1 files changed, 23 insertions, 62 deletions

diff --git a/engines/titanic/star_control/fpose.cpp b/engines/titanic/star_control/fpose.cpp
index 3f7b03df85..a3697ae6d5 100644
--- a/engines/titanic/star_control/fpose.cpp
+++ b/engines/titanic/star_control/fpose.cpp
@@ -83,6 +83,7 @@ void FPose::identity() {
 	_vector.clear();
 }
 
+// Source: https://en.wikipedia.org/wiki/Rotation_matrix
 void FPose::setRotationMatrix(Axis axis, float amount) {
 	const float ROTATION = 2 * M_PI / 360.0;
 	float sinVal = sin(amount * ROTATION);
@@ -104,11 +105,11 @@ void FPose::setRotationMatrix(Axis axis, float amount) {
 	case Y_AXIS:
 		_row1._x = cosVal;
 		_row1._y = 0.0;
-		_row1._z = sinVal;
+		_row1._z = -sinVal;
 		_row2._x = 0.0;
 		_row2._y = 1.0;
 		_row2._z = 0.0;
-		_row3._x = -sinVal;
+		_row3._x = sinVal;
 		_row3._y = 0.0;
 		_row3._z = cosVal;
 		break;
@@ -145,68 +146,28 @@ void FPose::copyFrom(const FMatrix &src) {
 	_row3 = src._row3;
 }
 
-FPose FPose::fn4() const {
-	float v2, v3, v6, v7, v8, v9, v10, v11;
-	float v12, v13, v14, v15, v16, v17, v18;
+FPose FPose::inverseTransform() const {
 	FPose result;
 
-	v16 = _row3._z * _row2._y;
-	v2 = _row1._x * v16;
-	v3 = 0.0;
-	v18 = v2;
-	if (v2 < 0.0) {
-		v3 = v18;
-		v2 = 0.0;
-	}
-	v6 = _row3._x * _row1._y * _row2._z;
-	if (v6 < 0.0)
-		v3 = v3 + v6;
-	else
-		v2 = v2 + v6;
-	v7 = _row3._y * _row1._z * _row2._x;
-	if (v7 < 0.0)
-		v3 = v3 + v7;
-	else
-		v2 = v2 + v7;
-	if (-(_row3._x * _row1._z * _row2._y) < 0.0)
-		v3 = v3 - _row3._x * _row1._z * _row2._y;
-	else
-		v2 = v2 - _row3._x * _row1._z * _row2._y;
-	if (-(_row1._y * _row2._x * _row3._z) < 0.0)
-		v3 = v3 - _row1._y * _row2._x * _row3._z;
-	else
-		v2 = v2 - _row1._y * _row2._x * _row3._z;
-	v17 = _row2._z * _row3._y;
-	if (-(_row1._x * v17) < 0.0)
-		v3 = v3 - _row1._x * v17;
-	else
-		v2 = v2 - _row1._x * v17;
-	v18 = v3 + v2;
-	assert(!(v18 == 0.0 || fabs(v18 / (v2 - v3)) < 1.0e-10));
-
-	v8 = 1.0 / v18;
-	v18 = v8;
-	result._row1._x = (v16 - v17) * v8;
-	result._row2._x = -(_row2._x * _row3._z - _row3._x * _row2._z) * v8;
-	result._row3._x = (_row3._y * _row2._x - _row3._x * _row2._y) * v8;
-	result._row1._y = -(_row1._y * _row3._z - _row3._y * _row1._z) * v8;
-	result._row2._y = (_row1._x * _row3._z - _row3._x * _row1._z) * v8;
-	result._row3._y = -(_row1._x * _row3._y - _row3._x * _row1._y) * v8;
-	result._row1._z = (_row1._y * _row2._z - _row1._z * _row2._y) * v8;
-	result._row2._z = -(_row1._x * _row2._z - _row1._z * _row2._x) * v8;
-	v9 = result._row1._x;
-	v10 = result._row2._y;
-	v11 = result._row3._y;
-	v12 = result._row1._z;
-	v13 = result._row2._z;
-	result._row3._z = (_row1._x * _row2._y - _row1._y * _row2._x) * v18;
-	v14 = v9;
-	v15 = result._row3._z;
-	result._vector._x = -(v14 * _vector._x
-		+ _vector._y * result._row2._x
-		+ _vector._z * result._row3._x);
-	result._vector._y = -(_vector._x * result._row1._y + v10 * _vector._y + v11 * _vector._z);
-	result._vector._z = -(v12 * _vector._x + v13 * _vector._y + v15 * _vector._z);
+	result._row1._x = _row1._x;
+	result._row2._x = _row1._y;
+	result._row3._x = _row1._z;
+	result._row1._y = _row2._x;
+	result._row2._y = _row2._y;
+	result._row3._y = _row2._z;
+	result._row1._z = _row3._x;
+	result._row2._z = _row3._y;
+	result._row3._z = _row3._z;
+
+	result._vector._x = -(_vector._x * result._row1._x
+		            + _vector._y * result._row2._x
+		            + _vector._z * result._row3._x);
+	result._vector._y = -(_vector._x * result._row1._y
+                           + _vector._y * result._row2._y
+                           + _vector._z * result._row3._y);
+	result._vector._z = -(_vector._x * result._row1._z
+                           + _vector._y * result._row2._z
+                           + _vector._z * result._row3._z);
 
 	return result;
 }