;Most of my programs/games are just helping me learn. so dont expect much :) im learning alot from making this!

;this is as close to a real game as i have gotten yet. its not fun, but it helped me with learning collision detection 
;(my formula still sucks real bad, but it worked.) and so there isnt much to this game yet. dont think i will even add on (maybe)
;just because its coded bad and will be hard to expand. i commented some of the first lines, but got lazy and stopped
;hope this can help anyone. but dont try to take my code as a good example, im just learning. so my code is quite rough
;and for lack of better words, a piece of shit. but hey :P oh well. ill get better!
;comments/questions -- doomsday2001@hotmail.com

	include "doorsos.h"			; general ROM calls
	include "graphlib.h"			; clr_scr function	
	include "userlib.h"			; idle_loop
	xdef	_main				; define program entry point
	xdef	_comment			; define program comment	
	xdef	_ti89				; compile for TI-89
	xdef	_exit
;
mask0 equ %11111110  			;(up\2nd\donw...)
mask1 equ %11111101  			;(Enter\clear...)
mask2 equ %11111011  			;( <- )
mask3 equ %11110111  			;(catalog...)
mask4 equ %11101111  			;(Mode...)
mask5 equ %11011111 				;(Home...)
mask6 equ %10111111  			;(ESC...)

DrawSpr	Macro				;macro i made for putting sprites
	move.w  \1,d0				;use "DrawSpr #,#,sprite name" to draw it at x,y
	move.w  \2,d1
	move.l  #\3,a0
	jsr     graphlib::put_sprite
	ENDM

delay:						;loop to delay the game, so it doesnt go to fast.
	move.w  #0,d0

delay_repeat:
    add.w   #1,d0
    cmp     delay_len,d0			;delay_len is speed, higher the number, the slower the game goes
    bne     delay_repeat
    rts

_main:						;start of program
	move.w		#0,nme_boom
	move.w		#150,exp_timer
	jsr		graphlib::clr_scr	;clears the screen
	WriteStr	#1,#1,#2,enter
	jsr		userlib::idle_loop
	jsr		graphlib::clr_scr	;clears the screen

keyloop:
	bra		getkey			;goto getkey
nextloop:
	bsr		getpos			;gets enemies position
	bsr		display
	bsr		test_collision
	cmp.w		#1,keytag
	beq		change_speed
	move.w		#2000,delay_len
	bra		game_speed
change_speed:
	move.w		#750,delay_len
	move.w		#0,keytag
game_speed:
	bsr		delay			;goto delay (delays the program for amount of time)
	bra		keyloop		;go back to mainloop

getkey:
        move.w 		#mask0,d0	;move key mask 0 into d0 (keys 2nd, left, right, up, down, etc.)
        bsr 		get_key		;goes to get_key, which will put the key that was pushed into d0
        btst.b 		#0,d0		;test to see if up was pressed
        beq		keyup		;up was pressed, goto keyup, else goto next line
        btst.b		#2,d0		;test to see if down was pressed
        beq 		keydown		;down was pressed, goto keydown, else goto next line
        btst.b		#1,d0		;check left
        beq 		keyleft		;left pressed
        btst.b 		#3,d0		;check right
        beq 		keyright	;right pressed
        btst.b 		#4,d0		;check 2nd
        beq 		key2nd		;2nd pressed
        move.b 		#mask6,d0	;put key mask 6 into d0, thats the esc key mask
	 bsr		get_key
        btst.b 		#0,d0		;check esc.
        beq 		_exit		;esc pressed, else goto next line
tst2nd:
        move.w 		#mask0,d0	;move key mask 0 into d0 (keys 2nd, left, right, up, down, etc.)
        bsr 		get_key		;goes to get_key, which will put the key that was pushed into d0
        btst.b 		#4,d0		;check 2nd
        beq 		key2nd		;2nd pressed
endgetkey:
        bra 		nextloop				;go back to mainloop


get_key:
	move.b  d0,($600019)		;keypad located at $600019 (wr) $60001b (re).
        move.w #50,d0			;give 89 time to store key press, about 50 loops
delay_c:
	dbra d0,delay_c			;loop 50 times
        move.b $60001b,d0		;gives bit stored into d0 i.e. bit 1-7
	rts

keyup:						;put instructions for when user presses up
	move.w		#1,keytag
	sub.w		#1,y
	cmp.w		#1,y
	beq		endup
	bra		tst2nd
endup:
	move.w		#2,y
	bra		tst2nd

keydown:						;put instructions for when user presses down
	move.w		#1,keytag
	add.w		#1,y
	cmp.w		#84,y
	beq		enddown
	bra		tst2nd
enddown:
	move.w		#83,y
	bra		tst2nd

keyleft:						;put instructions for when user presses left

	bra		tst2nd

keyright:						;put instructions for when user presses right

	bra		tst2nd

key2nd:						;put instructions for when user presses 2nd
	move.w		#1,keytag
	cmp.w		#2,bullet
	beq		endgetkey
	move.w		y,bullety
	add.w		#5,bullety
	move.w		#2,bullet
	bra		endgetkey

test_collision:
	cmp.w		#27,bulletx
	bcc		_exit
	cmp.w		#5,bulletx
	bls		_exit
	move.w		bullety,d0
	move.w		enemyy,d1
	cmp.w		d0,d1
	bcc		_exit
	add.w		#16,d1
	cmp.w		d0,d1
	bls		_exit
	bra		ithit
	rts

ithit:
	move.w		#2,nme_boom
	rts

getpos:
	cmp.w		#0,nme_boom
	bne		_exit
	cmp.w		#1,nmedir
	beq		nmedown
	bra		nmeup

nmedown:
	add.w		#1,enemyy
	cmp.w		#84,enemyy
	bne		_exit
	move.w		#2,nmedir
	rts
nmeup:
	sub.w		#1,enemyy
	cmp.w		#1,enemyy
	bne		_exit
	move.w		#1,nmedir
	rts

display:
	DrawSpr	#144,y,gun
	cmp.w		#0,nme_boom
	bne		draw_boom
	DrawSpr	enemyx,enemyy,enemys
	
bulletst:
	cmp.w		#1,bullet
	beq		_exit
	DrawSpr	bulletx,bullety,bullets
	sub.w		#1,bulletx
	cmp.w		#1,bulletx
	beq		endbullet
	rts

draw_boom:
	cmp.w		#150,exp_timer
	beq		erase_nme
finish_boom:
	sub.w		#1,exp_timer
	cmp.w		#1,exp_timer
	beq		boomfinish
	cmp.w		#125,exp_timer
	beq		erase_boom
finish_boom2:
	cmp.w		#100,exp_timer
	bcs		erase_boom2
	cmp.w		#125,exp_timer
	bcc		dboom1
	cmp.w		#125,exp_timer
	bcs		dboom2
erase_nme:
	DrawSpr	enemyx,enemyy,enemysd
	bra		finish_boom
erase_boom:
	DrawSpr	enemyx,enemyy,enemysd
	bra		finish_boom2
erase_boom2:
	DrawSpr	enemyx,enemyy,enemysd
	bra		bulletst
dboom1:
	DrawSpr	enemyx,enemyy,explode
	bra		bulletst

dboom2:
	DrawSpr	enemyx,enemyy,explode2
	bra		bulletst	

boomfinish:
	move.w		#0,nme_boom
	move.w		#50,exp_timer
	move.w		#30,enemyy
	bra		bulletst

endbullet:
	DrawSpr	bulletx,bullety,dbullets
	move.w		#1,bullet
	move.w		#136,bulletx
	rts

_exit:
	rts					; end of program



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; variable declaration section
enter		dc.b	"Press Enter",0
_comment	dc.b	"comment",0	; program comment
delay_len	dc.w	2000				;delay (game speed) lower number = faster speed
y		dc.w	40
bullet		dc.w	1				;tag to see if bullet has been shot (1 no, 2 yes)
bullety	dc.w	40
bulletx	dc.w	136
enemyy		dc.w	30
enemyx		dc.w	10
nmedir		dc.w	1				;direction of enemy 1=down, 2=up
keytag		dc.w	0				;sees if a key is being pressed or was pressed (0=no,1=yes)
nme_boom	dc.w	0				;sees if an enemy has died (plays anim) 0=no 1=yes
exp_timer	dc.w	150				;timer for explosion of nme

gun:
	dc.w	16
	dc.w	2
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000111
	dc.b	%00000000,%00001111
	dc.b	%00000000,%00111010
	dc.b	%00000000,%11111000
	dc.b	%11100001,%11010101
	dc.b	%10011111,%10001011
	dc.b	%11111111,%11111111
	dc.b	%11111101,%10111111
	dc.b	%11111111,%01010111
	dc.b	%11100001,%11101011
	dc.b	%00000000,%11111010
	dc.b	%00000000,%00111101
	dc.b	%00000000,%00001111
	dc.b	%00000000,%00000111
	dc.b	%00000000,%00000000
gun_mask
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111

bullets:
	dc.w	6
	dc.w	1
	dc.b	%00000000
	dc.b	%00110000
	dc.b	%11111110
	dc.b	%11111100
	dc.b	%00110000
	dc.b	%00000000
bullets_mask
	dc.b	%11111111
	dc.b	%11111111
	dc.b	%11111111
	dc.b	%11111111
	dc.b	%11111111
	dc.b	%11111111

dbullets:
	dc.w	6
	dc.w	1
	dc.b	%00000000
	dc.b	%00000000
	dc.b	%00000000
	dc.b	%00000000
	dc.b	%00000000
	dc.b	%00000000
dbullets_mask
	dc.b	%11111111
	dc.b	%11111111
	dc.b	%11111111
	dc.b	%11111111
	dc.b	%11111111
	dc.b	%11111111

enemys:
	dc.w	16
	dc.w	2
	dc.b	%00000000,%00000000
	dc.b	%00001110,%00000000
	dc.b	%00111001,%10000000
	dc.b	%01111100,%11110000
	dc.b	%01111111,%11111000
	dc.b	%01111110,%11101100
	dc.b	%01111110,%11000010
	dc.b	%01111111,%10000000
	dc.b	%01111111,%10000000
	dc.b	%01111110,%11000010
	dc.b	%01111110,%11101100
	dc.b	%01011111,%11111000
	dc.b	%01101111,%11110000
	dc.b	%00110111,%10000000
	dc.b	%00001110,%00000000
	dc.b	%00000000,%00000000
enemys_mask:
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111

explode:
	dc.w	16
	dc.w	2
	dc.b	%00000000,%00000000
	dc.b	%00000001,%00000000
	dc.b	%00000001,%10000000
	dc.b	%00011011,%10000000
	dc.b	%00011011,%11000000
	dc.b	%00010111,%11110000
	dc.b	%00111111,%11111100
	dc.b	%00111111,%11101110
	dc.b	%01111111,%10110000
	dc.b	%00001110,%11010000
	dc.b	%00101111,%11010000
	dc.b	%00111111,%11110000
	dc.b	%00011111,%10000000
	dc.b	%00001111,%10000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
explode_mask:
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111

explode2:
	dc.w	16
	dc.w	2
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%10000000
	dc.b	%00000010,%10000000
	dc.b	%00000000,%10000000
	dc.b	%00000110,%10010000
	dc.b	%00100111,%00010000
	dc.b	%00110111,%11101000
	dc.b	%01111111,%10110000
	dc.b	%00001110,%11010000
	dc.b	%00101111,%11010000
	dc.b	%00111110,%11110000
	dc.b	%00000110,%00000000
	dc.b	%00001111,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
explode2_mask:
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111

enemysd:
	dc.w	16
	dc.w	2
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
	dc.b	%00000000,%00000000
enemysd_mask:
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111
	dc.b	%11111111,%11111111

	end					; end of the source code