skia2/third_party/etc1/etc1.h
mtklein dcbaa8ab6d Revert of Depend on ETC1 via DEPS instead of a direct third_party checkin. (patchset #1 id:1 of https://codereview.chromium.org/1296253003/ )
Reason for revert:
This will make the google3 roll awkward.  Reverting.

Original issue's description:
> Depend on ETC1 via DEPS instead of a direct third_party checkin.
>
> Yes, this does mean we'll check out ~40M of code for 2 files...
>
> I think these trybots are moot... they gclient sync before patching.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/ca01d179347b5e848ded97c8228b79ffc6b5e7bf

TBR=robertphillips@google.com,djsollen@google.com,mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1290913008
2015-08-17 11:15:00 -07:00

115 lines
3.8 KiB
C

// Copyright 2009 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//////////////////////////////////////////////////////////////////////////////////////////
// This is a fork of the AOSP project ETC1 codec. The original code can be found
// at the following web site:
// https://android.googlesource.com/platform/frameworks/native/+/master/opengl/libs/ETC1/
//////////////////////////////////////////////////////////////////////////////////////////
#ifndef __etc1_h__
#define __etc1_h__
#define ETC1_ENCODED_BLOCK_SIZE 8
#define ETC1_DECODED_BLOCK_SIZE 48
#ifndef ETC1_RGB8_OES
#define ETC1_RGB8_OES 0x8D64
#endif
typedef unsigned char etc1_byte;
typedef int etc1_bool;
typedef unsigned int etc1_uint32;
#ifdef __cplusplus
extern "C" {
#endif
// Encode a block of pixels.
//
// pIn is a pointer to a ETC_DECODED_BLOCK_SIZE array of bytes that represent a
// 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 * (x + 4 * y) is the R
// value of pixel (x, y).
//
// validPixelMask is a 16-bit mask where bit (1 << (x + y * 4)) indicates whether
// the corresponding (x,y) pixel is valid. Invalid pixel color values are ignored when compressing.
//
// pOut is an ETC1 compressed version of the data.
void etc1_encode_block(const etc1_byte* pIn, etc1_uint32 validPixelMask, etc1_byte* pOut);
// Decode a block of pixels.
//
// pIn is an ETC1 compressed version of the data.
//
// pOut is a pointer to a ETC_DECODED_BLOCK_SIZE array of bytes that represent a
// 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 * (x + 4 * y) is the R
// value of pixel (x, y).
void etc1_decode_block(const etc1_byte* pIn, etc1_byte* pOut);
// Return the size of the encoded image data (does not include size of PKM header).
etc1_uint32 etc1_get_encoded_data_size(etc1_uint32 width, etc1_uint32 height);
// Encode an entire image.
// pIn - pointer to the image data. Formatted such that
// pixel (x,y) is at pIn + pixelSize * x + stride * y;
// pOut - pointer to encoded data. Must be large enough to store entire encoded image.
// pixelSize can be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image.
// returns non-zero if there is an error.
int etc1_encode_image(const etc1_byte* pIn, etc1_uint32 width, etc1_uint32 height,
etc1_uint32 pixelSize, etc1_uint32 stride, etc1_byte* pOut);
// Decode an entire image.
// pIn - pointer to encoded data.
// pOut - pointer to the image data. Will be written such that
// pixel (x,y) is at pIn + pixelSize * x + stride * y. Must be
// large enough to store entire image.
// pixelSize can be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image.
// returns non-zero if there is an error.
int etc1_decode_image(const etc1_byte* pIn, etc1_byte* pOut,
etc1_uint32 width, etc1_uint32 height,
etc1_uint32 pixelSize, etc1_uint32 stride);
// Size of a PKM header, in bytes.
#define ETC_PKM_HEADER_SIZE 16
// Format a PKM header
void etc1_pkm_format_header(etc1_byte* pHeader, etc1_uint32 width, etc1_uint32 height);
// Check if a PKM header is correctly formatted.
etc1_bool etc1_pkm_is_valid(const etc1_byte* pHeader);
// Read the image width from a PKM header
etc1_uint32 etc1_pkm_get_width(const etc1_byte* pHeader);
// Read the image height from a PKM header
etc1_uint32 etc1_pkm_get_height(const etc1_byte* pHeader);
#ifdef __cplusplus
}
#endif
#endif