GSOC 2026: System for Nodes Displaying Gizmos to Update Their Parameters

[Ayush2k02]

About

My name is Ayush Amawate (@Ayush2k02) and I worked on the "System for Nodes Displaying Gizmos to Update Their Parameters" project as a Graphite GSoC '26 contributor.

Synopsis

Gizmos are the draggable handles you see on a selected shape the dial that sets a polygon's side count, the points that stretch a star, the edges that add rows to a grid.

Only six shapes had them, and each one needed its own hand-written file of 200–400 lines. That made handles expensive, so anything that wasn't one of those six shapes simply went without.

This project replaced that with a table any node can add itself to. A node now says "this value of mine should have a handle, and it's a length" in about eight lines, and shared code builds the handle from that.

Final Report

What shipped

• All seven shapes now get their handles from the table. They behave exactly as they did before.
• The six hand-written files are gone 1,915 lines deleted.
• Two things that are not shapes Blur and Transform now have handles. That was the whole point: proving the system works for anything, not just shapes.
• A new shape, the Heart, with three handles of its own.
• A guide for the next person adding a handle.

PR	What it does	State
#4478	Adds the Heart shape	Open for review
#4479	Moves all seven shapes onto the new system	Open for review
#4480	Gives handles to Blur and Transform	Draft

Against the original deliverables

#	Deliverable	Done?
1	Gizmo Registry System	✅
2	Generic Gizmo Types Slider, Dial, Position, Angle	⚠️ All four work; the angle one is built on the slider rather than as its own type
3	Generic Gizmo Manager	✅
4	Migration all 6 existing shape gizmos	✅ Seven shapes, not six
5	New Node Gizmos Blur, Transform, optionally Gradient	⚠️ Blur and Transform done; Gradient not started
6	Documentation	✅

Being straight about two things. The total line count went up by roughly 800, not down — the shape-specific part shrank by about a third, but the branch also adds a new shape, a third type of handle, and documentation. And the Blur and Transform handles are written and unit-tested but I haven't sat down and used them yet, which is why that PR is still a draft. Nearly every bug I found in this project was found by using the editor, not by the tests passing.

What I'd do next

• Test the Blur and Transform handles by hand and take Give gizmos to nodes that are not shapes #4480 out of draft.
• Gradient stops the one thing from the proposal still untouched.
• Integration tests, since every fault so far turned up by hand.

A bug worth mentioning, because it isn't fixable by tuning. A circle's radius can be grabbed anywhere on its edge, and there is no rotational rule that behaves well everywhere: follow the direction you grabbed from and the handle goes dead at the top and bottom; use the raw distance instead and it lurches, because near the tangent a pixel of jitter flips the direction. The two things you'd want dragging up and down at the side doing nothing, dragging sideways at the top doing something — are the same motion at different angles. It now just reads left-right: right grows, left shrinks, wherever you grabbed it.

Demos

Screen.Recording.2026-08-27.at.3.05.54.AM.mov

Heart dragging the notch, then the size

1-polygon-sides-dial.mp4

Polygon the dial, 5 → 8 → 4 sides

2-star-radius-snapping-and-points-dial.mp4

Star dragging a point, with the snap marks where the points line up

3-circle-radius.mp4

Circle grabbing the edge from the top and from the bottom

6-spiral-turns.mp4

Spiral winding it from 6.72 to 10.37 turns

5-arc-sweep-endpoints.mp4

Arc sweeping an end round toward a full circle

7-grid-rows.mp4

Grid dragging the top edge to add rows

Thank you to my mentors and the entire Graphite team for their guidance, thorough code reviews, and support throughout this Google Summer of Code!