import random

const word verareg=$9f20

byte verahi  @verareg+0
byte veramid @verareg+1
byte veralo  @verareg+2

byte veradat @verareg+3
byte veradat2 @verareg+4
byte veractl @verareg+5
byte veraien @verareg+6
byte veraisr @verareg+7
#if 0
	lda #$14    ; $40040
	sta verahi
	lda #$40
	sta veralo
	lda #1
	sta veradat ; VGA output
#endif


const byte LAYER_ENABLE = 1
const byte TM_BPP1_16=(0<<5)
const byte TM_BPP1_256=(1<<5)
const byte TM_BPP2=(2<<5)
const byte TM_BPP4=(3<<5)
const byte TM_BPP8=(4<<5)
const byte BM_BPP2=(5<<5)
const byte BM_BPP4=(6<<5)
const byte BM_BPP8=(7<<5)
const byte TILEW8=0
const byte TILEW16=(1<<5)
const byte TILEH8=0
const byte TILEH16=(1<<4)
const byte MAPW32=(0)
const byte MAPW64=(1)
const byte MAPW128=(2)
const byte MAPW256=(3)

const byte MAPH32=(0<<2)
const byte MAPH64=(1<<2)
const byte MAPH128=(2<<2)
const byte MAPH256=(3<<2)

void to_vera(pointer source,byte count) {
byte c,x
	for c,0,until,count {
		for x,0,until,256 {
			veradat=source[x]
		}
		source.hi+=1
	}
}

void to_veratm8(pointer source,byte count) {
byte c,x
	for c,0,until,count {
		for x,0,until,256 {
			veradat=source[x]
			veradat=0
		}
		source.hi+=1
	}
}

void set_vera8(byte count,byte value) {
byte c,x
	for c,0,until,count {
		for x,0,until,256 {
			veradat=value
		}
	}
}

void set_vera16(byte count,word value) {
byte c,x
	for c,0,until,count {
		for x,0,until,256 {
			veradat=value.lo
			veradat=value.hi
		}
	}
}

void inc_vera16(byte count,word value) {
byte c,x
	for c,0,until,count {
		for x,0,until,256 {
			veradat=value.lo & $f
			veradat=value.hi
			value+=1
		}
	}
}

void tilemode() {
	//	actually $4000
	verahi = $10
	veramid = $40
	veralo = $00
	to_vera(tileset,14)
	//	$0000
	verahi = $10
	veramid = $00
	to_vera(tilemap,8)
	//	$40200
	verahi = $14
	veramid = $02
	to_vera(palette,2)

	//	layer 0 regs at $40000
	verahi = $14
	veramid = 0
	veradat = TM_BPP8 | LAYER_ENABLE
	veradat = TILEW16 | TILEH16
	veradat = 0
	veradat = 0
	veradat = $00	// tile_base
	veradat = $10 // tile_base
}

void main() {
word hscroll
byte c,x

	veractl = 0
	verahi = $14
	veramid = 0
	veralo = $40
	veradat = $1 //	vga

//	x & y scale
	veralo=$41
	veradat = 64
	veradat = 64

	tilemode()

	while true {

		verahi = $14
		veramid = 0
		veralo = 6
		veradat = hscroll.lo
		veradat = hscroll.hi

		hscroll+=1

		for c,0,until,9 {
			for x,0,until,256 {
				asm {
					nop
				}
			}
		}
	}
}

array tilemap=file("x16-demo-master/mode4-tilemap.bin")
array tileset=file("x16-demo-master/mode4-tiles.bin")
array palette=file("x16-demo-master/mode4-palette.bin")