************************************************************************** ** CODE : BLITTER SCROLLER ** CREDITS : CODED BY RAISTLIN, FONTS DRAWN BY NOTMAN ** NOTES : Main routine was adapted from MJCs tutorial source *************************************************************************** include source:include/hardware.i opt c- ;Any case lea $dff000,a5 move.l 4,a6 ;Exec jsr -132(a6) ;Forbid moveq.l #0,d0 ;Any Version lea gfxname,a1 jsr -552(a6) ;Open gfx lib tst.l d0 ;Did it open? beq quit move.l d0,gfxbase ;Save lib base address clr.w plop ;Clear the counters clr.w pausecnt clr.w charflag ***Set-Up Playfield (1 bitplane) move.l #screen,d0 ;Address of screen on d0 move.w d0,bpl1+2 ;Load bitplane pointers swap d0 move.w d0,bph1+2 ***Set-Up Hardware move.w #$20,dmacon(a5) ;Disable sprites move.l #copperlist,cop1lch(a5) move.w #0,copjmp1(a5) ;Run my copper Main cmpi.b #200,$dff006 ;Test vbl bne main bsr scroller ;Jump to scroller btst #6,$bfe001 ;Test LMB bne Main bra Clean_up ;Jump to exit ************************************************************************** ; SCROLLER ************************************************************************** ;The Font layout is ; space ; | ; !"#$%&'() ;As you can see there are 10 cahacters per ; *+,-./0123 ;line. Some of the symbols represent ; 456789:;<= ;something else in the scroller! ; >?@ABCDEFG ; HIJKLMNOPQ ; RSTUVWXYZ[ ; \]^_ scroller btst #$a,$dff016 ;RMB? beq Outscr ;If so pause text cmpi.w #0,pausecnt ;Is pause required? beq no_pause subi.w #1,pausecnt ;Decrease pause counter outscr rts No_pause cmpi.w #1,charflag ;is it end of text? beq no_need lea text,a4 ;Yes, then re-load counter no_need move.w #1,charflag cmpi.w #0,plop ;Do we need a new character? beq nextchar contscrl bsr scroll ;No, then scroll screen rts Nextchar bsr getchar ;Yes, then get it from text move.w #16,plop ;Reset plop counter bra contscrl ;An continue scrolling rts getchar lea font,a2 ;Address of fonts in a2 moveq.l #0,d0 move.b (a4)+,d0 ;Get curreny character cmpi.b #120,d0 ;Is it end of text? (x) bne notend clr.w charflag ;Yes, then reload text bra main notend move.w #$FFFc,bltalwm(a5) ;Mask out last line cmpi.b #99,d0 ;Is it a pause request? (c) beq pause ;Yes, goto pause cmpi.b #$0a,d0 beq outscr cmpi.b #58,d0 ;Checks for the double beq nomask ;fonts (ie Anthrax logo) cmpi.b #91,d0 beq nomask cmpi.b #60,d0 ;mask beq nomask cmpi.b #92,d0 beq nomask cmpi.b #93,d0 beq nomask cmpi.b #94,d0 beq nomask bra mask nomask move.w #$ffff,bltalwm(a5) ;No mask mask cmpi.b #41,d0 ;Are we on line 1? bgt Line2? bra line_1 line2? cmpi.b #51,d0 ;Are we on line 2? bgt Line3? bra line_2 line3? cmpi.b #61,d0 ;Line 3? bgt Line4? bra line_3 line4? cmpi.b #71,d0 ;Line 4? bgt line5? bra line_4 line5? cmpi.b #81,d0 ;Line 5? bgt line6? bra line_5 line6? cmpi.b #91,d0 ;Line 6? bgt line_7 bra line_6 line_1 sub #32,d0 ;Find posistion in Font mulu #4,d0 ;Find exact position add.l d0,a2 bsr plopit ;Plop character routine rts line_2 sub #42,d0 ;A little maths to find mulu #4,d0 ;The pos in font add.l #40*32,d0 add.l d0,a2 bsr plopit rts line_3 sub #52,d0 mulu #4,d0 add.l #40*64,d0 add.l d0,a2 bsr plopit rts line_4 sub #62,d0 mulu #4,d0 add.l #40*96,d0 add.l d0,a2 bsr plopit rts line_5 sub #72,d0 mulu #4,d0 add.l #40*128,d0 add.l d0,a2 bsr plopit rts line_6 sub #82,d0 mulu #4,d0 add.l #40*160,d0 add.l d0,a2 bsr plopit rts line_7 sub #92,d0 mulu #4,d0 add.l #40*192,d0 add.l d0,a2 bsr plopit rts pause move.w #140,pausecnt ;Set pause delay counter bra main rts ************************* **THE BLITTER ROUNTINES** ************************* Scroll lea screen+6524,a0 ;Address of screen + offset in a0 bsr tstbbusy ;Test if blitter is working move.l a0,bltapth(a5) ;Screen is source move.l a0,a1 sub.l #1,a1 ;-1 from screen address move.l a1,bltdpth(a5) ;This goes in destination move.w #0,bltamod(a5) ;No modulos move.w #0,bltdmod(a5) move.w #$ffff,bltafwm(a5) ;No masking move.w #$ffff,bltalwm(a5) move.w #%1110100111110000,bltcon0(a5) move.w #$0,bltcon1(a5) move.w #%00001000000010111,bltsize(a5) sub.w #1,plop ;Decrease plop counter rts Plopit lea screen+6524,a3 ;Address of screen + offset in a0 bsr tstbbusy ;Test if blitter is working move.l a2,bltapth(a5) ;Charcter in source move.l a3,bltdpth(a5) ;Screen in destination move.w #36,bltamod(a5) ;36 A modulo move.w #44,bltdmod(a5) ;44 D modulo (using overscan) move.w #%0000100111110000,bltcon0(a5) move.w #%0000100000000010,bltsize(a5) rts TstBBusy btst #14,dmaconr(a5) ;Test if blitter is working bne tstbbusy rts Clean_up move.w #$8e30,dmacon(a5) ;Re-enable sprites move.l gfxbase,a1 move.l 38(a1),cop1lch(a5) ;Restore sys copper move.w #0,copjmp1(a5) ;Run sys copper move.l 4,a6 ;Exec base jsr -138(a6) ;Permit move.l gfxbase,a1 ;Name of lib to close in a1 jsr -414(a6) ;Close lib quit rts ;Bye! Bye! ***************************************************************************** ; COPPER LIST ***************************************************************************** section copper,code_c ;Give us chip copperlist dc.w diwstrt,$2010 dc.w diwstop,$36D4 dc.w ddfstrt,$0030 dc.w ddfstop,$00D4 dc.w bplcon0,%0001001000000000 dc.w bplcon1,$0 dc.w bpl1mod,0004 dc.w bpl2mod,0004 dc.w color00,$000 bph1 dc.w bpl1pth,$0 bpl1 dc.w bpl1ptl,$0 dc.w $9f01,$fffe ;This section dc.w color00,$800 ;does ye olde dc.w $a001,$fffe ;copper bars dc.w color00,$c00 ;Havent done any dc.w $a101,$fffe ;copper bars for ages!! dc.w color00,$f00 dc.w $a301,$fffe ;PS these r d red uns dc.w color00,$c00 dc.w $a401,$fffe dc.w color00,$800 dc.w $a501,$fffe dc.w color00,$000 ;COPPER SHADING dc.w $a801,$fffe dc.w color01,$ff0 dc.w $aa01,$fffe dc.w color01,$fe0 dc.w $ac01,$fffe dc.w color01,$fd0 dc.w $ae01,$fffe dc.w color01,$fc0 dc.w $b101,$fffe dc.w color01,$fb0 dc.w $b301,$fffe dc.w color01,$fa0 dc.w $b501,$fffe dc.w color01,$f90 dc.w $b701,$fffe dc.w color01,$f80 dc.w $b901,$fffe dc.w color01,$f70 dc.w $ca01,$fffe dc.w color00,$800 dc.w $cb01,$fffe dc.w color00,$c00 dc.w $cc01,$fffe dc.w color00,$f00 dc.w $cd01,$fffe dc.w color00,$c00 dc.w $ce01,$fffe dc.w color00,$800 ;all that code for those dc.w $cf01,$fffe ;measily things!! dc.w color00,$000 dc.w $ffff,$fffe ;Program Variables gfxname dc.b 'graphics.library',0 even gfxbase ds.l 1 even screen dcb.b 356*46,0 ;Memory for screen even plop dc.w 0 ;Counters pausecnt dc.w 0 charflag dc.w 0 even Font incbin source:bitmaps1/font.bm text incbin source:raistlin/scrolltext