adding supports, switching util to shape, and trying to abstract ISO enter shape

shapes.scad

@@ -0,0 +1,53 @@
+$fs=.1;
+unit = 19.05;
+
+module key_shape(width, height, width_difference, height_difference, corner_size) {
+	if ($key_shape_type == "iso_enter") {
+		fakeISOEnter(width_difference/2);
+	} else if ($key_shape_type == "normal") {
+		roundedSquare([width - width_difference, height - height_difference], corner_size);
+	} else if ($key_shape_type == "circle") {
+		circle(d=width - width_difference);
+	}
+}
+
+// centered
+module roundedRect(size, radius, center=true) {
+	linear_extrude(height = size[2]){
+		roundedSquare([size[0], size[1]], radius, center=center);
+	}
+}
+
+module roundedSquare(size, radius, center = true) {
+		offset(r=radius){
+			square([size[0] - radius * 2, size[1] - radius * 2], center=center);
+		}
+}
+
+// corollary is roundedSquare
+// NOT 3D
+module fakeISOEnter(thickness_difference = 0){
+	// t is all modifications to the polygon array
+	// t used to contain a corner radius adjustment, but due to
+	// the offset we need that expansion back
+	t = (thickness_difference - (unit - 18.16));
+
+	function unit(length) = unit * length;
+
+  pointArray = [
+      [unit(-.625)  + t,      unit(-1)  + t],
+      [unit(0.625)  - t,      unit(-1)  + t],
+      [unit(0.625)  - t,      unit(1)   - t],
+      [unit(-0.875) + t,      unit(1)   - t],
+      [unit(-0.875) + t,      unit(0)   + t],
+      [unit(-0.625) + t,      unit(0)   + t]
+  ];
+
+	minkowski(){
+		circle(r=$corner_radius);
+		// gives us rounded inner corner
+		offset(r=-$corner_radius*2) {
+			polygon(points=pointArray);
+		}
+	}
+}