Code:
void Camera::walk(float units)
{
// move only on xz plane for land object
if( _cameraType == LANDOBJECT )
_pos += D3DXVECTOR3(_look.x, 0.0f, _look.z) * units;
if( _cameraType == AIRCRAFT )
_pos += _look * units;
}
void Camera::strafe(float units)
{
// move only on xz plane for land object
if( _cameraType == LANDOBJECT )
_pos += D3DXVECTOR3(_right.x, 0.0f, _right.z) * units;
if( _cameraType == AIRCRAFT )
_pos += _right * units;
}
void Camera::fly(float units)
{
if( _cameraType == AIRCRAFT )
_pos += _up * units;
}
void Camera::pitch(float angle)
{
D3DXMATRIX T;
D3DXMatrixRotationAxis(&T, &_right, angle);
// rotate _up and _look around _right vector
D3DXVec3TransformCoord(&_up,&_up, &T);
D3DXVec3TransformCoord(&_look,&_look, &T);
}
void Camera::yaw(float angle)
{
D3DXMATRIX T;
// rotate around world y (0, 1, 0) always for land object
if( _cameraType == LANDOBJECT )
D3DXMatrixRotationY(&T, angle);
// rotate around own up vector for aircraft
if( _cameraType == AIRCRAFT )
D3DXMatrixRotationAxis(&T, &_up, angle);
// rotate _right and _look around _up or y-axis
D3DXVec3TransformCoord(&_right,&_right, &T);
D3DXVec3TransformCoord(&_look,&_look, &T);
}
void Camera::roll(float angle)
{
// only roll for aircraft type
if( _cameraType == AIRCRAFT )
{
D3DXMATRIX T;
D3DXMatrixRotationAxis(&T, &_look, angle);
// rotate _up and _right around _look vector
D3DXVec3TransformCoord(&_right,&_right, &T);
D3DXVec3TransformCoord(&_up,&_up, &T);
}
}
void Camera::getViewMatrix(D3DXMATRIX* V)
{
// Keep camera's axes orthogonal to eachother
D3DXVec3Normalize(&_look, &_look);
D3DXVec3Cross(&_up, &_look, &_right);
D3DXVec3Normalize(&_up, &_up);
D3DXVec3Cross(&_right, &_up, &_look);
D3DXVec3Normalize(&_right, &_right);
// Build the view matrix:
float x = -D3DXVec3Dot(&_right, &_pos);
float y = -D3DXVec3Dot(&_up, &_pos);
float z = -D3DXVec3Dot(&_look, &_pos);
(*V)(0,0) = _right.x; (*V)(0, 1) = _up.x; (*V)(0, 2) = _look.x; (*V)(0, 3) = 0.0f;
(*V)(1,0) = _right.y; (*V)(1, 1) = _up.y; (*V)(1, 2) = _look.y; (*V)(1, 3) = 0.0f;
(*V)(2,0) = _right.z; (*V)(2, 1) = _up.z; (*V)(2, 2) = _look.z; (*V)(2, 3) = 0.0f;
(*V)(3,0) = x; (*V)(3, 1) = y; (*V)(3, 2) = z; (*V)(3, 3) = 1.0f;
}
I recommend reading the book Directx9 Game Programming - this camera class is in that book. You can use it for basic stuff. However I'm finding out that to implement more advanced things I probably will have to re-design it at some point.