/**************************************************************************/
/* image_decompress_etcpak.cpp */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
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/**************************************************************************/
#include "image_decompress_etcpak.h"
#include "core/os/os.h"
#include "core/string/print_string.h"
#include <DecodeRGB.hpp>
#define ETCPAK_R_BLOCK_SIZE 8
#define ETCPAK_RG_BLOCK_SIZE 16
#define ETCPAK_RGB_BLOCK_SIZE 8
#define ETCPAK_RGBA_BLOCK_SIZE 16
template <void (*decompress_func)(const void *, void *, size_t), int block_size, int pixel_size>
static inline void _safe_decompress_mipmap(int width, int height, const uint8_t *src, uint8_t *dst) {
// A stack-allocated output buffer large enough to contain an entire uncompressed block.
uint8_t temp_buf[4 * 4 * pixel_size];
// The amount of misaligned pixels on each axis.
const int width_diff = width - (width & ~0x03);
const int height_diff = height - (height & ~0x03);
// The amount of uncompressed blocks on each axis.
const int width_blocks = (width & ~0x03) / 4;
const int height_blocks = (height & ~0x03) / 4;
// The pitch of the image in bytes.
const int image_pitch = width * pixel_size;
// The pitch of a block in bytes.
const int block_pitch = 4 * pixel_size;
// The pitch of the last block in bytes.
const int odd_pitch = width_diff * pixel_size;
size_t src_pos = 0;
size_t dst_pos = 0;
// Decompress the blocks, starting from the top.
for (int y = 0; y < height_blocks; y += 1) {
// Decompress the blocks, starting from the left.
for (int x = 0; x < width_blocks; x += 1) {
decompress_func(&src[src_pos], &dst[dst_pos], width);
src_pos += block_size;
dst_pos += block_pitch;
}
// Decompress the block on the right.
if (width_diff > 0) {
decompress_func(&src[src_pos], temp_buf, 4);
// Copy the data from the temporary buffer to the output.
for (int i = 0; i < 4; i++) {
memcpy(&dst[dst_pos + i * image_pitch], &temp_buf[i * block_pitch], odd_pitch);
}
src_pos += block_size;
dst_pos += odd_pitch;
}
// Skip to the next row of blocks, the current one has already been filled.
dst_pos += 3 * image_pitch;
}
// Decompress the blocks at the bottom of the image.
if (height_diff > 0) {
// Decompress the blocks at the bottom.
for (int x = 0; x < width_blocks; x += 1) {
decompress_func(&src[src_pos], temp_buf, 4);
// Copy the data from the temporary buffer to the output.
for (int i = 0; i < height_diff; i++) {
memcpy(&dst[dst_pos + i * image_pitch], &temp_buf[i * block_pitch], block_pitch);
}
src_pos += block_size;
dst_pos += block_pitch;
}
// Decompress the block in the lower-right corner.
if (width_diff > 0) {
decompress_func(&src[src_pos], temp_buf, 4);
// Copy the data from the temporary buffer to the output.
for (int i = 0; i < height_diff; i++) {
memcpy(&dst[dst_pos + i * image_pitch], &temp_buf[i * block_pitch], odd_pitch);
}
src_pos += block_size;
dst_pos += odd_pitch;
}
}
}
template <void (*decompress_func)(const void *, void *, size_t), int block_size, int pixel_size>
static inline void _decompress_mipmap(int width, int height, const uint8_t *src, uint8_t *dst) {
size_t src_pos = 0;
size_t dst_pos = 0;
// The size of a single block in bytes.
const int block_pitch = 4 * pixel_size;
for (int y = 0; y < height; y += 4) {
for (int x = 0; x < width; x += 4) {
decompress_func(&src[src_pos], &dst[dst_pos], width);
src_pos += block_size;
dst_pos += block_pitch;
}
// Skip to the next row of blocks, the current one has already been filled.
dst_pos += 3 * width * pixel_size;
}
}
static void decompress_image(EtcpakFormat format, const void *src, void *dst, const uint64_t width, const uint64_t height) {
const uint8_t *src_blocks = reinterpret_cast<const uint8_t *>(src);
uint8_t *dec_blocks = reinterpret_cast<uint8_t *>(dst);
const uint64_t aligned_width = (width + 3) & ~0x03;
const uint64_t aligned_height = (height + 3) & ~0x03;
if (width != aligned_width || height != aligned_height) {
switch (format) {
case Etcpak_R: {
_safe_decompress_mipmap<DecodeRBlock, ETCPAK_R_BLOCK_SIZE, 4>(width, height, src_blocks, dec_blocks);
} break;
case Etcpak_RG: {
_safe_decompress_mipmap<DecodeRGBlock, ETCPAK_RG_BLOCK_SIZE, 4>(width, height, src_blocks, dec_blocks);
} break;
case Etcpak_RGB: {
_safe_decompress_mipmap<DecodeRGBBlock, ETCPAK_RGB_BLOCK_SIZE, 4>(width, height, src_blocks, dec_blocks);
} break;
case Etcpak_RGBA: {
_safe_decompress_mipmap<DecodeRGBABlock, ETCPAK_RGBA_BLOCK_SIZE, 4>(width, height, src_blocks, dec_blocks);
} break;
}
} else {
switch (format) {
case Etcpak_R: {
_decompress_mipmap<DecodeRBlock, ETCPAK_R_BLOCK_SIZE, 4>(width, height, src_blocks, dec_blocks);
} break;
case Etcpak_RG: {
_decompress_mipmap<DecodeRGBlock, ETCPAK_RG_BLOCK_SIZE, 4>(width, height, src_blocks, dec_blocks);
} break;
case Etcpak_RGB: {
_decompress_mipmap<DecodeRGBBlock, ETCPAK_RGB_BLOCK_SIZE, 4>(width, height, src_blocks, dec_blocks);
} break;
case Etcpak_RGBA: {
_decompress_mipmap<DecodeRGBABlock, ETCPAK_RGBA_BLOCK_SIZE, 4>(width, height, src_blocks, dec_blocks);
} break;
}
}
}
void _decompress_etc(Image *p_image) {
uint64_t start_time = OS::get_singleton()->get_ticks_msec();
int width = p_image->get_width();
int height = p_image->get_height();
Image::Format source_format = p_image->get_format();
Image::Format target_format = Image::FORMAT_RGBA8;
EtcpakFormat etcpak_format = Etcpak_R;
switch (source_format) {
case Image::FORMAT_ETC:
case Image::FORMAT_ETC2_RGB8:
etcpak_format = Etcpak_RGB;
break;
case Image::FORMAT_ETC2_RGBA8:
case Image::FORMAT_ETC2_RA_AS_RG:
etcpak_format = Etcpak_RGBA;
break;
case Image::FORMAT_ETC2_R11:
etcpak_format = Etcpak_R;
break;
case Image::FORMAT_ETC2_RG11:
etcpak_format = Etcpak_RG;
break;
default:
ERR_FAIL_MSG(vformat("etcpak: Can't decompress image %s with an unknown format: %s.", p_image->get_path(), Image::get_format_name(source_format)));
break;
}
int mm_count = p_image->get_mipmap_count();
int64_t target_size = Image::get_image_data_size(width, height, target_format, p_image->has_mipmaps());
// Decompressed data.
Vector<uint8_t> data;
data.resize(target_size);
uint8_t *wb = data.ptrw();
// Source data.
const uint8_t *rb = p_image->ptr();
// Decompress mipmaps.
for (int i = 0; i <= mm_count; i++) {
int mipmap_w = 0, mipmap_h = 0;
int64_t src_ofs = Image::get_image_mipmap_offset(width, height, source_format, i);
int64_t dst_ofs = Image::get_image_mipmap_offset_and_dimensions(width, height, target_format, i, mipmap_w, mipmap_h);
decompress_image(etcpak_format, rb + src_ofs, wb + dst_ofs, mipmap_w, mipmap_h);
}
p_image->set_data(p_image->get_width(), p_image->get_height(), p_image->has_mipmaps(), target_format, data);
// Swap channels if the format is using a channel swizzle.
if (source_format == Image::FORMAT_ETC2_RA_AS_RG) {
p_image->convert_ra_rgba8_to_rg();
}
print_verbose(vformat("etcpak: Decompression of %dx%d %s image %s with %d mipmaps took %d ms.",
p_image->get_width(), p_image->get_height(), Image::get_format_name(source_format), p_image->get_path(), p_image->get_mipmap_count(), OS::get_singleton()->get_ticks_msec() - start_time));
}