CompuServe Messages

Werner – Thanks for the response. I've tried setting RastPort.AreaInfo manually and it doesn't seem to work. (Well, it works for one pass, and then somehow resets to 0.) I'm opening a screen using OpenScreenTagList(), then referencing RastPort.AreaInfo and RastPort.TmpRas using the pointer I get from Screen.RastPort. Here, I'll show you: OPEN_SCREEN movea.l #0,a0 ; no NewScreen pointer lea ScTags,a1 ; new screen base address CALLSYS OpenScreenTagList,_IntuitionBase move.l d0,screen_p beq CLOSE_TRAS move.l d0,viewport_p add.l #sc_ViewPort,viewport_p move.l d0,rastport_p add.l #sc_RastPort,rastport_p So here I get the pointer to the screen's RastPort and load it into rastport_p. Then I call InitArea() and InitTmpRas(): * set up RastPort.AreaInfo lea areainfo,a0 ; pointer to AreaInfo structure lea areabuffer,a1 ; pointer to vector buffer move.l #MAXVECTORS,d0 ; number of vectors that buffer can hold CALLSYS InitArea,_GfxBase * set up RastPort.TmpRas lea tmpras,a0 ; pointer to TmpRas structure movea.l tmprasbuf,a1 ; pointer to TmpRas buffer move.l #PLANESIZE,d0 ; size of one bitplane is enough space CALLSYS InitTmpRas,_GfxBase Here's how I call AreaMove(), AreaDraw(), and AreaEnd(). Just to see if I did indeed have to set RastPort.AreaInfo manually, I stuck a little test in the loop: dopoly1: movea.l rastport_p,a1 moveq.l #10,d0 CALLSYS SetAPen,_GfxBase lea poly1dat,a2 movea.l rastport_p,a1 move.l rp_AreaInfo(a1),d4 lea areainfo,a3 cmp.l a3,d4 ; compare contents of RastPort.AreaInfo with ; actual location of struct AreaInfo bne signal_areainfo_error move.b #6,d2 ; point count (after initial) move.w (a2)+,d0 ; x-coord move.w (a2)+,d1 ; y-coord CALLSYS AreaMove,_GfxBase cmp.w #-1,d0 beq signal_areafn_error ; make sure AreaMove() doesn't fail dp1loop: move.w (a2)+,d0 move.w (a2)+,d1 CALLSYS AreaDraw,_GfxBase cmp.w #-1,d0 beq signal_areafn_error ; make sure AreaDraw() doesn't fail subq.b #1,d2 bne dp1loop CALLSYS AreaEnd,_GfxBase rts signal_areainfo_error: movea.l bm1_Planes,a4 ; trash screen a little if there's add.l #8200,a4 ; a problem movem.l d0-d7/a0-a7,(a4) add.l #200,a4 movem.l d0-d7/a0-a7,(a4) lea areainfo,a3 ; fix the problem? movea.l rastport_p,a4 move.l a3,rp_AreaInfo(a4) rts Here's what I saw when I traced it with MonAm: First, the program traps the incorrect RastPort.AreaInfo pointer (a 0, usually) and corrects it. Then it quits back to the calling function ("main"). The main loop calls the polygon routine again. It passes the AreaInfo pointer test, and the AreaMove() succeeds. Then it goes to the first AreaDraw() — and when AreaDraw() pulls the RastPort.AreaInfo pointer, it gets a 0! (Incidentally, I also stepped through AreaMove() and AreaDraw() and got totally confused at the end. It looks as though AreaMove() tried to change the pointer RastPort.BitMap!) Sorry to unload on you like this, but I seem to be hopelessly lost here. :l >> Tell me if this would not help, so I may E-Mail you some asm code >> fragment I use since day one to set up the TmpRas and AreaBuffer. That would help. Thanks. – Jim, on AP!