Finish implementation of distortion shader

[russell-taylor]

We need a .glsl file for the vertex and fragment shader for the Undistort_Shader class to read.

We need to finish the parameters for the shader.

We need to set the parameters and test all this.

We need to hook the shader into the calibration program, so that you can toggle to a view that renders using that shader with the current parameters.

We might want a simple sample application that renders a scene using the shader.

[rpavlik]

Is an HLSL (for DirectX) version also feasible?

[rpavlik]

cc @yboger

[russell-taylor]

I don't see why not. I don't know DirectX, so am probably not the person to do this. Always glad to learn new things...

[JeroMiya]

I also need an HLSL version of the distortion shaders for OSVR-MonoGame. Preferably in the form of a .fx file with the technique defined as well.

[DuFF14]

OsvrDistortion.shader in the Unity project should be very close to an HLSL version. Unity shaders use Cg, which is almost syntactically identical to HLSL. Maybe just remove the lines with CGINCLUDE, CGPROGRAM, etc..