Changeset 1932 for GTP/trunk/Lib/Vis/Preprocessing/src/Triangle3.cpp

Timestamp:

01/03/07 01:36:35 (17 years ago)

Author:

mattausch

Message:

 

File:

• GTP/trunk/Lib/Vis/Preprocessing/src/Triangle3.cpp (modified) (1 diff)

GTP/trunk/Lib/Vis/Preprocessing/src/Triangle3.cpp

@@ -185 +185 @@
 }
 
-}
+
+bool Triangle3::IntersectPlane(const Plane3 &plane, 
+                                                           Vector3 &intersectA, 
+                                                           Vector3 &intersectB) const
+{
+        int side[3];
+
+        // compute distance from plane
+        for (int i = 0; i < 3; ++ i)
+        {
+                side[i] = plane.Side(mVertices[i], Limits::Small);
+        }
+
+        /////
+        // no intersection => early exit
+        if (((side[0] > 0) && (side[1] > 0) && (side[2] > 0)) ||
+                ((side[0] < 0) && (side[1] < 0) && (side[2] < 0)))
+        {
+                return false;
+        }
+
+        /////////////
+        // at least 2 triangle vertices lie in plane => early exit
+
+        for (int i = 0; i < 3; ++ i)
+        {
+                if (!side[i] && !side[(i + 1) % 3])
+                {
+                        intersectA = mVertices[i];
+                        intersectB = mVertices[(i + 1) % 3];
+
+                        return true;
+                }
+        }
+
+        bool foundA = false;
+
+        // compute intersection points
+        for (int i = 0; i < 3; ++ i)
+        {
+                const int i_2 = (i + 1) % 3;
+
+                // intersection found
+                if ((side[i] >= 0) && (side[i_2] <= 0))
+                {       
+                        const float t = plane.FindT(mVertices[i], mVertices[i_2]);
+                        
+                        if (!foundA)
+                        {
+                                intersectA = mVertices[i] + t * (mVertices[i_2] - mVertices[i]);
+                                foundA = true;
+                        }
+                        else
+                        {
+                                intersectB = mVertices[i] + t * (mVertices[i_2] - mVertices[i]);
+                                return true;
+                        }
+                }
+        }
+
+        cout << "warning! wrong triangle - plane intersection" << endl;
+        return false; // something went wrong!
+}
+
+
+}