WIP: fix(macos): the mesh fallback's rotation follows the count draws and the growing records area #708
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Type: fix · Risk: medium · Tested on: macOS 26.7.1, Apple M4 Max (MoltenVK 1.4.2), arm64 and x86_64 under Rosetta · Needs: macOS, Apple silicon (a start to play on the rebased stack); Windows and Linux, any GPU on the compute fallback (build and start)
Why
#703 draws a dependent triangle program's mesh fallback on the Mac through a static rotation list (each triangle's last
corner first), as one indexed command read from offset 0 of the records buffer, the list sized to the first 64 MB records area.
#707 gives the fallback count draws (maxDrawCount commands in the arena, at
fallback_draw_offset) and a records area thatgrows. Together, a rotated count draw would read the arena's offset 0, and a grown area's corners would lie past the list (an index
read out of range). This PR joins the two: the rotation follows the count draws and the growing area, exactly, on macOS without
provokingVertexLast. It carries Integration 37's interim guard (which drew those draws unrotated) and replaces it in the same PR.It is part of the macOS port. See #420.
How to reproduce
Seen on: macOS 26.7.1, Apple M4 Max, MoltenVK 1.4.2
Settings and switches: defaults
Steps: probe MP-01's
RAWarms (standalone MoltenVK process; command inreports/2026-11-14-mesh-provoking.md§4): the meshfallback's single and count draws of a program with a flat input, areas grown past the first, the allowance holding the list back
Expected: every pixel takes its triangle's last corner (NVN's vertex), as a rotated single draw in the first area does
Actual: without this PR's rotation the count draws and grown areas take the first corner
What changed
All of it only where
provoking_first()holds (macOS, a device withoutprovokingVertexLast). Every other driver draws the fallbackas #707 alone does: the header carries the area's own words, the commands are 16 bytes.
fallback_record, after the buffers and pipelines:provoking_fallbackreturns aFallbackRotation(thelist, its corners, why a draw is kept, the area words the header carries); draw() draws and counts it (
provoking_fallback_drawn).provoking::fallback_corners, the epilogue's fit); past the first area's corners it growsonly when
mesh_area::affordableholds againstvram_usage(the area's own rule), else it stays at the first area's corners.provoking::fallback_area), sothe epilogue cuts the corners past it as past the area and the census counts them: no index past the list is read. Such draws are
logged at error level (the line says how many corners the list covers of how many the area holds) and counted on the
vk: provoking vertexline. Only then: an area whose last words hold less than a record keeps its own words (cc22ddfd,MeshProvoking's
79e2e006). Before it, a list of exactly the corners the area holds set the header to the list's words, the arealess its remainder (2^24 mod 27 = 10 words, mod 22 = 16): the same fit, so no corner was dropped, but every such draw was counted and
logged as cut. Start #32 (I38) counted 53,047 of them, with 69 error lines, each 10-16 words off the 16,777,216-word area, while the
mesh fallback's census of corners past the area stayed 0: 0 corners lost. What is drawn is the same for every draw.
VkDrawIndexedIndirectCommands 20 bytes apart: first instance 0 by one fill, then per record theheader's draw words copied over it (firstIndex the record's first corner); draw() binds the list once and draws them in the same loop
at
fallback_draw_offset.gpu/vk/vk_draw.cpp,gpu/vk/provoking.h,gpu/vk/VULKAN.md; tests:tests/test_mesh_provoking.py+tests/mesh_provoking_test.cpp(new),test_provoking_first,test_mesh_count_fallback,test_mesh_area,test_mesh_census,test_mesh_drawid,test_mesh_fallbackfollow the moved code;tests/seg_xfer_test.cppstands in the decision.Measurements
Verdict: fixed where measured: in MP-01 every step's image with this PR equalled the reference (each record drawn rotated on its own)
byte for byte, and the unrotated draw differed wherever anything was drawn; cut steps cut exactly the predicted corners. No per-draw
cost showed at this size.
Baseline: main does not start on macOS. MP-01 compares this PR's path (
A), a reference (REF) and the unrotated draw (RAW) in onestandalone MoltenVK 1.4.2 process.
Hardware: macOS 26.7.1, Apple M4 Max (40-core GPU), MoltenVK 1.4.2, 16-core CPU, 64 GB
Scene: MP-01: 22 steps: task + mesh and mesh-only, counts 0, 1, 16 and past, 1 and 3 commands a call, grown areas, the allowance
cutting, single draws
Method: MP-01
reports/MeshProvoking-files/mp01/runs-mp01-arm64/result.json(3d518854…),probe.log(f3879227…), released once onarm64
How to reproduce: MP-01's
runcommand (reports/2026-11-14-mesh-provoking.md§4)6c9edffe(unrotated, RAW)Start #32 (I38, with MeshProvoking at
3f872b0c, before this head's area fix): 53,047 rotated fallback draws logged as cut (69 errorlines, each 10-16 words off the 16,777,216-word area) while the census of corners past the area stayed 0: false cuts, 0 corners lost.
cc22ddfdstops counting and logging them; what is drawn is unchanged.Flags and settings
None: no switch. On macOS, on a device without
provokingVertexLast, only.Testing
Tested: on macOS 26.7.1, Apple M4 Max, at this head (main
6c9edffeplus #703, #707 and what they carry):cc22ddfd:tests/test_mesh_provoking.pywith/usr/bin/clang++andclang++ -arch x86_64(Rosetta): pass, 96 cases, 459,046checks, 0 failures (23,788 triangles rotated, 198 draws cut to the list, 132 draws on areas with a remainder not cut), 11 of 11
mutants killed (among them provoking-first's draw from offset 0, the interim guard and
56c09f1b's area trim, run #32's false cuts).With the head's tests on
56c09f1b(this PR before the area fix) it fails on both arches (a remainder, words 31 …: the header carries the area, or what the list covers).test_provoking_first,test_mesh_count_fallback,test_mesh_area,test_fan_key(each arm64 and x86_64) and
test_seg_xfer(--arch arm64,--arch x86_64): pass (reports/PubWave-files/PubNext/proof-mp-01/).At
56c09f1bthe test (86 cases, 10 mutants) also failed on this stack's joincfe4c014(reports/PubWave-files/PubLate4/proof-02/).gpu/vk/vk_draw.cppcompiled whole atcc22ddfdfor arm64 and x86_64 with main's renderer flags (#476's, #492's and #490's macOScompile pieces merged in a scratch tree only): exit 0 (
reports/PubWave-files/PubNext/compile/mesh-provoking-cc22ddfd/); at56c09f1bvk_draw.cpp,vk_replay.cppand the SPIR-V back-end files #707 changes: 12 objects, exit 0(
reports/PubWave-files/PubLate4/compile/mesh-provoking/).cfe4c014..56c09f1b):vk_draw.cppandprovoking.hdiffer, butprovoking_fallbackreturns the area's ownwords at its first statement (
provoking_first()is false there) (reports/PubWave-files/PubLate4/offapple-mesh-provoking-own.txt).Not tested: a game start with this stack (main does not start on macOS by itself); not built on Windows or Linux; its test request
covers it.
Must be tested:
vk: provoking vertex (…)lines with themesh fallback's draws rotated and none cut (by hand: the parent's game run).
cc22ddfd, it carries #703, #707 andwhat they carry) and #707's head the same way, start each to the title, expecting the same mesh lines and no
vk: provoking vertexline (by hand: test request T-XXXX).Risks
What could break: on macOS only: one fill per rotated count draw; a CPU-filled list that grows with the area (4 bytes a corner: a
128 MB area at 31 words is a 16 MB list), made once a growth and kept; where the allowance holds the list back, the corners past it are
cut (logged and counted), not drawn unrotated.
Turning it off: revert the PR (no switch).
Compatibility: Nothing changes for players outside macOS beyond #707. No file in the shader stamp changed by this PR's
own commits (
5f17d46487bac8f5, #707's). NoMKWVK_API_VERSIONchange.Reviewer notes
b8194380), with #707 merged in: reviewcfe4c014..cc22ddfdfor this PR's own work;cfe4c014is the merge (resolved as Integration 36/37 did,dcf593d9: both includes and reports; the fallback draw keeps the rotateddraw, otherwise MeshCountDraws' commands at
fallback_draw_offset; the counts carry both).b8f1bfe2= Integration 37'seb4d0204(theinterim guard: count draws and grown areas drawn unrotated), without its parts that need PRs not in this stack (the indirect quads'
sixth
provoking_notesite withtest_quad_draws,test_perf_lines,test_fan_indirect: sibling items, below);ff27435f=85675f30(seg_xfer_test.cppstands infallback_draw_area);88d2d2b3=macos/mesh-provoking3f872b0c(MP-01's code; theguard and
fallback_draw_areagone;VULKAN.mdwithout IndirectQuads' quads paragraph).56c09f1b(macOS only): MeshProvoking's two new functions asked the device alone; they now askprovoking_first(), as#703's other gates (tests and the fixture follow; the mutant that drops the gate still fails).
cc22ddfd= MeshProvoking's79e2e006(-x):provoking::fallback_arealeaves the area whole unless the list holds fewercorners than the area does (
n < area / words), so only a draw whose fit the list shrinks is counted and logged as cut; the errorline names the corners the list covers and the corners the area holds. Picked with one conflict, a doc comment of
provoking_fallback_drawn(56c09f1b's "Windows and Linux" kept); its code and test lines are the topic's line for line.39da60e1): with #705, the indirect quads' count getsprovoking_note(six sites intest_provoking_first); with #702, one line oftest_fan_indirect; with #704,test_perf_linesreadsprovoking_noteon the count lines andfallback_record_countsaysMeshFallback.Issues
See #420
Checklist
Everyone
type(scope): description) of the status line's type.main(maine090cc48).python -I -B tests/run_all.pypasses (any failure that also fails onmainis named). (On the wave's merge39da60e1= the nine late renderer PRs' heads (fan-key592cd8d3, fan-indirectfa6dd43a, provoking-firstb8194380, perf-instrea90d3ca, readback-whole-waits203b8b7c, fix/indirect-quadsc6e0c37f, indirect-quads978079d4, fix/mesh-count0a61a9e7, mesh-provoking56c09f1b) with their sibling fixes: 570 passed, 31 failed, 18 skipped against main 6c9edffe's 531/32/17 on this Mac; the 31 failures are main's own and nothing that passes on main fails;test_collect_widenow passes; 38 new tests pass;reports/PubWave-files/PubLate4/wave4/full-39da60e1/. This head's last commitcc22ddfdcame after that suite; the tests it touches and the narrow mesh and provoking tests pass at the head on both arches:reports/PubWave-files/PubNext/proof-mp-01/.)third_party/untouched (a new folder with aPROVENANCE.mdinstead).When it applies
Assisted-by:/Co-Authored-By:trailers.mainand passing here.tests/that reads changed source updated in this PR, not weakened.Every scan down vk_memory.cpp's import table by start (pool_lookup's covering import and merge plan, bg_drain, prefetch_chunks, import_in_background, memory_note_gpu_write and memory_guest_imported) stopped once an import ended more than 1 GiB below its address, on the belief that no import is larger than that. pool_lookup's own merge escape leaves an import above 1 GiB over the smaller ones inside it ("left overlapping"), and the device allows imports up to max_import_size: a scan stopped at a small import inside a large one, missed the large one, and the same bytes were imported again, two memories over the same bytes. import_reach.h counts the live imports by span class; its bound is above every live span, within twice the largest. imported_add and imported_take, now the table's only ways in and out, keep the count. A scan stops only where no import further down can reach its address, so it also stops sooner than before when the imports are small. The covering-import checks in pool_lookup and import_in_background look past the last import at or below the range for the same reason. Tests: test_import_reach.py runs the actual scans with a 4 GiB import over a 16 MiB chunk, left by the merge escape (imports are recorded ranges: no payload, no Vulkan, no game). Its lookup, query, note, drain, background and prefetch cases fail on main5e072fc8and pass here, and a source check keeps every change to the table in the two helpers. test_import_windows runs pool_lookup with the helpers; test_mirror_gpu_only names the new publication point. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]>044635ea added vma_startup_rollback (vk_vma.cpp, run after a failed replay_start), which calls vmaDestroyAllocator. vk_vma.cpp includes vk_work.h last so that RX_VK_RECORDER=defer/thread drains before its destructions, and every such boundary call in a vk_work.h file must be in RX_REC_BOUNDARIES with a drain-first macro. This one was not, and test_recorder_sync caught it ("vk_vma.cpp calls ['vmaDestroyAllocator'], which vk_work.h does not drain before"): it passes at 58c5c5aa (044635ea's parent) and fails at 044635ea. Add it to the list and to vk_work.h, next to vmaDestroyBuffer and vmaDestroyImage. With the recorder off (the default) boundary() is a relaxed load and a branch. Rollback runs before any image or buffer exists, so nothing should be held there today, but the allocator is no longer destroyed while a recorder could still hold packets. The test is unchanged (sources: 42 boundaries drained, was 41). Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]>A guest span larger than one device allocation (the cap on MoltenVK/M4 Max is 41,747,087,360 bytes) is bound as pieces: one descriptor per allocation segment, at the descriptor's own binding (reports/2026-11-14-full-range-design.md sections 4.1-4.4). This is the shader half; the draw side (descriptors, layout, gathers) comes later. - runtime_info.h: SegEntry {Storage|Table|TexBuf|ImgBuf, desc, pieces} and RuntimeInfo::segmented. - Back end: a segmented storage buffer is an array of pieces at its binding (a table count * pieces, entry k's piece j at k * pieces + j); its loads, stores and atomics call DontInline helpers made after main, which find the piece by the pieces' OpArrayLength in order, with constant indices. The global memory fallbacks sum the pieces' lengths for a segmented descriptor's bound end and branch to its piece (single, native candidate, table written out and in the loop). Texel and image buffers are arrays too, their fetches, reads, writes and atomics through helpers that pick the piece by OpImageQuerySize, and a texel buffer's size query sums the pieces. ImageQuery was declared for every module already. With RuntimeInfo::segmented empty nothing new is made: the SPIR-V is byte-identical. - vk_shader: SegSig (entries, hash) on Program, seg_sig and seg_variant; program_segmented finds or translates the variant of a plain program with plain's texture questions and answers and checks its descriptors are plain's; program_pick, mesh_program_locked, program_find_plain, loaded_variants and portable_variant keep the plain and segmented variants apart; every stage's RuntimeInfo::segmented comes from Program::seg. - vk_progcache: a segmented variant is never written to the program cache nor listed among the loaded programs. - tests/test_seg_shader.py + tests/seg_shader_ir.cpp: synthetic IR programs through the real back end, plain and segmented; structure checks, spirv-val (Vulkan 1.3, uniform buffer standard layout), and with --base-tree a byte comparison of the plain modules against an older tree. Five source-reading checks follow the new Program field and the atomics' new branch. The translator stamp changes with this (eden/, vk_shader.cpp, sizeof(Program)): every program cache is rebuilt once. Land it in the same release as the vk_api.h change that already does so. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit b7928876dab846485f667c1c934d34d25ecef035)The interfaces the four segmented-consumer lanes (SegBind, SegXfer, TexelDesc, NullShader; reports/2026-11-14-seg-consumer-plan.md section 3) code against, frozen before they fork. Inert: no caller of anything new, no SPIR-V, layout, push range or stream change, sizeof(Program) unchanged. - vk_internal.h / vk_memory.cpp, SegMem's consumer interface: gpu_span_any() (a relaxed count of the live domains, stored in seg_commit; domains are kept for the run), gpu_span (gpu_buffer's flavour of gpu_span_bind: import buffers, no written marks, no mirror), SpanLayout::bind_stamp (gpu_bind_stamp(): a segment can be imported again with its cuts kept, so cut_gen alone never keys piece buffers), span_unused_piece's semantics ({null_storage, 0, 1}), and the SegArena API (SegArenaRef, seg_arena_take, seg_gather, seg_scatter; stub bodies after stream_alloc that give no room and log, SegBind's to fill). - Review fixes in the same interface (renderer-core review P2-3, P3.2): every piece of gpu_span_bind carries its buffer's device address (the import's or the mirror's; 0 only with bufferDeviceAddress off), and its one-piece path stores the translated guest address, not a virtual one. - vk_texture.h/.cpp: texel_view_pieces / texel_piece_views, stubs that return 1 and false (TexelDesc's to fill). - vk_shader.h: Program::presence_words, in what was padding. - Back end: PRESENCE_PUSH_OFFSET (88), Profile::emulate_null_descriptors, Bindings::presence / presence_read with the bit numbering rule. - tests: test_resolver_coverage lists gpu_span_bind / gpu_span sites too (scoped to gpu/vk: gpu/render has an rx::gpu_span of its own), checks that gpu_span follows its own gpu_buffer, and splits SITES into SITES_BASE plus one block per lane. test_segmented_domains executes the contract (the count 0, 1, 2 -> 1 on a merge, 0; gpu_span's pieces; addresses with the fixture's gpu_buffer_bind returning none as the real one does; the bind stamp; a virtual address's guest). test_seg_shader accepts a base tree of this back end's generation and compares every module. - docs/segmented-binding.md: the gate (every new behaviour Apple-only, other platforms byte-identical) and one heading per lane. Conflict on this branch (not with main): tests/test_seg_shader.py's docstring, against the array_pointer_calls paragraph #P20's msl-arrayptr port added; both kept, this paragraph first. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit 95fa06d4e6526601bd2e1bc88c2f8f5720855350)The segmented single storage array's case (plan 4.3 item 5) had no negative: the check always cut its own tree. With --source <B2 archive> it fails as required ("moltenvk.segmented_single want=set got=push"). Conflict with #P28 (read_write textures; not with main): the docstring keeps #P28's paragraph with this usage line, and main() cuts from --source's vk_draw.cpp with #P28's read_write count (as in the macOS integration, Integration 17). Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit 5824f6828e21cf810dcceaa6be425a9224b15994)plaine37c097da2plaina997b3629aKosmicKrisp has no fillModeNonSolid and MoltenVK no POINT polygons, and Metal restarts an indexed strip or fan at the all-ones index whatever Vulkan's restart enable says. Before anything is fixed, count whether the game needs it (mode_census.h, Apple only; nothing built or drawn changes): - the graphics pipelines built, where st_pipelines counts them, and the draws recorded, where st_draws counts them, by NVN's polygon mode, with the first 8 LINE and POINT pipelines (program, pipeline key, topology) and programs named; - the indexed strip and fan draws with restart off; a direct one's indices are read whole, a page at a time, through memory_read_as_submitted for the index type's all-ones value (0xFF, 0xFFFF, 0xFFFFFFFF). An indirect one's range is the GPU's and a range the CPU cannot read is not guessed: both are counted as not scanned. Any other draw costs restart_off_strip's compares and its polygon mode's count on the thread's own counters. Printed with the frame statistics every 120 presents ("at present N") and at close ("at close"). The two tests that compile build_graphics and draw()'s binds from the source get a stand-in for the counts. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit 1bd30dceb348909ca03c4cf12709dccbb0900f4a)DI-01 (reports/2026-11-14-drawid-direct.md) ran the direct and one-record indirect forms on MoltenVK 1.4.2: the indirect form was exact in every shape (0 stale of 3,744 draw indices), and the direct plain, indexed and quad draws read stale words, but tessellated direct draws read draw index 0 (64 of 64, with update tags in the pool) while their indirect form took about 135 MB of GPU memory and 3 ms of submit a draw. So 3f1ee3da's choice to keep them direct stands, and the error line it logged for each ("writes a direct draw's draw index to the wrong word") was wrong for them: they are now counted in the vk: direct draws line only, as fans are (0 of 64 stale direct in DI-01). drawid_direct.h and VULKAN.md give DI-01's numbers; the fixture expects an error line only for a first instance without drawIndirectFirstInstance. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit 0a6956568f871c66b08c29dffc0a1b9614dfb5de)The mesh fallback draws one record a corner, in its mesh program's primitive order. On a device without provokingVertexLast, for a program that depends on the provoking vertex, its vertex draw is now vkCmdDrawIndexedIndirect of the same header through a static index list that reads each triangle's corners {2, 0, 1} and each line's {1, 0} (provoking::rotation): the last corner first, the winding kept. The list covers the program's record capacity (MESH_FALLBACK_RECORD_WORDS / fallback_record_words, the epilogue's fit), made once per corner count and larger when needed. The header {count, 1, 0, 0} reads as the indexed record; its fifth word, the allocator, is a first instance nothing reads (the generated vertex stage reads only its vertex index and the pipeline has no vertex input), so it needs drawIndirectFirstInstance, else the draw is drawn as before, logged. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit 1aced9b7e8b5458befea4dfc38df305913332ebc)provoking_list wrote the list into the recording's stream before the pipeline was chosen, ahead of the memory admission. The admission can hand the draw to a new recording (vk_replay.cpp admission_handoff: the old one submitted and waited, a new slot begun), which then bound an index range in the old slot's stream; that stream is rewritten when the old slot is reused, possibly while the new recording still reads it. A draw left out after the decision (no pipeline yet, a segmented variant lost) also counted a list it never drew. - provoking_list decides (the same conditions; room for the list in the stream now, stream_reserve; the game's indices read on the CPU as submitted, held by the list in the thread's lent buffer) and writes nothing. - provoking_write, at the draw (after the admission and the pipeline), allocates the list in the stream of the recording the draw is in and converts into it; the draw binds that buffer. If the stream cannot grow there (device memory), the draw is left out, logged at error level and counted ("left out, no room for the list in the stream at the draw"), since its pipeline is the list's. - listed counts the lists drawn, at the draw. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit 16216adc33ff7081bb3a0d3b687fbee947cb6519)592cd8d3) into the provoking-vertex branch 77e57c6e92On a GPU without VK_EXT_mesh_shader (MoltenVK, KosmicKrisp, AMD under Linux by default, Navi 21/22 task + mesh programs on Windows, GTX 10xx, RX 5000) task and mesh programs run as compute dispatches (issue 640), and fallback_record left every MultiDrawMeshTasksIndirectCount out: no dispatch takes a count, and each record needs its own draw index (reports/2026-11-14-mesh-gap.md 3.1-3.2). - count_draws.h and shaders/count_draws_record.glsl are generalized: a Layout reads copy_words words of a record and writes them, then `ones` words of 1. count_draws::plain(indexed) is the count draws' (every word copied, no ones: their records are byte for byte as before); count_draws::mesh() reads a record's count word and writes {count, 1, 1} under the count, {0, 0, 0} past it. The push block is eight words; the SPIR-V header is regenerated (glslang 16.6.0). - vk_draw.cpp count_rewrite_records holds the rewrite's commands (two full barriers, chunks, push descriptors); count_rewrite gives it the plain layout as before. - fallback_record_count: the records and count bound as draw_demands admits them (records across a segment's cut gathered into the arena), the header reset with the census row, the records rewritten into dispatch records, then per record i: its draw command emptied and its first vertex set to the allocator (i > 0; the allocator is never reset, so record i's draw command covers exactly the records its workgroups took), draw index i and its own record as the task's input pushed, the task (or mesh-only) dispatch indirect from dispatch record i, the mesh dispatch from the header, the command copied into the arena, a full barrier between steps. draw() then draws maxDrawCount commands with vkCmdDrawIndirect in one pass (one pass break a count draw), in record order, inside the occlusion query. Records at or past the count dispatch and draw nothing; records past maxDrawCount are never read. What cannot be bound or rewritten is left out loudly and counted. The fallback's records buffer is a transfer source too. - DrawID in a fallback task or mesh stage (a GLCompute entry point, where Vulkan has no BuiltIn DrawIndex) reads a pushed u32 at MESH_DRAW_ID_PUSH_OFFSET (76: the 4 bytes after a fallback task's u32 first, so no offset moves; PRESENCE_PUSH_OFFSET stays 88) and declares neither DrawIndex nor DrawParameters. Stages that do not load DrawID are emitted byte for byte as before. push_constants pushes 0 for single draws. - mesh_convert_bytes makes no 4096-record ring for a count draw where every mesh program takes the fallback. Every platform's fallback changes: count draws that were left out are drawn. Cost follows maxDrawCount: per record two dispatches, three transfers and four full barriers, then maxDrawCount draws (on MoltenVK encoded at submit). Tests: tests/count_draws_test.cpp runs the shader for both layouts (the mesh one over strides 8-20, count words 0-3, every count to past maxDrawCount); tests/test_mesh_count_fallback.py + mesh_count_fallback_test.cpp model the shader, the header steps and the epilogue's allocation under random workgroup orders (each record draws what it draws alone, in order; the census counts what a full area cuts) and check the source; tests/test_mesh_drawid.py + mesh_drawid_ir.cpp emit fallback stages with and without DrawID through the real back end (spirv-val, the pushed member, no builtin; the others byte for byte the base's); test_count_draws, test_resolver_coverage (SITES_MESH), test_mesh_fallback, test_mesh_census and seg_xfer_test follow. README and VULKAN.md say so. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit e9508f4b810c2e1859914c353b9a76cd2b8c4fa4)MeshCountDraws was written on the macOS integration branch, where fallback_record names each compute pipeline it binds for RX_VK_LMEM_LOG (private_memory_bound, MetalScratch). fallback_record_count's bind copied that line. This branch is on the count-draw rewrite, which has no RX_VK_LMEM_LOG, so vk_draw.cpp did not compile ("use of undeclared identifier 'private_memory_bound'"; the CPU tests cut the code out and passed). The line goes; the pipeline is bound as before. Whichever of this PR and the RX_VK_LMEM_LOG one lands second adds the line back, as fallback_record has it. vk_draw.cpp compiled whole for arm64 and x86_64 after the change. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]>0a61a9e7) into the provoking-vertex branch cfe4c014aeSemantic merge fix (Integration 37). tests/seg_xfer_test.cpp compiles fallback_record cut out of vk_draw.cpp with stand-ins for the thread's fallback draw state (fallback_draw_records, fallback_draw_offset, fallback_draw_count). eb4d0204 made fallback_record note the draw's records area in fallback_draw_area, so the fixture no longer compiled ("use of undeclared identifier 'fallback_draw_area'", i37-check-50-14/-15). It gets the same stand-in; nothing else changes. Assisted-by: Claude Opus 5.5 Co-Authored-By: Claude Opus 5.5 <[email protected]> (cherry picked from commit 85675f30379af284a52f8f944bddad3f44e2400b)cc22ddfd90881408f9ae881408f9aed24ecc70ecFolded into #851 (fix(macos): the Mac halves of indirect quads and mesh count draws)
Pull request closed