Struct Viewport 

pub struct Viewport { /* private fields */ }

The central 3D viewport: the engine’s render core + the app-owned offscreen texture + the egui blit that composites it into egui’s frame, plus the pointer/wheel/ViewCube routing. Borrows &mut EngineState to draw + drive; never owns the engine brain.

Implementations

impl Viewport

pub fn new(render_state: &RenderState) -> Self

Build the viewport’s GPU resources from eframe’s SHARED render state. We render in the engine’s native COLOR_FORMAT (Rgba8Unorm) — exactly what the headless artifact path uses, so colors are known-good — and the blit converts into eframe’s actual target format.

impl Viewport

pub fn last_rect(&self) -> Option<Rect>

The rect (egui points) the viewport last drew into. Now that the viewport is a dock PANE (its rect moves as the user re-frames it), the shell anchors the floating context / Finish-Cancel overlays to THIS rect’s right edge so they stay glued to the 3D view — see the top-right overlay in app.rs. None before the first draw (shell falls back to window-right until then).

pub fn viewport_rect_json(&self) -> String

The last viewport rect as {x, y, w, h} in egui points (verification: the origin lets the verifier map engine viewport-local pick coords → page px).

pub fn show(&mut self, ui: &mut Ui, state: &mut EngineState)

The clean entry the shell calls: fill the central panel with the 3D viewport — size tracking, input routing, on-demand render, and the blit composite. Borrows the engine brain to draw + drive.

impl Viewport

pub fn forget_document(&mut self)

Drop everything this viewport is holding ABOUT ONE DOCUMENT — called when the shell switches the active document (see crate::document).

The GPU cache is the load-bearing half: GpuScene keys its retained buffers by SOLID NAME and reuses one while the solid’s revision is unchanged, but revisions are per-EngineState and every document counts from the same place — so document B’s “Box” rev 1 would be served document A’s uploaded mesh. Only the active document renders, so a full re-upload on the switch is the right price. The transients after it (pick popup, open dimension editors, in-flight drags) all name entities of the document that is going away.

pub fn close_candidate_popup(&mut self) -> bool

Close the pick-list popup if open; returns whether one WAS open. The app shell’s global Escape routes here FIRST so dismissing the list never clears a selection built through it.