Add math library

math.scad

@@ -0,0 +1,5 @@
+function normalize(vec) = vec / norm(vec);
+
+function lerp(a,b,t) = a + (b - a) * t;
+
+function scale_xy(shape, xy, allow_zero = false) = let(s = allow_zero ? xy : sign(xy == 0 ? 1 : xy) * max(abs(xy), 0.0001)) [ for (i = shape) [i.x * s, i.y * s]];

round_polygon.scad

@@ -1,30 +1,9 @@
-$fn=32;
+use<math.scad>;
-
-card = 1;
-corn = 1 / sqrt(2);
-
-oct = [
-    [card,0],
-    [corn,corn],
-    [0,card],
-    [-corn,corn],
-    [-card,0],
-    [-corn,-corn],
-    [0,-card],
-    [corn,-corn]
-];
-
-function scale_xy(shape, xy, allow_zero = false) = let(s = allow_zero ? xy : sign(xy == 0 ? 1 : xy) * max(abs(xy), 0.0001)) [ for (i = shape) [i.x * s, i.y * s]];
-
-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, size = 0, sharpness = 0){
+  function grow(s, m) = [ for (i = s) i + normalize(i) * m];
+  function add_radius(s, r) = grow(s, r/cos(180/len(s)));
+
 corner_r = lerp(radius, 0, sharpness);
     corner_offset = lerp(0, radius, sharpness);
     
@@ -33,5 +12,3 @@ module round_poly(shape, radius, size = 0, sharpness = 0){
         circle(max(corner_r, 0.0001));
     }
 }
-
-round_poly(oct, radius, 4, 0);