DemoViewer.NET.Playback2D.Scene 2.1.1

DemoViewer.NET.Playback2D.Scene

The scene contract of DemoViewer.NET's 2D map: what one frame holds, how a layer draws, how the map's floors and panes are laid out, how a world point maps to the screen and to a named place. SkiaSharp and the BCL only, no UI framework. It is versioned with DemoViewer.NET.Extensions.Sdk.

<ItemGroup>
  <PackageReference Include="DemoViewer.NET.Extensions.Sdk" Version="1.2.*" />
  <PackageReference Include="DemoViewer.NET.Playback2D.Scene" Version="1.2.*" />
</ItemGroup>

The app ships this assembly and SkiaSharp, so copies in your extension's folder are never loaded. Build against the SkiaSharp version this package depends on.

Every type sits under DemoViewer.NET.Playback2D, matching the package's root namespace: the scene contract, place lookup, the sidecar identity records and the content key alike.

What is in it

The app's own layers (radar, markers, roster and the rest), the drawing tools, video export, keyframes and the render backends are not published. IMapTool is the contract to write a new tool against; IPointerTool is published for tools that hold the playback tab's token editor. Ink authoring is not: the annotation session and the authoring clock are not reachable from IToolServices.

Frames and layers

A Scene2DFrame is valid only for the call it is handed to: the app refills frames in place, so never keep one. Its properties are init-only, which lets a test or a fixture build one with an object initializer.

An ISceneLayer does its work in two steps. Advance runs on the UI thread before each frame is submitted and is the only place a layer may change its own state. Render draws one pane onto the SKCanvas it is given, already clipped and translated, using only the SceneRenderContext: Transform maps world to pane pixels, BelongsHere(z) says whether a world height belongs on the pane's floor, and Palette has the theme's colours. Render runs once per pane and may run on the render thread, so it must not change anything. Layer ids beginning playback2d. or hud. are the app's.

Tools

An IMapTool handles a pointer gesture on a map. OnPressed decides: return true to own the gesture, and the tool then sees each OnMoved and the OnReleased, or OnCancelled when the gesture is abandoned (Escape, a lost capture). A MapToolEvent carries the pane under the pointer, the point in the view, in the pane and in the world, the button and the keys held. The IMapToolContext finds the pane at a point, projects a world point through a pane's camera, gives the world units one pixel covers (for hit radii that stay the same size on screen) and asks for a repaint.