Shape fills

Three flat-filled shapes are built from two points. For the circle, the segment runs from the center to the edge; for the oval and rectangle, the endpoints define opposite corners of the bounding box. If the endpoints are too close to form a shape, null is returned. A click without movement therefore draws nothing.

The diamond uses the segment between the endpoints as its long diagonal. The triangles are built on the segment with fixed interior angles (30-60-90 and 45-45-90). The seed determines which angle is assigned to each corner and which side of the segment the apex lies on.

These fills sample the image at the point where it projects onto the line, then blend the result with a flat base color. The samples stretch into bands perpendicular to the line, much like a slit-scan photograph stretches a single slit over time.

The diamond and triangles use the same slit-scan fill.

Try drawing freely with the tools on this page.