Changeset 1328 for GTP/trunk/Lib/Vis/Preprocessing/src/Triangle3.cpp

Timestamp:

09/11/06 00:29:47 (18 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

@@ -1 +1 @@
 #include "Triangle3.h"
+#include "Ray.h"
+#include "AxisAlignedBox3.h"
+
 
 namespace GtpVisibilityPreprocessor {
 
-float
-Triangle3::GetSpatialAngle(const Vector3 &point) const
+        
+Triangle3::Triangle3(const Vector3 &a, const Vector3 &b, const Vector3 &c) 
 {
-  return 0.0f;
+        Init(a, b, c);
 }
 
+
+void Triangle3::Init(const Vector3 &a, const Vector3 &b, const Vector3 &c) 
+{
+        mVertices[0] = a;
+        mVertices[1] = b;
+        mVertices[2] = c;
+
 }
+
+
+float Triangle3::GetSpatialAngle(const Vector3 &point) const
+{
+        return 0.0f;
+}
+
+
+int Triangle3::CastRay(const Ray &ray, float &t, const float nearestT) const
+{
+        // get triangle edge vectors and plane normal
+        const Vector3 u = mVertices[1] - mVertices[0];
+    const Vector3 v = mVertices[2] - mVertices[0];
+
+    const Vector3 n = u * v;  // cross product
+
+    const Vector3 dir = ray.GetDir();           // ray direction vector
+    const Vector3 w0 = ray.GetLoc() - mVertices[0];
+
+        // params to calc ray-plane intersect
+    const float a = - DotProd(n, w0);
+    const float b = DotProd(n, dir);
+
+        if (fabs(b) < Limits::Small) 
+        {   
+                // ray is parallel to triangle plane
+        if (a == 0) // ray lies in triangle plane
+                {
+            return Ray::INTERSECTION_OUT_OF_LIMITS;
+                }
+        else
+                {
+                        return Ray::NO_INTERSECTION; // ray disjoint from plane
+                }
+    }
+
+    // get intersect point of ray with triangle plane
+    t = a / b;
+
+    if (t < 0.0) // ray goes away from triangle
+        {
+        return Ray::NO_INTERSECTION; // => no intersect
+        }
+
+    // for a segment, also test if (r > 1.0) => no intersect
+
+        // intersect point of ray and plane
+    const Vector3 pt = ray.GetLoc() + t * dir; 
+
+
+        ///////////////////////////////////////////////
+    //-- is point inside triangle?
+   
+        const Vector3 w = pt - mVertices[0];
+
+        const float uu = DotProd(u, u);
+    const float uv = DotProd(u, v);
+    const float vv = DotProd(v, v);
+    
+        const float wu = DotProd(w, u);
+    const float wv = DotProd(w, v);
+    const float D = uv * uv - uu * vv;
+
+    // get and test parametric coords
+    const float s = (uv * wv - vv * wu) / D;
+
+    if (s < 0.0 || s > 1.0) // pt is outside triangle
+        {
+        return Ray::NO_INTERSECTION;
+        }
+
+        const float s2 = (uv * wu - uu * wv) / D;
+
+    if (s2 < 0.0 || (s + s2) > 1.0) // pt is outside triangle
+        {
+        return Ray::NO_INTERSECTION;
+        }
+
+        return Ray::INTERSECTION; // I is in T
+}
+
+
+AxisAlignedBox3 Triangle3::GetBoundingBox() const
+{
+        AxisAlignedBox3 box;
+        box.Initialize();
+
+        box.Include(mVertices[0]);
+        box.Include(mVertices[1]);
+        box.Include(mVertices[2]);
+
+        return box;
+}
+
+
+Vector3 Triangle3::GetNormal() const 
+{
+        const Vector3 v1 = mVertices[0] - mVertices[1];
+        const Vector3 v2 = mVertices[2]-mVertices[1];
+
+        return Normalize(CrossProd(v2, v1));
+}
+
+
+Vector3 Triangle3::GetCenter() const 
+{
+        return (mVertices[0] + mVertices[1] + mVertices[2]) / 3.0f;
+}
+
+
+float Triangle3::GetArea() const 
+{
+        Vector3 v1=mVertices[0]-mVertices[1], v2=mVertices[2]-mVertices[1];
+        return 0.5f * Magnitude(CrossProd(v2, v1));
+}
+
+
+}