468f2ccc0e
The motivation for this change: while working on an animation recently, I found that there are some gaps that won't close easily via stroke extension or leak size checking. In D14698, I attempted to address this by changing the algorithm of the raster-space flood fill. This patch attempts to address the same issue in vector space by adding two new cases where stroke extensions are added, as suggested by @frogstomp: # **Points of high curvature:** when the curvature at a point is high enough that it's hard to visually distinguish between it and an endpoint, add a stroke extension out along the normal (pointing in the opposite direction of the stroke's acceleration.) This addresses cases where technically the endpoint points up, but there's a sharp corner right below it that should extend to connect. # **Stroke endpoints within a radius**: when two endpoints are close together, regardless of the angle they make, connect them if they are within a radius. This addresses cases like where the two endpoints have effectively parallel tangents, so extensions won't close the gap. Reviewed By: antoniov, mendio, frogstomp Differential Revision: https://developer.blender.org/D14809