pla@umich.UUCP (Paul Anderson) (05/22/86)
My apologies if this problem has already surfaced: I have found a quirk in the operation of the SCROLL command in Amiga Basic by MicroSoft. The following sample program sets up a screen with a little bit of random stuff on it, and then prompts for a scroll amount. With small negative numbers, it seems to work as we expect, but in other combinations, the area filled in after the scroll is larger than it should be. I would be grateful if anyone can comment on what is happening, and if there is anything that I can do about it. I realize that I can do a GET to and a PUT from an array to achieve much the same thing, but it takes too much memory. --------------------cut here---------------- LINE (0,0)-(616,186),3,bf LINE (100,50)-(300,150),2,bf LINE (100,100)-STEP(200,5),1,bf LINE (200,50)-STEP(10,100),1,bf INPUT "Enter delta x, delta y";dx,dy SCROLL (125,60)-(275,140),dx,dy REM Positive deltas seem to result in REM the background fill extending to REM the edge of the window. REM Negative deltas over about -15 or REM -20 (i.e. -30,-30) drag part of the REM window boundary END --------------------end of example---------- Thanks very much, Paul Anderson, University of Michigan EECS dept