Sprite size changes when the window size changes!!

If you are handling the WM_SIZE message in the WndProc correctly, then you
have the information to update any dependent code as to the ratio of change
in the viewport as well as sprite size changes. You will need to use the ratio of
change to augment the detection method you are using, as from the information
you have provided in the post it seems that you are using some hard coded
method, so you will need to add the increase in size to that data.