Editing Workflow

DemoSpline is designed as the interactive validation host for Spline.

Core editing gestures

Click to add a new corner point.
Alt+Click or click-drag to add a smooth point.
Shift+Click to extend the current point selection.
Double-click to toggle a point between smooth and corner behavior.
Drag tangent handles to set explicit tangents.
Shift+Drag on a tangent handle to constrain it to axis-aligned directions.
Press Delete or Backspace to remove selected points.
Use arrow keys to nudge points by 1 pixel, or Shift+Arrow for 10 pixels.

Tool modes

The sample exposes several tool modes through the menu:

Edit spline
Trace from freehand
Delete point tool
Glyph editing
Curve tuner

View and rendering controls

The main window also exposes:

grid visibility
zoom reset, fit, in, and out
raw cubic rendering toggle
knot reduction
curvature fairing
span straightening

These controls make it practical to compare interactive edits with the underlying library output.