diff --git a/shapes2d.scad b/shapes2d.scad index d87f58fd..3de6bcb4 100644 --- a/shapes2d.scad +++ b/shapes2d.scad @@ -1992,27 +1992,31 @@ function reuleaux_polygon(n=3, r, d, anchor=CENTER, spin=0) = // Synopsis: Creates a shape between a circle and a square, centered on the origin. // SynTags: Geom, Path // Topics: Shapes (2D), Paths (2D), Path Generators, Attachable -// See Also: circle(), square() +// See Also: circle(), square(), supershape() // Usage: As Module // squircle(squareness, size) [ATTACHMENTS]; // Usage: As Function // path = squircle(squareness, size); // Description: -// A squircle is a shape intermediate between a square/rectangle and a circle/ellipse. Squircles are sometimes used to make dinner plates (more area for the same radius as a circle), keyboard buttons, and smartphone icons. Old CRT television screens also resembled squircles. -// When called as a module, creates a 2D squircle with the desired squareness. Uses "intersect" type anchoring. +// A squircle is a shape intermediate between a square/rectangle and a circle/ellipse. A squircle is a special case of supershape (shown in `supershape()` example 3), but this implementation uses a different method that requires just two parameters, and the vertex distribution is optimized for smoothness. +// Squircles are sometimes used to make dinner plates (more area for the same radius as a circle), keyboard buttons, and smartphone icons. Old CRT television screens also resembled squircles. +// When called as a module, creates a 2D squircle with the desired squareness. Uses "intersect" type anchoring. // When called as a function, returns a 2D path for a squircle. // Arguments: -// squareness = Value between 0 and 1. Controls the shape of the squircle. When `squareness=0` the shape is a circle, and when `squareness=1` the shape is a square. Default: 0.8 +// squareness = Value between 0 and 1. Controls the shape of the squircle. When `squareness=0` the shape is a circle, and when `squareness=1` the shape is a square. Default: 0.7 // size = Bounding box of the squircle, same as the `size` parameter in `square()`, can be a single number or an `[xsize,ysize]` vector. Default: [10,10] // $fn = Number of points. Special variables `$fs` and `$fa` are ignored. If set, `$fn` must be 12 or greater, and is rounded to the nearest multiple of 4. Points are generated non-uniformly around the squircle so they are more dense sharper curves. Default if not set: 40 // Examples(2D): -// squircle(squareness=0.5, size=50); -// squircle(0.95, [80,60], $fn=64); +// squircle(squareness=0.4, size=50); +// squircle(0.8, [80,60], $fn=64); +// Examples(2D): Ten increments of squareness parameter +// for(sq=[0:0.1:1]) +// stroke(squircle(sq, 100, $fn=128), closed=true, width=0.5); // Examples(2D): Standard vector anchors are based on extents // squircle(0.8, 50) show_anchors(custom=false); // Examples(2D): Named anchors exist for the sides and corners // squircle(0.8, 50) show_anchors(std=false); -module squircle(squareness=0.8, size=[10,10], anchor=CENTER, spin=0) { +module squircle(squareness=0.7, size=[10,10], anchor=CENTER, spin=0) { check = assert(squareness >= 0 && squareness <= 1); bbox = is_num(size) ? [size,size] : point2d(size); assert(all_positive(bbox), "All components of size must be positive."); @@ -2034,10 +2038,11 @@ module squircle(squareness=0.8, size=[10,10], anchor=CENTER, spin=0) { } -function squircle(squareness=0.8, size=[10,10]) = +function squircle(squareness=0.7, size=[10,10]) = assert(squareness >= 0 && squareness <= 1) [ let( - sq = sqrt(squareness), // somewhat linearize the squareness response + sqlim = max(0, min(1, squareness)), + sq = sqrt(sqlim*(2-sqlim)), // somewhat linearize squareness response bbox = is_num(size) ? [size,size] : point2d(size), aspect = bbox[1] / bbox[0], r = 0.5 * bbox[0],