SECTION chipMeMory,data_c ;BY BLAINE EVANS ;1 ERITH WAY ;PONTYBODKIN ;NR MOLD ;CLWYD ;CH7 4TR ;TEL O352-771673 opt c-,d+ Height equ 256 Width equ 80 Depth equ 2 ScreenSize equ Height*Width LineHeight equ 16 LineWidth equ 1 LineDepth equ 2 Move.l 4.w,a6 ;FIND EXEC BASE lea gfxlib(pc),a1 ;lOAD GRAPHICS lIBRARY IN A1 Moveq #$00,d0 ;VERSION 0 jsr -552(a6) ;OPEN lIBRARY Move.l d0,_gfxBase ;STORE D0 (GFX ADDRESS ) Beq Nolib_exit ;ElSE EXIT Bsr Foreground_addresses ;BRANCH TO FOREGROUND ADDRESSES Bsr Init Move.l _gfxBase,a0 ;lOAD ADDRESS OF GRAPHICS lIB IN A0 Move.l 50(a0),Oldcop ;STORE CURRENT COPPER,ETC TO RETRIEVE lATER S Move.l #Newcop,50(a0) ;POINT TO OUR COPPERlIST Wait ;WAIT lOOP Cmp.b #255,$dff006 ;VERTICAl BlANKING GAP Bne.s wait ; ; Move.w #$fff,$180(a6) ;REMOVE TO MEASURE RASTER TIME Bsr GetXY Bsr line ; Move.w #$000,$180(a6) ;REMOVE TO MEASURE RASTER TIME Btst #$6,$bfe001 ;QUIT lEFT MOUSE PRESSED Bne.s Wait Ended ;ElSE lOOP TO WAIT Move.l _gfxBase,a0 ;lOAD GRAPHICS lIB ADDRESS IN A0 Move.l oldcop,50(a0) ;RESTORE OlD COPPER TO RETURN TO EDITTER NoMem_exit Move.l 4.w,a6 ;FIND EXEC BASE Move.l _gfxBase,a1 ;lOAD GRAPHICS BASE IN A1 jsr -414(a6) ;ClOSE lIBRARY Nolib_exit rts ;RETURN TO EDITER Foreground_addresses ;START OF FOREGROUND DATA Move.l #Foreground,d0 Move.w d0,Bpl0ptl ;lOW WORD IN BIT PlANE 0 lOW Swap d0 Move.w d0,Bpl0pth ;HIGH WORD IN BIT PlANE 0 HIGH Swap d0 Add.l #ScreenSize,d0 Move.w d0,Bpl1ptl ;lOW WORD IN BIT PlANE 1 lOW Swap d0 Move.w d0,Bpl1pth ;HIGH WORD IN BIT PlANE 1 HIGH Swap d0 rts Init Lea Connections(pc),a4 Move.l a4,ConnectSave Rts GetXY Moveq.l #0,d0 ; Clear work registers Moveq.l #0,d1 Moveq.l #0,d2 Moveq.l #0,d3 Move.l ConnectSave,a4 Move.l (a4)+,a0 Move.l (a4)+,a1 Move.w (a0)+,d0 ; x1=d0 Cmp.w End,d0 ; end marker reached Bne.s NoEnd ; no,then skip reset Lea Connections(pc),a4 ; reload connections Move.l a4,ConnectSave Move.l (a4)+,a0 Move.l (a4)+,a1 Move.w (a0)+,d0 ; x1=d0 NoEnd Move.w (a0)+,d1 ; y1=d1 Move.w (a1)+,d2 ; x2=d2 Move.w (a1)+,d3 ; y2=d3 Move.l a4,ConnectSave Rts Octant_taBle Dc.B 1,17,9,21,5,25,13,29 ; line only Even line lea $dff000,a5 ; custoM Base Move.l #Foreground,a0 ; start address of screen Move.l #Width,a1 ; width of screen Move.w a1,d4 ; Mulu.w d1,d4 ; Multiply y1 By width Moveq #-$10,d5 ; no leading chars And.w d0,d5 ; BottoM four Bits Masked froM x1 lsr.w #3,d5 ; reMainder divided By 8 Add.w d5,d4 ; y1*width+X1/8 Add.l a0,d4 ; +start of Bitplane Clr.l d5 Sub.w d1,d3 ; y2-y1 d3=Delta y Roxl.b d5 ; shift leading char froM delta y Tst.w d3 ; restore n-flag Bge.s Y2gy1 ; when dy=+ve,goto y2gy1 Neg.w d3 ; invert if not +ve Y2gy1 Sub.w d0,d2 ; x2-x1=delta X Roxl.b d5 ; Move leading char forM delta X Tst.w d2 ; restore n flag Bge.s X2gx1 ; when dx=+ve,goto x2gx1 Neg.w d2 ; invert if not +ve X2gx1 Move.w d3,d1 ; delta y Sub.w d2,d1 ; deltaY-deltaX Bge.s Dygdx ; when dy>dx,goto dygdx Exg d2,d3 ; sMaller delta in d2 Dygdx Roxl.b d5 ; d5=result of 3 coMparisons Move.b Octant_table(pc,d5),d5 ; Matching octants Add.w d2,d2 ; sMaller delta * 2 Move.w d2,SDelta_2 ; store Sub.w d3,d2 ; 2*sMaller delta-larger delta Bge.s Signn1 ; when 2*sd > l.delta Or.b #$40,d5 ; sign flag set Signn1 Move.w d2,SDelta_2_LDelta ; store Sub.w d3,d2 ; 2*s.delta-2*large delta Move.w d2,SDelta_2_LDelta_2 ; store And.w #$000f,d0 ; BottoM 4 Bits froM X1 Ror.w #4,d0 ; to START0-3 Or.w #$0Bca,d0 ; USEx and lFx Bits set lsl.w #6,d3 ; length * 64 Addq #2,d3 ; plus (Width=2) Move.w #(lineDepth)-1,d7 ; no of planes -1 Draw_loop Bsr Draw Add.l #ScreenSize,d4 ; next plane DBra d7,Draw_loop Rts Draw Bsr WBlit Move.w SDelta_2,$62(a5) ;BltBmod Move.w SDelta_2_LDelta,$52(a5) ;BltAptl Move.w SDelta_2_LDelta_2,$64(a5) ;BltAmod Move.w #$8000,$74(a5) ;BltAdat Move.w #$ffff,$72(a5) ;BltBdat Move.w #$ffff,$44(a5) ;Bltafwm Move.w d0,$40(a5) ;Bltcon0 Move.w d5,$42(a5) ;Bltcon1 Move.l d4,$48(a5) ;BltCpth Move.l d4,$54(a5) ;BltDpth Move.w a1,$60(a5) ;BltCmod Move.w a1,$66(a5) ;BltDmod Move.w d3,$58(a5) ;Bltsize Rts WBlit Btst #14,$2(a5) Bne.s WBlit Rts gfxlib dc.b "graphics.library",0 even _gfxBase dc.l 0 ;lONG WORD TO STORE GFX ADDRESS oldcop dc.l 0 ;OLD COPPERlIST ADDRESS LineAddress dc.l 0 Octant dc.l 0 ConnectSave dc.l 0 Blitlength dc.w 0 X dc.l 0 Y dc.l 0 Bltcon dc.w 0 SDelta_2 dc.w 0 SDelta_2_LDelta dc.w 0 SDelta_2_LDelta_2 dc.w 0 even Newcop dc.w $0100,%1010001000000000 dc.w $0102 Scroll dc.w $0000 ;SCROll VAlUE dc.w $0104,%0000000000000001 ;NO PRIORITIES dc.w $0108,$0000,$010a,$0000 ;MODUlAS dc.w $0092,$0038,$0094,$00d0 ;256*40 SCREEN dc.w $008e,$2c81,$0090,$2cc1 ;VISIBlE AREA Planes dc.w $00e0 Bpl0pth dc.w $0000,$00e2 Bpl0ptl dc.w $0000,$00e4 Bpl1pth dc.w $0000,$00e6 Bpl1ptl dc.w $0000,$00e8 Bpl2pth dc.w $0000,$00ea Bpl2ptl dc.w $0000,$00ec Bpl3pth dc.w $0000,$00ee Bpl3ptl dc.w $0000,$00f0 Bpl4pth dc.w $0000,$00f2 Bpl4ptl dc.w $0000,$00f4 Bpl5pth dc.w $0000,$00f6 Bpl5ptl dc.w $0000 Sprites ;SPRITES dc.w $0120 Spl0pth dc.w $0000,$0122 Spl0ptl dc.w $0000,$0124 Spl1pth dc.w $0000,$0126 Spl1ptl dc.w $0000 dc.w $0128,$0000,$012a,$0000 dc.w $012c,$0000,$012e,$0000 dc.w $0130,$0000,$0132,$0000 dc.w $0134,$0000,$0136,$0000 dc.w $0138,$0000,$013a,$0000 dc.w $013c,$0000,$013e,$0000 dc.w $0180,$0000,$0182,$0ff0 ;COlORS PlAY 1 dc.w $0184,$0d00,$0186,$0fff dc.w $0188,$0ff0,$018a,$00ff dc.w $018c,$008f,$018e,$0095 dc.w $0190,$0000,$0192,$0283 ;COlORS PlAY 2 dc.w $0194,$08f4,$0196,$0095 dc.w $0198,$0243,$019a,$00ff dc.w $019c,$0ff0,$019e,$0fa0 dc.w $01a0,$0000,$01a2,$0fff ;SPRITE COlORS dc.w $01a4,$0f00,$01a6,$0B00 dc.w $01a8,$0600,$01aa,$0F40 dc.w $01ac,$0F80,$01ae,$0Fa0 dc.w $01B0,$0Ff0,$01B2,$000f dc.w $01B4,$004f,$01B6,$008f dc.w $01B8,$00ff,$01Ba,$00f0 dc.w $01Bc,$0283,$01Be,$0f0f dc.w $ffff,$fffe ;END OF COPPERlIST A Dc.w 260,060 B Dc.w 260,120 C Dc.w 380,060 D Dc.w 380,120 E Dc.w 320,030 F Dc.w 440,030 G Dc.w 440,090 End Dc.w $ffff,$ffff Connections Dc.l A,B ; E#######F Dc.l C,D ; # ## Dc.l A,C ; # # # Dc.l B,D ; A#######C # Dc.l A,E ; # # G Dc.l C,F ; # # # Dc.l E,F ; # ## Dc.l D,G ; B#######D Dc.l G,F ; Dc.l End ; END MARKER Foreground dcb.b ScreenSize*Depth,$00