Merge newboolean branch into master.

This is for design task T67744, Boolean Redesign.
It adds a choice of solver to the Boolean modifier and the
Intersect (Boolean) and Intersect (Knife) tools.
The 'Fast' choice is the current Bmesh boolean.
The new 'Exact' choice is a more advanced algorithm that supports
overlapping geometry and uses more robust calculations, but is
slower than the Fast choice.
The default with this commit is set to 'Exact'. We can decide before
the 2.91 release whether or not this is the right choice, but this
choice now will get us more testing and feedback on the new code.

1 files changed, 46 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_float2.hh b/source/blender/blenlib/BLI_float2.hh
index e55a8de4633..1290eb6c65c 100644
--- a/source/blender/blenlib/BLI_float2.hh
+++ b/source/blender/blenlib/BLI_float2.hh
@@ -47,6 +47,11 @@ struct float2 {
     return &x;
   }
 
+  float length() const
+  {
+    return len_v2(*this);
+  }
+
   float2 &operator+=(const float2 &other)
   {
     x += other.x;
@@ -107,6 +112,47 @@ struct float2 {
     return stream;
   }
 
+  static float dot(const float2 &a, const float2 &b)
+  {
+    return a.x * b.x + a.y * b.y;
+  }
+
+  static float2 interpolate(const float2 &a, const float2 &b, float t)
+  {
+    return a * (1 - t) + b * t;
+  }
+
+  static float2 abs(const float2 &a)
+  {
+    return float2(fabsf(a.x), fabsf(a.y));
+  }
+
+  static float distance(const float2 &a, const float2 &b)
+  {
+    return (a - b).length();
+  }
+
+  static float distance_squared(const float2 &a, const float2 &b)
+  {
+    return float2::dot(a, b);
+  }
+
+  struct isect_result {
+    enum {
+      LINE_LINE_COLINEAR = -1,
+      LINE_LINE_NONE = 0,
+      LINE_LINE_EXACT = 1,
+      LINE_LINE_CROSS = 2,
+    } kind;
+    float lambda;
+    float mu;
+  };
+
+  static isect_result isect_seg_seg(const float2 &v1,
+                                    const float2 &v2,
+                                    const float2 &v3,
+                                    const float2 &v4);
+
   friend bool operator==(const float2 &a, const float2 &b)
   {
     return a.x == b.x && a.y == b.y;