Function SaveState_CompressScreenshot

pcsx2/SaveState.cpp:778–843

}

static bool SaveState_CompressScreenshot(SaveStateScreenshotData* data, zip_t* zf)
{
	zip_error_t ze = {};
	zip_source_t* const zs = zip_source_buffer_create(nullptr, 0, 0, &ze);
	if (!zs)
		return false;

	if (zip_source_begin_write(zs) != 0)
	{
		zip_source_free(zs);
		return false;
	}

	ScopedGuard zs_free([zs]() { zip_source_free(zs); });

	png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
	png_infop info_ptr = nullptr;
	if (!png_ptr)
		return false;

	ScopedGuard cleanup([&png_ptr, &info_ptr]() {
		if (png_ptr)
			png_destroy_write_struct(&png_ptr, info_ptr ? &info_ptr : nullptr);
	});

	info_ptr = png_create_info_struct(png_ptr);
	if (!info_ptr)
		return false;

	if (setjmp(png_jmpbuf(png_ptr)))
		return false;

	png_set_write_fn(png_ptr, zs, [](png_structp png_ptr, png_bytep data_ptr, png_size_t size) {
		zip_source_write(static_cast<zip_source_t*>(png_get_io_ptr(png_ptr)), data_ptr, size);
	}, [](png_structp png_ptr) {});
	png_set_compression_level(png_ptr, 5);
	png_set_IHDR(png_ptr, info_ptr, data->width, data->height, 8, PNG_COLOR_TYPE_RGBA,
		PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
	png_write_info(png_ptr, info_ptr);

	for (u32 y = 0; y < data->height; ++y)
	{
		// ensure the alpha channel is set to opaque
		u32* row = &data->pixels[y * data->width];
		for (u32 x = 0; x < data->width; x++)
			row[x] |= 0xFF000000u;

		png_write_row(png_ptr, reinterpret_cast<png_bytep>(row));
	}

	png_write_end(png_ptr, nullptr);

	if (zip_source_commit_write(zs) != 0)
		return false;

	const s64 file_index = zip_file_add(zf, EntryFilename_Screenshot, zs, 0);
	if (file_index < 0)
		return false;