WM_MOUSEMOVE not working with FPS camera implemetation in Direct3D

hey guys, i am trying to implement an开发者_开发技巧 FPS=Style camera. The mouse movement is working but without even touching the mouse. The camera is going on all degrees without me even touching the mouse. Basically, the yaw and the pitch are getting wrong values from the mouse without the movement of the mouse itself. here is the code for the win32 loop

    case WM_MOUSEMOVE:
        gCamera->Yaw() = (float)LOWORD(lparam);
        gCamera->Pitch() = (float)HIWORD(lparam);
        break;

the Yaw and Pitch methods basically return a reference to the data members mPitch and mYaw, and through them, i do the rotations for the basis vectors(right, up and look vectors)

Just to clarify, i WM_MOUSEMOVE is getting input(i checked through debugging), but it is getting very high and very wrong values because i am not even moving the mouse and because the camera is rotating in every direction like it just ate some rocket fuel.

P.S: i had to typecast the values because i am using the Yaw and the Pitch to create matrices, i have to use floats.

Appreciate the help, guys

Keep in mind your units. The WM_MOUSEMOVE lparam x & y values are in logical (screen pixel) coordinates, but most rotation values in games are expected in terms of degrees or radians. For instance, if the mouse is at say <400, 300> but your camera class expects radians, then you're multiplying a large number of rotations against some other (potentially varying) numbers in your transform math, potentially leading to crazy movement even though you're not moving the mouse. The solution in such a case is to convert your logical units into radians or degrees, using a scale factor of your choosing.

In response to further comments: One way to think about it is to ask yourself the question: how many logical units of movement (by the mouse) do you want to correspond to 360 degrees of rotation?

For instance, if you decided you wanted mouse movement across the full width of the window to correspond to 360 degrees, then then mathematical relationship is

screenW * scaleFactor = 2 * PI

Solve for scaleFactor then apply it to future mouse values using:

mouseX * scaleFactor = orientationInRadians

Keep in mind, this approach would link an absolute mouse location to an absolute camera orientation (for at least one DOF), so you may instead want to track changes in mouse position, rather than absolute mouse position; and then calculate changes in orientation (radians) to apply to existing orientation. The same formula can be used to convert the delta (change amount) from logical coords to radians.