Temporal Presentation

Milestone E adds a default-off temporal presentation path shared by OpenGL and Vulkan. It combines delayed GPU-time dynamic resolution with native-resolution temporal accumulation, while preserving the existing SMAA/spatial path as the immediate rollback.

Ownership Contract

The renderer selects one immutable presentation state at BeginFrame:

• sceneWidth and sceneHeight size the game-owned 3D and authored-post chain;
• outputWidth and outputHeight size the temporal histories and final output;
• 3D rendering and authored scene effects complete before temporal resolve;
• HUD, menus, console, and other root 2D views are submitted after that resolve directly at native output resolution.

Renderer ABI v11 exposes this frame state and one append-only temporal-resolve entry point to both game modules. The SP authored-post path owns two native-sized history render targets; direct and MP paths that do not use that post chain use an equivalent lazy backend-owned pair. Either owner swaps only after the exact frame/generation resolve is accepted. A generation change, native extent change, video/backend restart, map/session discontinuity, camera cut, capture, missing current-frame depth stamp, or rejected write invalidates continuity. A dynamic scene-size change does not: history is native-sized, so retaining it is required for TAAU.

No loose material or shader asset is required. Backend resolve programs are engine-owned resources, and retail Quake 4 materials remain unchanged.

Dynamic Resolution

r_rendererDynamicResolution 1 enables the controller and automatically enables the backend-neutral whole-frame timing stream needed by it. OpenGL uses the existing four-slot timestamp-query ring; Vulkan reads timestamps only after the ordinary frame fence for that slot retires. Neither backend waits for a current frame query.

The controller associates each delayed sample with the exact scale of its source frame, rejects stale/out-of-order/generation-mismatched samples, drops resolution quickly above budget, and raises it only after an under-budget streak. Dimensions are bounded and aligned before target allocation. Unsupported timing keeps the configured safe ceiling and reports dynamicActive=0.

Manual r_screenFraction scaling remains available when the automatic controller is off. With temporal AA active, even mode 0 uses the scene-target route so TAAU receives the requested low-resolution scene instead of the legacy back-buffer crop path. Root UI-only frames never enter either scaling route.

Relevant controls:

CVar	Default	Purpose
r_rendererDynamicResolution	0	Enable automatic 3D scene scaling
r_dynamicResolutionMinScale	50	Minimum automatic scale, percent
r_dynamicResolutionMaxScale	100	Maximum automatic scale, percent
r_dynamicResolutionTargetMsec	0	Explicit GPU budget; 0 derives it from presentation timing
r_dynamicResolutionTargetUtilization	90	Share of the presentation interval available to GPU work
r_dynamicResolutionDropStep	5	Maximum percentage-point drop per over-budget sample
r_dynamicResolutionRaiseStep	2	Percentage-point increase after a recovery streak
r_dynamicResolutionRaiseFrames	30	Retired under-budget samples required before a raise
r_dynamicResolutionAlignment	8	Scene-dimension alignment
r_dynamicResolutionCaptureNative	0	Force known captures to native scene resolution instead of freezing scale

rendererTemporalPresentationStatus prints the latched extents, delayed sample identity and age, target budget, controller decision, image-history generation, and capture state.

Temporal History And Motion

r_temporalAA 1 replaces the game SMAA tail only when the renderer accepts a validated temporal resolve command. Rejection leaves the established SMAA or spatial final pass in place. The resolve uses an eight-sample Halton sequence, previous camera projection, depth reprojection, object velocity where available, neighbourhood clamping, colour/depth disocclusion rejection, and conservative reactive rejection.

Every visible motion class has explicit ownership:

Domain	History treatment
Static world	Camera/depth reprojection and disocclusion testing
Rigid entities	OpenGL and Vulkan write eligible object velocity from the previous model and camera transforms; a missing transform or failed draw retains conservative packet-region rejection
Skinned geometry	Reactive rejection unless a backend supplies an explicitly validated previous palette and velocity stream
Particles/BSE	Reactive rejection
Material/generated deforms	Reactive rejection unless a backend supplies explicitly validated previous vertices
Portal, mirror, and remote subviews	Stable unjittered child render; sampled parent surface is reactive and marked as separate-history ownership
In-world GUI	Rigid/camera motion plus reactive rejection
First-person view model	Depth-hack-aware rigid/camera motion plus reactive rejection

The conservative reactive routes are deliberate ownership, not zero-vector claims: history is suppressed when a precise prior vertex stream is unavailable. The shared packet policy carries at most two conservative normalized regions; when a backend cannot establish that policy, it rejects history over the full view. Root 2D UI is never part of the temporal history or scene scaling.

Vulkan keeps TAA transform history separate from motion blur. It commits that history only after the matching color history write, and requires the previous backend frame, view identity, generation, model identity and scene extent to match. Captures, cuts, resizes, missing previous geometry and failed resource admission cannot reuse old vectors. Its single-sample RGBA16F velocity target tests fragments against the current resolved scene depth, including MSAA scenes. Vectors include camera motion and jitter once, use scene-pixel units, and scale to native presentation pixels in the resolve. Unsupported geometry keeps its explicit reactive ownership.

rendererTemporalPresentationStatus also reports Vulkan's eligible/drawn rigid surfaces, whether the last vector pass was complete, and completed vector views. The stock HDR gameplay gate checks that completed vector views increase during each scaled/restarted interval. A single frame can correctly reject history after a time discontinuity or newly visible entity; cumulative freshness proves the real production draws without requiring unsafe reuse on that frame.

r_temporalAAFeedback, r_temporalAAReactiveScale, and r_temporalAADebug control maximum history weight, rejection strength, and the velocity/reactive/ history-weight diagnostic views.

Cuts And Captures

Per-view identity includes the render world/map, root or subview chain, view id, flags, and capture surface provenance. History is rejected for identity or generation changes, native output resizes, time discontinuities, teleports, large rotation cuts, and projection cuts. Equal simulation times remain valid so high-refresh presentation can accumulate between game tics.

Known screenshot and save-preview frames render without temporal jitter. A capture that begins after the game queued its scene marks the source timing sample ineligible, advances only the image-history generation, and makes both backends bypass history reads and writes. The current scene is spatially presented for readback, then ordinary history starts cleanly on a later frame.

The stock renderer remains a numeric SDR pipeline: temporal targets preserve the same UNORM/code-value contract as their source, and neither resolve shader adds an sRGB or gamma transfer. Native UI is composed after the scene resolve.

Validation

Dependency-light policy coverage lives in openq4-temporal-presentation-core-test and openq4-temporal-history-core-test. The static cross-repository/backend contract is checked by tools/tests/renderer_temporal_presentation.py. Runtime acceptance uses windowed engine-TGA captures and mode-specific SP/MP gameplay; operating- system capture and injected user input are not part of the workflow.

rendererVulkanTemporalMotionSelfTest numerically reads GPU velocity and resolve attachments for positive/negative translation, rotation, perspective interpolation, camera plus jitter, invalid previous clip positions, asymmetric depth occlusion and scaled scissors. Thirty-six fixtures cover two scene extents and both stored image origins; missing geometry, new entities and stale view/frame/generation/extent/capture state must reject exact ownership. The required renderer-vk-temporal-motion-selftest matrix case repeats them after full restart with active validation. These tests establish numerical behavior, not moving-scene visual parity, performance or platform promotion.