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doc tweaks

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This commit is contained in:
Adrian Mariano 2021-10-11 22:57:19 -04:00
parent fd36b0020e
commit b0bcdade7e
1 changed files with 47 additions and 38 deletions
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85
regions.scad
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@ -156,7 +156,7 @@ function point_in_region(point, region, eps=EPSILON, _i=0, _cnt=0) =
// formed from a list of simple polygons that do not intersect each other.
// Arguments:
// region = region to check
// eps = tolerance for geometric omparisons. Default: `EPSILON` = 1e-9
// eps = tolerance for geometric comparisons. Default: `EPSILON` = 1e-9
function is_region_simple(region, eps=EPSILON) =
[for(p=region) if (!is_path_simple(p,closed=true,eps)) 1] == []
&&
@ -286,7 +286,7 @@ function _region_region_intersections(region1, region2, closed1=true,closed2=tru
// closed1 = if false then treat region1 as list of open paths. Default: true
// closed2 = if false then treat region2 as list of open paths. Default: true
// eps = Acceptable variance. Default: `EPSILON` (1e-9)
// Example:
// Example(2D):
// path = square(50,center=false);
// region = [circle(d=80), circle(d=40)];
// paths = split_region_at_region_crossings(path, region);
@ -706,64 +706,73 @@ function _point_dist(path,pathseg_unit,pathseg_len,pt) =
// return_faces = return face list. Default: False.
// firstface_index = starting index for face list. Default: 0.
// flip_faces = flip face direction. Default: false
// Example(2D):
// Example(2D,NoAxes):
// star = star(5, r=100, ir=30);
// #stroke(closed=true, star);
// stroke(closed=true, offset(star, delta=10, closed=true));
// Example(2D):
// #stroke(closed=true, star, width=3);
// stroke(closed=true, width=3, offset(star, delta=10, closed=true));
// Example(2D,NoAxes):
// star = star(5, r=100, ir=30);
// #stroke(closed=true, star);
// stroke(closed=true, offset(star, delta=10, chamfer=true, closed=true));
// Example(2D):
// #stroke(closed=true, star, width=3);
// stroke(closed=true, width=3,
// offset(star, delta=10, chamfer=true, closed=true));
// Example(2D,NoAxes):
// star = star(5, r=100, ir=30);
// #stroke(closed=true, star);
// stroke(closed=true, offset(star, r=10, closed=true));
// Example(2D):
// star = star(5, r=100, ir=30);
// #stroke(closed=true, star);
// stroke(closed=true, offset(star, delta=-10, closed=true));
// Example(2D):
// star = star(5, r=100, ir=30);
// #stroke(closed=true, star);
// stroke(closed=true, offset(star, delta=-10, chamfer=true, closed=true));
// Example(2D):
// star = star(5, r=100, ir=30);
// #stroke(closed=true, star);
// stroke(closed=true, offset(star, r=-10, closed=true, $fn=20));
// Example(2D): This case needs `quality=2` for success
// #stroke(closed=true, star, width=3);
// stroke(closed=true, width=3,
// offset(star, r=10, closed=true));
// Example(2D,NoAxes):
// star = star(7, r=120, ir=50);
// #stroke(closed=true, width=3, star);
// stroke(closed=true, width=3,
// offset(star, delta=-15, closed=true));
// Example(2D,NoAxes):
// star = star(7, r=120, ir=50);
// #stroke(closed=true, width=3, star);
// stroke(closed=true, width=3,
// offset(star, delta=-15, chamfer=true, closed=true));
// Example(2D,NoAxes):
// star = star(7, r=120, ir=50);
// #stroke(closed=true, width=3, star);
// stroke(closed=true, width=3,
// offset(star, r=-15, closed=true, $fn=20));
// Example(2D,NoAxes): This case needs `quality=2` for success
// test = [[0,0],[10,0],[10,7],[0,7], [-1,-3]];
// polygon(offset(test,r=-1.9, closed=true, quality=2));
// //polygon(offset(test,r=-1.9, closed=true, quality=1)); // Fails with erroneous 180 deg path error
// %down(.1)polygon(test);
// Example(2D): This case fails if `check_valid=true` when delta is large enough because segments are too close to the opposite side of the curve.
// Example(2D,NoAxes): This case fails if `check_valid=true` when delta is large enough because segments are too close to the opposite side of the curve.
// star = star(5, r=22, ir=13);
// stroke(star,width=.2,closed=true);
// stroke(star,width=.3,closed=true);
// color("green")
// stroke(offset(star, delta=-9, closed=true),width=.2,closed=true); // Works with check_valid=true (the default)
// stroke(offset(star, delta=-9, closed=true),width=.3,closed=true); // Works with check_valid=true (the default)
// color("red")
// stroke(offset(star, delta=-10, closed=true, check_valid=false), // Fails if check_valid=true
// width=.2,closed=true);
// width=.3,closed=true);
// Example(2D): But if you use rounding with offset then you need `check_valid=true` when `r` is big enough. It works without the validity check as long as the offset shape retains a some of the straight edges at the star tip, but once the shape shrinks smaller than that, it fails. There is no simple way to get a correct result for the case with `r=10`, because as in the previous example, it will fail if you turn on validity checks.
// star = star(5, r=22, ir=13);
// color("green")
// stroke(offset(star, r=-8, closed=true,check_valid=false), width=.1, closed=true);
// color("red")
// stroke(offset(star, r=-10, closed=true,check_valid=false), width=.1, closed=true);
// Example(2D): The extra triangles in this example show that the validity check cannot be skipped
// Example(2D,NoAxes): The extra triangles in this example show that the validity check cannot be skipped
// ellipse = scale([20,4], p=circle(r=1,$fn=64));
// stroke(ellipse, closed=true, width=0.3);
// stroke(offset(ellipse, r=-3, check_valid=false, closed=true), width=0.3, closed=true);
// Example(2D): The triangles are removed by the validity check
// stroke(offset(ellipse, r=-3, check_valid=false, closed=true),
// width=0.3, closed=true);
// Example(2D,NoAxes): The triangles are removed by the validity check
// ellipse = scale([20,4], p=circle(r=1,$fn=64));
// stroke(ellipse, closed=true, width=0.3);
// stroke(offset(ellipse, r=-3, check_valid=true, closed=true), width=0.3, closed=true);
// stroke(offset(ellipse, r=-3, check_valid=true, closed=true),
// width=0.3, closed=true);
// Example(2D): Open path. The path moves from left to right and the positive offset shifts to the left of the initial red path.
// sinpath = 2*[for(theta=[-180:5:180]) [theta/4,45*sin(theta)]];
// #stroke(sinpath);
// stroke(offset(sinpath, r=17.5));
// Example(2D): Region
// rgn = difference(circle(d=100), union(square([20,40], center=true), square([40,20], center=true)));
// #linear_extrude(height=1.1) for (p=rgn) stroke(closed=true, width=0.5, p);
// #stroke(sinpath, width=2);
// stroke(offset(sinpath, r=17.5),width=2);
// Example(2D,NoAxes): Region
// rgn = difference(circle(d=100),
// union(square([20,40], center=true),
// square([40,20], center=true)));
// #linear_extrude(height=1.1) stroke(rgn, width=1);
// region(offset(rgn, r=-5));
function offset(
path, r=undef, delta=undef, chamfer=false,
@ -936,8 +945,8 @@ function _filter_region_parts(region1, region2, keep1, keep2, eps=EPSILON) =
// Example(2D):
// shape1 = move([-8,-8,0], p=circle(d=50));
// shape2 = move([ 8, 8,0], p=circle(d=50));
// for (shape = [shape1,shape2]) color("red") stroke(shape, width=0.5, closed=true);
// color("green") region(union(shape1,shape2));
// for (shape = [shape1,shape2]) color("red") stroke(shape, width=0.5, closed=true);
function union(regions=[],b=undef,c=undef,eps=EPSILON) =
b!=undef? union(concat([regions],[b],c==undef?[]:[c]), eps=eps) :
len(regions)==0? [] :