Canvas Studio

Canvas Studio

A shared design surface built on Fabric.js. One real browser window runs the canvas; the human works in it directly (select, drag, recolor), and the local AI attaches to that exact page to see it (screenshots) and drive it (scripts the Fabric canvas). Same page, both of you.

Why Fabric.js: it gives pixel-level vector control (arbitrary bézier Paths), arbitrary hex + linear/radial gradients (shades/depth), image/pattern textures, shadows & blend modes (depth), groups/z-order (layers), and clean-enough SVG export — and it proved it can reproduce the real inspiration logos exactly. Crucially, on a real canvas depth and negative space are just layering (put a background-coloured shape between the stroke and the accent — WYSIWYG, no boolean cut), which is the exact thing that fought us in the headless path.

The canvas auto-seeds a gallery of design iterations on load (window.studio.gallery()) — versions laid out side by side as a visual history. Individual seeds (seedMindmap(), seedGraphene({…})) and clone() let you grow that history.

Workflow — the AGENT runs this (the human never touches a terminal)

1. Already running? curl -s localhost:5179/shapes — if it responds, skip to step 4.
2. Install once if needed: if canvas-studio/node_modules is missing, run cd canvas-studio && npm install (fabric + a browser; ~1 min).
3. Launch in the background (persists across turns; opens the canvas window on the user's screen):

   cd canvas-studio && npm run studio
   

   Then wait for readiness: until curl -s localhost:5179/shapes >/dev/null 2>&1; do sleep 1; done.
4. Draft from the brief. Build/adjust the mark via /eval, bringing depth + negative space in from the first pass. Screenshot, critique, refine 1–2 times.
5. Hand off. Tell the user the window is theirs; on each later turn, screenshot first to pick up their edits, then continue.

Runs on the user's machine (opens a real window). If there's no display, fall back to the gal-shir-brand-logo-design headless path.

The control API (the AI drives it with curl)

The page exposes window.canvas (the Fabric Canvas), window.fabric, and window.studio (shapes(), exportSvg(), clear(), radial(x1,y1,r1,x2,y2,r2,stops), add(obj), seedMindmap()).

Create / style / layer (via /eval):

(() => {
  const c = window.canvas, f = window.fabric;
  // a monoline stroke (arbitrary bézier, exact coords, round caps)
  const arm = new f.Path('M60 240 L60 130 Q110 80 160 130 L160 240', {
    fill: '', stroke: '#1a1a2e', strokeWidth: 26, strokeLineCap: 'round', strokeLineJoin: 'round' });
  // a node with a REAL radial gradient (depth), exact hex
  const node = new f.Circle({ left: 60, top: 70, radius: 30, originX: 'center', originY: 'center' });
  node.set('fill', window.studio.radial(20, 20, 0, 30, 30, 42,
    [{ offset: 0, color: '#8fe8dd' }, { offset: 1, color: '#0d9488' }]));
  // NEGATIVE SPACE by layering: paper-coloured halo ON TOP of the stroke, node on top of that
  const halo = new f.Circle({ left: 60, top: 70, radius: 42, originX: 'center', originY: 'center', fill: '#f7f7f4' });
  c.add(arm, halo, node);            // add-order = z-order (preserveObjectStacking is on)
  c.requestRenderAll();
  return window.studio.shapes().length;
})()

• Move / recolor: obj.set({ left, top, fill:'#123456', opacity:0.9 }); c.requestRenderAll();
• Depth: obj.set('shadow', new f.Shadow({ color:'rgba(0,0,0,.25)', blur:20, offsetX:0, offsetY:8 })); or a two-tone facet (a darker shape clipped/stacked on the node); or obj.globalCompositeOperation = 'multiply' for blends.
• Textures: new f.Pattern({ source: imgEl, repeat:'repeat' }) as a fill.
• Layer order: c.bringObjectToFront(obj) / c.sendObjectToBack(obj) / add-order.
• Delete / group: c.remove(obj) · new f.Group([a,b]).

Reference objects from /shapes (index/id) or window.canvas.getObjects().

Iterate by CLONING — never destroy prior versions

The canvas is a visual history of the design. When the user asks for a change, do not edit the current mark in place or reseed over it. Instead:

1. Clone the current iteration so the previous version stays on the canvas — curl -s -XPOST localhost:5179/eval --data 'window.studio.clone(430)' duplicates the selected group and drops the copy to the right (pass dx,dy). If nothing is selected, select the latest group first (window.canvas.setActiveObject(...)).
2. Modify the clone only — apply the requested change to the copy.
3. Line them up left→right (or top→bottom) so the user can compare the whole history. Keep each iteration as one group (so it clones/moves/labels as a unit) with a small caption above it. window.studio.gallery() reseeds the current comparison row.

Collaboration etiquette (every round)

1. Screenshot first — see the canvas (incl. the human's tweaks) before acting.
2. Clone, then make one intentful change on the copy (see above), then screenshot + critique against the goal. Loop.
3. Hand off — invite direct tweaks; screenshot next turn to pick them up.
4. Deliver — curl /export -o <name>.svg, then run it through SVGO if shipping.

The design brain (reuse it)

Canvas Studio is the hands. For the taste use the gal-shir-brand-logo-design skill: references/gal-shir-principles.md, references/idea-generation.md, and the reverse-engineered examples in references/inspirations/. Bring depth and negative space in from the first concept — and here they're easy (gradients, shadows, and layered paper-coloured shapes, all WYSIWYG).

Notes

• Colour is exact — arbitrary hex, linear/radial gradients, opacity, blends. (No more themed-palette remapping.)
• SVG export via canvas.toSVG() is clean for paths/gradients/shadows; run SVGO before shipping. Bitmap textures export as embedded images.
• Screenshots are UI-free (the canvas has no heavy chrome), so /screenshot is already a clean preview; /export is the vector.
• Local single-user + AI (not multi-user cloud).

See README.md for architecture and troubleshooting.