/// <summary>
/// Creates a matrix for a symmetric perspective-view frustum with far plane
/// at infinite for graphics hardware that doesn't support depth clamping.
/// </summary>
/// <param name="fovy">The fovy.</param>
/// <param name="aspect">The aspect.</param>
/// <param name="zNear">The z near.</param>
/// <returns></returns>
public static Matrix4f tweakedInfinitePerspective(float fovy, float aspect, float zNear)
{
float range = Trigonometric.Tan(fovy / (2)) * zNear;
float left = -range * aspect;
float right = range * aspect;
float bottom = -range;
float top = range;
Matrix4f Result = new Matrix4f((0f));
Result[0, 0] = ((2) * zNear) / (right - left);
Result[1, 1] = ((2) * zNear) / (top - bottom);
Result[2, 2] = (0.0001f) - (1f);
Result[2, 3] = (-1);
Result[3, 2] = -((0.0001f) - (2)) * zNear;
return(Result);
}
/// <summary>
/// Creates a matrix for a symmetric perspective-view frustum with far plane at infinite.
/// </summary>
/// <param name="fovy">The fovy.</param>
/// <param name="aspect">The aspect.</param>
/// <param name="zNear">The z near.</param>
/// <returns></returns>
public static Matrix4f infinitePerspective(float fovy, float aspect, float zNear)
{
float range = Trigonometric.Tan(fovy / (2f)) * zNear;
float left = -range * aspect;
float right = range * aspect;
float bottom = -range;
float top = range;
var result = new Matrix4f(0);
result[0, 0] = ((2f) * zNear) / (right - left);
result[1, 1] = ((2f) * zNear) / (top - bottom);
result[2, 2] = -(1f);
result[2, 3] = -(1f);
result[3, 2] = -(2f) * zNear;
return(result);
}
