0100 ;D1:MCP.M65
0110 ;
0120     .TITLE "MULTI-COLOR PLAYER"
0130 ; V.100685, BY PATRICK BASS
0140 ; (c) 1985, ANTIC PUBLISHING
0150 ;
0160     .SET 1,20
0170     .TAB 8,12,30
0180 TOTALCODE = ENDCODE-STARTOFCODE
0190     .OPT NO LIST
0200     .OPT NO MLIST
0210 ;
0220 STARTOFCODE = $3000
0230 ;
0240 ;-----------------------------
0250 ; Display List equates...
0260 ;
0270 ; OFFSET is the number of scan           lines down the line-by-line
0280 ;  coloring starts.
0290 OFFSET = $20
0300 BLANK8 = $70    ;Blank 8 lines.
0310 LMS =   $40     ;Load Mem Scan.
0320 MODE6 = 6       ;ANTIC mode 6.
0330 INT =   $80     ;DL Interrupt.
0340 JMPWT = $41     ;Jump, wait.
0350 ;
0360 ;-----------------------------
0370 ; Following are ATARI standard.
0380 WSYNC = $D40A   ;Hsync waiter.
0390 ;
0400 COLPM0 = $D012  ;Player/Missile
0410 COLPM1 = $D013  ;Hardware color
0420 COLPM2 = $D014  ;registers.
0430 COLPM3 = $D015
0440 ;
0450 SDLSTL = $0230  ;Dlist shadow
0460 VVBLKD = $0224  ;Vblank pointer
0470 VDSLST = $0200  ;DLI pointer
0480 HPOSP0 = $D000  ;H position.
0490 IRQEN = $D20E   ;IRQ enable.
0500 POKMSK = $10    ;...and shadow.
0510 NMIEN = $D40E   ;NMI enable.
0520 GPRIOR = $026F  ;Global priority
0530 PMBASE = $D407  ;Player base
0540 GRACTL = $D01D  ;Graphic control
0550 SDMCTL = $022F  ;Shadow DMA cont
0560 SKCTL = $D20F   ;Serial Control
0570 RANDOM = $D20A
0580 ;
0590 ;-----------------------------
0600 ; Default Player Box Boundaries.
0610 YMIN =  40
0620 YMAX =  170
0630 XMIN =  50
0640 XMAX =  190
0650 ;
0660 ;-----------------------------
0670 ; Default Vertical positions.
0680 VP0 =   YMIN+[[YMIN+YMAX]/8]
0690 VP1 =   [YMIN+YMAX]/2
0700 VP2 =   YMAX-[[YMIN+YMAX]/8]
0710 VP3 =   [YMIN+YMAX]/2
0720 ;
0730 ;-----------------------------
0740 ; Default Horizontal positions.
0750 HP0 =   [XMIN+XMAX]/2
0760 HP1 =   XMAX-[[XMIN+XMAX]/8]
0770 HP2 =   [XMIN+XMAX]/2
0780 HP3 =   XMIN+[[XMIN+XMAX]/8]
0790 ;
0800 ;-----------------------------
0810 ; Default Player Base color.
0820 P0C =   $30
0830 P1C =   $C0
0840 P2C =   $50
0850 P3C =   $90
0860 ;
0870 ;-----------------------------
0880 ; ...and claim how many players            are currently active.
0890 ACTIVE = 4
0900 ;
0910 ;-----------------------------
0920     *=  $2000
0930 ; Starting at $2000, hold a              place for the player number.
0940 CURRPLR
0950     .BYTE 0
0960 ;
0970 ;-----------------------------
0980 ; Remember in order, 0-1-2-3,           how fast everyone should move.
0990 MEMSPEED
1000     .BYTE 0,0,0,0
1010 ;
1020 ;-----------------------------
1030 ;
1040 ; Remember in order, 0-1-2-3,           how fast everyone is moving.
1050 SPEED
1060     .BYTE 0,0,0,0
1070 ;
1080 ;-----------------------------
1090 ;This is how many dots to move
1100 ;each step. Range 1-3.
1110 VSTEP
1120     .BYTE 1,1,1,1
1130 HSTEP
1140     .BYTE 1,1,1,1
1150 ;
1160 ;-----------------------------
1170 ; This is the shape that is              drawn onto each player.
1180 PLRGRAF0
1190     .BYTE 0,0,0,0
1200     .BYTE $18,$3C,$7E,$FF,$18,$18,$18,$7E
1210     .BYTE $42,$7E,$5A,$24,$18
1220     .BYTE 0,0,0,0,0,0,0
1230 ;
1240 PLRGRAF1
1250     .BYTE 0,0,0,0
1260     .BYTE $FF,$FF,$7E,$7E,$3C,$3C,$18,$FF
1270     .BYTE $FF,$18,$3C,$3C,$7E
1280     .BYTE 0,0,0,0,0,0,0
1290 ;
1300 PLRGRAF2
1310     .BYTE 0,0,0,0
1320     .BYTE $3C,$18,$3C,$42,$A9,$81,$42,$24
1330     .BYTE $3C,$3C,$5A,$42,$3C
1340     .BYTE 0,0,0,0,0,0,0
1350 ;
1360 PLRGRAF3
1370     .BYTE 0,0,0,0,24,126,255,255,255,255,255
1380     .BYTE 255,255,255,255,126,24,0,0,0,0,0
1390 ;
1400 ;-----------------------------
1410 ; Current player Horizontal             position while moving.
1420 HPOSITION
1430     .BYTE HP0,HP1,HP2,HP3
1440 ;
1450 ;-----------------------------
1460 ; Current Player Vertical               position while moving.
1470 VPOSITION
1480     .BYTE VP0,VP1,VP2,VP3
1490 ;
1500 ;-----------------------------
1510 ; 'PDIRECTION' is where we keep         track of which direction each
1520 ; player is currently moving.
1530 ;
1540 ; bit7 clear="move down"
1550 ; bit7   set="move up"
1560 ; bit6 clear="move right"
1570 ; bit6   set="move left"
1580 PDIRECTION
1590     .BYTE 0,$40,$80,$C0
1600 ;
1610 ;-----------------------------
1620 ; Another useful mem loc
1630 THISPLAYER
1640     .BYTE 0
1650 ;
1660 ;-----------------------------
1670 ; Reserve, at $6000, four pages         of memory for the players's
1680 ; color memory map.
1690 PCBASE = $6000
1700 P0COLR = PCBASE
1710 P1COLR = PCBASE+$0100
1720 P2COLR = PCBASE+$0200
1730 P3COLR = PCBASE+$0300
1740 ;
1750 ;-----------------------------
1760 ; Reserve, at $7000, four pages         of memory for the player
1770 ; shapes on the screen.
1780 PBASE = PCBASE+$1000
1790 P0RAM = PBASE+$0400
1800 P1RAM = PBASE+$0500
1810 P2RAM = PBASE+$0600
1820 P3RAM = PBASE+$0700
1830 ;
1840 ;-----------------------------
1850 ; Reserve space at $8000 for the        television display.
1860 SCREEN = PCBASE+$2000
1870 ;
1880 ;-----------------------------
1890 ; Build a table of player shape         addresses in player order.
1900 PLAYERTABLE
1910     .WORD P0RAM,P1RAM
1920     .WORD P2RAM,P3RAM,P3RAM
1930 ;
1940 ;-----------------------------
1950 ; Build a table of player color         addresses in player order.
1960 CPLAYERTABLE
1970     .WORD P0COLR,P1COLR
1980     .WORD P2COLR,P3COLR,P3COLR
1990 ;
2000 ;-----------------------------
2010 ; Build a table of player color         source addresses in plr order.
2020 SPLAYERTABLE
2030     .WORD P0COLG,P1COLG
2040     .WORD P2COLG,P3COLG,P3COLG
2050 ;
2060 ;-----------------------------
2070 ; Build a table of player shape         source addresses.
2080 GPLAYERTABLE
2090     .WORD PLRGRAF0,PLRGRAF1
2100     .WORD PLRGRAF2,PLRGRAF3
2110     .WORD PLRGRAF3
2120 ;
2130 ;-----------------------------
2140 ; This is a short Display List.
2150 TLIST
2160     .BYTE BLANK8,BLANK8,BLANK8
2170     .BYTE LMS+MODE6+INT
2180     .WORD SCREEN
2190 ;
2200     .BYTE JMPWT
2210     .WORD TLIST
2220 ;
2230 ;-----------------------------
2240 ; Reserve obscene amounts of Z
2250     *=  $80
2260 SWITCH *= *+1
2270 POINTER *= *+2
2280 ;
2290 ;-----------------------------
2300 ; DEFINE MACROS
2310 ; MACRO #1:"LDW source,memory"
2320 ; say:"Load-Word"
2330 ; This first macro will load            the WORD value of a label
2340 ; into a two-byte memory                location, forming a pointer.
2350 ; EXAMPLE:
2360 ;    LDW  SOURCE,POINTER
2370 ;...will load the LO, HI bytes          that make up the label SOURCE
2380 ; into memory locations POINTER,        POINTER+1.
2390 ;
2400     .MACRO LDW 
2410     LDA # <%1
2420     STA %2
2430     LDA # >%1
2440     STA %2+1
2450     .ENDM 
2460 ;
2470 ;-----------------------------
2480 ; MACRO #2 "NEWPAGE"
2490 ; This macro will force the             program counter to the
2500 ; next higher page number, even.
2510 ; EXAMPLE:
2520 ;  (program counter now $4322)
2530 ;      NEWPAGE
2540 ;  (program counter now $4400)
2550 ;
2560 ;Follow:          *=$4322
2570     .MACRO NEWPAGE 
2580     *=  *&$FF00 ; *=$4300
2590     *=  */$0100 ; *=$0043
2600     *=  *&$FF   ; *=$43
2610     *=  *+1     ; *=$44
2620     *=  **$0100 ; *=$4400
2630     .ENDM 
2640 ;Follow:          *=$4400
2650 ;
2660 ;-----------------------------
2670     *=  STARTOFCODE
2680     CLD 
2690     SEI 
2700     LDX #$FC
2710     TXS 
2720     JSR ALTINT  ;Finish init.
2730      LDW  TLIST,SDLSTL
2740      LDW  DBLANK,VVBLKD
2750     CLI 
2760 ;
2770 ; Since this demonstrations             action is controlled by both
2780 ; Vertical Blank and a DLI loop         no action is needed by the
2790 ; calling program.
2800 ;
2810 IDLE
2820     JMP IDLE
2830 ;
2840 ;-----------------------------
2850 ; This is where the player              coloring takes place.
2860 ;
2870 NMIVEC
2880     PHA         ;Pack .A and .X
2890     TXA 
2900     PHA 
2910     LDX #OFFSET ;Scan line start
2920 KERNAL
2930     STA WSYNC   ;Wait off-screen
2940     INX         ;next scan line.
2950     CPX #OFFSET+150 ;End-o-loop?
2960     BCS DLIDONE ;Branch if yes.
2970 ;
2980 ; Otherwise...
2990     LDA P0COLR,X ;Zero's color
3000     STA COLPM0  ;Stuff color
3010     LDA P1COLR,X ;And so forth.
3020     STA COLPM1
3030     LDA P2COLR,X
3040     STA COLPM2
3050     LDA P3COLR,X
3060     STA COLPM3
3070     JMP KERNAL  ;Stay in loop.
3080 ;
3090 DLIDONE
3100     PLA 
3110     TAX 
3120     PLA 
3130     RTI 
3140 ;
3150 ;-----------------------------
3160 DRAWTHEM
3170     LDX #ACTIVE-1
3180 PAGAIN
3190     STX CURRPLR
3200     LDA SPEED,X
3210     BPL PAGT1
3220 ;
3230     LDA MEMSPEED,X
3240     STA SPEED,X
3250 PAGT1
3260     DEC SPEED,X
3270     LDA SPEED,X
3280     BPL PAGX
3290 ;
3300     LDA PDIRECTION,X ;Moving L/R
3310     AND #$40    ;Move left bit.
3320     BNE PAG1    ;If moving left.
3330 ;
3340     LDA CURRPLR ;Moving right,
3350     JSR MOVERIGHT ;Player right.
3360     JMP PAG2    ;Jump Up or Down
3370 PAG1
3380     LDA CURRPLR ;Moving left,
3390     JSR MOVELEFT ;Player left.
3400 PAG2
3410     LDX CURRPLR ;Player number.
3420     LDA PDIRECTION,X ;Moving U/D
3430     BMI PAG3    ;if moving up.
3440 ;
3450     LDA CURRPLR ;Moving down,
3460     JSR MOVEDOWN ;Player down.
3470     JMP PAGX    ;Check next plr.
3480 PAG3
3490     LDA CURRPLR ;Player number
3500     JSR MOVEUP  ;Player Up.
3510 PAGX
3520     LDX CURRPLR ;Unpack player
3530     DEX         ;Count player.
3540     BPL PAGAIN  ;Branch if more.
3550 ;
3560     RTS 
3570 ;
3580 ;-----------------------------
3590 ;This is the Vertical Blank.
3600 DBLANK
3610      LDW  NMIVEC,VDSLST
3620     JSR DRAWTHEM ;New position.
3630 ;
3640     LDX #ACTIVE-1
3650 PAGG1
3660     LDA HPOSITION,X ;Shadow pos
3670     STA HPOSP0,X ;into hardware.
3680     TXA 
3690     PHA 
3700     JSR DODRAW
3710     PLA 
3720     TAX 
3730     DEX         ;count player...
3740     BPL PAGG1   ;..until finish.
3750 XITINT
3760     PLA         ;Stock return.
3770     TAY 
3780     PLA 
3790     TAX 
3800     PLA 
3810     RTI 
3820 ;
3830 ;-----------------------------
3840 ALTINT
3850     LDA #$C0
3860     STA IRQEN
3870     STA POKMSK
3880     STA NMIEN
3890     LDA #$11    ;Gang, priority.
3900     STA GPRIOR
3910     LDA # >PBASE ;Point/players.
3920     STA PMBASE
3930     LDA #3      ;Enable players.
3940     STA GRACTL
3950     LDA #$3E    ;Reg playfield.
3960     STA SDMCTL
3970     LDA #3      ;Enable keyboard
3980     STA SKCTL
3990 ;
4000     LDX #0
4010 CCAGAIN
4020     LDA #0
4030     STA P0COLR,X ;Erase colors.
4040     STA P1COLR,X
4050     STA P2COLR,X
4060     STA P3COLR,X
4070     LDA #0
4080     STA P0RAM,X ;Erase players.
4090     STA P1RAM,X
4100     STA P2RAM,X
4110     STA P3RAM,X
4120     INX 
4130     BNE CCAGAIN
4140 ;
4150     LDX #14
4160 PAGAIN1
4170     LDA PLRGRAF0,X ;Draw player.
4180     STA P0RAM+VP0,X
4190     LDA PLRGRAF1,X
4200     STA P1RAM+VP1,X
4210     LDA PLRGRAF2,X
4220     STA P2RAM+VP2,X
4230     LDA PLRGRAF3,X
4240     STA P3RAM+VP3,X
4250 ;
4260     LDA P0COLG,X ;Draw colors.
4270     STA P0COLR+VP0-4,X
4280     STA P1COLR+VP1-4,X
4290     STA P2COLR+VP2-4,X
4300     STA P3COLR+VP3-4,X
4310 ;
4320     DEX 
4330     BPL PAGAIN1
4340 ;
4350     RTS 
4360 ;
4370 ;-----------------------------
4380      NEWPAGE  
4390 P0COLG
4400     .BYTE 0,P1C+4,P1C+6,P1C+8
4410     .BYTE P1C+10,P1C+0,P1C+2
4420     .BYTE P1C+4,$18,$16
4430     .BYTE $32,$38,$34,$52,0
4440 ;
4450 P1COLG
4460     .BYTE 0,$2C,$2A,$28
4470     .BYTE $26,$24,$22,$20,$18
4480     .BYTE $1A,$52,$54,$56,$58,0
4490 ;
4500 P2COLG
4510     .BYTE 0,P3C+2,P3C+4,P3C+6
4520     .BYTE P3C+8,P3C+10,P3C+12
4530     .BYTE P3C+14,P3C+64+12
4540     .BYTE P3C+64+10,P3C+32+8
4550     .BYTE P3C+32+6,P3C+16+4
4560     .BYTE P3C+16+2,0
4570 ;
4580 P3COLG
4590     .BYTE 0,P0C+2,P0C+4,P0C+6
4600     .BYTE P0C+8,P0C+10,$20
4610     .BYTE $C4,$24,$20
4620     .BYTE P0C+10,P0C+8
4630     .BYTE P0C+6,P0C+4,P0C+2,0
4640     .BYTE 0,0,0,0,0,0,0
4650 ;
4660 ;-----------------------------
4670 DODRAW
4680     STA THISPLAYER
4690     ASL A
4700     TAX 
4710 ;
4720 ; Set POINTER to point at the           current player shape.
4730     LDA PLAYERTABLE,X
4740     STA POINTER
4750     LDA PLAYERTABLE+1,X
4760     STA POINTER+1
4770 ;
4780 ; Set POINTER+2 to point at the         current player color strip.
4790     LDA CPLAYERTABLE,X
4800     STA POINTER+2
4810     LDA CPLAYERTABLE+1,X
4820     STA POINTER+3
4830 ;
4840 ; The following example of self-        modifying code should never
4850 ; be used whenever there is the         slightest chance the code will
4860 ; wind up in ROM. I use it here         because this is only a
4870 ; demonstration program.
4880 ; We pick up the source of each         players colors in turn and
4890 ; physically modify the address         at Label RAMPOINTER.
4900 ;
4910     LDA SPLAYERTABLE,X
4920     STA RAMPOINTER+1
4930     LDA SPLAYERTABLE+1,X
4940     STA RAMPOINTER+2
4950 ;
4960     LDA GPLAYERTABLE,X
4970     STA GRAMPOINTER+1
4980     LDA GPLAYERTABLE+1,X
4990     STA GRAMPOINTER+2
5000 ;
5010 ; Then get this players current         vertical position into .Y
5020     LDX THISPLAYER
5030     LDA VPOSITION,X
5040     TAY 
5050 ; Now redraw the picture.
5060     LDX #0
5070 GRAMPOINTER
5080     LDA PLRGRAF0,X
5090     STA (POINTER),Y
5100     TYA 
5110     SEC 
5120     SBC #4
5130     TAY 
5140 ; Getting the colors through the        self-modified pointer.
5150 RAMPOINTER
5160     LDA P0COLG,X
5170     STA (POINTER+2),Y
5180     CLC 
5190     TYA 
5200     ADC #5
5210     TAY 
5220     INX 
5230     CPX #20
5240     BCC GRAMPOINTER
5250 ;
5260     RTS 
5270 ;
5280 ;-----------------------------
5290 ; The next four routines are all        identical in operation.
5300 ; Enter with desired player in          the accumulator. Try to move
5310 ; in the desired direction. If          not a good move, return to
5320 ; original position and toggle          the direction flag.
5330 MOVEUP
5340     TAX 
5350     SEC 
5360     LDA VPOSITION,X
5370     SBC VSTEP,X
5380     STA VPOSITION,X
5390     CMP #YMIN+1
5400     BCS MUX
5410 ;
5420     CLC 
5430     ADC VSTEP,X
5440     STA VPOSITION,X
5450 MU1A
5460     LDA RANDOM
5470     AND #3
5480     BEQ MU1A
5490 ;
5500     STA VSTEP,X
5510     LDA PDIRECTION,X
5520     EOR #$80
5530     STA PDIRECTION,X
5540 MUX
5550     RTS 
5560 ;
5570 ;-----------------------------
5580 MOVEDOWN
5590     TAX 
5600     CLC 
5610     LDA VPOSITION,X
5620     ADC VSTEP,X
5630     STA VPOSITION,X
5640     CMP #YMAX-1
5650     BCC MDX
5660 ;
5670     SEC 
5680     SBC VSTEP,X
5690     STA VPOSITION,X
5700 MD1A
5710     LDA RANDOM
5720     AND #3
5730     BEQ MD1A
5740 ;
5750     STA VSTEP,X
5760     LDA PDIRECTION,X
5770     EOR #$80
5780     STA PDIRECTION,X
5790 MDX
5800     RTS 
5810 ;
5820 ;-----------------------------
5830 MOVELEFT
5840     TAX 
5850     SEC 
5860     LDA HPOSITION,X
5870     SBC HSTEP,X
5880     STA HPOSITION,X
5890     CMP #XMIN+1
5900     BCS GOLX
5910 ;
5920     CLC 
5930     ADC HSTEP,X
5940     STA HPOSITION,X
5950 GOL1A
5960     LDA RANDOM
5970     AND #3
5980     BEQ GOL1A
5990 ;
6000     STA HSTEP,X
6010     LDA PDIRECTION,X
6020     EOR #$40
6030     STA PDIRECTION,X
6040 GOLX
6050     RTS 
6060 ;
6070 ;-----------------------------
6080 MOVERIGHT
6090     TAX 
6100     CLC 
6110     LDA HPOSITION,X
6120     ADC HSTEP,X
6130     STA HPOSITION,X
6140     CMP #XMAX-1
6150     BCC GORX
6160 ;
6170     SEC 
6180     SBC HSTEP,X
6190     STA HPOSITION,X
6200 GOR1A
6210     LDA RANDOM
6220     AND #3
6230     BEQ GOR1A
6240 ;
6250     STA HSTEP,X
6260     LDA PDIRECTION,X
6270     EOR #$40
6280     STA PDIRECTION,X
6290 GORX
6300     RTS 
6310 ;
6320 ;-----------------------------
6330     .BYTE "(c) 1985, "
6340     .BYTE "ANTIC PUBLISHING"
6350 ENDCODE
6360     *=  $02E0
6370     .WORD STARTOFCODE
6380     .OPT NO LIST
6390     .END