GPU_Null derives straight from GPUCommon and has no thin3d context, framebuffer
manager, texture cache or shaders. It runs display lists with the flow control,
bounding boxes, matrix loads (the hardware backends'), immediate vertices and
block transfers of the others, moves the vertex and index pointers past each
draw and curve, and charges the per-vertex and fill cost the software renderer
does. A DrawEngineCommon that queues nothing provides the vertex decoders.
It's for measuring the CPU emulation. From savestates, God of War, Tekken 6,
Wipeout Pure and LocoRoco flip the same frames in 10 emulated seconds as with
Vulkan and software, in 44-77% fewer instructions than Vulkan.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
