The creator's ruling on the webcam's properties: a "Shape" title above the
Mirror/Rect row; the drag hint indented under that row "to show parentage";
the same for Geometry, Border Color, Border Thickness; Remove and Blur indented
under Background; Strength indented under Blur.
One rule covers it: a title owns its content and the content is indented one
level (10px) under it - two levels where a title is itself nested (Strength
under Blur under Background). The titles are SemiBold 11px #a0a0b0 like the
ones already there.
The shape also stops being a toggle button that shows the NEXT action ("Round"
when the camera was a rectangle) and becomes a CHOICE: two segment options,
Rect | Circle, with Rect selected by default - which is what the creator asked
for ("Rect should be selected as a default if none exists"). The old
ShapeButtonText is gone.
The mutual exclusion lives in the MODEL: IsRectShape/IsRoundShape on
SceneElement, each setter flipping the shape through ToggleClipShape() (so the
pre-round rect is still stored/restored) and always re-raising, so a refused
write - the vertical Chat layout is rect-only (TASK 57) - makes the UI snap
back instead of sticking. Deliberately NOT a WPF RadioButton group: a group
unchecks its siblings by setting IsChecked in code, which makes WPF drop the
binding (stackoverflow 7376373; the same trap measured in 50980687/57275046).
The Circle option stays hidden where CanToggleClipShape is false, so the circle
is still not offered in the vertical Chat layout.
Guard: ytLive.Tests/PropertiesHierarchyTests.cs - the model half (Rect by
default, pick circle, pick rect, the locked Chat layout refuses the circle) and
the panel half (the Shape title owns both options, the circle is the gated one,
the hint is indented and follows the row, every titled block's content is at
10px, Strength at 20px). 432/432 green, 0 warnings.
The creator's locked table (2026-10-17) gives the Chat scene its own rules in
the 9:16 tier: RECT ONLY - the circle option is not offered - and a size that
is either the normal small tile or ENLARGED to fill one whole 607x540 area
(top or bottom). Unit 1 shipped the per-scene placement; this unit is the Chat
scene's own variant of it.
The rule lives on the MODEL, not on the button:
- Models/SceneElement.cs: ClipShape and ToggleClipShape() are now virtual.
- Models/WebcamSceneConfig.cs: VerticalShapeLocked (set per scene by the VM)
OVERRIDES the ClipShape property, so no writer can slip a circle in - the
toggle, the Shape button and the placement swap all go through it. The lock
is cleared BEFORE the 16:9 layout comes back, so the desktop shape returns.
- ViewModels/MainViewModel.Webcam.cs: CanToggleClipShape (the circle is NOT
offered in the vertical Chat layout - the Shape button disappears, it is not
merely greyed out), IsChatSceneCamera, ResizeWebcamInVerticalTier.
- Models/VerticalCameraLayout.cs: FillsArea (the "enlarged" state, derived -
no new column) and SizeFor - the Chat camera's TWO sizes, the tile or the
whole area, whichever is nearer the requested width, so the resize handle
has two detents instead of any size in between.
- An enlarged camera FILLS the area its centre is in (top or bottom), so
dragging it up/down swaps the areas.
- The Chat camera is auto-tiled like the Live one when the vertical tier is
picked - otherwise the vertical chat stream has no camera at all.
- Controls/PreviewPane.xaml.cs: the resize routes through the VM; the drag
assigns, lets the model clamp into the band, then snaps (so the enlarged
camera can be dragged from the top area to the bottom one).
Test: ytLive.Tests/VerticalChatCameraLayoutTests.cs - the ONE Good Dog test for
the unit: the vertical tier is picked -> the Chat camera comes into the band as
a small RECT tile -> the circle option is not offered and cannot be set even on
the model -> dragged up and enlarged it fills the TOP area exactly -> back to
16:9 the desktop layout is restored exactly and the circle option is offered
again. 430/430 tests pass, 0 warnings.
Research (the creator's table is the established practice, not our invention):
- Streamlabs' vertical guide: "splitting the screen in half horizontally,
placing the camera feed in the top half and the main content on the bottom
(or vice versa) may be the bet", and a just-chatting vertical wants the
camera "to take up most of the screen"
(streamlabs.com/content-hub/post/overlays-vertical-and-horizontal-streaming)
- Bloopbot's vertical overlay docs describe the same per-layer model we use at
scene granularity: "move or resize a layer on Vertical and it stops being
Auto-placed. It keeps the place you gave it, and the horizontal layout is not
touched" (bloopbot.com/docs/vertical-overlays-twitch-dual-format) - our
swap-at-tier-change, stored per scene.
- Landmine recorded: "about the bottom 560 px of the vertical video can be
covered by Twitch's chat and player controls on phones" (Bloopbot) - the Chat
camera's enlarged BOTTOM area may be half-hidden by the platform chrome;
TASK 53's safe-zone work decides that.
Memory in the same commit: ai.md (the Chat rules, the shape lock, the tests),
TASKS.md + TASKS/task-57-vertical-camera-layout.md (TASK 57 complete), HANDOFF.md,
MyMistakes.md (3 recipes: lock the model property not the UI button; two detents
for a discrete size set; the edit tool cannot match an oldString with an em
dash), Models/ViewModels/Controls index rows.
The vertical tier is a centred band crop of the SAME 1920x1080 master (band x
656.25, w 607.5, h 1080), so the 16:9 camera placement (x~1408) falls outside the
cropped window and the creator is simply not in the vertical stream. Each scene
now keeps its own vertical position, size and shape; switching back to 16:9
restores the desktop layout exactly (the creator's locked table, 2026-10-17).
Geometry only - NO render-path change. The preview and the compositor both read
the element's own X/Y/W/H + ClipShape, so the tier switch swaps the LIVE geometry:
- Models/VerticalCameraLayout.cs (new): the pure math - the band, its two 607x540
areas, the six spots (top/bottom x left/centre/right), the 32px inset and the
270x152 default tile (480x270 in the 1080x1920 output) in the bottom-right spot,
the corner the 16:9 default webcam uses.
- Models/WebcamSceneConfig.cs: the vertical placement lives in seven additive
columns (VerticalX/Y/Width/Height/ClipShape/RectWidth/RectHeight; NULL = "this
scene has no vertical placement yet"). The 16:9 layout stays in the old columns
and is parked in the transient Landscape* fields while the vertical tier is
live; Begin/EndVerticalLayout + CommitLiveLayoutToVertical do the swap. The
X/Y/W/H overrides clamp every write into the band - outside it the camera is
invisible in the vertical output.
- Models/SceneElement.cs: X/Y/Width/Height became virtual so the derived element
constrains every writer (drag, resize handle, typed fields) in ONE choke point
instead of three writers each re-implementing the rule.
- ViewModels/MainViewModel.Webcam.cs + .Streaming.cs: IsVerticalTier/VerticalBand,
ResolveVerticalCameraLayout(s) (the tier swap), MoveWebcamInVerticalTier /
SnapWebcamInVerticalTier (the six-spot snap, by the tile's centre),
EnsureVerticalCameraLayout; ApplyStreamQuality is the tier-change hook. The
Live scene gets its small tile automatically on the first vertical switch (the
vertical stream would otherwise have no camera at all); the other scenes keep
their 16:9 placement until the creator drags them into the band.
- Controls/PreviewPane.xaml.cs: the drag/resize route through the VM snap under
the vertical tier instead of free-floating over the master.
Controls/LeftPanel.xaml: the webcam properties gained a Geometry section
(X/Y/W/H) for the manual entry the creator asked for, bound to the LIVE
placement, gated on the VM's IsWebcamSelected (NOT SelectedElement.IsWebcam -
the TASK 51 test finds that panel by binding text and would match twice).
- The store: seven guarded ADD COLUMNs, the INSERT/SELECT extended, and the
X/Y/W/H/ClipShape columns stay the 16:9 layout - while the vertical tier is
live the save writes the parked values there and the live ones into Vertical*.
Test: ytLive.Tests/VerticalWebcamLayoutTests.cs - the ONE Good Dog test. The
vertical tier brings the Live camera INTO the band as a small tile; dragging it to
the top-right lands it top-right inside the band; back to 16:9 the desktop layout
is restored exactly (1408/778/480x270); both placements survive a save + reload.
Full suite 429/429, 0 warnings. LayerReorderPersistenceTests.RealMouseDrag fails
ALONE on a clean tree in this environment - pre-existing flake, proven by stashing
this work, not a regression.
Derivative work: OBS has no built-in per-aspect-ratio layout storage - the
maintainers' answer is "create a second scene and add the scene you want to send
as source" (obsproject.com/forum/threads/161307) - and Streamyard's dual-aspect
guide says the same ("no built-in way to store separate layouts per aspect ratio",
so you rely on manual workarounds and plugins):
https://streamyard.com/blog/dual-aspect-ratio-streaming-tool
Our per-scene, per-tier stored placement, resolved on the tier change, is the
step past both.
Memory in the same commit: ai.md (new section), TASKS.md + TASKS/task-57-*.md
(Unit 1 shipped, Unit 2 = the Chat scene still open), HANDOFF.md, MyMistakes.md
(the per-tier geometry-swap recipe, the binding-text panel trap, the store's
webcam-identity rule) and the Models/Services/ViewModels/Controls index rows.
Right-click now creates a transient ZoomSceneElement at z-index 1 whose pixels are a
genuine 2x magnified sample of the backdrop (live capture under art), composited into
stream/recording like any layer while the output crop stays the tier. All shapes are
centered on the click and clamped to frame; healed on load/scene-create, never persisted,
hidden from the layers list + element template (IsZoomLayer). BuildCompositorOptions is
now internal = always tier crop (test seam). ZoomFrameBuilder is a pure static sampler
(box/2 window centered on the box center, single-slot cache) proven by a banded-backdrop
test; LayerReorderPersistenceTests drag resolves rows by item since the collapsed zoom
row shifts container indices. Also books TASK 51 (webcam background Remove + Blur) and
syncs memory docs (HANDOFF, MyMistakes, indexes). Full suite: 405 passed, 0 warnings.
The Stream Alerts properties panel was incorrectly showing for the webcam
layer (a WebcamSceneConfig is not a Source) because IsAlertBox only existed
on Source, causing WPF binding to be treated as false-but-invisible context
or the trigger to bind against the wrong type. Adding a virtual IsAlertBox
to the base SceneElement (default false) and overriding on Source prevents
the UI block from rendering under webcam selection. Scope: Models/SceneElement.cs, Models/Source.cs, ytLive.Tests/AlertBoxPreviewVisibilityTests.cs. Build/test: app + 4 alert-box tests pass, other failures unrelated (float precision).
- Add ElementKind (Static/Dynamic) to SceneElement base; Source/WebcamSceneConfig classify
- Services/SceneGraph.cs: owns the Scenes collection (ViewModel's Scenes delegates to it),
the element mutation surface (Add/Insert/Remove/Move, each invalidating the bake), and the
queries that were scattered LINQ (GetBackground/GetWebcam/GetChatBoxes/GetSplitPoint/IsStatic)
- SceneCompositor: split-aware BakeStaticBase + CompositeLayers + Render(.., staticBase, split);
builds/caches the static base below the split point in source-rect space
- FramePump: optional SceneGraph -> optimized bake+composite path; falls back to full render
- MainViewModel: routes element mutations through the graph; invalidates the bake on static
layout/opacity/visibility/useDefaultBackground changes and after background heal/Ensure
- Integration test SceneGraphTests.BakedStaticBase_WithDynamicLayer_CompositesCorrectly
Derivative survey (mandated): tried before writing — OBS does per-source opacity/visibility
caching and static-scene baking; this mirrors OBS's 'cached static source' optimization.
3 documented defensive deviations from the spec (ChatOverlayLayer stays decoupled;
background helpers stay VM-static for direct testability; full facade peel deferred post-1.0)
in TASKS.md + ai.md. Scope check passed; clean build 0 warnings.
Same root cause as IsChatBox — SourceType binding fails on WebcamSceneConfig,
WPF defaults Visibility to Visible without calling the converter.
Added virtual bool IsCountdown on SceneElement, override in Source.
Swapped binding to BoolToVis. Removed dead SourceTypeToVisibility converters.
SceneElement was missing virtual IsChatBox property (unlike IsWebcam, IsWebSource, IsImageSource).
WPF binding failed silently when SelectedElement was a webcam, defaulting StackPanel to Visible.
Added virtual bool IsChatBox => false on SceneElement, made Source.IsChatBox override it.
The web source section's visibility was bound to SelectedElement.Type
via a converter, but WebcamSceneConfig has no Type property — the WPF
binding path didn't resolve correctly and the section leaked through.
Added IsWebSource virtual property to SceneElement (mirrors existing
IsWebcam pattern), overridden in Source to return
Type == SourceType.WebSource. Section visibility now binds directly to
SelectedElement.IsWebSource via BoolToVis.
1c of 7-issue polish batch. 207 tests, 0 warnings.
1. About box bg → #0A0C1A (matches icon bg)
2. Elements panel collapses when no element selected / scene changes
3. OpacityChip moved from preview overlay into Elements panel
4. Color picker fix: cast to SceneElement not Source (WebcamSceneConfig was silently blocked)
5. Red left accent bar on selected items in Scene/Source lists
6. ✓ character replaced with Path checkmark icon in Elements panel
7. Removed ToolTip='Applied' from green check buttons
8. Created bugs.md with first entry (iTunes audio on mic meter)
9. Full logo in README + About box uses ytLlive-logo.png
Software compositor that renders a scene into the encoder's master VideoFrame,
mirroring the XAML preview minus editing chrome: backdrop -> background ->
elements (UniformToFill cover-crop, round clip, mirror, opacity, border) ->
branding flash.
NOTE FOR USERS: this change shows NO difference in the app's UI — it is pure
backend scaffolding laying the groundwork for live video capture/streaming.
The preview you see is unchanged.
- Services/Compositor/: SceneCompositor (Render(scene, frameFor resolver,
flashFrame, CompositorOptions)), CompositorOptions (source rect + output
size; 16:9 full master, vertical 607x1080 -> 1080x1920), StretchMath (pure
UniformToFill + bilinear), StaticPixelCache (asset bytes -> BGRA8 frame)
- Frame sources injected via Func<SceneElement, VideoFrame?> resolver, so the
compositor is pure, WPF-free, and hermetic to test (D3D11 upgrade behind the
same seam later)
- SceneElement.TryGetBorderColor public (shared hex parse), stale
MainViewModel comment fixed, pre-existing CS1998 in YouTubeAuthServiceTests
cleaned up
- Tests: SceneCompositorTests integration (full scene + vertical tier + flash)
+ StretchMath units, docs updated (72 tests passing, 0 warnings)
gramps