Graphics Infrastructure Development of Full-Display-And-Render-Driver for Raspberry Pi 4 running Windows 10
The solution is in an experimental state and has untested code which is intended for 8x QPU cores.
Alongside this test are full skeleton boilerplates for DxgkDdi and D3dDdi aiming for WDDM 2.6 support.
Documentation for DXVA 2.0 has also been included in the hope that the H.264 hardware will be of use.
Direct3D presents the following HLSL-Based infrastructure to applications and graphics hardware:
- Vertex Shader - Handles individual points in 3D space for the next pipeline stage
- Pixel/Fragment Shader - Handles shading of 2D face regions marked by groups of points in 3D space
- Hull Tessellation Shader - Maps the vertices to 3D texture constructs called Patches
- Domain Tessellation Shader - Collects vertices from smoothing functions (e.g. Bezier) created from the patches
- Geometry Tessellation Shader - Applies Stream Modifiers to the vertices to conform to a certain shape
- Compute Shader - A Multi-purpose re-programmable Shader capable of performing user-specified procedures
- Input Assembler - Manages ID's of all of the constructs passed through the pipeline
- Constant/Uniform Buffer - Data Input Area that remains the same during the lifecycle of a shader
- Counter/Scoreboard - Keeps track of completed and pending operations in the pipeline
- Tiles/Bins - A method for dividing the work equally and fairly over multiple cores
- Rasterisation - Reproducing the final image from the output of the pipeline
- Viewport - Data Output Area of certain dimensions and location that receives the final image
- Resources - Abstraction for Data and Processes that shaders may be able to consume or copy
- Command Lists - Sequencing and Macro Control of collections of multiple graphics processes
- Query Interface - Filtering and Selection of Data based on Predicate Logic and Query Language
- States & Caches - Behaviour of current processes conditional on previously stored data labels
- Video Codecs - Converting Audio-Visual Data from one format to another on-batch and real-time
These Drivers can take one of these major forms:
- Infrastructure Driver - Connects with C-Style Method Callbacks [CB] (e.g. DirectX)
- Interface Driver - Connects with File Pipes and Socket-Based I/O Control Codes [IOCTL] (e.g. OpenGL)
- Compiler Driver - Connects with a String-Based Language and Memory Mapped I/O [MMIO] (e.g. Vulkan)
- Diagnostic Driver - No Connection to Hardware, only Serial Port Logging [UART] (e.g. Software Emulation)
- The Raspberry Pi 4's 16x QPU cores must be connected to a DirectX Render Class Driver.
- The Raspberry Pi 4's H.264, VPU and ISP cores should connect to DirectX Video Acceleration.
- The QPU Example Code in the hello_fft Raspberry Pi Userland Sample has partially been ported.
- The H.264 Example Code in the hello_video Raspberry Pi Userland Sample should be ported.
- Power and Clock Domain Management should also be a consideration in developing compliant drivers.
- Any other hardware ties that can be made available to Windows with frameworks should also be included.