diff --git a/shapes2d.scad b/shapes2d.scad index 772314f..477b355 100644 --- a/shapes2d.scad +++ b/shapes2d.scad @@ -1503,6 +1503,179 @@ module egg(length,r1,r2,R,d1,d2,D,anchor=CENTER, spin=0) } +// Function&Module: ring() +// Synopsis: Draws a 2D ring or partial ring or returns a region or path +// SynTags: Geom, Region, Path +// Topics: Shapes (2D), Paths (2D), Path Generators, Regions, Attachable +// See Also: arc(), circle() +// +// Usage: ring or partial ring from radii/diameters +// region=ring(n, r1=|d1=, r2=|d2=, [full=], [angle=], [start=]); +// Usage: ring or partial ring from radius and ring width +// region=ring(n, ring_width, r=|d=, [full=], [angle=], [start=]); +// Usage: ring or partial ring passing through three points +// region=ring(n, [ring_width], [r=,d=], points=[P0,P1,P2], [full=]); +// Usage: ring or partial ring from tangent point on segment `[P0,P1]` to the tangent point on segment `[P1,P2]`. +// region=ring(n, [ring_width], corner=[P0,P1,P2], [r=,d=], [r1|d1=], [r2=|d2=], [full=]); +// Usage: ring or partial ring based on setting a width at the X axis and height above the X axis +// region=ring(n, [ring_width], [r=|d=], width=, thickness=, [full=]); +// Usage: as a module +// ring(...) [ATTACHMENTS]; +// Description: +// If called as a function returns a region or path for a ring or part of a ring. If called as a module, creates the corresponding 2D ring or partial ring shape. +// The geometry of the ring can be specified using any of the methods supported by {{arc()}}. If `full` is true (the default) the ring will be complete and the +// returned value a region. If `full` is false then the return is a path describing a partial ring. The returned path is always clockwise with the larger radius arc first. +// A ring has two radii, the inner and outer. When specifying geometry you must somehow specify one radius, which can be directly with `r=` or `r1=` or by giving a point list with +// or without a center point. You specify the second radius by giving `r=` directly, or `r2=` if you used `r1=` for the first radius, or by giving `ring_width`. If `ring_width` +// the second radius will be larger than the first; if `ring_width` is negative the second radius will be smaller. +// Arguments: +// n = Number of vertices to use for the inner and outer portions of the ring +// ring_width = width of the ring. Can be positive or negative +// --- +// r1/d1 = inner radius or diameter of the ring +// r2/d2 = outer radius or diameter of the ring +// r/d = second radius or diameter of ring when r1 or d1 are not given +// full = if true create a full ring, if false create a partial ring. Default: true unless `angle` is given +// cp = Centerpoint of ring. +// points = Points on the ring boundary. +// corner = A path of two segments to fit the ring tangent to. +// long = if given with cp and points takes the long arc instead of the default short arc. Default: false +// cw = if given with cp and 2 points takes the arc in the clockwise direction. Default: false +// ccw = if given with cp and 2 points takes the arc in the counter-clockwise direction. Default: false +// width = If given with `thickness`, ring is defined based on an arc with ends on X axis. +// thickness = If given with `width`, ring is defined based on an arc with ends on X axis, and this height above the X axis. +// start = Start angle of ring. Default: 0 +// angle = If scalar, the end angle in degrees relative to start parameter. If a vector specifies start and end angles of ring. +// anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). (Module only) Default: `CENTER` +// spin = Rotate this many degrees around the Z axis after anchor. See [spin](attachments.scad#subsection-spin). (Module only) Default: `0` +// Examples(2D): +// ring(r1=5,r2=7, n=32); +// ring(r=5,ring_width=-1, n=32); +// ring(r=7, n=5, ring_width=-4); +// ring(points=[[0,0],[3,3],[5,2]], ring_width=2, n=32); +// ring(points=[[0,0],[3,3],[5,2]], r=1, n=32); +// ring(cp=[3,3], points=[[4,4],[1,3]], ring_width=1); +// ring(corner=[[0,0],[4,4],[7,3]], r2=2, r1=1.5,n=22,full=false); +// ring(r1=5,r2=7, angle=[33,110], n=32); +// ring(r1=5,r2=7, angle=[0,360], n=32); // full circle +// ring(r=5, points=[[0,0],[3,3],[5,2]], full=false, n=32); +// ring(32,-2, cp=[1,1], points=[[4,4],[-3,6]], full=false); +// ring(r=5,ring_width=-1, n=32); +// ring(points=[[0,0],[3,3],[5,2]], ring_width=2, n=32); +// ring(points=[[0,0],[3,3],[5,2]], r=1, n=32); +// ring(cp=[3,3], points=[[4,4],[1,3]], ring_width=1); +// Example(2D): Using corner, the outer radius is the one tangent to the corner +// corner = [[0,0],[4,4],[7,3]]; +// ring(corner=corner, r2=3, r1=2,n=22); +// stroke(corner, width=.1,color="red"); +// Example(2D): For inner radius tangent to a corner, specify `r=` and `ring_width`. +// corner = [[0,0],[4,4],[7,3]]; +// ring(corner=corner, r=3, ring_width=1,n=22,full=false); +// stroke(corner, width=.1,color="red"); +// Example(2D): +// $fn=128; +// region = ring(width=5,thickness=1.5,ring_width=2); +// path = ring(width=5,thickness=1.5,ring_width=2,full=false); +// stroke(region,width=.25); +// color("red") dashed_stroke(path,dashpat=[1.5,1.5],closed=true,width=.25); + +module ring(n,ring_width,r,r1,r2,angle,d,d1,d2,cp,points,corner, width,thickness,start, long=false, full=true, cw=false,ccw=false, anchor=CENTER, spin=0) +{ + R = ring(n=n,r=r,ring_width=ring_width,r1=r1,r2=r2,angle=angle,d=d,d1=d1,d2=d2,cp=cp,points=points,corner=corner, width=width,thickness=thickness,start=start, + long=long, full=full, cw=cw, ccw=ccw); + attachable(anchor,spin,two_d=true,region=is_region(R)?R:undef,path=is_region(R)?undef:R,extent=false) { + region(R); + children(); + } +} + +function ring(n,ring_width,r,r1,r2,angle,d,d1,d2,cp,points,corner, width,thickness,start, long=false, full=true, cw=false,ccw=false) = + let( + r1 = is_def(r1) ? assert(is_undef(d),"Cannot define r1 and d1")r1 + : is_def(d1) ? d1/2 + : undef, + r2 = is_def(r2) ? assert(is_undef(d),"Cannot define r2 and d2")r2 + : is_def(d2) ? d2/2 + : undef, + r = is_def(r) ? assert(is_undef(d),"Cannot define r and d")r + : is_def(d) ? d/2 + : undef, + full = is_def(angle) ? false : full + ) + assert(is_undef(start) || is_def(angle), "start requires angle") + assert(is_undef(angle) || num_defined([thickness,width,points,corner]), "Cannot give angle with points, corner, width or thickness") + assert(!is_vector(angle,2) || abs(angle[1]-angle[0]) <= 360, "angle gives more than 360 degrees") + assert(is_undef(points) || is_path(points,2), str("Points must be a 2d vector",points)) + assert(!any_defined([points,thickness,width]) || num_defined([r1,r2])==0, "Cannot give r1, r2, d1, or d2 with points, width or thickness") + is_def(width) && is_def(thickness)? + assert(!any_defined([r,cp,points,angle,start]), "Conflicting or invalid parameters to ring") + assert(all_positive([width,thickness]), "Width and thickness must be positive") + ring(n=n,r=r,ring_width=ring_width,points=[[width/2,0], [0,thickness], [-width/2,0]],full=full) + : full && is_undef(cp) && is_def(points) ? + assert(is_def(points) && len(points)==3, "Without cp given, must provide exactly three points") + assert(num_defined([r,ring_width]), "Must give r or ring_width with point list") + let( + ctr_rad = circle_3points(points), + dummy=assert(is_def(ctr_rad[0]), "Collinear points given to ring()"), + part1 = move(ctr_rad[0],circle(r=ctr_rad[1], $fn=is_def(n) ? n : $fn)), + first_r = norm(part1[0]-ctr_rad[0]), + r = is_def(r) ? r : first_r+ring_width, + part2 = move(ctr_rad[0],circle(r=r, $fn=is_def(n) ? n : $fn)) + ) + assert(first_r!=r, "Ring has zero width") + (first_r>r ? [part1, reverse(part2)] : [part2, reverse(part1)]) + : full && is_def(corner) ? + assert(is_path(corner,2) && len(corner)==3, "corner must be a list of 3 points") + assert(!any_defined([thickness,width,points,cp,angle.start]), "Conflicting or invalid parameters to ring") + let(parmok = (all_positive([r1,r2]) && num_defined([r,ring_width])==0) + || (num_defined([r1,r2])==0 && all_positive([r]) && is_finite(ring_width))) + assert(parmok, "With corner must give (r1 and r2) or (r and ring_width), but you gave some other combination") + let( + newr1 = is_def(r1) ? min(r1,r2) : min(r,r+ring_width), + newr2 = is_def(r2) ? max(r2,r1) : max(r,r+ring_width), + data = circle_2tangents(newr2,corner[0],corner[1],corner[2]), + cp=data[0] + ) + [move(cp,circle($fn=is_def(n) ? n : $fn, r=newr2)),move(cp, circle( $fn=is_def(n) ? n : $fn, r=newr1))] + : full && is_def(cp) && is_def(points) ? + assert(in_list(len(points),[1,2]), "With cp must give a list of one or two points.") + assert(num_defined([r,ring_width]), "Must give r or ring_width with point list") + let( + first_r=norm(points[0]-cp), + part1 = move(cp,circle(r=first_r, $fn=is_def(n) ? n : $fn)), + r = is_def(r) ? r : first_r+ring_width, + part2 = move(cp,circle(r=r, $fn=is_def(n) ? n : $fn)) + ) + assert(first_r!=r, "Ring has zero width") + first_r>r ? [part1, reverse(part2)] : [part2, reverse(part1)] + : full || angle==360 || (is_vector(angle,2) && abs(angle[1]-angle[0])==360) ? + let(parmok = (all_positive([r1,r2]) && num_defined([r,ring_width])==0) + || (num_defined([r1,r2])==0 && all_positive([r]) && is_finite(ring_width))) + assert(parmok, "Must give (r1 and r2) or (r and ring_width), but you gave some other combination") + let( + newr1 = is_def(r1) ? min(r1,r2) : min(r,r+ring_width), + newr2 = is_def(r2) ? max(r2,r1) : max(r,r+ring_width), + cp = default(cp,[0,0]) + ) + [move(cp,circle($fn=is_def(n) ? n : $fn, r=newr2)),move(cp, circle( $fn=is_def(n) ? n : $fn, r=newr1))] + : let( + parmRok = (all_positive([r1,r2]) && num_defined([r,ring_width])==0) + || (num_defined([r1,r2])==0 && all_positive([r]) && is_finite(ring_width)), + pass_r = any_defined([points,thickness]) ? assert(!any_defined([r1,r2]),"Cannot give r1, d1, r2, or d2 with a point list or width & thickness") + assert(num_defined([ring_width,r])==1, "Must defined exactly one of r and ring_width when using a pointlist or width & thickness") + undef + : assert(num_defined([r,r2])==1,"Cannot give r or d and r1 or d1") first_defined([r,r2]), + base_arc = clockwise_polygon(arc(r=pass_r,n=n,angle=angle,cp=cp,points=points, corner=corner, width=width, thickness=thickness,start=start, long=long, cw=cw,ccw=ccw,wedge=true)), + center = base_arc[0], + arc1 = list_tail(base_arc,1), + r_actual = norm(center-arc1[0]), + new_r = is_def(ring_width) ? r_actual+ring_width + : first_defined([r,r1]), + pts = [center+new_r*unit(arc1[0]-center), center+new_r*unit(arc1[floor(len(arc1)/2)]-center), center+new_r*unit(last(arc1)-center)], + second=arc(n=n,points=pts), + arc2 = is_polygon_clockwise(second) ? second : reverse(second) + ) new_r>r_actual ? concat(arc2, reverse(arc1)) : concat(arc1,reverse(arc2)); + // Function&Module: glued_circles() // Synopsis: Creates a shape of two circles joined by a curved waist.