🚀 go-pugleaf

In article <17ga9eINN221@chester.ksu.ksu.edu> sdoran@chester.ksu.ksu.edu (Steven Marcotte) writes:
>
>mucds@uxa.ecn.bgu.edu (Corey D. Stinson) writes:
>
>
>>	Could someone help me with a problem.  I have a small sprite
>>(bitmapped) and when animating, instead of re-drawing the picture over
>>and over to repesent the rotation stages I would like to develop some
>>algorithm to rotate the image.  And suggestions on one that would not
>>degrade the image?
>
>	Wouldn't the idea be the same as rotating a point on a screen
>except instead of moving a point on the screen you are moving a point 
>in an array?  Say you wanted an image rotated in 6 different directions.
>You would start out with your source bitmap, then apply the rotation
>function (which I don't remember right off hand, but it should be in
>any trig book) to all points in the array at intervals of 60 degrees.

This solution can result in `holes' in the destination image.  To prevent
this, take every point in the destination image, and perform the reverse
transformation back to the original image to determine the value for
the dest. image.

-neilb