1/*
2 * Copyright (C) 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
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 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. 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 APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "platform/graphics/GradientGeneratedImage.h"
28
29#include "platform/geometry/FloatRect.h"
30#include "platform/graphics/GraphicsContextStateSaver.h"
31
32namespace blink {
33
34void GradientGeneratedImage::draw(GraphicsContext* destContext, const FloatRect& destRect, const FloatRect& srcRect, CompositeOperator compositeOp, WebBlendMode blendMode)
35{
36    GraphicsContextStateSaver stateSaver(*destContext);
37    destContext->setCompositeOperation(compositeOp, blendMode);
38    destContext->clip(destRect);
39    destContext->translate(destRect.x(), destRect.y());
40    if (destRect.size() != srcRect.size())
41        destContext->scale(destRect.width() / srcRect.width(), destRect.height() / srcRect.height());
42    destContext->translate(-srcRect.x(), -srcRect.y());
43    destContext->setFillGradient(m_gradient);
44    destContext->fillRect(FloatRect(FloatPoint(), m_size));
45}
46
47void GradientGeneratedImage::drawPattern(GraphicsContext* destContext, const FloatRect& srcRect, const FloatSize& scale,
48    const FloatPoint& phase, CompositeOperator compositeOp, const FloatRect& destRect, WebBlendMode blendMode, const IntSize& repeatSpacing)
49{
50    float stepX = srcRect.width() + repeatSpacing.width();
51    float stepY = srcRect.height() + repeatSpacing.height();
52    int firstColumn = static_cast<int>(floorf((((destRect.x() - phase.x()) / scale.width()) - srcRect.x()) / srcRect.width()));
53    int firstRow = static_cast<int>(floorf((((destRect.y() - phase.y()) / scale.height())  - srcRect.y()) / srcRect.height()));
54    for (int i = firstColumn; ; ++i) {
55        float dstX = (srcRect.x() + i * stepX) * scale.width() + phase.x();
56        // assert that first column encroaches left edge of dstRect.
57        ASSERT(i > firstColumn || dstX <= destRect.x());
58        ASSERT(i == firstColumn || dstX > destRect.x());
59
60        if (dstX >= destRect.maxX())
61            break;
62        float dstMaxX = dstX + srcRect.width() * scale.width();
63        if (dstX < destRect.x())
64            dstX = destRect.x();
65        if (dstMaxX > destRect.maxX())
66            dstMaxX = destRect.maxX();
67        if (dstX >= dstMaxX)
68            continue;
69
70        FloatRect visibleSrcRect;
71        FloatRect tileDstRect;
72        tileDstRect.setX(dstX);
73        tileDstRect.setWidth(dstMaxX - dstX);
74        visibleSrcRect.setX((tileDstRect.x() - phase.x()) / scale.width() - i * stepX);
75        visibleSrcRect.setWidth(tileDstRect.width() / scale.width());
76
77        for (int j = firstRow; ; j++) {
78            float dstY = (srcRect.y() + j * stepY) * scale.height() + phase.y();
79            // assert that first row encroaches top edge of dstRect.
80            ASSERT(j > firstRow || dstY <= destRect.y());
81            ASSERT(j == firstRow || dstY > destRect.y());
82
83            if (dstY >= destRect.maxY())
84                break;
85            float dstMaxY = dstY + srcRect.height() * scale.height();
86            if (dstY < destRect.y())
87                dstY = destRect.y();
88            if (dstMaxY > destRect.maxY())
89                dstMaxY = destRect.maxY();
90            if (dstY >= dstMaxY)
91                continue;
92
93            tileDstRect.setY(dstY);
94            tileDstRect.setHeight(dstMaxY - dstY);
95            visibleSrcRect.setY((tileDstRect.y() - phase.y()) / scale.height() - j * stepY);
96            visibleSrcRect.setHeight(tileDstRect.height() / scale.height());
97            draw(destContext, tileDstRect, visibleSrcRect, compositeOp, blendMode);
98        }
99    }
100}
101
102} // namespace blink
103