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>
The render manager now records commands on the emu thread, keeping all
of its decisions there (lazy passes, clear merging, redundant state),
and they're encoded on a render thread, or inline when
bRenderMultiThreading is off, as in the Vulkan backend.
Before encoding, passes to the same framebuffer are merged across
independent work, by the rules of VulkanQueueRunner's render pass merge.
God of War alternates with block transfers to other framebuffers, and
went from about 41 to 18 render passes a frame, which more than halved
its GPU time.
Passes where nothing tests or writes depth or stencil leave the
attachment unloaded and unstored, like the Vulkan backend, which
doesn't attach depth then.
On the eight benchmark states, Metal now uses 4-13% less CPU than
Vulkan, with wall times from 6% faster to 4% slower.
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>
Resources that the GPU may still use are now released through the render
manager's per-frame list, freed once the frame's work completes, instead
of command buffers retaining everything that's bound.
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>
