From b56a50064caf2a590ba43699e0074690fcd431bf Mon Sep 17 00:00:00 2001 From: Jeff McGlynn Date: Wed, 20 Jun 2018 11:34:20 -0700 Subject: Initial version of astc-codec for open source release Contains an implementation of an ASTC decoder that is able to pass the dEQP ASTC LDR tests. astc-codec has no external dependencies for the main library, only for test code, and is licensed under the Apache license. Components: include/ - Public API that can decode ASTC LDR data into a RGBA UNORM8 buffer. src/base/ - Base library with common functionality not directly related to ASTC decoding. Contains a uint128 implementation, BitStream for reading/writing bits with a primitive (or uint128 type), Optional implementation (to not take a dependency on C++17), and more. src/decoder/ - Internal implementation of the ASTC decoder. src/base/test/, src/decoder/test/ - Unit tests (and a fuzzing test) for the astc decoder. src/decoder/testdata/ - Sample ASTC images and golden image results for testing. src/decoder/tools/ - A tool to inspect contents of an ASTC file. third_party/ - Third party libraries, only used for tests. Change-Id: Ia98e5a7dc847daa3d3a48c5e62d94b8fb1cb98bd --- include/astc-codec/astc-codec.h | 75 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 include/astc-codec/astc-codec.h (limited to 'include/astc-codec/astc-codec.h') diff --git a/include/astc-codec/astc-codec.h b/include/astc-codec/astc-codec.h new file mode 100644 index 0000000..1d41218 --- /dev/null +++ b/include/astc-codec/astc-codec.h @@ -0,0 +1,75 @@ +// Copyright 2018 Google LLC +// +// 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 +// +// https://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. + +#ifndef ASTC_CODEC_ASTC_CODEC_H_ +#define ASTC_CODEC_ASTC_CODEC_H_ + +#include +#include + +namespace astc_codec { + +// These are the valid ASTC footprints according to the specification in +// Section C.2.7. +enum class FootprintType { + k4x4, + k5x4, + k5x5, + k6x5, + k6x6, + k8x5, + k8x6, + k10x5, + k10x6, + k8x8, + k10x8, + k10x10, + k12x10, + k12x12, + + kCount +}; + +// Decompresses ASTC LDR image data to a RGBA32 buffer. +// +// Supports formats defined in the KHR_texture_compression_astc_ldr spec and +// returns UNORM8 values. sRGB is not supported, and should be implemented +// by the caller. +// +// |astc_data| - Compressed ASTC image buffer, must be at least |astc_data_size| +// bytes long. +// |astc_data_size| - The size of |astc_data|, in bytes. +// |width| - Image width, in pixels. +// |height| - Image height, in pixels. +// |footprint| - The ASTC footprint (block size) of the compressed image buffer. +// |out_buffer| - Pointer to a buffer where the decompressed image will be +// stored, must be at least |out_buffer_size| bytes long. +// |out_buffer_size| - The size of |out_buffer|, in bytes, at least +// height*out_buffer_stride. If this is too small, this +// function will return false and no data will be +// decompressed. +// |out_buffer_stride| - The stride that should be used to store rows of the +// decoded image, must be at least 4*width bytes. +// +// Returns true if the decompression succeeded, or false if decompression +// failed, or if the astc_data_size was too small for the given width, height, +// and footprint, or if out_buffer_size is too small. +bool ASTCDecompressToRGBA(const uint8_t* astc_data, size_t astc_data_size, + size_t width, size_t height, FootprintType footprint, + uint8_t* out_buffer, size_t out_buffer_size, + size_t out_buffer_stride); + +} // namespace astc_codec + +#endif // ASTC_CODEC_ASTC_CODEC_H_ -- cgit v1.2.3