Unproject the given window coordinates <code>(winX, winY)</code> by <code>this</code> matrix using the specified viewport.
<p>
This method first converts the given window coordinates to normalized device coordinates in the range <code>[-1..1]</code>
and then transforms those NDC coordinates by the inverse of <code>this</code> matrix.
<p>
As a necessary computation step for unprojecting, this method computes the inverse of <code>this</code> matrix.
In order to avoid computing the matrix inverse with every invocation, the inverse of <code>this</code> matrix can be built
once outside using {@link #invert(Matrix3x2d)} and then the method {@link #unprojectInv(double, double, int[], Vector2d) unprojectInv()} can be invoked on it.
@param winX
the x-coordinate in window coordinates (pixels)
@param winY
the y-coordinate in window coordinates (pixels)
@param viewport
the viewport described by <code>[x, y, width, height]</code>
@param dest
will hold the unprojected position
@return dest
Unproject the given window coordinates <code>(winX, winY)</code> by <code>this</code> matrix using the specified viewport. <p> This method first converts the given window coordinates to normalized device coordinates in the range <code>[-1..1]</code> and then transforms those NDC coordinates by the inverse of <code>this</code> matrix. <p> As a necessary computation step for unprojecting, this method computes the inverse of <code>this</code> matrix. In order to avoid computing the matrix inverse with every invocation, the inverse of <code>this</code> matrix can be built once outside using {@link #invert(Matrix3x2d)} and then the method {@link #unprojectInv(double, double, int[], Vector2d) unprojectInv()} can be invoked on it.
@see #unprojectInv(double, double, int[], Vector2d) @see #invert(Matrix3x2d)
@param winX the x-coordinate in window coordinates (pixels) @param winY the y-coordinate in window coordinates (pixels) @param viewport the viewport described by <code>[x, y, width, height]</code> @param dest will hold the unprojected position @return dest