From 2edbc11b1d7b38e3fdb0e88fb550313f176d538b Mon Sep 17 00:00:00 2001
From: Elmom <elmo.mantynen@iki.fi>
Date: Sun, 25 Jul 2010 18:03:04 +0300
Subject: [PATCH] Added curves.scad, includes helix_curve() ATM

---
 curves.scad | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 curves.scad

diff --git a/curves.scad b/curves.scad
new file mode 100644
index 0000000..68102fd
--- /dev/null
+++ b/curves.scad
@@ -0,0 +1,17 @@
+include <constants.scad>
+use <math.scad>
+
+
+/* A circular helix of radius a and pitch 2πb is described by the following parametrisation:
+x(t) = a*cos(t),
+y(t) = a*sin(t),
+z(t) = b*t
+*/
+
+
+function b(pitch) = pitch/(TAU);
+function t(pitch, z) = z/b(pitch);
+
+function helix_curve(pitch, radius, z) =
+    [radius*cos(deg(t(pitch, z))), radius*sin(deg(t(pitch, z))), z];
+