While you draw or drag, points snap to useful places near the cursor. The snap target is marked with a circle; the nearest shape's candidate points show as small circles.
Snap targets, from most to least preferred when two are equally close:
- Crossings of shapes.
- End points. While you drag a shape, both its ends can snap: the one that snapped shows in gold.
- Middle and quarter points of lines, curves and arcs, and every eighth of a circle (dropped when a shape is very small on screen).
- Tangent points on circles, for the line being drawn.
- Centres of circles and arcs.
- Your snap point (see below).
- Template points: the corners of library templates.
- Grid dots: the dots on screen, while the grid is shown and grid snapping is on.
Grid snapping is on by default. Switch it with View ▸ Snap to grid or by clicking Grid snap in the status bar. It needs the grid to be visible (G). Because the grid follows the zoom, zooming in snaps to a finer step.
Your own snap point. To move a selection by a point that isn't one of its own (the middle of a hole pattern, say), right-click there ▸ Set snap point here. It snaps like a drawn point and shows as a small green diamond. When you drag the selection, the snap point moves with it and snaps onto other shapes' points; it is also the only point of the drag that snaps to the grid dots, even with grid snapping off (the grid must be shown). Drawing and other edits can snap to it too. It moves along when you move, turn, scale or flip the selection, and goes away when you select something else, or with right-click ▸ Clear the snap point. It isn't saved with the project.
Hold Shift while drawing or dragging to keep a line or move horizontal or vertical.
Locked shapes, and shapes on locked layers, are still snapped to. Shapes on an ignored layer (Layer ▸ Ignore the active layer) are not.