> I see when I right click a graph anti-aliasing is an option. What does
> this feature on the graph allow you to do?

As Dennis points out, it smooths the image.  Specifically, computer 
graphics on a raster device have stair-steps or jaggies.  This occurs 
because a sloping line is being approximated by setting pixels in a grid 
to either the foreground or background color.  For this example, lets 
assume the BG is black and FG is white.  At 45 deg and certain other 
nice angles, the lines look relatively smooth, like the diagonals on a 
chess board, but at other angles, they are heavily aliased or jaggy.

Anti-aliasing sets the color of the pixels to black, white, or shades of 
gray depending on the amount of the pixel that intersects the 
mathematical definition of the line.  This extra math slows things down, 
and the fact that the anti-aliasing is done not by windows, by by an 
OpenGL driver in its own memory buffer slows it down further.  For 
slowly changing plots, they look quite nice.  This doesn't make sense 
for dense data or quickly changing data.

Greg McKaskle


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