1/*
2 * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
3 * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
4 * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
5 * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
6 * Copyright (C) Research In Motion Limited 2010. All rights reserved.
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public License
19 * along with this library; see the file COPYING.LIB.  If not, write to
20 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
22 */
23
24#include "config.h"
25
26#if ENABLE(FILTERS)
27#include "FEDisplacementMap.h"
28
29#include "Filter.h"
30#include "GraphicsContext.h"
31#include "RenderTreeAsText.h"
32#include "TextStream.h"
33
34#include <wtf/Uint8ClampedArray.h>
35
36namespace WebCore {
37
38FEDisplacementMap::FEDisplacementMap(Filter* filter, ChannelSelectorType xChannelSelector, ChannelSelectorType yChannelSelector, float scale)
39    : FilterEffect(filter)
40    , m_xChannelSelector(xChannelSelector)
41    , m_yChannelSelector(yChannelSelector)
42    , m_scale(scale)
43{
44}
45
46PassRefPtr<FEDisplacementMap> FEDisplacementMap::create(Filter* filter, ChannelSelectorType xChannelSelector,
47    ChannelSelectorType yChannelSelector, float scale)
48{
49    return adoptRef(new FEDisplacementMap(filter, xChannelSelector, yChannelSelector, scale));
50}
51
52ChannelSelectorType FEDisplacementMap::xChannelSelector() const
53{
54    return m_xChannelSelector;
55}
56
57bool FEDisplacementMap::setXChannelSelector(const ChannelSelectorType xChannelSelector)
58{
59    if (m_xChannelSelector == xChannelSelector)
60        return false;
61    m_xChannelSelector = xChannelSelector;
62    return true;
63}
64
65ChannelSelectorType FEDisplacementMap::yChannelSelector() const
66{
67    return m_yChannelSelector;
68}
69
70bool FEDisplacementMap::setYChannelSelector(const ChannelSelectorType yChannelSelector)
71{
72    if (m_yChannelSelector == yChannelSelector)
73        return false;
74    m_yChannelSelector = yChannelSelector;
75    return true;
76}
77
78float FEDisplacementMap::scale() const
79{
80    return m_scale;
81}
82
83bool FEDisplacementMap::setScale(float scale)
84{
85    if (m_scale == scale)
86        return false;
87    m_scale = scale;
88    return true;
89}
90
91void FEDisplacementMap::setResultColorSpace(ColorSpace)
92{
93    // Spec: The 'color-interpolation-filters' property only applies to the 'in2' source image
94    // and does not apply to the 'in' source image. The 'in' source image must remain in its
95    // current color space.
96    // The result is in that smae color space because it is a displacement of the 'in' image.
97    FilterEffect::setResultColorSpace(inputEffect(0)->resultColorSpace());
98}
99
100void FEDisplacementMap::transformResultColorSpace(FilterEffect* in, const int index)
101{
102    // Do not transform the first primitive input, as per the spec.
103    if (index)
104        in->transformResultColorSpace(operatingColorSpace());
105}
106
107void FEDisplacementMap::platformApplySoftware()
108{
109    FilterEffect* in = inputEffect(0);
110    FilterEffect* in2 = inputEffect(1);
111
112    ASSERT(m_xChannelSelector != CHANNEL_UNKNOWN);
113    ASSERT(m_yChannelSelector != CHANNEL_UNKNOWN);
114
115    Uint8ClampedArray* dstPixelArray = createPremultipliedImageResult();
116    if (!dstPixelArray)
117        return;
118
119    IntRect effectADrawingRect = requestedRegionOfInputImageData(in->absolutePaintRect());
120    RefPtr<Uint8ClampedArray> srcPixelArrayA = in->asPremultipliedImage(effectADrawingRect);
121
122    IntRect effectBDrawingRect = requestedRegionOfInputImageData(in2->absolutePaintRect());
123    RefPtr<Uint8ClampedArray> srcPixelArrayB = in2->asUnmultipliedImage(effectBDrawingRect);
124
125    ASSERT(srcPixelArrayA->length() == srcPixelArrayB->length());
126
127    Filter* filter = this->filter();
128    IntSize paintSize = absolutePaintRect().size();
129    float scaleX = filter->applyHorizontalScale(m_scale);
130    float scaleY = filter->applyVerticalScale(m_scale);
131    float scaleForColorX = scaleX / 255.0;
132    float scaleForColorY = scaleY / 255.0;
133    float scaledOffsetX = 0.5 - scaleX * 0.5;
134    float scaledOffsetY = 0.5 - scaleY * 0.5;
135    int stride = paintSize.width() * 4;
136    for (int y = 0; y < paintSize.height(); ++y) {
137        int line = y * stride;
138        for (int x = 0; x < paintSize.width(); ++x) {
139            int dstIndex = line + x * 4;
140            int srcX = x + static_cast<int>(scaleForColorX * srcPixelArrayB->item(dstIndex + m_xChannelSelector - 1) + scaledOffsetX);
141            int srcY = y + static_cast<int>(scaleForColorY * srcPixelArrayB->item(dstIndex + m_yChannelSelector - 1) + scaledOffsetY);
142            for (unsigned channel = 0; channel < 4; ++channel) {
143                if (srcX < 0 || srcX >= paintSize.width() || srcY < 0 || srcY >= paintSize.height())
144                    dstPixelArray->set(dstIndex + channel, static_cast<unsigned char>(0));
145                else {
146                    unsigned char pixelValue = srcPixelArrayA->item(srcY * stride + srcX * 4 + channel);
147                    dstPixelArray->set(dstIndex + channel, pixelValue);
148                }
149            }
150        }
151    }
152}
153
154void FEDisplacementMap::dump()
155{
156}
157
158static TextStream& operator<<(TextStream& ts, const ChannelSelectorType& type)
159{
160    switch (type) {
161    case CHANNEL_UNKNOWN:
162        ts << "UNKNOWN";
163        break;
164    case CHANNEL_R:
165        ts << "RED";
166        break;
167    case CHANNEL_G:
168        ts << "GREEN";
169        break;
170    case CHANNEL_B:
171        ts << "BLUE";
172        break;
173    case CHANNEL_A:
174        ts << "ALPHA";
175        break;
176    }
177    return ts;
178}
179
180TextStream& FEDisplacementMap::externalRepresentation(TextStream& ts, int indent) const
181{
182    writeIndent(ts, indent);
183    ts << "[feDisplacementMap";
184    FilterEffect::externalRepresentation(ts);
185    ts << " scale=\"" << m_scale << "\" "
186       << "xChannelSelector=\"" << m_xChannelSelector << "\" "
187       << "yChannelSelector=\"" << m_yChannelSelector << "\"]\n";
188    inputEffect(0)->externalRepresentation(ts, indent + 1);
189    inputEffect(1)->externalRepresentation(ts, indent + 1);
190    return ts;
191}
192
193} // namespace WebCore
194
195#endif // ENABLE(FILTERS)
196