Graphics Processor Fast Clears for 3D MSAA Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current graphics processing technologies face inefficiencies in memory bandwidth usage during operations like multi-sample anti-aliasing (MSAA) resolve, texture initialization, and mipmap generation, as they do not effectively utilize cleared status in source textures, leading to suboptimal performance and increased resource consumption.
Innovation Solution
Implementing hardware-supported fast clears and a control surface for render targets, which store metadata about sample locations or constant clear colors, allowing for reduced memory bandwidth consumption by preserving the state of cleared pixels and recognizing background colors as constant, thereby optimizing MSAA resolve and texture initialization processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional pixel shader sampling is used for MSAA resolve and texture initialization, then color compression is achieved, but memory bandwidth consumption increases and cleared status is not utilized
Solution Approach 1:
The system performs preliminary actions by setting cleared status flags on texture resources before MSAA resolve or initialization operations. This allows the graphics processor to recognize which pixels are already cleared and skip redundant sampling operations, reducing memory bandwidth consumption while maintaining processing efficiency.
Solution Approach 2:
The invention changes the parameter space by introducing cleared status flags and control surfaces that track the state of texture resources. This enables the pixel shader to receive additional information about which pixels are cleared, allowing optimization of the sampling process and reduction of memory bandwidth usage without sacrificing rendering quality.
2Productivity
If all texture pixels are sampled and written to destination, then complete texture initialization is achieved, but memory bandwidth and processing resources are wasted on already cleared pixels
Solution Approach 1:
Instead of fully sampling and writing all texture pixels to the destination, the system applies partial action by only processing pixels that need initialization. The cleared status flags enable the graphics processor to identify and skip already-cleared pixels, performing only the necessary minimum operations to achieve complete initialization without wasting resources on redundant operations.
Solution Approach 2:
The texture resource management system serves itself by automatically tracking and maintaining cleared status information. This self-service mechanism eliminates the need for manual tracking of cleared pixels, allowing the graphics processor to autonomously optimize its sampling behavior based on the stored status information.
3Ease of operation
If simple average of samples color is output to destination, then color compression is achieved, but cleared status information is not utilized for optimization
Solution Approach 1:
The control surface structure serves multiple functions simultaneously: it stores cleared status information, provides sample location metadata, and enables optimization of both color compression and rendering performance. This multi-functional approach allows the system to maintain color compression capabilities while leveraging cleared status information to improve rendering efficiency.
Solution Approach 2:
The system implements feedback by using the cleared status flags and control surface information to guide the pixel shader's sampling and writing operations. This feedback mechanism allows the rendering pipeline to adapt its behavior based on the state of texture resources, optimizing both color compression and performance by avoiding redundant operations on cleared pixels.
Data Source
AI summary
One embodiment provides a graphics processor comprising a hardware graphics rendering pipeline configured to perform multisample anti-aliasing, the hardware graphics rendering pipeline including pixel processing logic to determine that each sample location of a pixel of a multisample surface is associated with a clear value and resolve a color value for the pixel to a non-multisample surface via a write of metadata to indicate that the pixel has the clear value. The resolve can be a stenciled resolve that automatically bypasses execution of a pixel shader for pixels having clear color data.