Home | History | Annotate | Download | only in filters 
      1 /*
      2  * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann (at) kde.org>
      3  * Copyright (C) 2004, 2005 Rob Buis <buis (at) kde.org>
      4  * Copyright (C) 2005 Eric Seidel <eric (at) webkit.org>
      5  * Copyright (C) 2009 Dirk Schulze <krit (at) 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/ByteArray.h>
     35 
     36 namespace WebCore {
     37 
     38 FEDisplacementMap::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 
     46 PassRefPtr<FEDisplacementMap> FEDisplacementMap::create(Filter* filter, ChannelSelectorType xChannelSelector,
     47     ChannelSelectorType yChannelSelector, float scale)
     48 {
     49     return adoptRef(new FEDisplacementMap(filter, xChannelSelector, yChannelSelector, scale));
     50 }
     51 
     52 ChannelSelectorType FEDisplacementMap::xChannelSelector() const
     53 {
     54     return m_xChannelSelector;
     55 }
     56 
     57 bool FEDisplacementMap::setXChannelSelector(const ChannelSelectorType xChannelSelector)
     58 {
     59     if (m_xChannelSelector == xChannelSelector)
     60         return false;
     61     m_xChannelSelector = xChannelSelector;
     62     return true;
     63 }
     64 
     65 ChannelSelectorType FEDisplacementMap::yChannelSelector() const
     66 {
     67     return m_yChannelSelector;
     68 }
     69 
     70 bool FEDisplacementMap::setYChannelSelector(const ChannelSelectorType yChannelSelector)
     71 {
     72     if (m_yChannelSelector == yChannelSelector)
     73         return false;
     74     m_yChannelSelector = yChannelSelector;
     75     return true;
     76 }
     77 
     78 float FEDisplacementMap::scale() const
     79 {
     80     return m_scale;
     81 }
     82 
     83 bool FEDisplacementMap::setScale(float scale)
     84 {
     85     if (m_scale == scale)
     86         return false;
     87     m_scale = scale;
     88     return true;
     89 }
     90 
     91 void FEDisplacementMap::apply()
     92 {
     93     if (hasResult())
     94         return;
     95     FilterEffect* in = inputEffect(0);
     96     FilterEffect* in2 = inputEffect(1);
     97     in->apply();
     98     in2->apply();
     99     if (!in->hasResult() || !in2->hasResult())
    100         return;
    101 
    102     if (m_xChannelSelector == CHANNEL_UNKNOWN || m_yChannelSelector == CHANNEL_UNKNOWN)
    103         return;
    104 
    105     ByteArray* dstPixelArray = createPremultipliedImageResult();
    106     if (!dstPixelArray)
    107         return;
    108 
    109     IntRect effectADrawingRect = requestedRegionOfInputImageData(in->absolutePaintRect());
    110     RefPtr<ByteArray> srcPixelArrayA = in->asPremultipliedImage(effectADrawingRect);
    111 
    112     IntRect effectBDrawingRect = requestedRegionOfInputImageData(in2->absolutePaintRect());
    113     RefPtr<ByteArray> srcPixelArrayB = in2->asUnmultipliedImage(effectBDrawingRect);
    114 
    115     ASSERT(srcPixelArrayA->length() == srcPixelArrayB->length());
    116 
    117     Filter* filter = this->filter();
    118     IntSize paintSize = absolutePaintRect().size();
    119     float scaleX = filter->applyHorizontalScale(m_scale / 255);
    120     float scaleY = filter->applyVerticalScale(m_scale / 255);
    121     float scaleAdjustmentX = filter->applyHorizontalScale(0.5f - 0.5f * m_scale);
    122     float scaleAdjustmentY = filter->applyVerticalScale(0.5f - 0.5f * m_scale);
    123     int stride = paintSize.width() * 4;
    124     for (int y = 0; y < paintSize.height(); ++y) {
    125         int line = y * stride;
    126         for (int x = 0; x < paintSize.width(); ++x) {
    127             int dstIndex = line + x * 4;
    128             int srcX = x + static_cast<int>(scaleX * srcPixelArrayB->get(dstIndex + m_xChannelSelector - 1) + scaleAdjustmentX);
    129             int srcY = y + static_cast<int>(scaleY * srcPixelArrayB->get(dstIndex + m_yChannelSelector - 1) + scaleAdjustmentY);
    130             for (unsigned channel = 0; channel < 4; ++channel) {
    131                 if (srcX < 0 || srcX >= paintSize.width() || srcY < 0 || srcY >= paintSize.height())
    132                     dstPixelArray->set(dstIndex + channel, static_cast<unsigned char>(0));
    133                 else {
    134                     unsigned char pixelValue = srcPixelArrayA->get(srcY * stride + srcX * 4 + channel);
    135                     dstPixelArray->set(dstIndex + channel, pixelValue);
    136                 }
    137             }
    138         }
    139     }
    140 }
    141 
    142 void FEDisplacementMap::dump()
    143 {
    144 }
    145 
    146 static TextStream& operator<<(TextStream& ts, const ChannelSelectorType& type)
    147 {
    148     switch (type) {
    149     case CHANNEL_UNKNOWN:
    150         ts << "UNKNOWN";
    151         break;
    152     case CHANNEL_R:
    153         ts << "RED";
    154         break;
    155     case CHANNEL_G:
    156         ts << "GREEN";
    157         break;
    158     case CHANNEL_B:
    159         ts << "BLUE";
    160         break;
    161     case CHANNEL_A:
    162         ts << "ALPHA";
    163         break;
    164     }
    165     return ts;
    166 }
    167 
    168 TextStream& FEDisplacementMap::externalRepresentation(TextStream& ts, int indent) const
    169 {
    170     writeIndent(ts, indent);
    171     ts << "[feDisplacementMap";
    172     FilterEffect::externalRepresentation(ts);
    173     ts << " scale=\"" << m_scale << "\" "
    174        << "xChannelSelector=\"" << m_xChannelSelector << "\" "
    175        << "yChannelSelector=\"" << m_yChannelSelector << "\"]\n";
    176     inputEffect(0)->externalRepresentation(ts, indent + 1);
    177     inputEffect(1)->externalRepresentation(ts, indent + 1);
    178     return ts;
    179 }
    180 
    181 } // namespace WebCore
    182 
    183 #endif // ENABLE(FILTERS)
    184