xserver/mi/mizerclip.c

72 	For X major lines:
76 	For Y major lines:
83 	X major	e = 2Mdy - 2Ndx - dx - B
86 	Y major	e = 2Ndx - 2Mdy - dy - B
92 	X major	e = 2Mdy - 2Ndx - dx - B
95 	Y major e = 2Ndx - 2Mdy - dy - B
103 end of the line and an X major vs. a Y major line.  In any of these
113 Case 1:  X major, starting X coordinate moved by M steps
127 Case 1b: X major, ending X coordinate moved to M steps
134 Case 2: X major, ending X coordinate moved by M steps
151 Case 2b: X major, starting X coordinate moved to M steps from end
161 Case 3: Y major, starting X coordinate moved by M steps
175 Case 3b: Y major, ending X coordinate moved to M steps
185 Case 4: Y major, ending X coordinate moved by M steps
200 Case 4b: Y major, starting X coordinate moved to M steps from end
209 Case 5: X major, starting Y coordinate moved by N steps
222 Case 5b: X major, ending Y coordinate moved to N steps
232 Case 6: X major, ending Y coordinate moved by N steps
245 Case 6b: X major, starting Y coordinate moved to N steps from end
252 Case 7: Y major, starting Y coordinate moved by N steps
265 Case 7b: Y major, ending Y coordinate moved to N steps
272 Case 8: Y major, ending Y coordinate moved by N steps
287 Case 8b: Y major, starting Y coordinate moved to N steps from the end
299 	1:  X major move x1 to x1+M	floor((2Mdy + dx - B) / 2dx)
300 	1b: X major move x2 to x1+M	floor((2Mdy + dx - B) / 2dx)
301 	2:  X major move x2 to x2-M	floor((2Mdy + dx + B - 1) / 2dx)
302 	2b: X major move x1 to x2-M	floor((2Mdy + dx + B - 1) / 2dx)
304 	3:  Y major move x1 to x1+M	floor((2Mdy - dy + B - 1) / 2dx) + 1
305 	3b: Y major move x2 to x1+M	floor((2Mdy + dy + B - 1) / 2dx)
306 	4:  Y major move x2 to x2-M	floor((2Mdy - dy - B) / 2dx) + 1
307 	4b: Y major move x1 to x2-M	floor((2Mdy + dy - B) / 2dx)
309 	5:  X major move y1 to y1+N	floor((2Ndx - dx + B - 1) / 2dy) + 1
310 	5b: X major move y2 to y1+N	floor((2Ndx + dx + B - 1) / 2dy)
311 	6:  X major move y2 to y2-N	floor((2Ndx - dx - B) / 2dy) + 1
312 	6b: X major move y1 to y2-N	floor((2Ndx + dx - B) / 2dy)
314 	7:  Y major move y1 to y1+N	floor((2Ndx + dy - B) / 2dy)
315 	7b: Y major move y2 to y1+N	floor((2Ndx + dy - B) / 2dy)
316 	8:  Y major move y2 to y2-N	floor((2Ndx + dy + B - 1) / 2dy)
317 	8b: Y major move y1 to y2-N	floor((2Ndx + dy + B - 1) / 2dy)
337 For X Major lines we know that dx > 0 and since 2Mdy is >= 0 due to the
341 So (2Mdy - dy) > 0, since they are Y major lines.  Also, (2Mdy + dy) >= 3dy