Add base to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@8 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 376 insertions, 0 deletions

diff --git a/base/gfx/png_decoder.cc b/base/gfx/png_decoder.cc
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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.
+
+#include "base/gfx/png_decoder.h"
+
+#include "base/logging.h"
+#include "skia/include/SkBitmap.h"
+
+extern "C" {
+#include "png.h"
+}
+
+namespace {
+
+// Converts BGRA->RGBA and RGBA->BGRA.
+void ConvertBetweenBGRAandRGBA(const unsigned char* input, int pixel_width,
+                               unsigned char* output) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &input[x * 4];
+    unsigned char* pixel_out = &output[x * 4];
+    pixel_out[0] = pixel_in[2];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[0];
+    pixel_out[3] = pixel_in[3];
+  }
+}
+
+void ConvertRGBAtoRGB(const unsigned char* rgba, int pixel_width,
+                      unsigned char* rgb) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgba[x * 4];
+    unsigned char* pixel_out = &rgb[x * 3];
+    pixel_out[0] = pixel_in[0];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[2];
+  }
+}
+
+}  // namespace
+
+// Decoder --------------------------------------------------------------------
+//
+// This code is based on WebKit libpng interface (PNGImageDecoder), which is
+// in turn based on the Mozilla png decoder.
+
+namespace {
+
+// Gamma constants: We assume we're on Windows which uses a gamma of 2.2.
+const double kMaxGamma = 21474.83;  // Maximum gamma accepted by png library.
+const double kDefaultGamma = 2.2;
+const double kInverseGamma = 1.0 / kDefaultGamma;
+
+// Maximum pixel dimension we'll try to decode.
+const png_uint_32 kMaxSize = 4096;
+
+class PngDecoderState {
+ public:
+  PngDecoderState(PNGDecoder::ColorFormat ofmt, std::vector<unsigned char>* o)
+      : output_format(ofmt),
+        output_channels(0),
+        output(o),
+        row_converter(NULL),
+        width(0),
+        height(0),
+        done(false) {
+  }
+
+  PNGDecoder::ColorFormat output_format;
+  int output_channels;
+
+  std::vector<unsigned char>* output;
+
+  // Called to convert a row from the library to the correct output format.
+  // When NULL, no conversion is necessary.
+  void (*row_converter)(const unsigned char* in, int w, unsigned char* out);
+
+  // Size of the image, set in the info callback.
+  int width;
+  int height;
+
+  // Set to true when we've found the end of the data.
+  bool done;
+
+ private:
+  DISALLOW_EVIL_CONSTRUCTORS(PngDecoderState);
+};
+
+void ConvertRGBtoRGBA(const unsigned char* rgb, int pixel_width,
+                      unsigned char* rgba) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgb[x * 3];
+    unsigned char* pixel_out = &rgba[x * 4];
+    pixel_out[0] = pixel_in[0];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[2];
+    pixel_out[3] = 0xff;
+  }
+}
+
+void ConvertRGBtoBGRA(const unsigned char* rgb, int pixel_width,
+                      unsigned char* bgra) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgb[x * 3];
+    unsigned char* pixel_out = &bgra[x * 4];
+    pixel_out[0] = pixel_in[2];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[0];
+    pixel_out[3] = 0xff;
+  }
+}
+
+// Called when the png header has been read. This code is based on the WebKit
+// PNGImageDecoder
+void DecodeInfoCallback(png_struct* png_ptr, png_info* info_ptr) {
+  PngDecoderState* state = static_cast<PngDecoderState*>(
+      png_get_progressive_ptr(png_ptr));
+
+  int bit_depth, color_type, interlace_type, compression_type;
+  int filter_type, channels;
+  png_uint_32 w, h;
+  png_get_IHDR(png_ptr, info_ptr, &w, &h, &bit_depth, &color_type,
+               &interlace_type, &compression_type, &filter_type);
+
+  // Bounds check. When the image is unreasonably big, we'll error out and
+  // end up back at the setjmp call when we set up decoding.
+  if (w > kMaxSize || h > kMaxSize)
+    longjmp(png_ptr->jmpbuf, 1);
+  state->width = static_cast<int>(w);
+  state->height = static_cast<int>(h);
+
+  // Expand to ensure we use 24-bit for RGB and 32-bit for RGBA.
+  if (color_type == PNG_COLOR_TYPE_PALETTE ||
+      (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8))
+    png_set_expand(png_ptr);
+
+  // Transparency for paletted images.
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+    png_set_expand(png_ptr);
+
+  // Convert 16-bit to 8-bit.
+  if (bit_depth == 16)
+    png_set_strip_16(png_ptr);
+
+  // Expand grayscale to RGB.
+  if (color_type == PNG_COLOR_TYPE_GRAY ||
+      color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    png_set_gray_to_rgb(png_ptr);
+
+  // Deal with gamma and keep it under our control.
+  double gamma;
+  if (png_get_gAMA(png_ptr, info_ptr, &gamma)) {
+    if (gamma <= 0.0 || gamma > kMaxGamma) {
+      gamma = kInverseGamma;
+      png_set_gAMA(png_ptr, info_ptr, gamma);
+    }
+    png_set_gamma(png_ptr, kDefaultGamma, gamma);
+  } else {
+    png_set_gamma(png_ptr, kDefaultGamma, kInverseGamma);
+  }
+
+  // Tell libpng to send us rows for interlaced pngs.
+  if (interlace_type == PNG_INTERLACE_ADAM7)
+    png_set_interlace_handling(png_ptr);
+
+  // Update our info now
+  png_read_update_info(png_ptr, info_ptr);
+  channels = png_get_channels(png_ptr, info_ptr);
+
+  // Pick our row format converter necessary for this data.
+  if (channels == 3) {
+    switch (state->output_format) {
+      case PNGDecoder::FORMAT_RGB:
+        state->row_converter = NULL;  // no conversion necessary
+        state->output_channels = 3;
+        break;
+      case PNGDecoder::FORMAT_RGBA:
+        state->row_converter = &ConvertRGBtoRGBA;
+        state->output_channels = 4;
+        break;
+      case PNGDecoder::FORMAT_BGRA:
+        state->row_converter = &ConvertRGBtoBGRA;
+        state->output_channels = 4;
+        break;
+      default:
+        NOTREACHED() << "Unknown output format";
+        break;
+    }
+  } else if (channels == 4) {
+    switch (state->output_format) {
+      case PNGDecoder::FORMAT_RGB:
+        state->row_converter = &ConvertRGBAtoRGB;
+        state->output_channels = 3;
+        break;
+      case PNGDecoder::FORMAT_RGBA:
+        state->row_converter = NULL;  // no conversion necessary
+        state->output_channels = 4;
+        break;
+      case PNGDecoder::FORMAT_BGRA:
+        state->row_converter = &ConvertBetweenBGRAandRGBA;
+        state->output_channels = 4;
+        break;
+      default:
+        NOTREACHED() << "Unknown output format";
+        break;
+    }
+  } else {
+    NOTREACHED() << "Unknown input channels";
+    longjmp(png_ptr->jmpbuf, 1);
+  }
+
+  state->output->resize(state->width * state->output_channels * state->height);
+}
+
+void DecodeRowCallback(png_struct* png_ptr, png_byte* new_row,
+                       png_uint_32 row_num, int pass) {
+  PngDecoderState* state = static_cast<PngDecoderState*>(
+      png_get_progressive_ptr(png_ptr));
+
+  DCHECK(pass == 0) << "We didn't turn on interlace handling, but libpng is "
+                       "giving us interlaced data.";
+  if (static_cast<int>(row_num) > state->height) {
+    NOTREACHED() << "Invalid row";
+    return;
+  }
+
+  unsigned char* dest = &(*state->output)[
+      state->width * state->output_channels * row_num];
+  if (state->row_converter)
+    state->row_converter(new_row, state->width, dest);
+  else
+    memcpy(dest, new_row, state->width * state->output_channels);
+}
+
+void DecodeEndCallback(png_struct* png_ptr, png_info* info) {
+  PngDecoderState* state = static_cast<PngDecoderState*>(
+      png_get_progressive_ptr(png_ptr));
+
+  // Mark the image as complete, this will tell the Decode function that we
+  // have successfully found the end of the data.
+  state->done = true;
+}
+
+// Automatically destroys the given read structs on destruction to make
+// cleanup and error handling code cleaner.
+class PngReadStructDestroyer {
+ public:
+  PngReadStructDestroyer(png_struct** ps, png_info** pi) : ps_(ps), pi_(pi) {
+  }
+  ~PngReadStructDestroyer() {
+    png_destroy_read_struct(ps_, pi_, NULL);
+  }
+ private:
+  png_struct** ps_;
+  png_info** pi_;
+};
+
+}  // namespace
+
+// static
+bool PNGDecoder::Decode(const unsigned char* input, size_t input_size,
+                      ColorFormat format, std::vector<unsigned char>* output,
+                      int* w, int* h) {
+  if (input_size < 8)
+    return false;  // Input data too small to be a png
+
+  // Have libpng check the signature, it likes the first 8 bytes.
+  if (png_sig_cmp(const_cast<unsigned char*>(input), 0, 8) != 0)
+    return false;
+
+  png_struct* png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
+                                               png_voidp_NULL,
+                                               png_error_ptr_NULL,
+                                               png_error_ptr_NULL);
+  if (!png_ptr)
+    return false;
+
+  png_info* info_ptr = png_create_info_struct(png_ptr);
+  if (!info_ptr) {
+    png_destroy_read_struct(&png_ptr, NULL, NULL);
+    return false;
+  }
+
+  PngReadStructDestroyer destroyer(&png_ptr, &info_ptr);
+  if (setjmp(png_jmpbuf(png_ptr))) {
+    // 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.
+    return false;
+  }
+
+  PngDecoderState state(format, output);
+
+  png_set_progressive_read_fn(png_ptr, &state, &DecodeInfoCallback,
+                              &DecodeRowCallback, &DecodeEndCallback);
+  png_process_data(png_ptr, info_ptr, const_cast<unsigned char*>(input), input_size);
+
+  if (!state.done) {
+    // Fed it all the data but the library didn't think we got all the data, so
+    // this file must be truncated.
+    output->clear();
+    return false;
+  }
+
+  *w = state.width;
+  *h = state.height;
+  return true;
+}
+
+// static
+bool PNGDecoder::Decode(const std::vector<unsigned char>* data,
+                        SkBitmap* bitmap) {
+  DCHECK(bitmap);
+  if (!data || data->empty())
+    return false;
+  int width, height;
+  std::vector<unsigned char> decoded_data;
+  if (PNGDecoder::Decode(&data->front(), data->size(), PNGDecoder::FORMAT_BGRA,
+                         &decoded_data, &width, &height)) {
+    bitmap->setConfig(SkBitmap::kARGB_8888_Config, width, height);
+    bitmap->allocPixels();
+    memcpy(bitmap->getPixels(), &decoded_data.front(), width * height * 4);
+    return true;
+  }
+  return false;
+}
+
+//static
+SkBitmap* PNGDecoder::CreateSkBitmapFromBGRAFormat(
+    std::vector<unsigned char>& bgra, int width, int height) {
+  SkBitmap* bitmap = new SkBitmap();
+  bitmap->setConfig(SkBitmap::kARGB_8888_Config, width, height);
+  bitmap->allocPixels();
+
+  bool opaque = false;
+  unsigned char* bitmap_data =
+      reinterpret_cast<unsigned char*>(bitmap->getAddr32(0, 0));
+  for (int i = width * height * 4 - 4; i >= 0; i -= 4) {
+    unsigned char alpha = bgra[i + 3];
+    if (!opaque && alpha != 255) {
+      opaque = false;
+    }
+    bitmap_data[i + 3] = alpha;
+    bitmap_data[i] = (bgra[i] * alpha) >> 8;
+    bitmap_data[i + 1] = (bgra[i + 1] * alpha) >> 8;
+    bitmap_data[i + 2] = (bgra[i + 2] * alpha) >> 8;
+  }
+
+  bitmap->setIsOpaque(opaque);
+  return bitmap;
+}