Thread: direct x creating projection matrix

I want to create a projection matrix without using D3dx. This is the code I have so far:

They are both Left Handed matrices.

Code:

void Engine::CameraSetProjection(float fov, float aspect, float znear, float zfar)
{
    float yscale = cos(fov)/sin(fov);
    float xscale = aspect/yscale;
    
    D3DMATRIX mat;
    mat._11 = xscale;
    mat._22 = yscale;
    mat._33 = zfar/(zfar-znear);
    mat._34 = 1;
    mat._43 = -znear*zfar/(zfar-znear);
    
    device->SetTransform(D3DTS_PROJECTION, &mat);
}

This is the formula d3dx uses to create a projection matrix:

Code:

xScale     0          0               0
0        yScale       0               0
0          0       zf/(zf-zn)         1
0          0       -zn*zf/(zf-zn)     0
where:
yScale = cot(fovY/2)

xScale = aspect ratio / yScale

How ever, that doesn't seem to be working. I am not seeing the triangles that I did when I used d3dx (I don't see any triangles). And the paramters stayed the same.

I belive my error is in the cot function, I read cot = cos/sin. I also tried cot = 1/tan but neither seem to work.

Any ideas?

Nope, that doesn't work either. Unless do I have to set every value to 0?

Mine worked, I had to ZeroMemory it first.