private static extern Matrix4f_Raw ovrMatrix4f_OrthoSubProjection( Matrix4f projection, Vector2f orthoScale, float orthoDistance, float hmdToEyeViewOffsetX);
/// <summary>
/// Used for 2D rendering, Y is down
/// orthoScale = 1.0f / pixelsPerTanAngleAtCenter
/// orthoDistance = distance from camera, such as 0.8m
/// </summary>
public static Matrix4f GetOrthoSubProjection(Matrix4f projection, Vector2f orthoScale, float orthoDistance, float hmdToEyeViewOffsetX)
{
return new Matrix4f(ovrMatrix4f_OrthoSubProjection(projection, orthoScale, orthoDistance, hmdToEyeViewOffsetX));
}