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+// Copyright 2008, Google Inc.
+// 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.
+
+#ifndef BASE_GFX_PNG_ENCODER_H__
+#define BASE_GFX_PNG_ENCODER_H__
+
+#include <vector>
+
+#include "base/basictypes.h"
+
+// Interface for encoding PNG data. This is a wrapper around libpng,
+// which has an inconvenient interface for callers. This is currently designed
+// for use in tests only (where we control the files), so the handling isn't as
+// robust as would be required for a browser (see Decode() for more). WebKit
+// has its own more complicated PNG decoder which handles, among other things,
+// partially downloaded data.
+class PNGEncoder {
+ public:
+ enum ColorFormat {
+ // 3 bytes per pixel (packed), in RGB order regardless of endianness.
+ // This is the native JPEG format.
+ FORMAT_RGB,
+
+ // 4 bytes per pixel, in RGBA order in memory regardless of endianness.
+ FORMAT_RGBA,
+
+ // 4 bytes per pixel, in BGRA order in memory regardless of endianness.
+ // This is the default Windows DIB order.
+ FORMAT_BGRA
+ };
+
+ // Encodes the given raw 'input' data, with each pixel being represented as
+ // given in 'format'. The encoded PNG data will be written into the supplied
+ // vector and true will be returned on success. On failure (false), the
+ // contents of the output buffer are undefined.
+ //
+ // When writing alpha values, the input colors are assumed to be post
+ // multiplied.
+ //
+ // w, h: dimensions of the image
+ // row_byte_width: the width in bytes of each row. This may be greater than
+ // w * bytes_per_pixel if there is extra padding at the end of each row
+ // (often, each row is padded to the next machine word).
+ // discard_transparency: when true, and when the input data format includes
+ // alpha values, these alpha values will be discarded and only RGB will be
+ // written to the resulting file. Otherwise, alpha values in the input
+ // will be preserved.
+ static bool Encode(const unsigned char* input, ColorFormat format,
+ int w, int h, int row_byte_width,
+ bool discard_transparency,
+ std::vector<unsigned char>* output);
+
+ private:
+ DISALLOW_EVIL_CONSTRUCTORS(PNGEncoder);
+};
+
+#endif // BASE_GFX_PNG_ENCODER_H__