TITANIC: fmatrix refactor, common code for matrix product

Changed the left and right matrix product to use the matrix
product function with the matrix order reversed.

2 files changed, 48 insertions, 32 deletions

diff --git a/engines/titanic/star_control/fmatrix.cpp b/engines/titanic/star_control/fmatrix.cpp
index 21b2e4e385..04f9c889da 100644
--- a/engines/titanic/star_control/fmatrix.cpp
+++ b/engines/titanic/star_control/fmatrix.cpp
@@ -29,6 +29,12 @@ FMatrix::FMatrix() :
 	_row1(1.0, 0.0, 0.0), _row2(0.0, 1.0, 0.0), _row3(0.0, 0.0, 1.0) {
 }
 
+FMatrix::FMatrix(const FVector &row1, const FVector &row2, const FVector &row3) {
+	_row1 = row1;
+	_row2 = row2;
+	_row3 = row3;
+}
+
 FMatrix::FMatrix(const DAffine &src) {
 	copyFrom(src);
 }
@@ -81,6 +87,13 @@ void FMatrix::identity() {
 	_row3 = FVector(0.0, 0.0, 1.0);
 }
 
+void FMatrix::set(const FMatrix &m) {
+	_row1 = m._row1;
+	_row2 = m._row2;
+	_row3 = m._row3;
+}
+
+
 void FMatrix::set(const FVector &row1, const FVector &row2, const FVector &row3) {
 	_row1 = row1;
 	_row2 = row2;
@@ -104,36 +117,30 @@ void FMatrix::set(const FVector &v) {
 	_row2.normalize();
 }
 
-void FMatrix::matRProd(const FMatrix &m) {
-	float x1 = _row1._y * m._row2._x + _row1._z * m._row3._x + _row1._x * m._row1._x;
-	float y1 = _row1._x * m._row1._y + m._row2._y * _row1._y + m._row3._y * _row1._z;
-	float z1 = _row1._x * m._row1._z + _row1._y * m._row2._z + _row1._z * m._row3._z;
-	float x2 = m._row1._x * _row2._x + m._row3._x * _row2._z + m._row2._x * _row2._y;
-	float y2 = m._row3._y * _row2._z + m._row1._y * _row2._x + m._row2._y * _row2._y;
-	float z2 = _row2._z * m._row3._z + _row2._x * m._row1._z + _row2._y * m._row2._z;
-	float x3 = m._row1._x * _row3._x + _row3._z * m._row3._x + _row3._y * m._row2._x;
-	float y3 = _row3._y * m._row2._y + _row3._z * m._row3._y + _row3._x * m._row1._y;
-	float z3 = _row3._x * m._row1._z + _row3._y * m._row2._z + _row3._z * m._row3._z;
+void FMatrix::matProd(const FMatrix &a, const FMatrix &m, FMatrix &C) {
+	C._row1._x = a._row1._y * m._row2._x + a._row1._z * m._row3._x + a._row1._x * m._row1._x;
+        C._row1._y = a._row1._x * m._row1._y + m._row2._y * a._row1._y + m._row3._y * a._row1._z;
+        C._row1._z = a._row1._x * m._row1._z + a._row1._y * m._row2._z + a._row1._z * m._row3._z;
+        C._row2._x = m._row1._x * a._row2._x + m._row3._x * a._row2._z + m._row2._x * a._row2._y;
+        C._row2._y = m._row3._y * a._row2._z + m._row1._y * a._row2._x + m._row2._y * a._row2._y;
+        C._row2._z = a._row2._z * m._row3._z + a._row2._x * m._row1._z + a._row2._y * m._row2._z;
+        C._row3._x = m._row1._x * a._row3._x + a._row3._z * m._row3._x + a._row3._y * m._row2._x;
+        C._row3._y = a._row3._y * m._row2._y + a._row3._z * m._row3._y + a._row3._x * m._row1._y;
+        C._row3._z = a._row3._x * m._row1._z + a._row3._y * m._row2._z + a._row3._z * m._row3._z;
+}
 
-	_row1 = FVector(x1, y1, z1);
-	_row2 = FVector(x2, y2, z2);
-	_row3 = FVector(x3, y3, z3);
+void FMatrix::matRProd(const FMatrix &m) {
+        FMatrix C = FMatrix();
+        FMatrix A = FMatrix(_row1,_row2,_row3);
+        matProd(A,m,C);
+        this->set(C);
 }
 
 void FMatrix::matLProd(const FMatrix &m) {
-	float x1 = _row2._x * m._row1._y + m._row1._z * _row3._x + _row1._x * m._row1._x;
-	float y1 = m._row1._x * _row1._y + _row3._y * m._row1._z + _row2._y * m._row1._y;
-	float z1 = m._row1._x * _row1._z + m._row1._y * _row2._z + m._row1._z * _row3._z;
-	float x2 = _row1._x * m._row2._x + _row2._x * m._row2._y + _row3._x * m._row2._z;
-	float y2 = _row3._y * m._row2._z + _row1._y * m._row2._x + _row2._y * m._row2._y;
-	float z2 = m._row2._z * _row3._z + m._row2._x * _row1._z + m._row2._y * _row2._z;
-	float x3 = _row1._x * m._row3._x + m._row3._z * _row3._x + m._row3._y * _row2._x;
-	float y3 = m._row3._y * _row2._y + m._row3._z * _row3._y + m._row3._x * _row1._y;
-	float z3 = m._row3._x * _row1._z + m._row3._y * _row2._z + m._row3._z * _row3._z;
-
-	_row1 = FVector(x1, y1, z1);
-	_row2 = FVector(x2, y2, z2);
-	_row3 = FVector(x3, y3, z3);
+        FMatrix C = FMatrix();
+        FMatrix A = FMatrix(_row1,_row2,_row3);
+        matProd(m,A,C);
+        this->set(C);
 }
 
 } // End of namespace Titanic
diff --git a/engines/titanic/star_control/fmatrix.h b/engines/titanic/star_control/fmatrix.h
index e783a2342c..3970ac8eb2 100644
--- a/engines/titanic/star_control/fmatrix.h
+++ b/engines/titanic/star_control/fmatrix.h
@@ -47,6 +47,7 @@ public:
 	FVector _row3;
 public:
 	FMatrix();
+	FMatrix(const FVector &, const FVector &, const FVector &);
 	FMatrix(const DAffine &src);
 	FMatrix(const FMatrix &src);
 
@@ -73,6 +74,11 @@ public:
 	/**
 	 * Sets the data for the matrix
 	 */
+	void set(const FMatrix &m);
+
+	/**
+	 * Sets the data for the matrix
+	 */
 	void set(const FVector &row1, const FVector &row2, const FVector &row3);
 
 	/**
@@ -86,16 +92,19 @@ public:
 	void set(const FVector &v);
 
         /**
-         * Changes this matrix, A, to be C, where C=Am.
-         * Matrix m multiplies this matrix (A) on its Right.
-         * Matrix m is said to premultiply A (previous this matrix).
+         * Puts the matrix product between a and m in C, C = am
+         */
+	void matProd(const FMatrix &a, const FMatrix &m, FMatrix &C);
+
+        /**
+         * Changes this matrix, A, to be C, where C=Am. Matrix m multiplies this matrix (A) on its Right.
+         * m is said to premultiply A (the previous this matrix).
          */
 	void matRProd(const FMatrix &m);
 
         /**
-         * Changes this matrix, A, to be C, where C=mA.
-         * Matrix m multiplies this matrix (A) on its Left.
-         * m is said to postmultiply A (previous this matrix).
+         * Changes this matrix, A, to be C, where C=mA. Matrix m multiplies this matrix (A) on its Left.
+         * m is said to postmultiply A (the previous this matrix).
          */
 	void matLProd(const FMatrix &m);