Pipeline states are created on compile threads, along with the shader
functions they need, which compile once on first use. Draws record a
handle to the pipeline state, and the render thread waits for it if it
gets there first, as with Vulkan, so the emu thread never waits for a
compile. Translation to MSL stays synchronous, as recording needs the
texture masks it produces.
Each game's shader IDs and pipeline keys are saved to a
<discID>.mtlshadercache, and recreated while the game boots. macOS's own
Metal cache then makes them quick: Wipeout Pure's 36 pipelines took
25 ms, or 260 ms with an empty Metal cache, instead of stalls during
play.
Cold Wipeout Pure, 5 emulated seconds from a savestate: 3.0 s before,
1.6 s with the background compiles alone.
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>
