| // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef BASE_GFX_PNG_ENCODER_H_ |
| #define BASE_GFX_PNG_ENCODER_H_ |
| |
| #include <vector> |
| |
| #include "base/basictypes.h" |
| |
| class SkBitmap; |
| |
| // 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); |
| |
| // Call PNGEncoder::Encode on the supplied SkBitmap |input|, which is assumed |
| // to be BGRA, 32 bits per pixel. The params |discard_transparency| and |
| // |output| are passed directly to Encode; refer to Encode for more |
| // information. During the call, an SkAutoLockPixels lock is held on |input|. |
| static bool EncodeBGRASkBitmap(const SkBitmap& input, |
| bool discard_transparency, |
| std::vector<unsigned char>* output); |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(PNGEncoder); |
| }; |
| |
| #endif // BASE_GFX_PNG_ENCODER_H_ |