Files
aurora/lib/gfx/png_io.cpp
Pieter-Jan Briers f7f3d52cfc Texture loading fixes (#170)
* Implement PNG & arb texture replacements

Fixes #119

For arb textures it's just making sure the file parsing can handle them. Idk if we need to do something special for it.

* Allow non-mipmapped textures to be replaced by mipmapped textures

Some of Henriko's textures (like the cuttable grass) rely on this.

The mipmap bool is no longer part of the runtime key.

* Make texture name the texture replacement key

Might as well? Helped me debug some stuff

* Oops that broke it bad

* libpng instead of spng

* I did it again

* Update libpng fetch

* Add zlib fetch

* Forgot to set the hash

* Add zlib redirect

* Add INCLUDE_DIR(S) to redirect

* Prefer shared for libpng

* Set CMAKE_FIND_PACKAGE_TARGETS_GLOBAL

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Co-authored-by: Luke Street <luke@street.dev>
2026-05-12 20:32:43 -06:00

102 lines
2.8 KiB
C++

#include "png_io.hpp"
#include <fstream>
#include "dds_io.hpp"
#include "png.h"
#include "../fs_helper.hpp"
static aurora::Module Log("aurora::gfx::png");
namespace aurora::gfx::png {
struct PngStructs {
png_structp pStruct;
png_infop pInfo;
std::ifstream file;
~PngStructs() {
png_destroy_read_struct(&pStruct, &pInfo, nullptr);
}
};
static void readPngData(png_structp png, png_bytep data, const size_t length) {
auto structs = static_cast<PngStructs*>(png_get_io_ptr(png));
structs->file.read(reinterpret_cast<char*>(data), static_cast<std::streamsize>(length));
if (structs->file.eof() || structs->file.fail()) {
png_error(png, "file read failed!");
}
}
std::optional<ConvertedTexture>
load_png_file(const std::filesystem::path& path) noexcept {
PngStructs structs{};
structs.file = std::move(std::ifstream(path, std::ifstream::in | std::ifstream::binary));
if (!structs.file) {
Log.error("failed to open file: {}", fs_path_to_string(path));
return std::nullopt;
}
structs.pStruct = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
if (!structs.pStruct) {
Log.error("png_create_read_struct failed");
return std::nullopt;
}
structs.pInfo = png_create_info_struct(structs.pStruct);
if (!structs.pInfo) {
Log.error("png_create_info_struct failed");
return std::nullopt;
}
// I'm scared of putting any locals after that setjmp.
std::vector<png_bytep> rowPointers;
ByteBuffer imageData{};
png_uint_32 width, height;
int bit_depth, color_type, interlace_type, compression_type, filter_type;
size_t rowBytes;
int i;
if (setjmp(png_jmpbuf(structs.pStruct))) {
Log.error("libpng encountered an error");
return std::nullopt;
}
png_set_read_fn(structs.pStruct, &structs, readPngData);
png_read_info(structs.pStruct, structs.pInfo);
if (!png_get_IHDR(structs.pStruct, structs.pInfo, &width, &height, &bit_depth, &color_type, &interlace_type, &compression_type, &filter_type)) {
Log.error("libpng unable to read IHDR");
return std::nullopt;
}
// Always read as RGBA8.
png_set_gray_to_rgb(structs.pStruct);
png_set_filler(structs.pStruct, 0xFF, PNG_FILLER_AFTER);
png_set_expand(structs.pStruct);
png_set_strip_16(structs.pStruct);
png_read_update_info(structs.pStruct, structs.pInfo);
rowBytes = png_get_rowbytes(structs.pStruct, structs.pInfo);
rowPointers.resize(height);
imageData.append_zeroes(rowBytes * height);
for (i = 0; i < height; i++) {
rowPointers[i] = imageData.data() + i * rowBytes;
}
png_read_image(structs.pStruct, rowPointers.data());
png_read_end(structs.pStruct, nullptr);
return ConvertedTexture{
.format = wgpu::TextureFormat::RGBA8Unorm,
.width = width,
.height = height,
.mips = 1,
.data = std::move(imageData)
};
}
}