Function store_image_block

Source/astcenc_image.cpp:345–573

See header for documentation. */

/* See header for documentation. */
void store_image_block(
	astcenc_image& img,
	const image_block& blk,
	const block_size_descriptor& bsd,
	size_t pos_x,
	size_t pos_y,
	size_t pos_z,
	const astcenc_swizzle& swz
) {
	size_t size_x = img.dim_x;
	size_t start_x = pos_x;
	size_t end_x = astc::min(size_x, pos_x + bsd.dim_x);
	size_t count_x = end_x - start_x;
	size_t nudge_x = bsd.dim_x - count_x;

	size_t size_y = img.dim_y;
	size_t start_y = pos_y;
	size_t end_y = astc::min(size_y, pos_y + bsd.dim_y);
	size_t count_y = end_y - start_y;
	size_t nudge_y = (bsd.dim_y - count_y) * bsd.dim_x;

	size_t size_z = img.dim_z;
	size_t start_z = pos_z;
	size_t end_z = astc::min(size_z, pos_z + bsd.dim_z);

	size_t idx = 0;

	// True if any non-identity swizzle
	bool needs_swz = (swz.r != ASTCENC_SWZ_R) || (swz.g != ASTCENC_SWZ_G) ||
	                 (swz.b != ASTCENC_SWZ_B) || (swz.a != ASTCENC_SWZ_A);

	// True if any swizzle uses Z reconstruct
	bool needs_z = (swz.r == ASTCENC_SWZ_Z) || (swz.g == ASTCENC_SWZ_Z) ||
	               (swz.b == ASTCENC_SWZ_Z) || (swz.a == ASTCENC_SWZ_Z);

	if (img.data_type == ASTCENC_TYPE_U8)
	{
		for (size_t z = start_z; z < end_z; z++)
		{
			// Fetch the image plane
			uint8_t* data8 = static_cast<uint8_t*>(img.data[z]);

			for (size_t y = start_y; y < end_y; y++)
			{
				uint8_t* data8_row = data8 + (4 * size_x * y) + (4 * start_x);

				for (size_t x = 0; x < count_x; x += ASTCENC_SIMD_WIDTH)
				{
					size_t max_texels = ASTCENC_SIMD_WIDTH;
					size_t used_texels = astc::min(count_x - x, max_texels);

					// Unaligned load as rows are not always SIMD_WIDTH long
					vfloat data_r(blk.data_r + idx);
					vfloat data_g(blk.data_g + idx);
					vfloat data_b(blk.data_b + idx);
					vfloat data_a(blk.data_a + idx);

					// Clamp values to [0.0, 1.0] range before unorm conversion