1/*
2 * Copyright (C) 2011 Apple Inc.
3 * Copyright (C) 2010 Sencha, Inc.
4 * Copyright (C) 2010 Igalia S.L.
5 * 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 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 ShadowBlur_h
30#define ShadowBlur_h
31
32#include "Color.h"
33#include "ColorSpace.h"
34#include "FloatRect.h"
35#include "RoundedIntRect.h"
36#include <wtf/Noncopyable.h>
37
38namespace WebCore {
39
40class AffineTransform;
41class GraphicsContext;
42class ImageBuffer;
43
44class ShadowBlur {
45    WTF_MAKE_NONCOPYABLE(ShadowBlur);
46public:
47    ShadowBlur(float radius, const FloatSize& offset, const Color&, ColorSpace);
48
49    void setShadowsIgnoreTransforms(bool ignoreTransforms) { m_shadowsIgnoreTransforms = ignoreTransforms; }
50    bool shadowsIgnoreTransforms() const { return m_shadowsIgnoreTransforms; }
51
52    void drawRectShadow(GraphicsContext*, const FloatRect&, const RoundedIntRect::Radii&);
53    void drawInsetShadow(GraphicsContext*, const FloatRect&, const FloatRect& holeRect, const RoundedIntRect::Radii& holeRadii);
54
55private:
56    void drawShadowBuffer(GraphicsContext*);
57
58    void adjustBlurRadius(GraphicsContext*);
59    void blurLayerImage(unsigned char*, const IntSize&, int stride);
60
61    enum ShadowDirection {
62        OuterShadow,
63        InnerShadow
64    };
65
66    IntRect calculateLayerBoundingRect(GraphicsContext*, const FloatRect& layerArea, const IntRect& clipRect);
67    IntSize templateSize(const RoundedIntRect::Radii&) const;
68
69    void drawRectShadowWithoutTiling(GraphicsContext*, const FloatRect&, const RoundedIntRect::Radii&, const IntRect& layerRect);
70    void drawRectShadowWithTiling(GraphicsContext*, const FloatRect&, const RoundedIntRect::Radii&, const IntSize& shadowTemplateSize);
71
72    void drawInsetShadowWithoutTiling(GraphicsContext*, const FloatRect&, const FloatRect& holeRect, const RoundedIntRect::Radii&, const IntRect& layerRect);
73    void drawInsetShadowWithTiling(GraphicsContext*, const FloatRect&, const FloatRect& holeRect, const RoundedIntRect::Radii&, const IntSize& shadowTemplateSize);
74
75    void drawLayerPieces(GraphicsContext*, const FloatRect& shadowBounds, const RoundedIntRect::Radii&, float roundedRadius, const IntSize& templateSize, ShadowDirection);
76
77    void blurShadowBuffer(const IntSize& templateSize);
78    void blurAndColorShadowBuffer(const IntSize& templateSize);
79
80    enum ShadowType {
81        NoShadow,
82        SolidShadow,
83        BlurShadow
84    };
85
86    ShadowType m_type;
87
88    Color m_color;
89    ColorSpace m_colorSpace;
90    float m_blurRadius;
91    FloatSize m_offset;
92
93    ImageBuffer* m_layerImage; // Buffer to where the temporary shadow will be drawn to.
94
95    FloatRect m_sourceRect; // Sub-rect of m_layerImage that contains the shadow pixels.
96    FloatPoint m_layerOrigin; // Top-left corner of the (possibly clipped) bounding rect to draw the shadow to.
97    FloatSize m_layerSize; // Size of m_layerImage pixels that need blurring.
98    FloatSize m_layerContextTranslation; // Translation to apply to m_layerContext for the shadow to be correctly clipped.
99
100    bool m_shadowsIgnoreTransforms;
101};
102
103} // namespace WebCore
104
105#endif // ShadowBlur_h
106