third_party/android_opengl/etc1/etc1.h

   1 // Copyright 2009 Google Inc.
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 // This is branched from AOSP's frameworks/base/opengl/include/ETC1/etc1.h
  16 //
  17 // It has been modified to implement Chromium's ETC1 API.  The decoding path
  18 // has been removed as we do not require it.
  19
  20 #ifndef THIRD_PARTY_ANDROID_OPENGL_ETC1_ETC1_H_
  21 #define THIRD_PARTY_ANDROID_OPENGL_ETC1_ETC1_H_
  22
  23 // Return the size of the encoded image data.
  24
  25 unsigned int etc1_get_encoded_data_size(unsigned int width, unsigned int height);
  26
  27 // Encode an entire image.
  28 // pIn - pointer to the image data. Formatted such that
  29 //       pixel (x,y) is at pIn + pixelSize * x + stride * y;
  30 // pOut - pointer to encoded data. Must be large enough to store entire encoded image.
  31 // pixelSize can be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image.
  32 // returns non-zero if there is an error.
  33
  34 bool etc1_encode_image(const unsigned char* pIn, unsigned int width, unsigned int height,
  35          unsigned int pixelSize, unsigned int stride, unsigned char* pOut, unsigned int outWidth,
  36          unsigned int outHeight);
  37
  38 // Decode an entire image.
  39 // pIn - pointer to encoded data.
  40 // pOut - pointer to the image data. Will be written such that
  41 //        pixel (x,y) is at pIn + pixelSize * x + stride * y. Must be
  42 //        large enough to store entire image.
  43 // pixelSize can be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image.
  44 // returns false if there is an error.
  45
  46 bool etc1_decode_image(const unsigned char* pIn, unsigned char* pOut,
  47         unsigned int width, unsigned int height,
  48         unsigned int pixelSize, unsigned int stride);
  49
  50 // Size of a PKM header, in bytes.
  51
  52 #define ETC_PKM_HEADER_SIZE 16
  53
  54 // Format a PKM header
  55
  56 void etc1_pkm_format_header(unsigned char* pHeader, unsigned int width, unsigned int height);
  57
  58 // Check if a PKM header is correctly formatted.
  59
  60 bool etc1_pkm_is_valid(const unsigned char* pHeader);
  61
  62 // Read the image width from a PKM header
  63
  64 unsigned int etc1_pkm_get_width(const unsigned char* pHeader);
  65
  66 // Read the image height from a PKM header
  67
  68 unsigned int etc1_pkm_get_height(const unsigned char* pHeader);
  69
  70 #endif // THIRD_PARTY_ANDROID_OPENGL_ETC1_ETC1_H_