.nolist
#include "ion.inc"	;altered so I don't have to redefine equates
#include "ti83plus.inc" ;altered to be compatible with tasm not zilog
	.list

	.org progstart-2
	.db $BB,$6D
	xor a
	jr nc,Start
string:
 .db "physics",0

Start:
	di
	ld hl,map_data
	ld (savesscreen),hl

	ld b,(190-64)/2
outer:
	push bc


	ld a,96
	ld b,0
loop:
	cp 96-64
	jp z,done
	dec a
	push af
	push bc

	ld d,0
	ld e,b

	sra b
	add a,b

	ld h,d
	ld l,e

	add hl,hl
	add hl,de
	add hl,hl
	add hl,hl
	ld de,plotsscreen
	ex de,hl
	add hl,de


	ld ix,(savesscreen)
	add ix,de
	
	push af
	sra a\ sra a
	ld b,a
	add a,a
	add a,b
	add a,a
	add a,a
	neg
	ld e,a
	ld d,-1
	add ix,de
	pop af

	push af
	ld b,a
	ld a,96
	sub b
	sra a

	ld c,a
	pop af

	call scale

	pop bc
	inc b
	pop af
	
	jr loop
done:
	call ionfastcopy
	ld hl,(savesscreen)
	ld de,24
	add hl,de
	ld (savesscreen),hl
	pop bc
	djnz outer

	
	
	ret



#macro repeatcode( num )
	rlc c
	rrc c
	rl d
	add a,e
	jp nc,++_
	rlc c
	ex af,af'
	rlca
	jp nc,+_
	inc ix
	ld c,(ix)
_:
	ex af,af'
_:
#if num>1
	repeatcode( eval(num-1) )	
#endif
#endmacro


;----------------------
;A = the line width of the original image to scale into 96 pixels
;C = the x origin to scale from
;B = the y origin to scale from
;HL = target
;IX = source


Scale:
	push af
	push hl
	ld a,c
	srl c
	srl c
	srl c
	ld l,b
	ld b,0
	add ix,bc
	and 7
	ld e,a
	pop hl
	pop af

	ld b,96
	call FractionToFix8
	ld a,e

	ld e,c
donewline:
	ex af,af'
	ld a,1
	ex af,af'
	ld c,(ix)
	ld d,0
	or a
	jp z,skipintial
intialskip:
	rlc c
	push af
	ld a,d
	add a,e
	ld d,a
	pop af
	ex af,af'
	rlca
	ex af,af'
	dec a
	jp nz,intialskip
skipintial:
	ld b,12
	ld a,d
pixelloop:
	repeatcode(8)
	ld (hl),d
	inc hl
	dec b
	jp nz,pixelloop
	ret




FractionToFix8:
Frac:

	sla c
	add a,a
	jr c,$+5
	cp b
	jr c,$+4
	sub b
	inc c

	sla c
	add a,a
	jr c,$+5
	cp b
	jr c,$+4
	sub b
	inc c

	sla c
	add a,a
	jr c,$+5
	cp b
	jr c,$+4
	sub b
	inc c

	sla c
	add a,a
	jr c,$+5
	cp b
	jr c,$+4
	sub b
	inc c

	sla c
	add a,a
	jr c,$+5
	cp b
	jr c,$+4
	sub b
	inc c

	sla c
	add a,a
	jr c,$+5
	cp b
	jr c,$+4
	sub b
	inc c

	sla c
	add a,a
	jr c,$+5
	cp b
	jr c,$+4
	sub b
	inc c

	sla c
	add a,a
	ret c
	cp b
	ret c
	sub b
	inc c

	ret

.echo $-scale

map_data:
#include map.bmp