#include "ti82.h"
#include "keys.inc"

temp_x = TEXT_MEM
temp_y = TEXT_MEM+1
BallOffset = TEXT_MEM+2
BoxOffset = TEXT_MEM+3
BallOrBox = TEXT_MEM+4		;bit 0 reset = ball, bit 0 set = box

Board	= APD_BUF
 .org    START_ADDR
 .db	"DStar v1.0 by AVD",0
Start:
 ld	a,$8C
 out	(2),a
 call	CLRGBU
 call	put_status
JustATadBeforeKeyloop:
 call	SetUpLevel		;uncompresses and draws current level
keyloop:
 ld	a,(BallOrBox)
 or	a
 jr	z,IsBall		;if 'BallOrBox' is 0, we are moving the ball
 ld	hl,BoxOffset		;otherwise we are moving the box
 jr	OnWithKeyloop
IsBall:
 ld	hl,BallOffset
OnWithKeyloop:
 push	hl			;does GET_KEY destroy hl? I just wanted to be safe :)
 call	GET_KEY
 pop	hl
 cp	G_CLEAR
 ret	z			;Exit if the Exit key has been pressed
 cp	G_UP
 jr	z,up
 cp	G_DOWN
 jr	z,down
 cp	G_LEFT
 jp	z,left
 cp	G_RIGHT
 jp	z,right
 cp	G_2nd
 jp	z,switch
 cp	G_PLUS
 jr	z,AdvanceLevel
 cp	G_MINUS
 jp	z,DownLevel
 cp	G_DEL
 call	z,SetUpLevel
 ld	hl,Board
 ld	b,144			;there are 144 pieces in the playing field (9*16)
CheckWinLoop:
 ld	a,(hl)
 cp	2
 jr	z,keyloop		;if any one of them is 2 (clear ball), keep playing
 inc	hl
 djnz	CheckWinLoop
 jr	AdvanceLevel
up:
 ld	a,-16
 jr	Move_It
down:
 ld	a,16
 jr	Move_It
left:
 ld	a,-1
 jr	Move_It
right:
 ld	a,1
 jr	Move_It
switch:
 ld	hl,BallOrBox
 bit	0,(hl)
 jr	z,SwitchToBox
 res	0,(hl)			;we are now moving the ball
 jp	keyloop
SwitchToBox:
 set	0,(hl)			;switch to box move mode
 jp	keyloop

Move_It:
 ld	(Modify_This),a
 ld	(Modify_This_Too),a
 ld	(Me_Three),a
Move_It_Again:
 ld	d,0
 ld	a,(hl)
 ld	e,a
 ld	ix,Board
 add	ix,de			;get offset to piece being moved into ix
 ld	a,(BallOrBox)
 ld	b,a			;put BallOrBox into b so it can be tested
 .db $DD,$7E			;ld a,(ix+XX)
Modify_This:
 .db $00
 bit	0,b
 jr	z,goonstd
 cp	2
 jp	z,DoneWithMove
goonstd:
 cp	2			;if it is 2, we can run over it
 jr	z,ItIsGood
 or	a			;if the piece isn't 0, we can't go there, so we go back to checking for keys
 jp	nz,DoneWithMove
ItIsGood:
 ld	a,(ix)
 ld	(ix),0
 .db $DD,$77			;ld (ix+XX),a
Modify_This_Too:
 .db $00
 ld	a,(hl)
 .db $C6			;add a,XX
Me_Three:
 .db $00
 ld	(hl),a
 jr	Move_It_Again

DoneWithMove:
 call	DrawBoard
 jp	keyloop

AdvanceLevel:
 ld	a,(LevelNum)
 cp	24
 jr	z,BeatAll25
 inc	a
 ld	(LevelNum),a
 ld	hl,(Level)
 ld	bc,38
 add	hl,bc
 ld	(Level),hl
 jp	JustATadBeforeKeyloop

DownLevel:
 ld	a,(LevelNum)
 or	a
 call	z,wrap_to_end
 dec	a
 ld	(LevelNum),a
 ld	hl,(Level)
 ld	bc,-38
 add	hl,bc
 ld	(Level),hl
 jp	JustATadBeforeKeyloop

wrap_to_end:
 ld	 a,25
 ld	hl,950
 ld	(Level),hl
 ret

BeatAll25:
 xor	a
 ld	hl,LevelNum
 ld	(hl),a
 inc	hl
 ld	(hl),a
 inc	hl
 ld	(hl),a
 jp	JustATadBeforeKeyloop

SetUpLevel:
 xor	a			;ld a,0 (but in a smaller and faster way)
 ld	(BallOrBox),a
 ld	hl,(Level)
 ld	de,Levels
 add	hl,de			;get address of level data
 ld	de,BallOffset
 ld	bc,2
 ldir				;the first 2 bytes are BallOffset and BoxOffset, respectively
 ld	de,Board		;this is where the uncompressed level goes
 ld	b,9			;the board is 9 high
y_loop:
 push	bc
 ld	b,4			;and each compressed line is 4 bytes wide (each byte hold 4 elemenets, 4*4=16)
x_loop:
 push	bc
 ld	a,(hl)
 srl	a
 srl	a
 srl	a
 srl	a
 srl	a
 srl	a			;shift 6 times to get the first piece
 and	%11			;we only need the rightmost 2 bits
 ld	(de),a			;put it in the temp area
 inc	de			;and increment de (address of current place in temp area)
 ld	a,(hl)
 srl	a
 srl	a
 srl	a
 srl	a			;we only need to shift 4 times for the second piece
 and	%11
 ld	(de),a
 inc	de
 ld	a,(hl)
 srl	a
 srl	a			;2 for the third piece...
 and	%11
 ld	(de),a
 inc	de
 ld	a,(hl)
 and	%11			;and none for the fourth one
 ld	(de),a
 inc	de
 inc	hl
 pop	bc
 djnz	x_loop
 pop	bc
 djnz	y_loop
 ld	hl,Board
 ld	a,(BallOffset)
 ld	d,0
 ld	e,a
 add	hl,de
 ld	(hl),3			;put ball where it belongs
 ld	hl,Board
 ld	a,(BoxOffset)
 ld	d,0
 ld	e,a
 add	hl,de
 ld	(hl),4			;put box where it belongs

DrawBoard:
 push	hl
 ld	hl,Board
 xor	a
 ld	(temp_y),a
 ld	b,9
yloop1:
 push	bc
 xor	a
 ld	(temp_x),a
 ld	b,8
xloop1:
 push	bc
 ld	a,(temp_x)
 ld	b,a
 ld	a,(temp_y)
 ld	c,a
 ld	a,(hl)
 push	hl
 add	a,a
 add	a,a
 add	a,a
 ld	hl,Sprites
 ld	d,0
 ld	e,a
 add	hl,de
 CALL	PutSprite
 pop	hl
 ld	a,(temp_x)
 add	a,6
 ld	(temp_x),a
 inc	hl

 ld	a,(temp_x)
 ld	b,a
 ld	a,(temp_y)
 ld	c,a
 ld	a,(hl)
 push	hl
 add	a,a
 add	a,a
 add	a,a
 ld	hl,Sprites
 ld	d,0
 ld	e,a
 add	hl,de
 CALL	PutSprite
 pop	hl
 ld	a,(temp_x)
 add	a,6
 ld	(temp_x),a
 inc	hl

 pop	bc
 djnz	xloop1
 ld	a,(temp_y)
 add	a,6
 ld	(temp_y),a
 pop	bc
 djnz	yloop1
 ld	hl,GRAPH_MEM
 CALL	SHOW_SCREEN
 pop	hl
 ret

PutSprite: ; Puts a sprite stored at (HL) at B,C
 push 	bc
 push 	de
 push 	hl
 push 	hl
 ld	a,63
 sub	c
 ld	c,a
 call 	FIND_PIXEL
 ld 	de,$88B8
 add 	hl,de
 ex 	de,hl
 pop 	hl
 ld 	b,(hl)
 inc 	hl
 ld 	c,(hl)
 inc 	hl
 push 	hl
 pop 	ix
 ex 	de,hl
PS_NewRow:
 push 	bc
 ld 	d,(ix)
 inc 	ix
 push 	af
 push 	hl
PS_NewCol:
 rl 	d
 ld 	e,a
 jr 	nc,PS_NoPixel
 or 	(hl)
 ld 	(hl),a
 jr 	PS_NextPixel
PS_NoPixel:
 cpl
 and 	(hl)
 ld 	(hl),a
PS_NextPixel:
 ld 	a,e
 rrca
 jr 	nc,PS_SameByte
 inc 	hl
PS_SameByte:
 djnz 	PS_NewCol
 pop 	hl
 pop 	af
 ld 	de,12
 add 	hl,de
 pop 	bc
 dec 	c
 jr 	nz,PS_NewRow
 pop 	hl
 pop 	de
 pop 	bc
 ret



CLRGBU:
 ld 	hl,GRAPH_MEM
 ld 	de,GRAPH_MEM+1
 ld 	bc,768
 ld 	(hl),0
 ldir
 ret

put_status:
 ld	de,StatusPicture
 ld	hl,GRAPH_MEM+(12*55)+3
 ld	b,7
status_loop:
 push	bc
 ex	de,hl
 ld	bc,7
 ldir
 ex	de,hl
 ld	bc,5
 add	hl,bc
 pop	bc
 djnz	status_loop
 ret

 .include showscrn.h

LevelNum:
 .db 0
Level:
 .dw 0

Sprites:			;1=edge, 2=clear ball 3=moveable ball 4=moveable block
 .db 	6,6
 .db	%00000000
 .db	%00000000
 .db	%00000000
 .db	%00000000
 .db	%00000000
 .db	%00000000

 .db	6,6
 .db	%01111000
 .db	%10101100
 .db	%11010100
 .db	%10101100
 .db	%11010100
 .db	%01111000

 .db	6,6
 .db	%00000000
 .db	%00110000
 .db	%01001000
 .db	%01001000
 .db	%00110000
 .db	%00000000

 .db	6,6
 .db	%00000000
 .db	%00110000
 .db	%01101000
 .db	%01111000
 .db	%00110000
 .db	%00000000

 .db	6,6
 .db	%00000000
 .db	%01111000
 .db	%01111000
 .db	%01111000
 .db	%01111000
 .db	%00000000

Levels:
 .db	17,30				;ball offset, box offset
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000101,%00000000,%00000000,%10010001
 .db	%01000000,%00000000,%00000010,%00010101
 .db	%01000000,%00000000,%01011000,%00000001
 .db	%01000000,%01010010,%00000000,%00000101
 .db	%01010010,%00001000,%00000000,%10000001
 .db	%01001000,%00000000,%00100101,%00100001
 .db	%01000000,%00000101,%10000000,%00001001
 .db	%01010101,%01010101,%01010101,%01010101
level2:
 .db	30,86
 .db	%00010000,%01000100,%01000000,%01000101
 .db	%01000000,%10000000,%00000000,%00000001
 .db	%00000001,%10000001,%10000000,%10000000
 .db	%01000100,%10000000,%00001000,%00010001
 .db	%00000000,%00000100,%00001000,%00000100
 .db	%01000000,%00010001,%00001000,%00000001
 .db	%00000001,%00000100,%01000000,%01101001
 .db	%01000000,%00000000,%00000000,%00000100
 .db	%00010000,%01000000,%00000000,%00010000
level3:
 .db	30,46
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000000,%00000000,%00000000,%10010001
 .db	%01000000,%01010000,%00000000,%01010001
 .db	%01000000,%01100000,%00000010,%00000001
 .db	%01001000,%00000000,%10010100,%00001001
 .db	%01000110,%00001000,%00100100,%00100101
 .db	%01000101,%10000110,%00001000,%10010101
 .db	%01100000,%00000101,%10000000,%00000001
 .db	%01010101,%01010101,%01010101,%01010101
level4:
 .db	125,30
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000000,%00000000,%00000000,%00010001
 .db	%01000000,%00000100,%00000000,%00000001
 .db	%01011001,%10001001,%10011001,%10011001
 .db	%01000100,%01100010,%01000100,%01000101
 .db	%01011001,%10011000,%10011001,%10011001
 .db	%01000000,%00000100,%00000000,%00000001
 .db	%01000000,%01000000,%00000000,%01000001
 .db	%01010101,%01010101,%01010101,%01010101
level5:
 .db	17,110
 .db	%00010101,%01010101,%01010101,%01010100
 .db	%01000000,%01000000,%01000001,%00000001
 .db	%01000001,%10000100,%10000010,%00010001
 .db	%01010000,%00000000,%01000001,%00000001
 .db	%01100001,%10010000,%00000000,%00000101
 .db	%01010000,%00000001,%00100001,%00000001
 .db	%01100100,%00010001,%00010000,%00010001
 .db	%01000000,%01000000,%00100100,%00011001
 .db	%00010101,%01010101,%01010101,%01010100
level6:
 .db	65,113
 .db	%00000000,%01010101,%01010101,%01010101
 .db	%00000001,%00000010,%00000001,%10001001
 .db	%00000100,%00000010,%00000000,%01000101
 .db	%00010000,%00000010,%00000000,%00000001
 .db	%01000000,%00000010,%00000000,%00000001
 .db	%01010000,%00000010,%00000100,%00000101
 .db	%01000000,%00000010,%00000000,%01000001
 .db	%01000001,%00000010,%00000101,%10000001
 .db	%01010101,%01010101,%01010101,%01010101
level7:
 .db	115,122
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000000,%00000000,%00000000,%00000001
 .db	%00010100,%01010100,%00011000,%01011001
 .db	%00011000,%00011000,%01000100,%01000100
 .db	%00000100,%00010000,%01010100,%01010000
 .db	%00010100,%00010000,%01100100,%01100100
 .db	%01000000,%00000000,%00000000,%00000001
 .db	%01000000,%01100000,%00000000,%00011001
 .db	%01010101,%01010101,%01010101,%01010101
level8:
 .db	108,98
 .db	%01010101,%01010101,%01010101,%01010100
 .db	%01000010,%01010000,%00000000,%00000101
 .db	%01000001,%10000001,%01001000,%00000001
 .db	%01000010,%01010001,%00011000,%00000001
 .db	%01010000,%00000001,%01000001,%10010001
 .db	%01010001,%00000000,%00000010,%01100001
 .db	%01100010,%01000000,%10000001,%00010001
 .db	%01010000,%00000000,%00000000,%00000001
 .db	%00010101,%01010101,%01010101,%01010101
level9:
 .db	30,72
 .db	%00000100,%01010101,%01010101,%01010100
 .db	%00011001,%10000000,%00000001,%00000001
 .db	%01100010,%01000000,%00100000,%00000100
 .db	%00010001,%00001001,%01000010,%01000001
 .db	%01000001,%10000110,%00100000,%00001001
 .db	%01000000,%00001001,%01000000,%00000100
 .db	%01100110,%00000000,%00000000,%00010000
 .db	%01000000,%00000000,%00000000,%01000000
 .db	%01010101,%01010101,%01010101,%00000000
level10:
 .db	93,36
 .db	%00000000,%01010101,%01010101,%01010100
 .db	%01010101,%00100000,%00000000,%00000001
 .db	%01000000,%00000101,%01100010,%01001001
 .db	%01001000,%00000110,%00011000,%00000100
 .db	%01000000,%00000100,%00100000,%01001001
 .db	%01100110,%00000100,%10010000,%01000100
 .db	%00011000,%00000101,%01000001,%01010000
 .db	%01000000,%00000000,%00000100,%01000100
 .db	%00010101,%01010101,%01010000,%01000001
level11:
 .db	30,108
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000000,%00000001,%00000000,%00000001
 .db	%01000001,%10100000,%00000010,%10000101
 .db	%01010000,%00100000,%00010100,%00001001
 .db	%01100000,%00000110,%01101000,%00010101
 .db	%01010001,%01000000,%00010100,%00000001
 .db	%01100000,%10010010,%00000000,%00001001
 .db	%01011001,%01010000,%00000100,%00000101
 .db	%00010100,%01010101,%01010101,%01010100
level12:
 .db	17,92
 .db	%01010000,%00000001,%01000001,%01010100
 .db	%01000101,%01010110,%00010101,%00100101
 .db	%01000000,%00101000,%00000000,%10000001
 .db	%01000101,%00000101,%10000001,%10010001
 .db	%01000100,%10000101,%01100001,%01000001
 .db	%01000101,%00000101,%00000001,%00010001
 .db	%01000000,%00001000,%00000000,%00000001
 .db	%01000000,%00000000,%00100000,%00000001
 .db	%01010101,%01010101,%01010101,%01010101
level13:
 .db	18,113
 .db	%00010101,%01010101,%01010101,%01010100
 .db	%01000001,%00000000,%00000000,%10000101
 .db	%01000100,%00000110,%00000010,%01010001
 .db	%01000000,%00000000,%10000000,%00010001
 .db	%01001000,%00000000,%00000000,%00011001
 .db	%01000100,%00000000,%00100000,%00000001
 .db	%01010000,%00000000,%10001000,%00011001
 .db	%01000000,%01000000,%00100001,%00010001
 .db	%00010101,%01010101,%01010101,%01010100
level14:
 .db	36,50
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01100110,%00000000,%00000000,%10011001
 .db	%01001001,%00000000,%00000001,%01000001
 .db	%01000000,%00000000,%00000010,%00000001
 .db	%01000000,%00000000,%00100100,%00000001
 .db	%01000000,%00000010,%00000000,%00000001
 .db	%01001001,%00000000,%00000000,%01000001
 .db	%01100110,%00000000,%00000000,%10011001
 .db	%01010101,%01010101,%01010101,%01010101
level15:
 .db	51,76
 .db	%00010101,%01010100,%01010101,%01010100
 .db	%01000000,%00001001,%00000000,%00100001
 .db	%01000100,%10000100,%00010000,%00100001
 .db	%01000000,%01000000,%01101000,%01100001
 .db	%00010001,%00000001,%00100000,%00010001
 .db	%01100000,%00000000,%00010000,%01100001
 .db	%00010000,%00000000,%10000000,%00000100
 .db	%01100000,%00000000,%00000000,%00001001
 .db	%00010101,%01010101,%01010101,%01010100
level16:
 .db	35,19
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01010000,%01100010,%00000000,%00001001
 .db	%01100000,%10011000,%00000000,%00000101
 .db	%01010001,%01010000,%00001000,%00000101
 .db	%01010000,%00000010,%01100100,%00000001
 .db	%01101000,%00000000,%00001001,%10000001
 .db	%01010010,%00000000,%01010101,%10000001
 .db	%01011001,%00000100,%00000000,%00000001
 .db	%01010101,%01010101,%01010101,%01010101
level17:
 .db	29,124
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01001001,%00000000,%00000000,%01000001
 .db	%01000100,%00100110,%10011000,%00010001
 .db	%01000000,%00011001,%01100100,%10000001
 .db	%01001001,%00000000,%00000010,%01000001
 .db	%01000010,%01100000,%00001001,%00000001
 .db	%01000100,%00010001,%01100100,%00010001
 .db	%01000000,%00100001,%10000000,%00000001
 .db	%01010101,%01010101,%01010101,%01010101
level18:
 .db	115,26
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01001000,%00000010,%00000001,%00000001
 .db	%01000001,%10011000,%00000110,%00000001
 .db	%01000000,%01100100,%00000001,%10000001
 .db	%01000000,%10000001,%00000010,%01100001
 .db	%01000110,%01000000,%01001001,%00000001
 .db	%01001001,%10000100,%10000100,%00000001
 .db	%01100100,%00000100,%00000000,%01000001
 .db	%01010101,%01010101,%01010101,%01010101
level19:
 .db	126,110
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01100000,%00010100,%00000000,%01011001
 .db	%01000100,%00010000,%00000000,%01100001
 .db	%01001001,%00000010,%01010000,%10000001
 .db	%01000100,%00000001,%10000000,%00000001
 .db	%01000000,%00010000,%00100100,%00000001
 .db	%01000101,%00100100,%01011000,%00010001
 .db	%01001001,%00011000,%00000000,%01010001
 .db	%01010101,%01010101,%01010101,%01010101
level20:
 .db	77,66
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000000,%10011000,%00000000,%00000001
 .db	%01011000,%00100100,%01011000,%00000101
 .db	%01000100,%01001000,%00000100,%00010001
 .db	%01000000,%01000001,%01000001,%00001001
 .db	%01000100,%00010000,%00100001,%00010001
 .db	%01010000,%00100101,%00011000,%00100101
 .db	%01000000,%00000000,%00100110,%00000001
 .db	%01010101,%01010101,%01010101,%01010101
level21:
 .db	103,105
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000101,%01000000,%00001000,%00000101
 .db	%01000000,%01000000,%00000000,%01000101
 .db	%01000000,%01011000,%00000000,%00100001
 .db	%01000010,%00000000,%10000000,%10000101
 .db	%01000000,%00010000,%00000101,%01100001
 .db	%01000010,%00100000,%00000010,%00101001
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%00000000,%00000000,%00000000,%00000000
level22:
 .db	103,105
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01100100,%00011001,%00011000,%00010001
 .db	%01000000,%00010000,%00000000,%00000001
 .db	%01100000,%00010000,%01100000,%10000001
 .db	%01010001,%10000000,%00000010,%00010101
 .db	%01001000,%01000000,%01010110,%00000001
 .db	%01000000,%00000100,%01000000,%10000001
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%00000000,%00000000,%00000000,%00000000
level23:
 .db	103,105
 .db	%00010101,%01010101,%01010101,%01010100
 .db	%01000100,%00011001,%00011000,%00010001
 .db	%01000000,%00100000,%01000000,%00000001
 .db	%01010000,%00010000,%00100001,%10000001
 .db	%01000001,%10000001,%00001010,%00100001
 .db	%01011000,%01000000,%01010010,%00000001
 .db	%01000000,%00000100,%01000000,%10000001
 .db	%00010101,%01010101,%01010101,%01010100
 .db	%00000000,%00000000,%00000000,%00000000
level24:
 .db	103,105
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000000,%00000100,%00000000,%00000101
 .db	%01000101,%10001000,%00000001,%01100101
 .db	%01000110,%00000000,%00100100,%00010101
 .db	%01001010,%00001001,%00010100,%00000001
 .db	%01000110,%00100001,%00000000,%01010001
 .db	%01000101,%00000000,%01000101,%01101001
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%00000000,%00000000,%00000000,%00000000
level25:
 .db	103,105
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%01000000,%00000000,%00000000,%00010001
 .db	%01001000,%01011000,%00001000,%00000001
 .db	%01000000,%01100000,%10000001,%01000001
 .db	%01001000,%00000001,%01000001,%10000001
 .db	%01000110,%00000010,%01000000,%00100001
 .db	%01000101,%10000100,%00000000,%00000001
 .db	%01010101,%01010101,%01010101,%01010101
 .db	%00000000,%00000000,%00000000,%00000000

StatusPicture:
 .db $00,$00,$80,$00,$00,$80,$00
 .db $00,$00,$C0,$39,$00,$C0,$00
 .db $E3,$79,$4E,$25,$11,$40,$F0
 .db $94,$11,$2A,$39,$21,$29,$48
 .db $93,$12,$EC,$24,$C2,$E9,$48
 .db $B4,$92,$2A,$24,$42,$26,$58
 .db $E7,$12,$09,$3C,$42,$02,$70


.end