In a selected area of a display defined by a polygon, magnifying is simulated.
The selected area may be, for example, a circle simulating a magnifying glass.
Textures are represented by texel coordinates U and V, which specify the location
of color components within a set of image data. Within the area selected to appear
magnified, the present invention perturbs the texel location selection to simulate
an angle of refraction in the selected area and offset texel coordinates.
