I've written a couple other openGL camera's before, but for some reason this one is giving me trouble and I just can't see where the problem is.
class Camera {
public:
Camera(const Camera & cam) {
_transform = cam._transform;
}
Camera(Vector & position, Vector & lookAtPoint, Vector & up) {
Vector look = lookAtPoint - position;
VectorMath::Normalize(look);
Vector right = VectorMath::Cross(up, look);
_transform.GetColumn(0) = right;
_transform.GetColumn(1) = VectorMath::Cross(look, right);
_transform.GetColumn(2) = look;
_transform.GetColumn(3) = position;
_normalize();
_transform.InvertAffine();
}
void SetView() {
glLoadMatrixf(_transform.ToGLMatrix());
}
void SetPosition(Vector & position) {
_transform[3] = position * -1.0f;
}
void Rotate(float amount, Vector & axis) {
float temp[16];
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadMatrixf(_transform.ToGLMatrix());
glRotatef(-amount, axis.x, axis.y, axis.z);
glGetFloatv(GL_MODELVIEW_MATRIX, temp);
_transform.FromGLMatrix(temp);
glPopMatrix();
}
void Move(Vector & amount) {
_transform[3].x += -amount.x;
_transform[3].y += -amount.y;
_transform[3].z += -amount.z;
}
inline Vector GetPosition() {
return _transform[3] * -1.0f;
}
inline Vector GetLook() {
return _transform.GetRow(2);
}
private:
void _normalize() {
VectorMath::Normalize(_transform[0]);
VectorMath::Normalize(_transform[1]);
VectorMath::Normalize(_transform[2]);
}
Matrix _transform;
};
And in my rendering loop:
mainCam.SetView();
// For brevity the input handling code is omitted but certain
// input calls the following functions
mainCam.Rotate(len * 0.5f, axis);
mainCam.Move(Vector(dx * 0.05f, -dy * 0.05f));
The problem is that rotations don't properly rotate the camera. When I call Rotate() it just rotates the objects around the origin rather than rotating the camera around it's local coordinates. I'm sure I just am having a mental block but I've been playing with it for a few hours and haven't made any progress.
