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      1 /*
      2  * Copyright (C) 2009 Dirk Schulze <krit (at) webkit.org>
      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 COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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 "ImageBuffer.h"
     28 
     29 #if !PLATFORM(CG)
     30 
     31 #include <math.h>
     32 
     33 namespace WebCore {
     34 
     35 void ImageBuffer::transformColorSpace(ImageColorSpace srcColorSpace, ImageColorSpace dstColorSpace)
     36 {
     37     if (srcColorSpace == dstColorSpace)
     38         return;
     39 
     40     // only sRGB <-> linearRGB are supported at the moment
     41     if ((srcColorSpace != LinearRGB && srcColorSpace != DeviceRGB) ||
     42         (dstColorSpace != LinearRGB && dstColorSpace != DeviceRGB))
     43         return;
     44 
     45     Vector<int> lookUpTable;
     46     if (dstColorSpace == LinearRGB) {
     47         if (m_linearRgbLUT.isEmpty()) {
     48             for (unsigned i = 0; i < 256; i++) {
     49                 float color = i  / 255.0f;
     50                 color = (color <= 0.04045f ? color / 12.92f : pow((color + 0.055f) / 1.055f, 2.4f));
     51                 color = std::max(0.0f, color);
     52                 color = std::min(1.0f, color);
     53                 m_linearRgbLUT.append(static_cast<int>(color * 255));
     54             }
     55         }
     56         platformTransformColorSpace(m_linearRgbLUT);
     57     } else if (dstColorSpace == DeviceRGB) {
     58         if (m_deviceRgbLUT.isEmpty()) {
     59             for (unsigned i = 0; i < 256; i++) {
     60                 float color = i  / 255.0f;
     61                 color = pow(1.055f * color, 1.0f / 2.4f) - 0.055f;
     62                 color = std::max(0.0f, color);
     63                 color = std::min(1.0f, color);
     64                 m_deviceRgbLUT.append(static_cast<int>(color * 255));
     65             }
     66         }
     67         platformTransformColorSpace(m_deviceRgbLUT);
     68     }
     69 }
     70 
     71 }
     72 
     73 #endif // PLATFORM(CG)
     74