Calculate Projection Matrix in QT 5.12 Based On Screen Resolution

[ilan_sw]

Hello, all!
I am projecting a rectangle onto a trapezoid in QT 5.12, using a transformation matrix which I calculated using python openCV, by projecting rectangle edges to trapezoid edges:

matrix: Qt.matrix4x4(0.576341147, -0.0977674354, 0, 290.206329,
                                     0, 0.135014208, 0, 0,
                                     0, 0, 1, 0,
                                     0, -0.000142726177, 0, 1)

Now I need to update the trapezoid size relative to screen resolution. How can I do this? I have several possibilities:

somehow re-calculate the matrix for each resolution (which I don't know how to do in QT)
multiply the matrix by a screen size factor
something else QT offers?
How can this be done in the most reliable, straightforward way in QT? Thanks!