int stop = findStop(value);
118 const ColorStop& lastStop = m_stops[stop];
119 const ColorStop& nextStop = m_stops[stop + 1];
120 float stopFraction = (value - lastStop.stop) / (nextStop.stop - lastStop.stop);
121 *r = lastStop.red + (nextStop.red - lastStop.red) * stopFraction;
122 *g = lastStop.green + (nextStop.green - lastStop.green) * stopFraction;
123 *b = lastStop.blue + (nextStop.blue - lastStop.blue) * stopFraction;
124 *a = lastStop.alpha + (nextStop.alpha - lastStop.alpha) * stopFraction;
125 }
126
findStop(float value) const127 int Gradient::findStop(float value) const
128 {
129 ASSERT(value >= 0);
130 ASSERT(value <= 1);
131 ASSERT(m_stopsSorted);
132
133 int numStops = m_stops.size();
134 ASSERT(numStops >= 2);
135 ASSERT(m_lastStop < numStops - 1);
136
137 int i = m_lastStop;
138 if (value < m_stops[i].stop)
139 i = 1;
140 else
141 i = m_lastStop + 1;
142
143 for (; i < numStops - 1; ++i)
144 if (value < m_stops[i].stop)
145 break;
146
147 m_lastStop = i - 1;
148 return m_lastStop;
149 }
150
setSpreadMethod(GradientSpreadMethod spreadMethod)151 void Gradient::setSpreadMethod(GradientSpreadMethod spreadMethod)
152 {
153 // FIXME: Should it become necessary, allow calls to this method after m_gradient has been set.
154 ASSERT(m_gradient == 0);
155 m_spreadMethod = spreadMethod;
156 }
157
setGradientSpaceTransform(const TransformationMatrix & gradientSpaceTransformation)158 void Gradient::setGradientSpaceTransform(const TransformationMatrix& gradientSpaceTransformation)
159 {
160 m_gradientSpaceTransformation = gradientSpaceTransformation;
161 setPlatformGradientSpaceTransform(gradientSpaceTransformation);
162 }
163
164 #if !PLATFORM(SKIA)
setPlatformGradientSpaceTransform(const TransformationMatrix &)165 void Gradient::setPlatformGradientSpaceTransform(const TransformationMatrix&)
166 {
167 }
168 #endif
169
170
171 } //namespace
172