Method Rasterizer

PanzerChasm/client/software_renderer/rasterizer.cpp:14–84

{

Rasterizer::Rasterizer(
	const unsigned int viewport_size_x,
	const unsigned int viewport_size_y,
	const unsigned int row_size,
	uint32_t* const color_buffer )
	: viewport_size_x_( int(viewport_size_x) )
	, viewport_size_y_( int(viewport_size_y) )
	, row_size_( int(row_size) )
	, color_buffer_( color_buffer )
{
	{ // Setup depth buffer and depth buffer hierarchy.
		unsigned int memory_for_depth_required= 0u;
		depth_buffer_width_= ( viewport_size_x + 1u ) & (~1u);
		const unsigned int depth_buffer_memory_size= depth_buffer_width_ * viewport_size_y;
		memory_for_depth_required+= depth_buffer_memory_size;

		for( unsigned int i= 0u; i < c_depth_buffer_hierarchy_levels; i++ )
		{
			const unsigned int hierarchy_cell_size= c_first_depth_hierarchy_level_size << i;
			depth_buffer_hierarchy_[i].width = ( depth_buffer_width_ + ( hierarchy_cell_size - 1u ) ) / hierarchy_cell_size;
			depth_buffer_hierarchy_[i].height= (    viewport_size_y_ + ( hierarchy_cell_size - 1u ) ) / hierarchy_cell_size;

			memory_for_depth_required+= depth_buffer_hierarchy_[i].width * depth_buffer_hierarchy_[i].height;
		}

		depth_buffer_storage_.resize( memory_for_depth_required );

		unsigned int offset= 0u;
		depth_buffer_= depth_buffer_storage_.data();
		offset+= depth_buffer_memory_size;

		for( unsigned int i= 0u; i < c_depth_buffer_hierarchy_levels; i++ )
		{
			depth_buffer_hierarchy_[i].data= depth_buffer_storage_.data() + offset;
			offset+= depth_buffer_hierarchy_[i].width * depth_buffer_hierarchy_[i].height;
		}
	}
	 // Setup occlusion buffer
	{
		const unsigned int top_hierarchy_level_cell_size= 16u << ( (c_occlusion_hierarchy_levels-1u) * 2u );
		const unsigned int top_hierarchy_level_cell_size_minus_one= top_hierarchy_level_cell_size - 1u;
		const unsigned int viewport_size_x_ceil= ( viewport_size_x + top_hierarchy_level_cell_size_minus_one ) / top_hierarchy_level_cell_size * top_hierarchy_level_cell_size;
		const unsigned int viewport_size_y_ceil= ( viewport_size_y + top_hierarchy_level_cell_size_minus_one ) / top_hierarchy_level_cell_size * top_hierarchy_level_cell_size;

		// Main buffer
		occlusion_buffer_width_ = viewport_size_x_ceil / 8u;
		occlusion_buffer_height_= viewport_size_y_ceil;
		occlusion_buffer_storage_.resize( occlusion_buffer_width_ * occlusion_buffer_height_ );
		occlusion_buffer_= occlusion_buffer_storage_.data();

		// Hierarchy
		unsigned int hexopixels_requested= 0u;
		for( unsigned int i= 0u; i < c_occlusion_hierarchy_levels; i++ )
		{
			auto& level= occlusion_hierarchy_levels_[i];
			const unsigned int heirarchy_cell_size= 16u << ( i * 2u );
			level.size[0]= ( viewport_size_x_ceil + ( heirarchy_cell_size - 1u ) ) / heirarchy_cell_size;
			level.size[1]= ( viewport_size_y_ceil + ( heirarchy_cell_size - 1u ) ) / heirarchy_cell_size;