Switch focus to 2d to avoid 3d mink

poly_gates.scad

@@ -56,28 +56,20 @@ function throw_faces(points) = let(length = len(points), half = len(points) / 2)
 
 function lerp(a,b,t) = a + (b - a) * t;
 
-module shape_gate (shape, throw, shaft_r, sharpness = 0) {
+module shape_gate (shape, throw, shaft_r, sharpness = 1) {
-  sharpness = lerp(1, shaft_r, max(0, min(sharpness, 1)));
+  corner_r = shaft_r * sharpness;
-
+  corner_offset = shaft_r - corner_r;
-  corner_r = shaft_r / sharpness;
-  corner_offset = corner_r * (sharpness - 1);
 
   points = throw_points(shape, throw, corner_offset);
-  echo(points);
+  
-  echo(corner_offset);
-  echo(abs(corner_offset) * tan(throw));
-
-  difference(){
   minkowski(){
     polyhedron(points, throw_faces(points));
     cylinder(1, corner_r);
   }
-  translate([0,0,gate_height + 16])
-    cube(32, true);
-  }
 }
 
-sharpness = sin(180 * $t);
+sharpness = $t;
 echo(sharpness);
 
-shape_gate(sq_poly, 10, 9 / 2, sharpness);
+shape_gate(sq_poly, 10, 9 / 2, 1);
+  

round_polygon.scad

@@ -0,0 +1,41 @@
+$fn=32;
+
+scale = 1;
+card = scale;
+corn = scale / sqrt(2);
+
+function scale_xy(xy, m) = [ for (i = m) [i.x * xy, i.y * xy]];
+
+function normalize(vec) = vec / norm(vec);
+
+function grow(shape, mag) = [ for (i = shape) i + normalize(i) * mag];
+
+function add_radius(shape, rad) = grow(shape, rad/cos(180/len(shape)));
+
+function lerp(a,b,t) = a + (b - a) * t;
+
+module round_poly(shape, radius, sharpness = 0){
+    corner_r = lerp(radius, 0, sharpness);
+    corner_offset = lerp(0, radius, sharpness);
+    
+    
+    minkowski(){
+        polygon(add_radius(shape,corner_offset));
+        circle(max(corner_r, 0.0001));
+    }
+}
+
+oct = [
+    [card,0],
+    [corn,corn],
+    [0,card],
+    [-corn,corn],
+    [-card,0],
+    [-corn,-corn],
+    [0,-card],
+    [corn,-corn]
+];
+
+radius = 1;
+
+round_poly(oct,radius, 1);