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>
The view controller creates a Metal context when that's the configured
backend, and the backbuffer gets its size from the layer's bounds, as the
drawable size isn't set up yet when the surface is created.
Also pass --options the process was launched with (from Xcode or
devicectl) on to the command line parser, so --graphics=metal works.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Selectable with --graphics=metal, the backend choice in settings and the
Mac menu bar. SDL creates a Metal view for it, and headless renders
offscreen. Games run on the null GPU until there's a GPU/Metal.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
thin3d on Metal, plus a small render manager that owns frames, command
buffers, lazily started render passes and a per-frame push buffer.
Shaders are the same Vulkan GLSL the Vulkan backend gets, translated to
MSL through glslang and SPIRV-Cross, with the Vulkan binding numbers as
Metal buffer/texture indices. flip_vert_y makes Metal's clip space match
Vulkan's, so everything else follows the Vulkan conventions.
Adds GPUBackend::METAL (4) and builds the files on Apple platforms. Not
yet selectable: the SDL window setup, the UI choice and the GPU core
come next.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
