.PAGE 'OMEGA004'

;*--------------------------------------------------*
;*  SHIP'S MISSLE, MOVE, CHECK LIMIT AND COLLISION  *
;*  COLLISION CHECK SHIP TO ENEMY                   *
;*--------------------------------------------------*

MSLMOV
	LDX #04
	STX SPRIDX
MSL100
	LDX SPRIDX
	LDA SPRITA,X    ;SPRITE EXIST?
	BPL MSL110      ;YES
MSL104
	DEC SPRIDX
	BPL MSL100
	JMP ENMMSL      ;ENEMY'S MISSLE MODULE

MSL110
	CPX #00         ;SHIP CHECK?
	BEQ MSL130      ;YES

	JSR SPRMOV      ;SPRITE MOVE

	LDA WK5         ;MISSLE ARIVE LIMIT?
	BMI MSL130      ;NO
;
;-----  MISSLE ARIVE LIMIT

MSL120
	LDA #$FF
	STA SPRITA,X    ;OFF MISSLE MODE
	EOR MASKS,X
	AND SPENA
	STA SPENA       ;OFF SPRITE ENABLE BIT

	LDA MASKS,X     ;OFF X POINT MSB
	EOR #$FF
	AND MSIGX
	STA MSIGX

	JMP MSL300
;
;-----  COLLISION CHECK SHIP-MISSLE TO ANOTHER

MSL130
	LDA SPRITA      ;SHIP LIVE?
	BMI MSL104      ;NO,  NOT COLLISION CHECK
	LDX SPRIDX
	TXA
	ASL A
	TAY             ;Y=X*2
	LDA #00
	STA WK1
	LDA MASKS,X
	AND MSIGX       ;GET X MSB
	BEQ *+4
	INC WK1         ;SAVE IT
	LDA SP0X,Y      ;GET X POINT
	STA WK0         ;SAVE IT
	LDA SP0Y,Y      ;GET Y POINT
	STA WK2         ;SAVE IT
	LDA COLLSS      ;GET SPRITE TO SPRITE
	AND MASKS,X     ;COLLISION?
	BNE MSL140      ;YES
	JMP MSL200      ;NO, GO TO SPRITE TO CHRACTER
;
;----- SPRITE TO SPRITE

MSL140
	LDX #$07
MSL150
	LDA SPRITA,X    ;SPRITE EXIST?
	BPL MSL170      ;YES
MSL160
	DEX
	CPX #$04
	BNE MSL150
	JMP MSL200      ;CHECK END SPRITE TO SPRITE
MSL170
	JSR SPRSTS      ;CHECK COLLISION POINT
	LDA SPRITA,X
	BPL MSL160
	BMI MSL104      ;JMP


;*--------------------------------------------------*
;* SPRITE TO SPRITE COLLISION POINT CHECK           *
;*--------------------------------------------------*

SPRSTS
	TXA
	PHA             ;PUSH X
	LDA COLLSS
	AND MASKS,X     ;SPRITE N COLLISION?
	BNE *+5         ;YES
	JMP STS090      ;NO
	LDA SPRITA,X    ;SPRITE N LIVE?
	BMI STS090      ;NO

	TXA
	ASL A
	TAY
	LDA SP0Y,Y
	STA WK5         ;WK5=SPNY
	LDA SP0X,Y
	STA WK3         ;WK3=SPNX L
	LDA #00
	STA WK4         ;WK4=SPNX H
	LDA MSIGX
	AND MASKS,X
	BEQ *+4
	INC WK4

	LDA SPRITA,X
	CMP #02         ;ENEMY0?
	BCC STS010      ;NO
	LDA #08         ;Y1+12 < Y2+4 TRUE NOT COLLISION
	STA WK6
	LDA #04         ;Y1+8 > Y2+12 TRUE NOT COLLISION
	STA WK7
	LDA #06         ;X1+10 < X2+4 TRUE NOT COLLISION
	STA WK8
	LDA #06+06      ;X1+6 > X2+12 TRUE NOT COLLISION
	STA WK9
	JSR CKCOLL      ;CHECK 8X8 COLLISION
	BCC STS090      ;NO COLLISION
	LDA #$25        ;2500 POINT
	BNE STS020      ;JMP
STS010
	LDA #10         ;Y1+12 < Y2+2 TRUE NOT COLLISION
	STA WK6
;                       ;X1+12 < X2+2 TRUE NOT COLLISION
	STA WK8
	LDA #11         ;Y1+2 > Y2+13 TRUE NOT COLLISION
	STA WK7
	LDA #11+10      ;X1+2 > X2+13 TRUE NOT COLLISION
	STA WK9
	JSR CKCOLL      ;CHECK 16X16 COLLISION
	BCC STS090      ;NO COLLISION
	LDA #$15        ;1500 POINT
	CPX #07
	BEQ STS030      ;YES
STS020
	JSR SCORUP      ;SCORING
STS030
	LDA #$FF
	STA SPRITA,X    ;KILL SPRITE N
	EOR MASKS,X
	AND SPENA
	STA SPENA
	LDX SPRIDX
	LDA #$80
	STA SPRITA,X    ;BOMB START
STS090
	PLA             ;PULL X
	TAX
	RTS

;
;-----  SPRITE TO CHARACTER ENEMY2

MSL200
	LDX SPRIDX
	LDA COLLSC      ;GET SPRITE TO CHRACTER
	AND MASKS,X     ;COLLISION?
	BNE MSL204      ;YES
	JMP MSL104      ;THIS MISSLE NO COLLISION

MSL204
	LDX #$0A
MSL210
	LDA ENMY2A,X
	CMP #$FF        ;ENEMY2 LIVE?
	BNE MSL230      ;YES
MSL220
	DEX
	BPL MSL210
	JMP MSL300      ;NOT COLLISION ENEMY2, GO TO ENEMY3 CHECK

MSL230
	LDA EN2XPL,X
	STA WK3
	LDA EN2XPH,X
	STA WK4
	LDA EN2YP,X
	STA WK5
	LDA #08         ;Y1+12 < Y2+2+2 TRUE NOT COLLISION
	STA WK6
	LDA #07         ;Y1+8 > Y2+13+2 TRUE NOT COLLISION
	STA WK7
	LDA #09         ;X1+10 < X2+2-1 TRUE NOT COLLISION
	STA WK8
	LDA #06+09      ;X1+6 > X2+13-1 TRUE NOT COLLISION
	STA WK9
	JSR CKCOLL      ;CHECK 16X16 COLLISION
	BCC MSL220      ;NO COLLISION

;
;-----  COLLISION ENEMY2

	LDA #$10        ;1000 POINT
	JSR SCORUP      ;SCORE UP

	LDA #$FF
	STA ENMY2A,X    ;KILL ENEMY2
	LDA SPRIDX
	JSR BADSET      ;BOMB ADDRESS SET
;
;----- ENEMY2 CLEAR ON SCREEN

	JSR BITCHR      ;GET SCREEN ADDRESS (WK0,WK1)
	CLC
	LDA WK0
	STA WORK+$00
	ADC #40
	STA WORK+$06
	LDA WK1
	STA WORK+$01
	ADC #00
	STA WORK+$07
	CLC
	LDA WK0
	ADC #80
	STA WORK+$0C
	LDA WK1
	ADC #00
	STA WORK+$0D
	LDA #00
	STA WORK+$02
	STA WORK+$03
	STA WORK+$04
	STA WORK+$08
	STA WORK+$09
	STA WORK+$0A
	STA WORK+$0E
	STA WORK+$0F
	STA WORK+$10
	LDY #$FE
	STY WORK+$05
	STY WORK+$0B
	INY
	STY WORK+$11

	LDX #<WORK
	LDY #>WORK
	JSR CHROUT

	LDX #<GMFRAM
	LDY #>GMFRAM
	JSR CHROUT

MSL290
	LDX SPRIDX
	LDA #$80
	STA SPRITA,X    ;BOMB START SPRITE 0---4
	JMP MSL104
;
;-----  SPRITE TO CHARACTER ENEMY3

MSL300
	LDX SPRIDX
	LDA COLLSC      ;GET SPRITE TO CHRACTER
	AND MASKS,X     ;COLLISION?
	BNE MSL304      ;YES
	JMP MSL104      ;THIS MISSLE NO COLLISION

MSL304
	LDX #07
MSL310
	LDA ENMY3A,X    ;ENEMY3 LIVE?
	CMP #$FF
	BNE MSL330      ;YES
MSL320
	DEX
	BPL MSL310
	JMP MSL104

MSL330
	LDA EN3YP,X
	STA WK5
	LDA EN3XPL,X
	STA WK3
	LDA EN3XPH,X
	STA WK4
	LDA #06         ;Y1+12 < Y2+4+2 TRUE NOT COLLISION
	STA WK6
	LDA #12         ;Y1+2 > Y2+12+2 TRUE NOT COLLISION
	STA WK7
	LDA #09         ;X1+12 < X2+4-1 TRUE NOT COLLISION
	STA WK8
	LDA #09+09      ;X1+2 > X2+12-1 TRUE NOT COLLISION
	STA WK9
	JSR CKCOLL      ;CHECK 8X8 COLLISION
	BCC MSL320      ;NO COLLISION
;
;-----  COLLISION ENEMY3

	LDA #$02
	STA WK0         ;200 POINT
	LDA ENMY3A,X
	BEQ *+4
	ASL WK0
	LDA WK0         ;400 POINT
	JSR SCORUP      ;SCORE UP

	LDA #$FF
	STA ENMY3A,X    ;KILL ENEMY3

	TXA
	CLC
	ADC #11
	TAX

	LDA SPRIDX
	JSR BADSET      ;BOMB ADDRESS SET

	JSR BITCHR      ;GET SCREEN ADDRESS (WK0.WK1)
	LDA WK0
	STA WORK+$00
	LDA WK1
	STA WORK+$01
	LDY #00
	STY WORK+$02
	DEY
	STY WORK+$03

	LDX #<WORK
	LDY #>WORK
	JSR CHROUT      ;CLEAR ENEMY3

MSL390
	LDX SPRIDX
	LDA #$80
	STA SPRITA,X    ;BOMB START SPRITE 0---4
	JMP MSL104


;*--------------------------------------------------*
;*  COLLISION CHECK                                 *
;*   INPUT:   WK0 SOURCE      X POINT L    (X1)     *
;*            WK1             X POINT H             *
;*            WK2             Y POINT      (Y1)     *
;*            WK3 DESTINATION X POINT L    (X2)     *
;*            WK4             X POINT H             *
;*            WK5             Y POINT      (Y2)     *
;*            WK6=J, J=N-M, (Y1)+M < (Y2)+N ? ,N<M  *
;*            WK7=K, K=P-Q, (Y1)+Q >=(Y2)+P ? ,P>Q  *
;*            WK8=R, R=S-T, (X1)+T < (X2)+S ? ,T<S  *
;*            WK9=Z, U=V-W, (X1)+W >=(X2)+V ? ,V>W  *
;*                   Z=R+U                          *
;*--------------------------------------------------*

CKCOLL
;
;-----  CHECK Y COLLISION

	SEC             ;WK5-WK6 >= WK2?
	LDA WK5
	SBC WK6
	CMP WK2
	BCS CKCL80      ;NONE COLLISION

	CLC             ;WK5+WK7 < WK2?
	LDA WK5
	ADC WK7
	CMP WK2
	BCC CKCL80      ;NONE COLLISION
;
;-----  CHECK X COLLISION

	SEC             ;(WK3,WK4)-WK8 >= (WK0,WK1)?
	LDA WK3
	SBC WK8
	STA WK3
	LDA WK4
	SBC #00
	STA WK4
	SEC
	LDA WK3
	SBC WK0
	LDA WK4
	SBC WK1
	BCS CKCL80      ;NONE COLLISION

	LDA WK3         ;(WK3,WK4)+WK9 < (WK0,WK1)?
	ADC WK9
	STA WK3
	LDA WK4
	ADC #00
	STA WK4

	SEC
	LDA WK3
	SBC WK0
	LDA WK4
	SBC WK1
	BCC CKCL80      ;NONE COLLISION
	RTS             ;COLLISION EXIT

CKCL80
	CLC
	RTS             ;NONE COLLISION EXIT


;*--------------------------------------------------*
;*  SCORE UPDATE                                    *
;*--------------------------------------------------*

SCORUP
	STX WORK        ;SAVE X-REG
	CMP #$10
	BCC SCR010
	DEC NUMENM      ;DEC. ENEMY NUMBER
	BPL SCR010      ;NOT AT ALL ENEMY DONE
	LDA #$40
	STA TIMER2
	LDA #$7F
	STA TIMER3      ;SET NEW ROUND BIGEN WAIT TIME
	LDA #$0F        ;BACK MUSIC CHENG
	STA SNDDAT
	LDA #$06        ;ALL KILL SOUND ON
	JSR SOUND

SCR010
	CLC
	SED
	ADC SCORE+1
	STA SCORE+1
	LDA SCORE+2
	ADC #$00
	STA SCORE+2
	CLD
	JSR DSPSCR      ;SCORE DISPLAY

	LDA XTRA        ;CHECK FOR EXTRA SHIP
	BNE SCR090      ;ALREADY
	LDA SCORE+2
	CMP #$04
	BCC SCR090

	LDA #01
	STA XTRA
	INC NUMSHP
	JSR DSPSHP
	LDA #$01        ;BOUNUS SOUND
	JSR SOUND
SCR090
	LDX WORK
	RTS


;*--------------------------------------------------*
;*  BOMB ADDRESS RESET                              *
;*--------------------------------------------------*

BADSET
	STA WK0         ;SAVE MISSLE SPRITE INDEX
	ASL A
	TAY
	LDA EN2YP,X
	STA SP0Y,Y      ;SET BOMB Y POINT
	LDA EN2XPL,X
	STA SP0X,Y      ;SET BOMB X POINT
	LDY WK0
	LDA EN2XPH,X
	BEQ BAD010
	LDA MASKS,Y
	ORA MSIGX
	BNE BAD020
BAD010
	LDA MASKS,Y
	EOR #$FF
	AND MSIGX
BAD020
	STA MSIGX       ;SET BOMB X POINT MSB
	RTS


;*--------------------------------------------------*
;* BOMB DISPLAY BY SPRITE                           *
;*--------------------------------------------------*

BMBSPR
	LDX #07
BMB005
	LDA SPRITA,X
	BMI BMB020
BMB010
	DEX
	BPL BMB005
	RTS
BMB020
	CMP #$FF        ;NONE USED ?
	BEQ BMB010      ;YES
	INC SPRITA,X
	LDA SPRITA,X
	CMP #$82
	BEQ BMB060      ;BOMB0 DSP.
	CMP #$90
	BEQ BMB07A      ;BOMB1 DSP.
	CMP #$A0
	BEQ BMB08A      ;BOBN0 DSP.
	CMP #$B0
	BNE BMB030
	CPX #00
	BNE BMB040
BMB030
	CMP #$C0
	BEQ BMB07A      ;BOMB1 DSP.
	CMP #$D0
	BEQ BMB08A      ;BOMB0 DSP.
	CMP #$F0
	BNE BMB010
;
;----- BOMB OFF

BMB040
	LDA #$FF
	STA SPRITA,X    ;KILL MODE
	LDA MASKS,X
	EOR #$FF
	AND SPENA
	STA SPENA       ;SPRITE DISABLE

	LDA STABLE,X
	STA SV07F8,X

	LDA MASKS,X
	EOR #$FF
	AND MSIGX
	STA MSIGX       ;OFF X MSB

	CPX #00
	BNE BMB050
	DEC NUMSHP      ;SHIP COUNT DOWN
	LDA #$40
	STA TIMER2      ;SET NEW ROUND WAIT TIME
	LDA #$7F
	STA TIMER3
	LDA #BLACK
	STA EXTCOL      ;BORDER COLOR
	STA BGCOL0      ;BACKGROUND COLOR 0
	LDA KOLOR
	STA SP0COL
	STA SP1COL
	STA SP2COL
	JSR SPRCLR
	LDA #$85        ;EXPLOD. SOUND OFF
	JSR SOUND       ;OFF
BMB050
	JSR SPRCLR      ;USED RAM AREA CLEAR
	JMP BMB010

BMB07A	JMP BMB070
BMB08A	JMP BMB080
;
;----- BOMB0 DISPLAY

BMB060
	LDY #$F8        ;$FE00
	CPX #00
	BEQ *+5
	JMP BMB068
	LDA #03
	STA SPRITA+1
	STA SPRITA+2
	STA SPRITC+1
	STA SPRITC+2
	LDA #$00
	STA SPRITD+1
	LDA #$06
	STA SPRITD+2
	LDY #02
	LDX #01
	JSR SETEN0
	LDY #03
	LDX #02
	JSR SETEN0
	LDY #04
	LDX #03
	JSR SETEN0
	LDA #BLACK
	STA SP0COL
	STA SP1COL
	STA SP2COL
	LDA SP0X
	STA SP1X
	STA SP2X
	LDA MSIGX
	AND #$01
	BEQ BMB064
	LDA #$0E
	ORA MSIGX
	STA MSIGX
BMB064
	LDA SP0Y
	STA SP1Y
	STA SP2Y
	LDA SPENA
	ORA #$0E
	STA SPENA
	LDY #$FA
	LDA #$83        ;THRUST SOUND OFF
	JSR SOUND
	LDX #$02
	JSR WAIT
	LDA #$05        ;EXPLOD. ON
	JSR SOUND
	BNE BMB069
BMB068
	LDA #$04        ;ENEMY BOMB
	JSR SOUND
BMB069
	TYA
	STA SV07F8,X    ;SET SPRITE MAP
	JMP BMB010
;
;----- BOMB1 DISPLAY

BMB070
	LDY #$F9        ;$FE40
	CPX #00
	BNE BMB074
	LDA #ORANGE
	STA EXTCOL      ;
	STA BGCOL0      ;
	INY
	INY
BMB074
	TYA
	STA SV07F8,X
	JMP BMB010

BMB080
	LDY #$F8        ;$FE00
	CPX #00
	BNE BMB084
	LDA #RED
	STA EXTCOL      ;
	STA BGCOL0      ;
	STA TIMER3
	INY
	INY
BMB084
	TYA
	STA SV07F8,X    ;SET SPRITE MAP
	JMP BMB010

.END