webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 126 insertions, 0 deletions

diff --git a/Source/WebCore/platform/image-encoders/PNGImageEncoder.cpp b/Source/WebCore/platform/image-encoders/PNGImageEncoder.cpp
new file mode 100644
index 000000000..3aa51229a
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+++ b/Source/WebCore/platform/image-encoders/PNGImageEncoder.cpp
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2006-2009, Google Inc. All rights reserved.
+ * Copyright (c) 2009 Torch Mobile, Inc. All rights reserved.
+ * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "PNGImageEncoder.h"
+
+#include "IntSize.h"
+#include <png.h>
+#include <wtf/Vector.h>
+
+namespace WebCore {
+
+// Encoder --------------------------------------------------------------------
+//
+// This section of the code is based on nsPNGEncoder.cpp in Mozilla
+// (Copyright 2005 Google Inc.)
+
+// Passed around as the io_ptr in the png structs so our callbacks know where
+// to write data.
+struct PNGEncoderState {
+    PNGEncoderState(Vector<char>* o) : m_dump(o) {}
+    Vector<char>* m_dump;
+};
+
+// Called by libpng to flush its internal buffer to ours.
+void encoderWriteCallback(png_structp png, png_bytep data, png_size_t size)
+{
+    PNGEncoderState* state = static_cast<PNGEncoderState*>(png_get_io_ptr(png));
+    ASSERT(state->m_dump);
+
+    size_t oldSize = state->m_dump->size();
+    state->m_dump->resize(oldSize + size);
+    char* destination = state->m_dump->data() + oldSize;
+    memcpy(destination, data, size);
+}
+
+// Automatically destroys the given write structs on destruction to make
+// cleanup and error handling code cleaner.
+class PNGWriteStructDestroyer {
+public:
+    PNGWriteStructDestroyer(png_struct** ps, png_info** pi)
+        : m_pngStruct(ps)
+        , m_pngInfo(pi)
+    {
+    }
+
+    ~PNGWriteStructDestroyer()
+    {
+        png_destroy_write_struct(m_pngStruct, m_pngInfo);
+    }
+
+private:
+    png_struct** m_pngStruct;
+    png_info** m_pngInfo;
+};
+
+bool compressRGBABigEndianToPNG(unsigned char* rgbaBigEndianData, const IntSize& size, Vector<char>& pngData)
+{
+    png_struct* pngPtr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+    if (!pngPtr)
+        return false;
+
+    png_info* infoPtr = png_create_info_struct(pngPtr);
+    if (!infoPtr) {
+        png_destroy_write_struct(&pngPtr, 0);
+        return false;
+    }
+    PNGWriteStructDestroyer destroyer(&pngPtr, &infoPtr);
+
+    // The destroyer will ensure that the structures are cleaned up in this
+    // case, even though we may get here as a jump from random parts of the
+    // PNG library called below.
+    if (setjmp(png_jmpbuf(pngPtr)))
+        return false;
+
+    // Set our callback for libpng to give us the data.
+    PNGEncoderState state(&pngData);
+    png_set_write_fn(pngPtr, &state, encoderWriteCallback, 0);
+
+    int pngOutputColorType = PNG_COLOR_TYPE_RGB_ALPHA;
+
+    png_set_IHDR(pngPtr, infoPtr, size.width(), size.height(), 8, pngOutputColorType,
+                 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
+                 PNG_FILTER_TYPE_DEFAULT);
+    png_write_info(pngPtr, infoPtr);
+
+    unsigned bytesPerRow = size.width() * 4;
+    for (unsigned y = 0; y < size.height(); ++y) {
+        png_write_row(pngPtr, rgbaBigEndianData);
+        rgbaBigEndianData += bytesPerRow;
+    }
+
+    png_write_end(pngPtr, infoPtr);
+    return true;
+}
+
+} // namespace WebCore