1;
2;	Dither patterns, ordered by increasing intensity (0..11)
3;	Functions expects intensity in A and Y coordinate in C
4;
5;	On exit A will hold the current value for pattern
6;
7;	Stefano Bodrato, 18/3/2009
8;
9;	$Id: dither_pattern.asm $
10;
11
12	SECTION  code_graphics
13	PUBLIC	dither_pattern
14
15.dither_pattern
16		and	a
17		ret	z
18
19		cp	11
20		jr	c,nomax
21		ld	a,255
22		ret
23.nomax
24		rla
25		rla
26		and	@11111100
27		ld	l,a
28		ld	a,c	; Y
29		and	3
30		or	l
31		ld	l,a
32		ld	h,0
33		ld	de,_dithpat-4
34		add	hl,de
35		ld	a,(hl)
36		ret
37
38        SECTION rodata_graphics
39_dithpat:
40
41	defb	@00000010	; 1
42	defb	@00000000
43	defb	@00100000
44	defb	@00000000
45
46	defb	@00000010	; 2
47	defb	@10000000
48	defb	@00100000
49	defb	@00001000
50
51	defb	@00010100	; 3
52	defb	@01000001
53	defb	@00010100
54	defb	@01000001
55
56	defb	@00010100	; 4
57	defb	@01000001
58	defb	@10010100
59	defb	@01001001
60
61	defb	@01000101	; 5
62	defb	@10101000
63	defb	@00010101
64	defb	@10101010
65
66	defb	@01010101	; 6
67	defb	@10101010
68	defb	@01010101
69	defb	@10101010
70
71	defb	@11001100	; 7
72	defb	@00110011
73	defb	@11001100
74	defb	@00110011
75
76	defb	@11011101	; 8
77	defb	@10101010
78	defb	@01110111
79	defb	@10101010
80
81	defb	@11011101	; 9
82	defb	@01110111
83	defb	@11011101
84	defb	@01110111
85
86	defb	@11111101	; 10
87	defb	@01111111
88	defb	@11011111
89	defb	@11110111
90
91