101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Copyright 2009 Google Inc. 201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Licensed under the Apache License, Version 2.0 (the "License"); 401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// you may not use this file except in compliance with the License. 501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// You may obtain a copy of the License at 601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// http://www.apache.org/licenses/LICENSE-2.0 801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Unless required by applicable law or agreed to in writing, software 1001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// distributed under the License is distributed on an "AS IS" BASIS, 1101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// See the License for the specific language governing permissions and 1301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// limitations under the License. 1401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 1501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#ifndef __etc1_h__ 1601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#define __etc1_h__ 1701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 1801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#define ETC1_ENCODED_BLOCK_SIZE 8 1901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#define ETC1_DECODED_BLOCK_SIZE 48 2001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 2101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#ifndef ETC1_RGB8_OES 2201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#define ETC1_RGB8_OES 0x8D64 2301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#endif 2401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 2501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichtypedef unsigned char etc1_byte; 2601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichtypedef int etc1_bool; 2701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichtypedef unsigned int etc1_uint32; 2801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 2901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#ifdef __cplusplus 3001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichextern "C" { 3101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#endif 3201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 3301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Encode a block of pixels. 3401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 3501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pIn is a pointer to a ETC_DECODED_BLOCK_SIZE array of bytes that represent a 3601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 * (x + 4 * y) is the R 3701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// value of pixel (x, y). 3801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 3901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// validPixelMask is a 16-bit mask where bit (1 << (x + y * 4)) indicates whether 4001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// the corresponding (x,y) pixel is valid. Invalid pixel color values are ignored when compressing. 4101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 4201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pOut is an ETC1 compressed version of the data. 4301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 4401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichvoid etc1_encode_block(const etc1_byte* pIn, etc1_uint32 validPixelMask, etc1_byte* pOut); 4501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 4601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Decode a block of pixels. 4701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 4801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pIn is an ETC1 compressed version of the data. 4901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 5001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pOut is a pointer to a ETC_DECODED_BLOCK_SIZE array of bytes that represent a 5101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 * (x + 4 * y) is the R 5201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// value of pixel (x, y). 5301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 5401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichvoid etc1_decode_block(const etc1_byte* pIn, etc1_byte* pOut); 5501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 5601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Return the size of the encoded image data (does not include size of PKM header). 5701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 5801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichetc1_uint32 etc1_get_encoded_data_size(etc1_uint32 width, etc1_uint32 height); 5901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 6001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Encode an entire image. 6101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pIn - pointer to the image data. Formatted such that 6201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pixel (x,y) is at pIn + pixelSize * x + stride * y; 6301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pOut - pointer to encoded data. Must be large enough to store entire encoded image. 6401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pixelSize can be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image. 6501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// returns non-zero if there is an error. 6601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 6701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichint etc1_encode_image(const etc1_byte* pIn, etc1_uint32 width, etc1_uint32 height, 6801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich etc1_uint32 pixelSize, etc1_uint32 stride, etc1_byte* pOut); 6901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 7001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Decode an entire image. 7101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pIn - pointer to encoded data. 7201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pOut - pointer to the image data. Will be written such that 7301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pixel (x,y) is at pIn + pixelSize * x + stride * y. Must be 7401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// large enough to store entire image. 7501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// pixelSize can be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image. 7601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// returns non-zero if there is an error. 7701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 7801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichint etc1_decode_image(const etc1_byte* pIn, etc1_byte* pOut, 7901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich etc1_uint32 width, etc1_uint32 height, 8001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich etc1_uint32 pixelSize, etc1_uint32 stride); 8101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 8201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Size of a PKM header, in bytes. 8301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 8401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#define ETC_PKM_HEADER_SIZE 16 8501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 8601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Format a PKM header 8701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 8801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichvoid etc1_pkm_format_header(etc1_byte* pHeader, etc1_uint32 width, etc1_uint32 height); 8901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 9001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Check if a PKM header is correctly formatted. 9101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 9201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichetc1_bool etc1_pkm_is_valid(const etc1_byte* pHeader); 9301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 9401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Read the image width from a PKM header 9501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 9601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichetc1_uint32 etc1_pkm_get_width(const etc1_byte* pHeader); 9701cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 9801cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich// Read the image height from a PKM header 9901cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 10001cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevichetc1_uint32 etc1_pkm_get_height(const etc1_byte* pHeader); 10101cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 10201cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#ifdef __cplusplus 10301cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich} 10401cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#endif 10501cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich 10601cc538b290ecc9ccfdf1907fb714b76cf0f648bJack Palevich#endif 107