1/*
2 * Copyright 2006, The Android Open Source Project
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *  * Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 *  * Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "Gradient.h"
28
29#include "android_graphics.h"
30#include "CSSParser.h"
31#include "GraphicsContext.h"
32#include "NotImplemented.h"
33#include "SkCanvas.h"
34#include "SkColorShader.h"
35#include "SkGradientShader.h"
36#include "SkPaint.h"
37
38class PlatformGradientRec {
39public:
40    PlatformGradientRec() : m_shader(NULL) {}
41    ~PlatformGradientRec() { m_shader->safeUnref(); }
42
43    SkShader*           m_shader;
44    SkShader::TileMode  m_tileMode;
45    int                 m_colorCountWhenShaderWasBuilt;
46};
47
48namespace WebCore {
49
50void Gradient::platformDestroy()
51{
52    delete m_gradient;
53    m_gradient = 0;
54}
55
56static U8CPU F2B(float x)
57{
58    return (int)(x * 255);
59}
60
61SkShader* Gradient::getShader(SkShader::TileMode mode)
62{
63    if (NULL == m_gradient)
64        m_gradient = new PlatformGradientRec;
65    else if (mode == m_gradient->m_tileMode)
66        return m_gradient->m_shader;
67
68    // need to ensure that the m_stops array is sorted. We call getColor()
69    // which, as a side effect, does the sort.
70    // TODO: refactor Gradient.h to formally expose a sort method
71    {
72        float r, g, b, a;
73        this->getColor(0, &r, &g, &b, &a);
74    }
75
76    SkPoint pts[2] = { m_p0, m_p1 };    // convert to SkPoint
77
78    const size_t count = m_stops.size();
79    SkAutoMalloc    storage(count * (sizeof(SkColor) + sizeof(SkScalar)));
80    SkColor*        colors = (SkColor*)storage.get();
81    SkScalar*       pos = (SkScalar*)(colors + count);
82
83    Vector<ColorStop>::iterator iter = m_stops.begin();
84    for (int i = 0; iter != m_stops.end(); i++) {
85        pos[i] = SkFloatToScalar(iter->stop);
86        colors[i] = SkColorSetARGB(F2B(iter->alpha), F2B(iter->red),
87                                   F2B(iter->green), F2B(iter->blue));
88        ++iter;
89    }
90
91    SkShader* s;
92    if (m_radial)
93        s = SkGradientShader::CreateTwoPointRadial(pts[0],
94                                                   SkFloatToScalar(m_r0),
95                                                   pts[1],
96                                                   SkFloatToScalar(m_r1),
97                                                   colors, pos, count, mode);
98    else
99        s = SkGradientShader::CreateLinear(pts, colors, pos, count, mode);
100
101    if (NULL == s)
102        s = new SkColorShader(0);
103
104    // zap our previous shader, if present
105    m_gradient->m_shader->safeUnref();
106    m_gradient->m_shader = s;
107    m_gradient->m_tileMode = mode;
108    SkMatrix matrix = m_gradientSpaceTransformation;
109    s->setLocalMatrix(matrix);
110
111    return s;
112}
113
114void Gradient::fill(GraphicsContext* context, const FloatRect& rect)
115{
116    SkRect r;
117    SkPaint paint;
118    // we don't care about the mode, so try to use the existing one
119    SkShader::TileMode mode = m_gradient ? m_gradient->m_tileMode :
120                                            SkShader::kClamp_TileMode;
121
122    paint.setAntiAlias(true);
123    paint.setShader(this->getShader(mode));
124    android_gc2canvas(context)->drawRect(rect, paint);
125}
126
127
128} //namespace
129