godot/thirdparty/astcenc/astcenc_image.cpp

// SPDX-License-Identifier: Apache-2.0
// ----------------------------------------------------------------------------
// Copyright 2011-2024 Arm Limited
//
// 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.
// ----------------------------------------------------------------------------

/**
 * @brief Functions for creating in-memory ASTC image structures.
 */

#include <cassert>
#include <cstring>

#include "astcenc_internal.h"

/**
 * @brief Loader pipeline function type for data fetch from memory.
 */
pixel_loader;

/**
 * @brief Loader pipeline function type for swizzling data in a vector.
 */
pixel_swizzler;

/**
 * @brief Loader pipeline function type for converting data in a vector to LNS.
 */
pixel_converter;

/**
 * @brief Load a 8-bit UNORM texel from a data array.
 *
 * @param data          The data pointer.
 * @param base_offset   The index offset to the start of the pixel.
 */
static vfloat4 load_texel_u8(
	const void* data,
	int base_offset
) { … }

/**
 * @brief Load a 16-bit fp16 texel from a data array.
 *
 * @param data          The data pointer.
 * @param base_offset   The index offset to the start of the pixel.
 */
static vfloat4 load_texel_f16(
	const void* data,
	int base_offset
) { … }

/**
 * @brief Load a 32-bit float texel from a data array.
 *
 * @param data          The data pointer.
 * @param base_offset   The index offset to the start of the pixel.
 */
static vfloat4 load_texel_f32(
	const void* data,
	int base_offset
) { … }

/**
 * @brief Dummy no-op swizzle function.
 *
 * @param data   The source RGBA vector to swizzle.
 * @param swz    The swizzle to use.
 */
static vfloat4 swz_texel_skip(
	vfloat4 data,
	const astcenc_swizzle& swz
) { … }

/**
 * @brief Swizzle a texel into a new arrangement.
 *
 * @param data   The source RGBA vector to swizzle.
 * @param swz    The swizzle to use.
 */
static vfloat4 swz_texel(
	vfloat4 data,
	const astcenc_swizzle& swz
) { … }

/**
 * @brief Encode a texel that is entirely LDR linear.
 *
 * @param data       The RGBA data to encode.
 * @param lns_mask   The mask for the HDR channels than need LNS encoding.
 */
static vfloat4 encode_texel_unorm(
	vfloat4 data,
	vmask4 lns_mask
) { … }

/**
 * @brief Encode a texel that includes at least some HDR LNS texels.
 *
 * @param data       The RGBA data to encode.
 * @param lns_mask   The mask for the HDR channels than need LNS encoding.
 */
static vfloat4 encode_texel_lns(
	vfloat4 data,
	vmask4 lns_mask
) { … }

/* See header for documentation. */
void load_image_block(
	astcenc_profile decode_mode,
	const astcenc_image& img,
	image_block& blk,
	const block_size_descriptor& bsd,
	unsigned int xpos,
	unsigned int ypos,
	unsigned int zpos,
	const astcenc_swizzle& swz
) { … }

/* See header for documentation. */
void load_image_block_fast_ldr(
	astcenc_profile decode_mode,
	const astcenc_image& img,
	image_block& blk,
	const block_size_descriptor& bsd,
	unsigned int xpos,
	unsigned int ypos,
	unsigned int zpos,
	const astcenc_swizzle& swz
) { … }

/* See header for documentation. */
void store_image_block(
	astcenc_image& img,
	const image_block& blk,
	const block_size_descriptor& bsd,
	unsigned int xpos,
	unsigned int ypos,
	unsigned int zpos,
	const astcenc_swizzle& swz
) { … }