Runs the same compute shaders as the Vulkan backend, translated to MSL,
in the upload command buffer: levels decode unscaled into the push
buffer and get scaled into a view of the level. Push constants go in a
buffer of their own. Multipass shaders (NNEDI3) use scratch textures
that live for the frame.
Shaders with a constant buffer (only the smiley test shader) aren't
supported.
All the texture shaders give the same result as Vulkan's on LocoRoco
and God of War savestates.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Draws use an unretained encoder pointer and pipeline struct pointers
instead of passing ObjC objects around (each return goes through
autorelease and retain), and only bind the texture slots the fragment
shader uses. Brings the emu thread's retain/release work down to 0.6%,
and instruction counts 2-11% below Vulkan's on the benchmark states.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
GPU/Metal, modelled on GPU/Vulkan since the shaders are the same Vulkan
GLSL, translated to MSL. Drawing goes through the render manager's state
setters, so it shares encoders with thin3d.
thin3d fixes found along the way:
- Binding the framebuffer that's already the target continues the pass,
applying clears and ignoring DontCare, like VulkanRenderManager.
- Separate depth or stencil copies, through a buffer, so the stencil
survives a framebuffer resize (Need for Speed Shift).
- Stencil export, so stencil uploads take one pass.
Out of the 1061 dumps in ppsspp-framedumps, 1058 render identically to
Vulkan (two of the others are bad dumps), as do the eight benchmark
savestates.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
