More consolidation of the view map creation.

Made an attempt to fix "2D intersection out of range" warnings.
These warnings may cause "3D intersection out of range" warnings,
which often lead to a crash.

source/blender/freestyle/intern/geometry/GeomUtils.cpp

@@ -152,7 +152,8 @@ namespace GeomUtils {
 						  const Vec2r& p3,
 						  const Vec2r& p4,
 						  real& t,
-						  real& u) {
+						  real& u,
+                          real epsilon) {
     real a1, a2, b1, b2, c1, c2; // Coefficients of line eqns
     real r1, r2, r3, r4;         // 'Sign' values
     real denom, num;             // Intermediate values
@@ -189,7 +190,7 @@ namespace GeomUtils {
 
     // Line segments intersect: compute intersection point.
     denom = a1 * b2 - a2 * b1;
-    if (fabs(denom) < M_EPSILON)
+    if (fabs(denom) < epsilon)
       return (COLINEAR);
     
     real d1, d2, e1;