Pick a rectangular window in model space with the existing PLOTWINDOW command (now enabled in model space, previously paper-space only) and export it to a PDF at a chosen ISO paper size (A4-A0), orientation and scale (fit or ratio). The window is a hard clip boundary. Adds paper-size presets, a window-to-sheet transform, scale + clip support in the PDF exporter, and Page Setup controls (format/orientation/pick window).
The batched hatch pass evaluates its fill procedurally per fragment — a
point-in-polygon test over the whole boundary plus the pattern test, with a
`discard` that disables early-Z. When the view sits inside a hatch its quad
covers the screen, so panning / zooming re-runs that full-screen shader every
frame (~40 ms/frame on a hatch-heavy plan) even though the rest of the scene
is cheap — the wire pass and CPU prepare are negligible by comparison.
Suppress the hatch pass while the view is actively panning / zooming /
orbiting, detected from `camera_generation` plus a short settle timer
(`Scene::navigating_lod`), and fold that state into the render signature so
the moment the view settles it renders hatches once and the scene-render
cache holds that full-quality frame. A brief `is_settling` subscription keeps
requesting frames just past the settle point so the hatched frame renders
even when no input event would otherwise fire. Mirrors AutoCAD's adaptive
degradation. The paper sheet keeps its fills.
Every cursor movement over the viewport re-rendered the entire GPU scene
(all wires, hatches, meshes) even when nothing visible changed: iced redraws
the whole window on each input message, and the shader's draw/prepare/render
runs every time. On large drawings one such redraw exceeds the frame budget,
so moving the mouse or panning stutters — and it gets worse the bigger the
drawing.
The pipeline already resolves each frame into a persistent, clip-sized
resolve texture and blits that to the surface. This hashes the inputs that
determine the rendered image (camera uniforms, geometry/selection
generations, wire content id, render-mode flags, clip size, live preview
coordinates) into a per-viewport signature. When a frame's signature matches
the previous one the image is pixel-identical, so `prepare` skips the buffer
uploads + per-frame scissor/LOD recompute and `render` skips passes 1-7 plus
the MSAA resolve, re-blitting the resolve texture instead. A pure cursor move
becomes a single fullscreen blit rather than an O(N) re-rasterization.
The ViewCube is excluded from the signature (it renders in its own always-on
pass) so cube hover still tracks while the scene is cached. Any real change —
edit (geometry_epoch), select/hover (selection_generation), camera move or
render-mode toggle — differs the signature and forces a full render, so
nothing goes stale. Navigation still renders every frame (the view genuinely
changes); this targets the wasted re-render on cursor-only movement.