Modifies the viewport extents relative to the current values.
virtual CSize ScaleViewportExt(
Specifies the amount by which to multiply the current x-extent.
Specifies the amount by which to divide the result of multiplying the current x-extent by the value of the xNum parameter.
Specifies the amount by which to multiply the current y-extent.
Specifies the amount by which to divide the result of multiplying the current y-extent by the value of the yNum parameter.
The previous viewport extents (in device units) as a CSize object.
The formulas are written as follows:
xNewVE = ( xOldVE * xNum ) / xDenom
yNewVE = ( yOldVE * yNum ) / yDenom
The new viewport extents are calculated by multiplying the current extents by the given numerator and then dividing by the given denominator.