Antialiasing
- for each pixel (x,y), compute inverse mapping for three points: (x,y), (x+1,y) and (x,y+1)
- for these three points in the texture image find the minimal coordinate-aligned rectangle containing all three points
- the two dimensions of the rectangle give us two scaling factors to use for filtering
- Use the resizing algorithm from the previous homework to compute pixels; scaling factors change from pixel to pixel