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// 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 <cstddef>
#include <cstdint>
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_
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