I'm making a fps style camera in a 3d game and was learning about Quaternions. I just want the camera to have pitch and heading, but no bank. And not track euler angles over multiple frames. Whats the best way to do this? The code I have looks like this.

1 2 3 4 5 6 7 8 9 10 11 | //Get the change in mouse position V2 diff = normalize(v2_minus(mouseP, state->lastMouseP)); float sensitivity = 3; float angleX = sensitivity*diff.y*dt; float angleY = -sensitivity*diff.x*dt; Quaternion rot = eulerAnglesToQuaternion(angleY, angleX, 0); //rotate the camera orientation by the change in rotation camera.orientation = quaternion_mult(camera.orientation, rot); |

I was wondering if this looks correct and is it equivalent to the below code, which is tracking Euler angles over frames.

1 2 3 4 5 6 7 8 9 10 11 | static V2 eulerXY = {}; float sensitivity = 3; float angleX = sensitivity*diff.y*dt; float angleY = -sensitivity*diff.x*dt; eulerXY.x += angleX; eulerXY.y += angleY; camera.orientation = eulerAnglesToQuaternion(eulerXY.y, eulerXY.x, 0); |

Also in the first code snippet, is:

1 | camera.orientation = quaternion_mult(camera.orientation, rot); |

the same as:

1 | camera.orientation = quaternion_mult(rot, camera.orientation); |

Thanks for your help, any info about the best way to use Quaternions would be great.