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      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) 2013 Google Inc. 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 #include "platform/graphics/filters/FEColorMatrix.h"
     26 
     27 #include "SkColorFilterImageFilter.h"
     28 #include "SkColorMatrixFilter.h"
     29 #include "platform/graphics/GraphicsContext.h"
     30 #include "platform/graphics/filters/SkiaImageFilterBuilder.h"
     31 #include "platform/graphics/skia/NativeImageSkia.h"
     32 #include "platform/text/TextStream.h"
     33 #include "wtf/MathExtras.h"
     34 #include "wtf/Uint8ClampedArray.h"
     35 
     36 namespace blink {
     37 
     38 FEColorMatrix::FEColorMatrix(Filter* filter, ColorMatrixType type, const Vector<float>& values)
     39     : FilterEffect(filter)
     40     , m_type(type)
     41     , m_values(values)
     42 {
     43 }
     44 
     45 PassRefPtr<FEColorMatrix> FEColorMatrix::create(Filter* filter, ColorMatrixType type, const Vector<float>& values)
     46 {
     47     return adoptRef(new FEColorMatrix(filter, type, values));
     48 }
     49 
     50 ColorMatrixType FEColorMatrix::type() const
     51 {
     52     return m_type;
     53 }
     54 
     55 bool FEColorMatrix::setType(ColorMatrixType type)
     56 {
     57     if (m_type == type)
     58         return false;
     59     m_type = type;
     60     return true;
     61 }
     62 
     63 const Vector<float>& FEColorMatrix::values() const
     64 {
     65     return m_values;
     66 }
     67 
     68 bool FEColorMatrix::setValues(const Vector<float> &values)
     69 {
     70     if (m_values == values)
     71         return false;
     72     m_values = values;
     73     return true;
     74 }
     75 
     76 static void saturateMatrix(float s, SkScalar matrix[20])
     77 {
     78     matrix[0] = 0.213f + 0.787f * s;
     79     matrix[1] = 0.715f - 0.715f * s;
     80     matrix[2] = 0.072f - 0.072f * s;
     81     matrix[3] = matrix[4] = 0;
     82     matrix[5] = 0.213f - 0.213f * s;
     83     matrix[6] = 0.715f + 0.285f * s;
     84     matrix[7] = 0.072f - 0.072f * s;
     85     matrix[8] = matrix[9] = 0;
     86     matrix[10] = 0.213f - 0.213f * s;
     87     matrix[11] = 0.715f - 0.715f * s;
     88     matrix[12] = 0.072f + 0.928f * s;
     89     matrix[13] = matrix[14] = 0;
     90     matrix[15] = matrix[16] = matrix[17] = 0;
     91     matrix[18] = 1;
     92     matrix[19] = 0;
     93 }
     94 
     95 static void hueRotateMatrix(float hue, SkScalar matrix[20])
     96 {
     97     float cosHue = cosf(hue * piFloat / 180);
     98     float sinHue = sinf(hue * piFloat / 180);
     99     matrix[0] = 0.213f + cosHue * 0.787f - sinHue * 0.213f;
    100     matrix[1] = 0.715f - cosHue * 0.715f - sinHue * 0.715f;
    101     matrix[2] = 0.072f - cosHue * 0.072f + sinHue * 0.928f;
    102     matrix[3] = matrix[4] = 0;
    103     matrix[5] = 0.213f - cosHue * 0.213f + sinHue * 0.143f;
    104     matrix[6] = 0.715f + cosHue * 0.285f + sinHue * 0.140f;
    105     matrix[7] = 0.072f - cosHue * 0.072f - sinHue * 0.283f;
    106     matrix[8] = matrix[9] = 0;
    107     matrix[10] = 0.213f - cosHue * 0.213f - sinHue * 0.787f;
    108     matrix[11] = 0.715f - cosHue * 0.715f + sinHue * 0.715f;
    109     matrix[12] = 0.072f + cosHue * 0.928f + sinHue * 0.072f;
    110     matrix[13] = matrix[14] = 0;
    111     matrix[15] = matrix[16] = matrix[17] = 0;
    112     matrix[18] = 1;
    113     matrix[19] = 0;
    114 }
    115 
    116 static void luminanceToAlphaMatrix(SkScalar matrix[20])
    117 {
    118     memset(matrix, 0, 20 * sizeof(SkScalar));
    119     matrix[15] = 0.2125f;
    120     matrix[16] = 0.7154f;
    121     matrix[17] = 0.0721f;
    122 }
    123 
    124 static SkColorFilter* createColorFilter(ColorMatrixType type, const float* values)
    125 {
    126     SkScalar matrix[20];
    127     switch (type) {
    128     case FECOLORMATRIX_TYPE_UNKNOWN:
    129         break;
    130     case FECOLORMATRIX_TYPE_MATRIX:
    131         for (int i = 0; i < 20; ++i)
    132             matrix[i] = values[i];
    133 
    134         matrix[4] *= SkScalar(255);
    135         matrix[9] *= SkScalar(255);
    136         matrix[14] *= SkScalar(255);
    137         matrix[19] *= SkScalar(255);
    138         break;
    139     case FECOLORMATRIX_TYPE_SATURATE:
    140         saturateMatrix(values[0], matrix);
    141         break;
    142     case FECOLORMATRIX_TYPE_HUEROTATE:
    143         hueRotateMatrix(values[0], matrix);
    144         break;
    145     case FECOLORMATRIX_TYPE_LUMINANCETOALPHA:
    146         luminanceToAlphaMatrix(matrix);
    147         break;
    148     }
    149     return SkColorMatrixFilter::Create(matrix);
    150 }
    151 
    152 void FEColorMatrix::applySoftware()
    153 {
    154     ImageBuffer* resultImage = createImageBufferResult();
    155     if (!resultImage)
    156         return;
    157 
    158     FilterEffect* in = inputEffect(0);
    159 
    160     IntRect drawingRegion = drawingRegionOfInputImage(in->absolutePaintRect());
    161 
    162     SkAutoTUnref<SkColorFilter> filter(createColorFilter(m_type, m_values.data()));
    163 
    164     RefPtr<Image> image = in->asImageBuffer()->copyImage(DontCopyBackingStore);
    165     RefPtr<NativeImageSkia> nativeImage = image->nativeImageForCurrentFrame();
    166     if (!nativeImage)
    167         return;
    168 
    169     SkPaint paint;
    170     paint.setColorFilter(filter);
    171     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
    172     resultImage->context()->drawBitmap(nativeImage->bitmap(), drawingRegion.x(), drawingRegion.y(), &paint);
    173 
    174     if (affectsTransparentPixels()) {
    175         IntRect fullRect = IntRect(IntPoint(), absolutePaintRect().size());
    176         resultImage->context()->clipOut(drawingRegion);
    177         resultImage->context()->fillRect(fullRect, Color(m_values[4], m_values[9], m_values[14], m_values[19]));
    178     }
    179     return;
    180 }
    181 
    182 bool FEColorMatrix::affectsTransparentPixels()
    183 {
    184     // Because the input pixels are premultiplied, the only way clear pixels can be
    185     // painted is if the additive component for the alpha is not 0.
    186     return m_type == FECOLORMATRIX_TYPE_MATRIX && m_values[19] > 0;
    187 }
    188 
    189 PassRefPtr<SkImageFilter> FEColorMatrix::createImageFilter(SkiaImageFilterBuilder* builder)
    190 {
    191     RefPtr<SkImageFilter> input(builder->build(inputEffect(0), operatingColorSpace()));
    192     SkAutoTUnref<SkColorFilter> filter(createColorFilter(m_type, m_values.data()));
    193     SkImageFilter::CropRect rect = getCropRect(builder->cropOffset());
    194     return adoptRef(SkColorFilterImageFilter::Create(filter, input.get(), &rect));
    195 }
    196 
    197 static TextStream& operator<<(TextStream& ts, const ColorMatrixType& type)
    198 {
    199     switch (type) {
    200     case FECOLORMATRIX_TYPE_UNKNOWN:
    201         ts << "UNKNOWN";
    202         break;
    203     case FECOLORMATRIX_TYPE_MATRIX:
    204         ts << "MATRIX";
    205         break;
    206     case FECOLORMATRIX_TYPE_SATURATE:
    207         ts << "SATURATE";
    208         break;
    209     case FECOLORMATRIX_TYPE_HUEROTATE:
    210         ts << "HUEROTATE";
    211         break;
    212     case FECOLORMATRIX_TYPE_LUMINANCETOALPHA:
    213         ts << "LUMINANCETOALPHA";
    214         break;
    215     }
    216     return ts;
    217 }
    218 
    219 TextStream& FEColorMatrix::externalRepresentation(TextStream& ts, int indent) const
    220 {
    221     writeIndent(ts, indent);
    222     ts << "[feColorMatrix";
    223     FilterEffect::externalRepresentation(ts);
    224     ts << " type=\"" << m_type << "\"";
    225     if (!m_values.isEmpty()) {
    226         ts << " values=\"";
    227         Vector<float>::const_iterator ptr = m_values.begin();
    228         const Vector<float>::const_iterator end = m_values.end();
    229         while (ptr < end) {
    230             ts << *ptr;
    231             ++ptr;
    232             if (ptr < end)
    233                 ts << " ";
    234         }
    235         ts << "\"";
    236     }
    237     ts << "]\n";
    238     inputEffect(0)->externalRepresentation(ts, indent + 1);
    239     return ts;
    240 }
    241 
    242 } // namespace blink
    243