X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=funcs.scad.cpp;h=007ac4568297745bf2c695767ceac8bcab051411;hb=3a559f2503f11a583d9da3708f5d08b18a3c428b;hp=29d5a1e6dd2ab9bc0a103ad28203d98e20a7dd29;hpb=35c4ebb85758082fd30687a14098f399a6abd914;p=reprap-play.git

diff --git a/funcs.scad.cpp b/funcs.scad.cpp
index 29d5a1e..007ac45 100644
--- a/funcs.scad.cpp
+++ b/funcs.scad.cpp
@@ -1,14 +1,17 @@
 // -*- C -*-
 
-function dist(a,b) =
+function vecdiff2d(a,b) = [b[0]-a[0], b[1]-a[1]];
+function vecdiff(a,b)   = [b[0]-a[0], b[1]-a[1], b[2]-a[2]];
+
 #define dsq(i) (a[i]-b[i])*(a[i]-b[i])
-	       sqrt(dsq(0) + dsq(1));
+function dist2d(a,b) = sqrt(dsq(0) + dsq(1));
+function dist(a,b)   = sqrt(dsq(0) + dsq(1) + dsq(2));
 #undef dsq
 
 function circle_point(c, r, alpha) = [ c[0] + r * cos(alpha),
 				       c[1] + r * sin(alpha) ];
 
-#define d     (dist(a,c))
+#define d     (dist2d(a,c))
 #define alpha (atan2(a[1]-c[1],a[0]-c[0]))
 #define gamma (asin(r / d))
 #define beta  (alpha + 90 - gamma)
@@ -23,5 +26,8 @@ function tangent_intersect_b(c,r,a) =
 #undef gamma
 #undef beta
 
+function tangents_intersect_beta(cbig,rbig,csmall,rsmall) =
+        tangent_intersect_beta(cbig,rbig-rsmall,csmall);
+
 function reflect_in_y(p) = [-p[0], p[1]];