added operator*(Vector,double) and operator/(Vector,double) to util/Vector; added lookAt() to util/Transform (needs testing)

git-svn-id: svn://anubis/fart/trunk@63 7f9b0f55-74a9-4bce-be96-3c2cd072584d

util/Transform.cc

@@ -13,6 +13,29 @@ Transform Transform::getInverse()
     return inv;
 }
 
+void Transform::lookAt(const Vector & eye,
+                       const Vector & focus,
+                       const Vector & up)
+{
+    Vector forward = focus - eye;
+    forward.normalize();
+    Vector up_projected_onto_forward = forward * (up % forward) / up.mag2();
+    Vector perpendicular_up = (up - up_projected_onto_forward).normalize();
+    Vector right = forward * perpendicular_up;
+    Matrix mult;
+    mult[0][0] = right[0];
+    mult[0][1] = right[1];
+    mult[0][2] = right[2];
+    mult[1][0] = forward[0];
+    mult[1][1] = forward[1];
+    mult[1][2] = forward[2];
+    mult[2][0] = perpendicular_up[0];
+    mult[2][1] = perpendicular_up[1];
+    mult[2][2] = perpendicular_up[2];
+    m_matrix *= mult;
+    translate(-eye[0], -eye[1], -eye[2]);
+}
+
 void Transform::translate(double x, double y, double z)
 {
     Matrix t = Matrix::identity();

util/Transform.h

@@ -12,6 +12,9 @@ class Transform
     public:
         Transform();
         Transform getInverse();
+        void lookAt(const Vector & eye,
+                    const Vector & focus,
+                    const Vector & up);
         void translate(double x, double y, double z);
         void rotate(double angle, double xv, double yv, double zv);
         void scale(double xs, double ys, double zs);

util/Vector.cc

@@ -79,3 +79,21 @@ Vector operator-(const Vector & v1, const Vector & v2)
     result[2] = v1[2] - v2[2];
     return result;
 }
+
+Vector operator*(const Vector & v1, double scale)
+{
+    Vector result = v1;
+    result[0] *= scale;
+    result[1] *= scale;
+    result[2] *= scale;
+    return result;
+}
+
+Vector operator/(const Vector & v1, double scale)
+{
+    Vector result = v1;
+    result[0] /= scale;
+    result[1] /= scale;
+    result[2] /= scale;
+    return result;
+}

util/Vector.h

@@ -24,5 +24,7 @@ double operator%(const Vector & v1, const Vector & v2);
 Vector operator*(const Vector & v1, const Vector & v2);
 Vector operator+(const Vector & v1, const Vector & v2);
 Vector operator-(const Vector & v1, const Vector & v2);
+Vector operator*(const Vector & v1, double scale);
+Vector operator/(const Vector & v1, double scale);
 
 #endif