godot/thirdparty/basis_universal/encoder/basisu_gpu_texture.h

// basisu_gpu_texture.h
// Copyright (C) 2019-2024 Binomial LLC. All Rights Reserved.
//
// 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.
#pragma once
#include "../transcoder/basisu.h"
#include "basisu_etc.h"

namespace basisu
{
	// GPU texture "image"
	class gpu_image
	{ … };

	gpu_image_vec;

	// KTX1 file writing
	bool create_ktx_texture_file(uint8_vec &ktx_data, const basisu::vector<gpu_image_vec>& gpu_images, bool cubemap_flag);
	
	bool does_dds_support_format(texture_format fmt);
	bool write_dds_file(uint8_vec& dds_data, const basisu::vector<gpu_image_vec>& gpu_images, bool cubemap_flag, bool use_srgb_format);
	bool write_dds_file(const char* pFilename, const basisu::vector<gpu_image_vec>& gpu_images, bool cubemap_flag, bool use_srgb_format);

	// Currently reads 2D 32bpp RGBA, 16-bit HALF RGBA, or 32-bit FLOAT RGBA, with or without mipmaps. No tex arrays or cubemaps, yet.
	bool read_uncompressed_dds_file(const char* pFilename, basisu::vector<image>& ldr_mips, basisu::vector<imagef>& hdr_mips);

	// Supports DDS and KTX
	bool write_compressed_texture_file(const char *pFilename, const basisu::vector<gpu_image_vec>& g, bool cubemap_flag, bool use_srgb_format);
	bool write_compressed_texture_file(const char* pFilename, const gpu_image_vec& g, bool use_srgb_format);
	bool write_compressed_texture_file(const char *pFilename, const gpu_image &g, bool use_srgb_format);
	
	bool write_3dfx_out_file(const char* pFilename, const gpu_image& gi);

	// GPU texture block unpacking
	// For ETC1, use in basisu_etc.h: bool unpack_etc1(const etc_block& block, color_rgba *pDst, bool preserve_alpha)
	void unpack_etc2_eac(const void *pBlock_bits, color_rgba *pPixels);
	bool unpack_bc1(const void *pBlock_bits, color_rgba *pPixels, bool set_alpha);
	void unpack_bc4(const void *pBlock_bits, uint8_t *pPixels, uint32_t stride);
	bool unpack_bc3(const void *pBlock_bits, color_rgba *pPixels);
	void unpack_bc5(const void *pBlock_bits, color_rgba *pPixels);
	bool unpack_bc7_mode6(const void *pBlock_bits, color_rgba *pPixels);
	bool unpack_bc7(const void* pBlock_bits, color_rgba* pPixels); // full format
	bool unpack_bc6h(const void* pSrc_block, void* pDst_block, bool is_signed, uint32_t dest_pitch_in_halfs = 4 * 3); // full format, outputs HALF values, RGB texels only (not RGBA)
	void unpack_atc(const void* pBlock_bits, color_rgba* pPixels);
	// We only support CC_MIXED non-alpha blocks here because that's the only mode the transcoder uses at the moment.
	bool unpack_fxt1(const void* p, color_rgba* pPixels);
	// PVRTC2 is currently limited to only what our transcoder outputs (non-interpolated, hard_flag=1 modulation=0). In this mode, PVRTC2 looks much like BC1/ATC.
	bool unpack_pvrtc2(const void* p, color_rgba* pPixels);
	void unpack_etc2_eac_r(const void *p, color_rgba* pPixels, uint32_t c);
	void unpack_etc2_eac_rg(const void* p, color_rgba* pPixels);
	
	// unpack_block() is primarily intended to unpack texture data created by the transcoder.
	// For some texture formats (like ETC2 RGB, PVRTC2, FXT1) it's not yet a complete implementation.
	// Unpacks LDR texture formats only.
	bool unpack_block(texture_format fmt, const void *pBlock, color_rgba *pPixels);

	// Unpacks HDR texture formats only.
	bool unpack_block_hdr(texture_format fmt, const void* pBlock, vec4F* pPixels);
	
	bool write_astc_file(const char* pFilename, const void* pBlocks, uint32_t block_width, uint32_t block_height, uint32_t dim_x, uint32_t dim_y);
							
} // namespace basisu