[comp.graphics] Inverse rendering?????

cn@allgfx.agi.oz (Con Neri) (02/21/90)

Does anybody know of an algorithm that can be used to derive the endpoints of
a line in a raster given the rendered points? The accuracy I wish to work to 
is 1/2 a pixel.

ie.	Given

		0 1 2 3 4 5 6 7 8 9 
 	       0| | | | | | | | | | | |
 		| | | | | | | | | | | |
 		| |X|X|X| | | | | | | |
 		| | | |X|X|X| | | | | |
 		| | | | | |X|X|X| | | |
 		| | | | | | | | | | | |

	the endpoints would be: (1,2.5) (5,5.5)

	AND
			
		0 1 2 3 4 5 6 7 8 9 
 		| | | | | | | | | | | |
 		| | | | | | | | | | | |
 		| |X| | | |X| | | | | |
 		| | |X| | |X| | | | | |
 		| | | |X| |X| | | | | |
 		| | | | |X|X| | | | | |
 		| | | | | |X| | | | | |
 		| | | | | | | | | | | |

	would produce: (1,2.5) (6,7.5) (6,2)

Any help or giudance in how to approach this problem would be much appreciated.
If you have any suggestions can you please e-mail rather than posting because
sometimes the gremlins eat up the news en route to OZ.

Thanks in advance.
CON NERI

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