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      1 /*
      2  * Copyright (C) 2006, 2007, 2008 Apple Computer, Inc.  All rights reserved.
      3  * Copyright (C) 2008 Eric Seidel <eric (at) webkit.org>
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #include "config.h"
     28 #include "Pattern.h"
     29 
     30 #include "AffineTransform.h"
     31 #include "GraphicsContext.h"
     32 
     33 #include <ApplicationServices/ApplicationServices.h>
     34 
     35 namespace WebCore {
     36 
     37 static void patternCallback(void* info, CGContextRef context)
     38 {
     39     CGImageRef platformImage = static_cast<Image*>(info)->getCGImageRef();
     40     if (!platformImage)
     41         return;
     42 
     43     CGRect rect = GraphicsContext(context).roundToDevicePixels(
     44         FloatRect(0, 0, CGImageGetWidth(platformImage), CGImageGetHeight(platformImage)));
     45     CGContextDrawImage(context, rect, platformImage);
     46 }
     47 
     48 static void patternReleaseCallback(void* info)
     49 {
     50     static_cast<Image*>(info)->deref();
     51 }
     52 
     53 CGPatternRef Pattern::createPlatformPattern(const AffineTransform& userSpaceTransformation) const
     54 {
     55     IntRect tileRect = tileImage()->rect();
     56 
     57     AffineTransform patternTransform = userSpaceTransformation * m_patternSpaceTransformation;
     58     patternTransform.scaleNonUniform(1, -1);
     59     patternTransform.translate(0, -tileRect.height());
     60 
     61     // If FLT_MAX should also be used for xStep or yStep, nothing is rendered. Using fractions of FLT_MAX also
     62     // result in nothing being rendered.
     63     // INT_MAX is almost correct, but there seems to be some number wrapping occurring making the fill
     64     // pattern is not filled correctly.
     65     // To make error of floating point less than 0.5, we use the half of the number of mantissa of float (1 << 22).
     66     CGFloat xStep = m_repeatX ? tileRect.width() : (1 << 22);
     67     CGFloat yStep = m_repeatY ? tileRect.height() : (1 << 22);
     68 
     69     // The pattern will release the tile when it's done rendering in patternReleaseCallback
     70     tileImage()->ref();
     71 
     72     const CGPatternCallbacks patternCallbacks = { 0, patternCallback, patternReleaseCallback };
     73     return CGPatternCreate(tileImage(), tileRect, patternTransform, xStep, yStep,
     74         kCGPatternTilingConstantSpacing, TRUE, &patternCallbacks);
     75 }
     76 
     77 }
     78