Function encodeVertexBlock

SHTest/Externals/meshoptimizer/vertexcodec.cpp:264–297

}

static unsigned char* encodeVertexBlock(unsigned char* data, unsigned char* data_end, const unsigned char* vertex_data, size_t vertex_count, size_t vertex_size, unsigned char last_vertex[256])
{
	assert(vertex_count > 0 && vertex_count <= kVertexBlockMaxSize);

	unsigned char buffer[kVertexBlockMaxSize];
	assert(sizeof(buffer) % kByteGroupSize == 0);

	// we sometimes encode elements we didn't fill when rounding to kByteGroupSize
	memset(buffer, 0, sizeof(buffer));

	for (size_t k = 0; k < vertex_size; ++k)
	{
		size_t vertex_offset = k;

		unsigned char p = last_vertex[k];

		for (size_t i = 0; i < vertex_count; ++i)
		{
			buffer[i] = zigzag8(vertex_data[vertex_offset] - p);

			p = vertex_data[vertex_offset];

			vertex_offset += vertex_size;
		}

		data = encodeBytes(data, data_end, buffer, (vertex_count + kByteGroupSize - 1) & ~(kByteGroupSize - 1));
		if (!data)
			return NULL;
	}

	memcpy(last_vertex, &vertex_data[vertex_size * (vertex_count - 1)], vertex_size);

	return data;
}

#if defined(SIMD_FALLBACK) || (!defined(SIMD_SSE) && !defined(SIMD_NEON) && !defined(SIMD_AVX) && !defined(SIMD_WASM))
static const unsigned char* decodeBytesGroup(const unsigned char* data, unsigned char* buffer, int bitslog2)