Design: Editor Geode Chrome Migration

Status: Draft Author: Codex Created: 2026-05-28 Related: 0044-2-editor_fluid_canvas_rendering

Summary

Editor ropes and chips are mostly ImGui chrome today. The next low-risk step is to move their decorative rendering into a Geode-backed screen-space chrome layer while keeping ImGui responsible for labels, hit testing, focus, and tooltips.

This gives the editor a visual and performance path toward Geode without forcing a full UI or text migration immediately.

Current Rendering Split

• SVG content: Geode texture in Geode editor builds.
• Selection/path overlay, AABBs, handles, and marquee: OverlayRenderer renders into an svg::Renderer; Geode builds produce a RendererTextureSnapshot, then ImGui presents it as an image.
• Source-reference ropes: ImGui draw list. TextEditor::renderFocusReferenceLinks() simulates the rope, converts it to a Donner Path, then StrokeDonnerPath() emits ImGui path and bezier commands.
• Source style chips, reference chips, and selection-size chip: ImGui draw-list rectangles plus ImGui text.

Final composition still goes through ImGui draw lists, but the expensive canvas and overlay texture payloads are already Geode-backed.

Next Steps

1. Render source-reference ropes through Geode. Add a clipped screen-space chrome layer and feed it the existing rope donner::Path geometry. This is the lowest-risk first move because the rope path construction already exists.
2. Move chip decorative rendering to Geode. Draw chip backgrounds, borders, glow, and connector flair through Geode. Keep chip labels in ImGui until Geode has a UI-grade text path.
3. Keep ImGui as the interaction owner. Preserve the current ImGui hit rects, hover state, keyboard focus, and tooltips as invisible interaction surfaces over the Geode-rendered chrome.
4. Match existing clip behavior. Clip the Geode chrome layer to the source text area or canvas pane, matching the current ImGui PushClipRect behavior so ropes and chips cannot bleed into adjacent panes.

Guardrails

• The path overlay must remain in lockstep with the SVG content beneath it. Chrome migration must not introduce a separate cached overlay path that can drift during drag, pan, or zoom.
• Do not migrate chip text until Geode has UI-grade text rendering and comparable interaction semantics.
• Do not replace ImGui state ownership in this step. This migration is visual-first: Geode draws the high-churn decorative pixels, while ImGui keeps input semantics stable.
• Reuse the source-pane culling and clipping rules from 0044-2 so chrome cost remains bounded by visible UI.

Acceptance Criteria

• Source-reference ropes can render through a Geode-backed screen-space layer with the same visible shape and clipping as the ImGui implementation.
• Chip backgrounds, borders, glows, and connector flair can render through Geode while labels still render through ImGui.
• Existing ImGui hit rects and tooltips continue to behave as they do today.
• No decorative chrome renders outside the source text area or canvas pane.
• The migration does not require a full editor UI/text rewrite.