WarAmp

You will need to give us more than just your drawing code if you want us to help with a collision issue

It's likely that you are only testing ballvec.X/Y in your collision routine rather than the whole Rectangle, show us how you are determining the collision and 'bounce' and we can help you further

struct MyVertex
{
float x, y, z;  // Vertex
float nx, ny, nz; // Normal
float u, v;   // Texcoords
float a, r, g, b; // Color
float padding[4];
};

My openGL is a bit rusty, but I believe you want the value passed into the gl*Pointer() functions to actually point to the part of the struct that is relevant.
ie:

glNormalPointer(  GL_FLOAT, sizeof(MyVertex), &(*RenderListIT)->RenderMesh->VertexData.nx  );
glTexCoordPointer( 2, GL_FLOAT, sizeof(MyVertex), &(*RenderListIT)->RenderMesh->VertexData.u  );
glColorPointer(  3, GL_FLOAT, sizeof(MyVertex), &(*RenderListIT)->RenderMesh->VertexData.a  );
//etc....

If you are just trying to transform [0, 360] to [180, -180] then just:

newAngle = 180 - angle;

But what would really help us help you is some context. We can sort of see that you are having a problem with OpenAL, but other than just saying 'Not hearable at certain angles' we have no idea what you are doing vs. what the result is you are trying to achieve. Maybe even draw us some pictures to illustrate the problem?

Spend some time explaining the situation and we can spend more time trying to help. The more information you give us, the more we have to work with.

By 'radius for cap' I assume you mean the width of the light at the maximum range?
If so, the angle of the cone is simply given by our old nemesis, Trigonometry.

Tan(angle) = Opposite / Adjacent. In our case, that translates to Tan(angle) = CapRadius/Range

So to get our cosAngle, we do

float angle = atan(Spotlight.CapRadius / Spotlight.Range);
Spotlight.cosAngle = cos(angle);

I recommend just calculating that value once for each spotlight and storing it.

First, compute the distance from the camera to the spotlight. If this distance is greater than the range of the spotlight, then you are not in the cone.

Second, take that Vector that you used for the distance, and dot it with the facing vector of the spotlight. If that value is LESS than the cosine of the angle of the cone, you are OUTSIDE the cone. Else you are in.

bool IsCameraInSpotlightCone
{
	 Vector toCamera = Camera.Position - Spotlight.Position;
	 float dist = toCamera.Length();
	 if (dist > Spotlight.Range)
	 {
		  return false;
	 }
	 toCamera /= dist; 	
	 float cosAngle = dot(toCamera, Spotlight.Direction);
	 if (cosAngle < Spotlight.cosAngle)
	 {
		  return false;
	 }
	 return true;
}

I'm not sure if this should be here or in the Math & Physics forum, if the mods want to move it, I won't complain.

I think I may have solved the Out-scattering integral as given in the GPU-Gems 2 article on atmospheric scattering.

I've written a solution and explanation on my crappy blog.

I would love it if some of you fine folks could go over my solution for me and let me know if I'm right, and perhaps even figure out how to apply it to solving the full In-scattering integral as well.

Thanks!