Faset_Engine/docs/IMPLEMENTATION.md

Implementation checkpoints

This log records working implementation and observed validation. It does not replace the acceptance criteria in PLAN.md. Incomplete platform or workflow checks remain open.

Current result: the C++ MVP is accepted in the recorded Linux and Windows profiles. The final dossier maps M0–M9 to evidence and keeps unverified compatibility scenarios explicit. Earlier pending/failure statements below describe their respective checkpoints, not the final status.

Checkpoint 1 — native foundation and independent subsystems

Implemented:

• C++20 CMake presets, pinned dependency archives with SHA-256 verification, and separate targets.
• Core persistent IDs, SHA-256, atomic file replacement, JSON IO, and project path boundaries.
• Explicit schema registration, document transactions, revisions, retry keys, Undo/Redo, recovery records, unknown extension preservation, migrations, and nested template resolution.
• EnTT runtime with real Box2D/Box3D, fixed ticks, deferred changes, checked handles, interpolation, and statically linked example behaviors.
• GLB/glTF asset import, cooked mesh data, stable source identity, cache generations, reimport conflicts, cancellation, and the optional Blender export add-on.
• Direct Vulkan renderer, Slang shaders, sprites/meshes, basic PBR and directional shadows, texture upload, resize, capture, and SDL input.
• English MkDocs/Material manual and an image prototype for the future retained editor UI.

Observed validation on Linux:

• Integrated headless CTest: authoring, runtime, asset pipeline, Blender bundle, core — 5/5 passed.
• Integrated Clang 21.1.8/Ninja build with Vulkan: 7/7 tests passed, including offscreen GPU rendering.
• Independent runtime and asset AddressSanitizer/UndefinedBehaviorSanitizer checks passed.
• Renderer offscreen/visible tests exercised NVIDIA RTX 2080 Ti with Vulkan validation.
• MkDocs strict build passed with MkDocs 1.6.1 and Material 9.7.7.

The full editor, user-project build pipeline, MCP integration, standalone exports, and Windows acceptance were still being implemented at that checkpoint. Later progress is recorded below.

Known intermediate constraints include box-only physics colliders, root-level physics objects, static glTF triangles/UV0, a conservative serial renderer, and then-unfinished world-preserving authoring reparent operations (completed in checkpoint 2). These remain implementation work or explicit profile limits to review during final acceptance.

Checkpoint 2 — integrated Editor, gameplay iteration and export

Implemented and integrated:

• Separate Player and SchemaExporter executables; statically linked project gameplay, configurable simulation settings, real contact-based grounded queries, and four compiled scripting tutorials embedded directly into the English MkDocs manual.
• Shared authoring commands and a real stdio MCP server, optimistic revisions, transactional retries, jobs/cancellation, recovery of unsaved documents, and viewport capture in graphical sessions only.
• Cancellable native subprocess execution, incremental project builds, schema export, binary scene/resource packaging, distinct Debug development and Release export directories, immutable published generations and retained last-good builds.
• A native retained UI with pinned FreeType/HarfBuzz and bundled Noto Sans: scene tree, schema Inspector, viewport camera/picking/gizmos, assets, diagnostics, build/play controls, commands, recovery and startup-loaded extension action panels.
• Exact-build native Editor SDK, dependency validation, owner-bound registrations, example Beacon runtime component/editor command/panel, and unknown-data preservation.
• Full world-preserving TRS reparent with explicit rejection of unsupported shear.
• Read-only cooked asset target for Player. Import/build/editor/MCP services remain outside the shipping runtime dependency graph.

Observed validation:

• Integrated Linux Clang 21 build: 19 CTests pass, including GPU rendering, retained widgets, Editor authoring interaction, actual plugin loading, real MCP stdio, process/cook contracts, and all four compiled gameplay tutorials.
• Real 2D and imported-glTF 3D standalone exports render with zero Vulkan validation errors on NVIDIA RTX 2080 Ti. Changing gameplay rebuilds metadata; failed C++ compilation preserves the last successful published build.
• Runtime/tutorial checks also pass with Clang 18; runtime ASan/UBSan checks pass.
• Unmodified Blender 4.5.3 exports through the optional add-on. Real Editor imports preserve output IDs after rename/geometry edits, report deleted-output conflicts, retain the last generation on failure, and preserve separate scene placement/color. Reproduce with tools/verify_blender_roundtrip.py --blender PATH --editor PATH.
• Strict MkDocs build passes. Tutorial source snippets are compiled by CTest.
• Previous checkpoint headless Linux and Windows GitHub CI passed after portability fixes. New checkpoint and full Windows graphical/export checks are separate work; Linux validation does not imply Windows validation.

This is an implementation checkpoint, not an MVP release. Finished playable sample projects, complete Windows graphical/export acceptance, fresh-install checks, performance measurements, and final UX review remain. Standalone image import is integrated but its dedicated PNG/JPEG edge-case checks are the next asset task.

The baseline profile currently uses box colliders, root-level rigid bodies, static triangle glTF meshes/UV0, basic PBR/directional shadows and a conservative serial Vulkan renderer. Advanced rendering and broader content profiles remain later work. The generated UI reference determines visual direction only; architecture, behavior and acceptance criteria remain authoritative.

Checkpoint 3 — playable projects and complete authoring workflows

Implemented and exercised on Linux:

• Two playable C++ projects with real Box2D/Box3D input routes, pickups, a physical gate, an exit condition and reset. The 3D project includes a reproducible original Blender arch, .blend source, stable-ID bundle and import instructions.
• Native project launcher, retained folder browser, real recent projects, keyboard navigation and safe project switching. GUI/MCP sessions retain one fixed project.
• Nested template UI, source navigation, local additions/suppression/reparent, per-field origin/Revert and conflict preservation. Parented gizmos have tested transforms, cancellation and one committed Undo operation.
• Explicit Project settings with file-content revisions and atomic save; per-scene Simulation remains a separate authoring transaction. Live theme/layout reload validates candidates and keeps working state on malformed edits.
• Standalone PNG/JPEG assets; versioned material records and explicit portable cache profile/toolchain identity. Clearing cache preserves identity and overrides when original sources and sidecars are reimported.
• Normalized Slang reflection, shader artifact hashes and renderer ABI compatibility validation. Real compile failure, changed binding/matrix layout and invalid SPIR-V keep a working pipeline; compatible pixel-changing reload succeeds.
• Physics debug box outlines, bounded raw Player profiles, observed validation activation, CPU/GPU/readback durations and allocation counters.
• MCP broken-pipe/EOF handling and fresh GUI capture after presentation back-pressure. A real GUI + stdio regression performs 12 PNG captures, a conflicting edit and Undo.
• English manual guides for workspace, templates, Blender, export and profiling, alongside compiled C++ tutorials. Generated UI references remain visual guidance.

Acceptance evidence:

• The integrated Linux test suite passes 29/29 tests, including ten GPU tests: native CPU, Vulkan, UI, real MCP transport, plugins, schema, physics and playable input routes. Strict MkDocs also passes.
• tools/verify_playable_exports.py exported the exact 2D/3D samples in Release, imported the Blender arch, checked package hashes and relocated each package outside its project. With the source-project paths unavailable, both passed validation and 120 offscreen frames on RTX 2080 Ti with the Khronos layer active and zero errors.
• Renderer/shader regressions also passed the pinned Linux SwiftShader driver. This is additional software-driver coverage, separate from Windows execution.
• tools/measure_workflows.py recorded a fresh sample Debug build and incremental iteration, including stale-schema transitions. On the development host, the initial build took 93.06 s, unchanged build 5.59 s, changed gameplay build 11.18 s, and the subsequent one-frame Player process 0.37 s. The first/cached small Blender arch imports each took about 0.047 s including Editor startup. Ambient builds were running; these are observations, not release budgets.
• Profiling identified uncached readback memory as a concrete bottleneck. In a small paired five-frame diagnostic, preferring compatible HOST_CACHED memory reduced median readback from 27.87 to 0.47 ms and renderer-call wall time from 30.81 to 2.92 ms. GPU work was about 0.58 ms. A longer final baseline is still required.

This remains an implementation checkpoint. Windows full graphics/export CI is still building its pinned software driver. A review also identified Windows Unicode path boundaries that must be corrected before cross-platform acceptance. Clean offline build verification, final performance baselines and the final acceptance record remain open; no MVP tag has been created.

Checks after checkpoint 3

• Public commit: d834cfad67cd81d8c4998b90c16791361ca8c0f8.
• Linux and Windows headless CI plus strict manual passed in GitHub run 35295534027.
• A clean committed source snapshot built all native targets with external networking disabled; all 19 CPU tests passed. The recorded build/test phase took 174.03 s. Offline evidence distinguishes prepared system tools from source/dependency inputs. GPU/window checks remain separate.
• The first full Windows graphics job compiled the whole Editor successfully, then failed creating a Vulkan instance with its CI software driver. Its CPU SceneView test also reported a texture-loading error. These are acceptance failures under investigation, not verified Windows graphics/export support.

Checkpoint 4 — portability and acceptance hardening

Implemented after concrete regression findings:

• UTF-8 project, resource, plugin, CLI and subprocess boundaries. Windows native paths stay wide internally; Editor/Player/SchemaExporter normalize wmain arguments. File reads, hashes and atomic writes use extended native paths. All Faset Windows executables declare long-path support; CI enables the documented developer policy.
• Normal Stop requests Player shutdown before bounded termination fallback. Real onDestroy execution was observed, and a dedicated Player fixture verifies that callback diagnostics also reach logs during shutdown. Custom component versions are checked against the linked gameplay schema, including data-only components.
• POSIX subprocess cleanup keeps the exited leader's PID reserved while terminating its owned process group, then reaps it. A regression verifies that a descendant ignoring SIGTERM cannot survive normal leader exit or cancellation, without losing the leader's stdout tail or signaling a reused process-group ID.
• Transparent sprites use stable layer/depth ordering without depth writes, avoiding invisible sprites hiding objects behind them. GPU regressions cover alpha layering, shader/capture paths longer than 300 characters, and window capture after resize.
• Editor/launcher DPI scaling, logical-unit layout persistence and safe cancellation of unfinished drags on scale changes. Retained UI tests cover 1×/2× text rasterization, clipping, hit testing and text-input rectangles.
• Manual import-removal review with exact IDs/names and explicit acceptance. Both the reviewed candidate and active generation are checked before publishing, so stale confirmation cannot apply a different import. The GUI regression exercises rejection, fresh review and successful acceptance through actual widget events.
• Extended template workflow now saves through UI controls and opens a new Session, comparing IDs, nested origins, local additions and resolved values.
• Blender verification now updates two instances in one live Editor/SceneView, preserves placement, tint, physics and opaque gameplay fields, and retains both visible meshes after a removal conflict. Blender evidence.

Observed Linux integration: 32 passed, 1 skipped, 0 failed in the 33-test suite. The skip is native Wayland programmatic restore, which the compositor declined; the same lifecycle scenario passed under XWayland. ASan/UBSan passed 17/17 tests. Strict MkDocs passed. Recovery evidence records actual Editor termination and failed save/import/build/Player scenarios. Release baseline records the two relocated Unicode-path packages and 240-frame profiles with their scope and hashes.

Windows execution of these fixes remains a separate gate. The previous fast CPU run isolated a 264-character cooked path failure; the new native-path fixes must pass on Windows before that issue is considered closed there. Native OS IME composition and moving between physical monitors still have less coverage than deterministic widget and platform-boundary tests. No MVP tag has been created.

The final build-service review also reproduced a publication defect: an invalid custom-field default can pass the build stage's shallow schema check before the Editor rejects it. Full schema validation before publishing last_build.json is the next bounded correction; checkpoint 4 does not claim this gate is already complete.

Acceptance corrections after checkpoint 4

Gameplay schema publication now uses the same complete metadata validation as the Editor, before either the Player generation or last_build.json is published. A native fixture drives the real BuildService with valid custom schema v2 and twelve invalid manifests, checking that the previous binary, schema, manifest and pointer remain unchanged. The focused authoring/process/schema/Session/MCP suite passed 5/5. An authoring-disabled Player configuration still builds without editor services.

Windows native checks passed for checkpoint 4 (45bc352) and afd773f, including the previous long-path regression. The full graphics runner also passed its Vulkan 1.3 device probe after registering the pinned software ICD on the disposable elevated runner. Full Windows graphics and export acceptance is still in progress; a successful probe alone does not close that gate.

The final audit identified additional bounded work: source/dependency freshness in the Assets panel, scrolling keyboard focus into view, delivery of explicit gameplay schema migrations, GPU pass labels, and wiring optional ImGui diagnostics. These remain under implementation and verification; the research map now links current implementation evidence instead of claiming the engine has not been started.

Checkpoint 5 — close the final authoring and diagnostics gaps

• Asset freshness compares source, bundle payload, external buffer/image, recipe, importer and profile contents without publishing a generation. GUI and MCP expose the same state/reasons; selecting a stale imported row prepares Reimport. Cook and export reject stale referenced sources while keeping the previous successful result.
• Gameplay schemas carry validated declarative migration steps. Inspector and MCP apply component.migrate as an explicit revision-checked Undo transaction. Opening old data remains possible without rules. Tests cover local components, instance-local additions, opening inherited sources, missing/manual rules and overflow rollback. The Manual explains the sparse-override limitation when field units change.
• Keyboard focus scrolls long and nested Inspector/Assets lists into view at 1×/2×, preserves unfinished text and keeps invalid numeric edits visible. Template preview and conflicts are also invalidated when schema metadata changes without a scene edit.
• Vulkan passes emit optional debug-utils labels. An optional FASET_DEBUG_IMGUI=ON Editor module shows real renderer diagnostics via F12; the Player remains independent. GPU tests cover textured/clipped ImGui geometry and event ownership for gestures crossing the panel in either direction. Offscreen clipboard operations are local to that renderer and never touch the desktop clipboard.
• The Windows launcher fixture compares canonical filesystem identities, including hosted-runner short TEMP aliases, and now distinguishes selection/path failures.

Integrated Linux with optional diagnostics enabled: 34 passed, 1 skipped, 0 failed of 35 tests. The skip remains native Wayland programmatic restore; XWayland passed. ASan/UBSan passed 18/18, including process cleanup, metadata publication and migration transactions. Strict MkDocs and local Markdown file-link checks passed.

Windows run 35299805623 at e0b9651 passed all 34 tests in its CPU/GPU/UI suite, including the launcher fix, and proceeded to real native Release exports. That run predates checkpoint 5's new authoring/diagnostic changes, whose Windows checks remain separate. The next full Windows build enables the optional diagnostic module too. No MVP tag is claimed at this checkpoint.

Checkpoint 5 acceptance and source relocation correction

The clean 0f34b03 Linux checkout built offline with 20/20 CPU tests, then created and rendered a fresh project using the Manual's command. Both checked-in games were exported in Release, moved outside the SDK into Unicode paths and run for 120 frames with source projects hidden; Khronos validation was active with no errors. All seven recovery scenarios and the real Blender/live-Editor round-trip passed. Exact inputs, hashes and limits are in the Linux acceptance record.

A subsequent source-relocation regression was reproduced and corrected: a cache-hit rename/move updated the logical source pointer while retaining the historical payload path, so the new freshness check incorrectly kept the asset stale. Publication now stores both paths atomically. Earlier pointers remain readable by resolving the payload relative to the moved logical source; immutable content generations and cache keys are unchanged. Regression cases cover PNG, Blender bundles and external glTF buffers/images, with both new and legacy pointer records. Full Linux integration remains 34 passed / 1 explicit Wayland skip / 0 failed; targeted ASan/UBSan asset/cook checks passed 2/2 after this correction.

Windows run 35299805623 at e0b9651 completed successfully, including both Release integration exports, incremental C++ rebuilding, and the two checked-in games with Unicode relocation. It used SwiftShader without the Khronos validation layer and is functional software-Vulkan evidence, not a physical-GPU benchmark. Checkpoint 5's newer Windows graphics/export run and the relocation correction have their own revision-specific gates.

MVP acceptance — v0.1.0-mvp

Final engine source: 4cb82556de31268d2bde73948dd1ff1b6c02f162. The publication commit adds documentation, acceptance records and research-viewer wording; it does not change the accepted engine, gameplay, shader or build-system sources.

• Final Linux evidence: 34 passed, one explicit native Wayland restore skip, zero failed. Both exact-source Release games passed manifest validation and 120 frames after Unicode relocation with their source projects hidden. An additional private namespace hid the entire SDK, build directories, Editor and cached tools; both games still passed another 120 frames with matching captures, active Khronos validation and zero errors.
• Final Windows evidence: run 35301244334 passed the fresh full Editor build with ImGui diagnostics, 35/35 tests, real BuildService Release exports/incremental Debug rebuild and both checked-in games after Unicode relocation. Each rendered 120 frames. SwiftShader supplied software Vulkan; the Khronos layer was unavailable. This is functional Windows execution, not physical Windows GPU or hardware-performance evidence.
• Native/manual CI passed for the same final source. The earlier clean offline build and first project launch, seven recovery scenarios, actual Blender/live-Editor round-trip and full 18-test sanitizer run retain their 0f34b03 provenance. The two affected asset/cook sanitizer checks passed again after the relocation correction.
• PLAN now closes M0–M9 against the dossier. The English Manual documents the working C++ tutorials, metadata/migrations, authoring, assets, MCP, extensions and export. A final instruction check corrected the 3D sample's required first bundle import. The recorded reference-scene thresholds are initial P1 tracking budgets.

Final publication checks passed: strict MkDocs build, both research-map tests and its production build, 318 local Markdown links, retained Windows evidence hashes, all validation JSON records and git diff --check. The engine-source diff from the accepted commit is empty; no untested engine changes were bundled into publication.

The post-publication documentation check also verified hashes against Git blobs, which normalize Windows JSON line endings to LF. Evidence indices now identify both the retained repository bytes and original CRLF artifacts explicitly. This follow-up changes only documentation metadata and preserves the first MVP tag and engine code.

Known coverage limits remain: real OS IME composition, movement between physical monitors with different scales, native Wayland programmatic restore and additional GPU/driver families. Widget composition/DPI, SDL text-input boundaries, XWayland and Windows window lifecycle have their own passing evidence. The narrow static-mesh, root-level box-physics, one-window/C++ MVP profile remains explicit. Lua and advanced graphics are later work. UI references guide appearance; they do not define behavior.

Post-MVP checkpoint — P2 GPU visibility and prepared mesh LOD

The historical MVP statement above describes the v0.1.0-mvp scope. Subsequent work added the optional Lua module and the P2 visibility path. The P2 renderer keeps VisibilityMode::Direct as its default and reference. Scene extraction supplies stable per-primitive keys and view metadata. DrawItem accepts optional prepared coarse meshes. The renderer tracks generation-checked temporal identity and previous rendered transforms, derives conservative bounds, and selects a prepared LOD by projected size with hysteresis. There is no automatic mesh decimator or cluster/streaming geometry system.

For opaque static meshes, GpuFrustum groups compatible geometry/material into fixed bins and fills indirect instance counts/visible IDs on the GPU. GpuOcclusion adds previous-frame HZB classification, Main raster, a current forward-Z furthest-depth HZB, and Post culling/raster so a newly revealed object can appear in the same final frame. History resets on camera cut, changed view/extent/projection, and incompatible instance identity. Shadow casters, transparent meshes, sprites and UI remain on their independent paths; they are not hidden by the camera's opaque HZB. The GPU modes are lazy-initialized and require the checked Vulkan capabilities and shader bundle. Shader reload rebuilds both direct and GPU scene pipelines, preserving the working pipelines on failure.

The Editor's ImGui diagnostics can select Direct, GPU frustum or GPU occlusion, inspect pass timings/counters and request a current-HZB preview. A Player run can choose --visibility direct|gpu-frustum|gpu-occlusion; Direct remains its default. The profile records the requested mode and per-frame gpu_visibility_active so a silent fallback is not mistaken for measured GPU work. The Release Player CLI test checks all three modes and rejects an invalid value. Counter and HZB readback are opt-in diagnostics; the visibility decision itself stays on the GPU. The existing framebuffer capture still waits for completion and reads back each frame. Consequently, full-frame benchmark times include that path and must not be presented as isolated culling costs.

At renderer checkpoint ae537c0, the Linux reference build's full CTest suite reported 57 registered tests, zero failures and one existing native-window lifecycle skip. Fifteen offscreen P2 acceptance cases passed with Vulkan validation active and zero reported errors, including capacity boundaries, door reveal, camera changes, multi-view history, LOD hysteresis, shadow independence and transparency. Shader reflection/export and GPU shader reload have focused tests. The P2 acceptance protocol contains the command, tolerance and scene definitions. The initial three-run benchmark report retains all 810 raw frame records, device/build details, p50/p95 values and limits. At that pre-optimization checkpoint, GPU MainCull took about 3.9–18.2 ms p50 in three synthetic Debug/validation scenes, far above the direct path's 0.24–0.50 ms whole-GPU p50. This was an actionable regression, not the final P2 performance.

Optimization checkpoint 3be3d0d moves GPU-written indirect arguments, visible IDs and deferred buffers into device-local memory, uses staging copies for initialization and optional diagnostics, and replaces contended CAS loops with bounded atomic add. The three-variant follow-up isolates memory placement and then the shader change. With the same Debug/validation scenes, MainCull p50 fell to 0.030–0.042 ms. Full GPU-command p50 for the open GPU-frustum scene was 0.139 ms versus 0.498 ms direct; the occluded GPU-occlusion scene was 0.188 ms versus 0.496 ms direct. All 2,430 sampled frames across variants reported zero Vulkan validation errors; the final focused suite passed 18/18 and both culling shaders passed spirv-val. These synthetic results do not establish a shipping-frame speedup, especially on another device or game scene. These checks establish the tested Linux configuration; they do not establish P2 behavior on a physical Windows GPU or a broad driver matrix. The profiling manual explains how to interpret the timings.

The independent Linux Release build completed all targets, including the prepared LOD example. Its full CTest run reported 57 registered tests, zero failures and one existing native-window lifecycle skip. The focused Release Player CLI test selected all three visibility modes, verified active GPU status in the profile, and rejected an invalid mode. Release build/test success establishes functional coverage; at that checkpoint, Windows P2 was still unverified.

As an additional Linux software-Vulkan check, Lavapipe ran all 15 labelled P2 acceptance cases plus the standalone GPU visibility test and both example modes. The GPU route was active and Vulkan validation reported zero errors. This adds a second implementation for functional checks; Lavapipe timings are not physical-GPU performance evidence.

The P2 Linux evidence dossier retains the exact Release builds, labelled GPU cases and relocated standalone Player checks. Both sample games passed a fresh Release export, Unicode relocation away from the SDK and 120 headless frames with validation and zero errors. Their packages also ran six frames in each GPU visibility mode with an active GPU path and zero validation errors. The 2D Direct/GPU captures matched pixel-for-pixel. The 3D GPU modes matched each other; each differed from Direct at 7 of 921,600 raster-edge pixels, with no missing geometry. Direct CPU vertex transformation and GPU shader vertex transformation round differently at subpixel triangle boundaries. The Debug benchmarks above and this Release functional record have different purposes; neither establishes physical Windows GPU coverage.

Compatibility checkpoint 433bce0 followed the first red Windows P2 CI run. The pinned SwiftShader device does not expose shaderDrawParameters; the Slang SV_InstanceID builtin had emitted a SPIR-V DrawParameters capability, so the renderer rejected the GPU route. Both GPU vertex entries now use raw SV_VulkanInstanceID while their fixed indirect commands keep firstInstance = 0. The renderer no longer requests that optional feature. The GPU smoke case now has the gpu;p2 CTest labels, so CPU-only native checks exclude it. A reflection test rejects DrawParameters in the two generated vertex modules. On matching Linux SwiftShader, all 16 P2 cases passed with the GPU path active; a deliberately driverless CPU-only selection passed 26/26.

At this revision, Windows graphics CI passed all 58 tests on pinned SwiftShader, including the P2 route and Windows window/editor tests. Its two relocated Release example games each rendered 120 frames in the default Direct mode. Native/manual CI also passed. The SwiftShader compatibility dossier records the cause, local commands, CI run and export report. Windows did not have the Khronos validation layer, and no physical Windows GPU or driver-family performance claim follows from this software-Vulkan result.

Independent P2 source review then found two contract gaps. Requested GPU occlusion could silently run GPU frustum when HZB was unavailable, and stable instance slot/generation lived only in the CPU tracker while GPU candidates used dense frame-local indices. Follow-up 22012c1 records the requested and effective visibility mode per frame in renderer statistics, Player profiles/output and Editor diagnostics, with a CPU capability-policy regression. GPU instance records now carry stable slot and all 64 generation bits in previously reserved metadata; dense indices remain addresses into the current frame's instance buffer. A focused reorder/replacement/anonymous-instance test covers the metadata packing. The reviewer rechecked both fixes and found no remaining load-bearing issue in those paths. On this revision, full Linux Debug and Release CTest each reported 57 registered tests, zero failures and one existing native-window lifecycle skip. The dedicated ImGui overlay test passed 1/1; pinned Linux SwiftShader passed all 16 P2 cases and Player diagnostics; a driverless CPU-only Release selection passed 26/26. The final Windows graphics CI run passed all 58 tests without skips on SwiftShader; both relocated Release games rendered 120 frames in Direct mode. The corresponding native/manual CI run passed on Linux and Windows. Unsupported-HZB integration and physical Windows GPU coverage remain untested.

Post-MVP checkpoint — P1 gameplay iteration

P1 adds a complete-input native build stamp and a content-addressed Scripts copy. The package key binds configuration, recipe, source, Lua declaration, toolchain, shader and runtime artifacts. A second unchanged build reuses a verified schema and package generation without invoking SchemaExporter; CMake/Ninja still verify the native graph. Malformed/corrupt generations, modified headers/tools and detected source mismatches cannot publish a false hit. The live tree and staged copy are rehashed after native build and before reuse/publication; a same-user write-and-restore during compiler reads remains outside this check. Failed jobs preserve the previous successful pointer, while Inspector metadata becomes stale.

Compiler and Lua output now produce bounded structured Console diagnostics with raw logs retained. Source opening accepts only project Scripts files and passes literal file/line/column arguments to the configured external editor. A real compile failure revealed that compiler paths pointed to the staged copy; d7a7a7c maps only the verified snapshot subtree back to project-relative source. The same correction retains a later actionable error after 250 unrelated warnings. Four runnable C++/Lua × 2D/3D starters are available in launcher and CLI; the existing scaffold default remains compatible. Named dirty scenes autosave after two idle seconds by default; unnamed scenes require Save As, and disk/revision conflicts retain the journal and never overwrite external edits.

The P1 dated dossier retains a clean-revision 6c2e8fa Debug workflow with every raw command/profile. On the Ryzen 7 1700/RTX 2080 Ti Linux host, five unchanged builds had median 11.53 s, five changed-C++ builds 28.16 s, five changed-header builds 23.89 s, and five watched Lua reloads 0.502 s. All five unchanged builds reported a verified generation reuse. The 3,000-frame profile showed no growth in the explicit Vulkan allocation counter (15,787,008 bytes). A seeded 527-object synthetic scene reached 149.39 ms p95 wall time, dominated by CPU simulation/snapshot; this is a visible scalability issue, not a tiny-demo Release budget comparison. The historical exact-scene Release budgets were met in the earlier 2026-09-18 record, but that evolving working-tree baseline does not certify the current revision. A clean 4a3453e physical-GPU rerun now covers both exact-scene source-hidden Release games, sequentially for 240 frames at 1280×720 with active Khronos validation. 2D/3D p95 frame wall was 2.694/3.036 ms, GPU 0.573/0.617 ms, readback 0.559/0.561 ms, simulation 0.242/0.300 ms, snapshot 0.197/0.288 ms; startup from main() was 295.4/248.3 ms. These meet their initial tracking budgets. Explicit Vulkan allocation instead reached 45,112,032/45,212,272 bytes (43.02/43.12 MiB), exceeding the 20 MiB target: eager 2048² D32 sun and local atlases consume 16 MiB each even in the 2D fixture with zero shadow raster. This memory miss is recorded, not silently rebaselined. The same clean build exported and source-hidden relocated C++ 2D, C++ 3D with Blender import, and Lua-only games; all rendered 120 frames with validation active and zero reported errors.

Linux focused cache, diagnostics, schema and workflow-math tests pass; a real failed-build replay now reports navigable Scripts/Gameplay.cpp:73:2. The Lua-only Release result validated and rendered after source-hidden relocation on the physical Linux GPU. At 6c2e8fa, native/manual CI passed on Linux and Windows. Its Windows graphics job passed all 61 CTests on SwiftShader, then hit an invalid integration fixture under the engine checkout; 4ac02ee moved the fixture to runner temporary storage. The subsequent Windows graphics run passed all 61 CTests and the real export integration. Two C++ and one Lua-only Release package validated and rendered 120 frames each after relocation with source paths unavailable; the raw Windows report records hashes and software Vulkan device identity. The later d7a7a7c real-diagnostic-navigation assertion is covered by the clean combined 4a3453e Windows graphics run: 74/74 CTests, real export integration and three relocated games passed. Windows had no active Khronos validation layer, and no physical Windows GPU performance result is claimed.

P3 lighting checkpoint — authored lights and bounded shadow views

At source revision b191ae0, the versioned faset.light schema and SceneView extract directional, point, and spot lights. Any authored Light, even disabled, suppresses the compatibility sun; scenes without a Light keep their previous appearance. The renderer validates all local records, then selects at most 128 by priority, projected influence, and stable ID. A single typed lighting descriptor ABI serves Direct and P2 GPU graphics: materials remain set 0, lighting is set 1, GPU scene graphics data moves to set 2, and existing push constant sizes remain unchanged. Both paths shade the same sun/local PBR lights before tone mapping.

A pure CPU shadow planner builds up to four texel-snapped sun cascades from an explicit camera frustum, ending at at most 80 world units; a low-level Snapshot without the frustum keeps one shadow view. Shadow caster bounds come from the source LOD-0 draw and are tested against the light view, independently of camera/P2 culling. The Vulkan backend renders the sun to its own D32 atlas and point/spot shadows to a separate 4×4 D32 atlas. A point light claims six faces atomically, a spot one. Both atlases try 2048² and then 1024² if required by capabilities or allocation. The combined frame budget is 4096 caster draws; scheduled tiles are cleared and redrawn each frame. Overflow, disabled shadow, or unavailable atlas leaves a submitted light illuminating without shadow. There is no hidden sun raster when the sun is absent, its shadow is disabled, or the scene only has sprites. Atlas ownership, dropout, submitted light counts, actual raster work and GPU timings are exposed in FrameStats, Player profiles and the optional Editor diagnostics overlay.

The implementation's Linux Debug checkpoint at a5fb216 built all targets and ran 60 CTests with no failures; the existing native window lifecycle test skipped under the compositor. The optional ImGui overlay passed its dedicated test in an enabled build. After benchmark integration at b191ae0, six focused tests passed, including the real Vulkan benchmark smoke. These are bounded checks, not a final P3 acceptance run. The lighting validation record lists cases, exact revision, and remaining Windows/Release evidence.

The fixed-scene Release reference-GPU sweep uses 1920×1080, 0/4/16/32/64/128 lights, Direct/GPU frustum/GPU occlusion, shadows on/off, three independent repeats, ten warm-up and thirty measured frames per configuration. It reached the agreed Forward+ gate: main-raster overhead at 32 lights was about 0.50 ms relative to the matching zero-light case, roughly 30% of that GPU frame; 64 and 128 lights added about 1.02 and 2.03 ms. Its exact-revision raw CSV and report are retained in study 22.

Revision a0a4e29 adds an explicit depth-free 16×16 tiled Forward+ path. One compute invocation tests every submitted point/spot range sphere against a tile's four screen-space planes and writes at most 64 stable-order indices. An overflowing tile scans the entire submitted list in the fragment shader; there is no dropped light. The tile shader has exact reflection validation, package/build integration, GPU timing, optional occupancy readback, and reload rollback. Direct, GPU frustum and GPU occlusion image tests cover a cropped viewport, resize, near-plane light/shadow, and overflow. A 128-light localized 1920×1080 forward/tiled capture matched byte for byte.

The paired Release study measured tile build plus raster on the same RTX 2080 Ti source revision and shader bundle. At 32/64/128 broad overlapping lights it was 0.064/0.122/0.222 ms slower; all 8160 tiles overflowed at 128. A separate localized-range scene was 0.103/0.214/0.440 ms faster at those counts, with no overflows. There is no robust scene/device runtime predictor yet, so Auto remains forward and Tiled is explicit. Linux Debug passed 62 CTests with one window skip; pinned Linux SwiftShader passed all six P3 cases. At a0a4e29, native/manual CI and Windows graphics/SwiftShader CI passed. The Windows job completed all 64 CTests and ran two relocated Release games for 120 frames each. The later combined and temporal acceptance follows below; this paragraph describes only the original lighting checkpoint.

P1+P3 combined renderer checkpoint

At clean source 4a3453e, the integrated P1 cache, P3 lighting/Forward+ and first-generation temporal renderer built on Linux and passed 72 of 73 Debug CTests with one compositor-dependent native window skip and no failures. The native/manual CI passed on Linux and Windows; the Windows graphics CI passed 74/74 CTests on pinned SwiftShader, the real Release export integration, and three relocated 120-frame C++ 2D, C++ 3D and Lua-only games. The matching Linux physical-GPU export check rendered the same three source-hidden packages for 120 frames with active Khronos validation and no reported errors; the P1 final Release dossier also profiles the exact C++ demo scenes for 240 frames. Their time budgets passed, but the old ≤20 MiB explicit-allocation target missed at 43.02/43.12 MiB due to two eager 16 MiB shadow atlases.

The integrated P3 lighting repeat retains 7,560 per-frame raw rows at 1920×1080, both shadow states, three visibility paths and a separately labelled localized-light workload. On the dense fixture, tile build plus raster was 11–13% slower at 32–128 lights; localized light ranges made it 43–54% faster. Auto therefore remains forward and Tiled explicit. This is pass-local cost on a single GPU, not a full-game speedup or a physical Windows performance claim. The temporal dossier records Off, TAA and 0.67 Upscale raw image sequences and bounded 720p cost on the physical Linux GPU, with its own exact shader-source revision. TAA/Upscale remain opt-in because scene quality and whole-frame timing require game-specific comparison.

At clean source ed523c6, the final integrated temporal matrix repeated all 1,386 lossless frames across Direct, GPU frustum and GPU occlusion after adding optional accepted/rejected-history pixel diagnostics and fixing the resize path with diagnostic readback enabled. The failed Direct-to-GPU mode switch now restores active TAA pipelines and history for a safe retry; a real Vulkan RED test reproduced the old null-pipeline failure. Every frame used active Vulkan validation and reported zero errors; the 1,388 generated PNGs, including two contact sheets, were byte-identical to the earlier branch matrix. The final matrix dossier records the exact binary and shader hashes, eight post-open disocclusion frames, reset comparisons, the 2× spatial reference and a separate 90-frame 720p Off/TAA/Upscale profile. This bounded fixture shows reduced static-wire frame variation, but its spatial reference has lower error and 0.67 Upscale does not improve whole-frame GPU time. Both temporal modes remain opt-in; the diagnostic GPU counter remains off during performance measurements.

At the same clean revision, Build and Export results carry the worker's validated gameplay-source hash. A controlled queued-edit test first reproduced the false stale-schema state, then passed after the fix. The complete Linux Debug suite passed 76 of 77 CTests with one compositor-dependent window skip; 24 focused Linux Release tests passed. The real Release Editor exported the C++ 2D, C++ 3D with Blender asset, and Lua-only games; each relocated package ran 120 offscreen frames on the physical RTX 2080 Ti with active Vulkan validation and zero errors while the source project paths were hidden. The final combined dossier holds the clean-source verifier report and package manifests.