third_party/WebKit/Source/platform/graphics/Gradient.h

   1 /*
   2  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
   3  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
   4  * Copyright (C) 2008 Torch Mobile, Inc.
   5  * Copyright (C) 2013 Google Inc. All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  20  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  23  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  24  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef Gradient_h
  30 #define Gradient_h
  31
  32 #include "platform/PlatformExport.h"
  33 #include "platform/geometry/FloatPoint.h"
  34 #include "platform/graphics/Color.h"
  35 #include "platform/graphics/GraphicsTypes.h"
  36 #include "platform/transforms/AffineTransform.h"
  37 #include "wtf/PassRefPtr.h"
  38 #include "wtf/RefCounted.h"
  39 #include "wtf/RefPtr.h"
  40 #include "wtf/Vector.h"
  41
  42 class SkShader;
  43
  44 namespace blink {
  45
  46 class PLATFORM_EXPORT Gradient : public RefCounted<Gradient> {
  47 public:
  48     static PassRefPtr<Gradient> create(const FloatPoint& p0, const FloatPoint& p1)
  49     {
  50         return adoptRef(new Gradient(p0, p1));
  51     }
  52     static PassRefPtr<Gradient> create(const FloatPoint& p0, float r0, const FloatPoint& p1, float r1, float aspectRatio = 1)
  53     {
  54         return adoptRef(new Gradient(p0, r0, p1, r1, aspectRatio));
  55     }
  56     ~Gradient();
  57
  58     struct ColorStop {
  59         float stop;
  60         Color color;
  61
  62         ColorStop(float s, const Color& c) : stop(s), color(c) { }
  63     };
  64     void addColorStop(const ColorStop&);
  65     void addColorStop(float value, const Color& color) { addColorStop(ColorStop(value, color)); }
  66
  67     bool shaderChanged() const { return !m_gradient; }
  68
  69     bool isRadial() const { return m_radial; }
  70     bool isZeroSize() const { return m_p0.x() == m_p1.x() && m_p0.y() == m_p1.y() && (!m_radial || m_r0 == m_r1); }
  71
  72     const FloatPoint& p0() const { return m_p0; }
  73     const FloatPoint& p1() const { return m_p1; }
  74
  75     void setP0(const FloatPoint& p)
  76     {
  77         if (m_p0 == p)
  78             return;
  79
  80         m_p0 = p;
  81     }
  82
  83     void setP1(const FloatPoint& p)
  84     {
  85         if (m_p1 == p)
  86             return;
  87
  88         m_p1 = p;
  89     }
  90
  91     float startRadius() const { return m_r0; }
  92     float endRadius() const { return m_r1; }
  93
  94     void setStartRadius(float r)
  95     {
  96         if (m_r0 == r)
  97             return;
  98
  99         m_r0 = r;
 100     }
 101
 102     void setEndRadius(float r)
 103     {
 104         if (m_r1 == r)
 105             return;
 106
 107         m_r1 = r;
 108     }
 109
 110     float aspectRatio() const { return m_aspectRatio; }
 111
 112     SkShader* shader();
 113
 114     void setDrawsInPMColorSpace(bool drawInPMColorSpace);
 115
 116     void setSpreadMethod(GradientSpreadMethod);
 117     GradientSpreadMethod spreadMethod() const { return m_spreadMethod; }
 118     void setGradientSpaceTransform(const AffineTransform& gradientSpaceTransformation);
 119     AffineTransform gradientSpaceTransform() { return m_gradientSpaceTransformation; }
 120
 121 private:
 122     Gradient(const FloatPoint& p0, const FloatPoint& p1);
 123     Gradient(const FloatPoint& p0, float r0, const FloatPoint& p1, float r1, float aspectRatio);
 124
 125     void destroyShader();
 126
 127     void sortStopsIfNecessary();
 128
 129     FloatPoint m_p0;
 130     FloatPoint m_p1;
 131     float m_r0;
 132     float m_r1;
 133     float m_aspectRatio; // For elliptical gradient, width / height.
 134     Vector<ColorStop, 2> m_stops;
 135     bool m_radial;
 136     bool m_stopsSorted;
 137     bool m_drawInPMColorSpace;
 138     GradientSpreadMethod m_spreadMethod;
 139     AffineTransform m_gradientSpaceTransformation;
 140
 141     RefPtr<SkShader> m_gradient;
 142 };
 143
 144 } // namespace blink
 145
 146 #endif