filament/third_party/meshoptimizer/gltf/basisenc.cpp

#ifdef WITH_BASISU

#define BASISU_NO_ITERATOR_DEBUG_LEVEL

#ifdef __clang__
#pragma GCC diagnostic ignored "-Wunknown-warning-option"
#endif

#ifdef __GNUC__
#pragma GCC diagnostic ignored "-Wclass-memaccess"
#pragma GCC diagnostic ignored "-Wunused-value"
#endif

#include "encoder/basisu_comp.h"

#include "gltfpack.h"

struct BasisSettings
{
	int etc1s_l;
	int etc1s_q;
	int uastc_l;
	float uastc_q;
};

static const BasisSettings kBasisSettings[10] = {
    {1, 1, 0, 1.5f},
    {1, 6, 0, 1.f},
    {1, 20, 1, 1.0f},
    {1, 50, 1, 0.75f},
    {1, 90, 1, 0.5f},
    {1, 128, 1, 0.4f},
    {1, 160, 1, 0.34f},
    {1, 192, 1, 0.29f}, // default
    {1, 224, 2, 0.26f},
    {1, 255, 2, 0.f},
};

static void fillParams(basisu::basis_compressor_params& params, const char* input, const char* output, bool uastc, int width, int height, const BasisSettings& bs, const ImageInfo& info, const Settings& settings)
{
	if (uastc)
	{
		static const uint32_t s_level_flags[basisu::TOTAL_PACK_UASTC_LEVELS] = {basisu::cPackUASTCLevelFastest, basisu::cPackUASTCLevelFaster, basisu::cPackUASTCLevelDefault, basisu::cPackUASTCLevelSlower, basisu::cPackUASTCLevelVerySlow};

		params.m_uastc = true;

		params.m_pack_uastc_flags &= ~basisu::cPackUASTCLevelMask;
		params.m_pack_uastc_flags |= s_level_flags[bs.uastc_l];

		params.m_rdo_uastc = bs.uastc_q > 0;
		params.m_rdo_uastc_quality_scalar = bs.uastc_q;
		params.m_rdo_uastc_dict_size = 1024;
	}
	else
	{
		params.m_compression_level = bs.etc1s_l;
		params.m_quality_level = bs.etc1s_q;
		params.m_max_endpoint_clusters = 0;
		params.m_max_selector_clusters = 0;

		params.m_no_selector_rdo = info.normal_map;
		params.m_no_endpoint_rdo = info.normal_map;
	}

	params.m_perceptual = info.srgb;

	params.m_mip_gen = true;
	params.m_mip_srgb = info.srgb;

	params.m_resample_width = width;
	params.m_resample_height = height;

	params.m_y_flip = settings.texture_flipy;

	params.m_create_ktx2_file = true;
	params.m_ktx2_srgb_transfer_func = info.srgb;

	if (uastc)
	{
		params.m_ktx2_uastc_supercompression = basist::KTX2_SS_ZSTANDARD;
		params.m_ktx2_zstd_supercompression_level = 9;
	}

	params.m_read_source_images = true;
	params.m_write_output_basis_files = true;

	params.m_source_filenames.resize(1);
	params.m_source_filenames[0] = input;

	params.m_out_filename = output;

	params.m_status_output = false;
}

static const char* prepareEncode(basisu::basis_compressor_params& params, const cgltf_image& image, const char* input_path, const ImageInfo& info, const Settings& settings, TempFile& temp_input, TempFile& temp_output)
{
	std::string img_data;
	std::string mime_type;
	std::string result;

	if (!readImage(image, input_path, img_data, mime_type))
		return "error reading source file";

	int width = 0, height = 0;
	if (!getDimensions(img_data, mime_type.c_str(), width, height))
		return "error parsing image header";

	adjustDimensions(width, height, settings);

	temp_input.create(mimeExtension(mime_type.c_str()));
	temp_output.create(".ktx2");

	if (!writeFile(temp_input.path.c_str(), img_data))
		return "error writing temporary file";

	int quality = settings.texture_quality[info.kind];
	bool uastc = settings.texture_mode[info.kind] == TextureMode_UASTC;

	const BasisSettings& bs = kBasisSettings[quality - 1];

	fillParams(params, temp_input.path.c_str(),temp_output.path.c_str(), uastc, width, height, bs, info, settings);

	return nullptr;
}

void encodeImages(std::string* encoded, const cgltf_data* data, const std::vector<ImageInfo>& images, const char* input_path, const Settings& settings)
{
	basisu::basisu_encoder_init();

	basisu::vector<basisu::basis_compressor_params> params(data->images_count);
	basisu::vector<basisu::parallel_results> results(data->images_count);

	std::vector<TempFile> temp_inputs(data->images_count);
	std::vector<TempFile> temp_outputs(data->images_count);

	for (size_t i = 0; i < data->images_count; ++i)
	{
		const cgltf_image& image = data->images[i];
		ImageInfo info = images[i];

		if (settings.texture_mode[info.kind] == TextureMode_Raw)
			continue;

		if (const char* error = prepareEncode(params[i], image, input_path, info, settings, temp_inputs[i], temp_outputs[i]))
			encoded[i] = error;

		// image is ready to encode in parallel
	}

	uint32_t num_threads = settings.texture_jobs == 0 ? std::thread::hardware_concurrency() : settings.texture_jobs;

	basisu::basis_parallel_compress(num_threads, params, results);

	for (size_t i = 0; i < data->images_count; ++i)
	{
		if (params[i].m_source_filenames.empty())
			; // encoding was skipped or preparation resulted in an error
		else if (results[i].m_error_code == basisu::basis_compressor::cECFailedReadingSourceImages)
			encoded[i] = "error decoding source image";
		else if (results[i].m_error_code != basisu::basis_compressor::cECSuccess)
			encoded[i] = "error encoding image";
		else if (!readFile(temp_outputs[i].path.c_str(), encoded[i]))
			encoded[i] = "error reading temporary file";
	}
}
#endif