poster-tube-lid: sloping bottom of catch tip

[reprap-play.git] / funcs.scad.cpp

diff --git a/funcs.scad.cpp b/funcs.scad.cpp
index 007ac4568297745bf2c695767ceac8bcab051411..5857c933a837f888bf22faedda5b455e6df0e973 100644 (file)
--- a/funcs.scad.cpp
+++ b/funcs.scad.cpp
@@ -8,6 +8,52 @@ function dist2d(a,b) = sqrt(dsq(0) + dsq(1));
 function dist(a,b)   = sqrt(dsq(0) + dsq(1) + dsq(2));
 #undef dsq
 
+#define vsq(i) (v[i]*v[i])
+function vectorlen2d(v) = sqrt(vsq(0) + vsq(1));
+function vectorlen(v)   = sqrt(vsq(0) + vsq(1) + vsq(2));
+#undef vsq
+
+function unitvector2d(v) = v / vectorlen2d(v);
+function unitvector(v)   = v / vectorlen(v);
+
+function atan2vector(v) = atan2(v[1], v[0]);
+
+// | m[0][0] m[0][1] |
+// | m[1][0] m[1][1] |
+function determinant2(m) = (m[0][0] * m[1][1] - m[0][1] * m[1][0]);
+
+function clockwise2d(v) = [v[1], -v[0]];
+
+// intersection of lines p1..p2 and p3..p4
+function line_intersection_2d(p1,p2,p3,p4) = [
+  // from https://en.wikipedia.org/wiki/Line%E2%80%93line_intersection#Given_two_points_on_each_line
+  #define XY12 determinant2([p1,p2])
+  #define XY34 determinant2([p3,p4])
+  #define XU12 QU(0,1,2)
+  #define XU34 QU(0,3,4)
+  #define YU12 QU(1,1,2)
+  #define YU34 QU(1,3,4)
+  #define QU(c,i,j) determinant2([[ p##i[c], 1 ], \
+                                [ p##j[c], 1 ]])
+  #define DENOM \
+   determinant2([[ XU12, YU12 ], \
+                [ XU34, YU34 ]])
+   //----
+   determinant2([[ XY12, XU12 ],
+                [ XY34, XU34 ]]) / DENOM,
+   determinant2([[ XY12, YU12 ],
+                [ XY34, YU34 ]]) / DENOM,
+   ];
+  #undef XY12
+  #undef XY34
+  #undef XU12
+  #undef XU34
+  #undef YU12
+  #undef YU34
+  #undef QU
+  #undef DENOM
+
+
 function circle_point(c, r, alpha) = [ c[0] + r * cos(alpha),
                                       c[1] + r * sin(alpha) ];
 
@@ -31,3 +77,7 @@ function tangents_intersect_beta(cbig,rbig,csmall,rsmall) =
 
 function reflect_in_y(p) = [-p[0], p[1]];
 
+function angle_map_range(in,base) =
+  in <  base       ? in + 360 :
+  in >= base + 360 ? in - 360 :
+  in;