summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/video/relief.c
blob: 1ea77515786f866636d1886839696e1cd376cf79 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/***************************************************************************

    Atari "Round" hardware

****************************************************************************/

#include "driver.h"
#include "machine/atarigen.h"
#include "relief.h"



/*************************************
 *
 *  Tilemap callbacks
 *
 *************************************/

static TILE_GET_INFO( get_playfield_tile_info )
{
	UINT16 data1 = atarigen_playfield[tile_index];
	UINT16 data2 = atarigen_playfield_upper[tile_index] & 0xff;
	int code = data1 & 0x7fff;
	int color = 0x20 + (data2 & 0x0f);
	SET_TILE_INFO(0, code, color, (data1 >> 15) & 1);
}


static TILE_GET_INFO( get_playfield2_tile_info )
{
	UINT16 data1 = atarigen_playfield2[tile_index];
	UINT16 data2 = atarigen_playfield_upper[tile_index] >> 8;
	int code = data1 & 0x7fff;
	int color = data2 & 0x0f;
	SET_TILE_INFO(0, code, color, (data1 >> 15) & 1);
}



/*************************************
 *
 *  Video system start
 *
 *************************************/

VIDEO_START( relief )
{
	static const atarimo_desc modesc =
	{
		1,					/* index to which gfx system */
		1,					/* number of motion object banks */
		1,					/* are the entries linked? */
		0,					/* are the entries split? */
		0,					/* render in reverse order? */
		0,					/* render in swapped X/Y order? */
		0,					/* does the neighbor bit affect the next object? */
		8,					/* pixels per SLIP entry (0 for no-slip) */
		0,					/* pixel offset for SLIPs */
		0,					/* maximum number of links to visit/scanline (0=all) */

		0x100,				/* base palette entry */
		0x100,				/* maximum number of colors */
		0,					/* transparent pen index */

		{{ 0x00ff,0,0,0 }},	/* mask for the link */
		{{ 0 }},			/* mask for the graphics bank */
		{{ 0,0x7fff,0,0 }},	/* mask for the code index */
		{{ 0 }},			/* mask for the upper code index */
		{{ 0,0,0x000f,0 }},	/* mask for the color */
		{{ 0,0,0xff80,0 }},	/* mask for the X position */
		{{ 0,0,0,0xff80 }},	/* mask for the Y position */
		{{ 0,0,0,0x0070 }},	/* mask for the width, in tiles*/
		{{ 0,0,0,0x0007 }},	/* mask for the height, in tiles */
		{{ 0,0x8000,0,0 }},	/* mask for the horizontal flip */
		{{ 0 }},			/* mask for the vertical flip */
		{{ 0 }},			/* mask for the priority */
		{{ 0 }},			/* mask for the neighbor */
		{{ 0 }},			/* mask for absolute coordinates */

		{{ 0 }},			/* mask for the special value */
		0,					/* resulting value to indicate "special" */
		0					/* callback routine for special entries */
	};
	
	/* MOs are 5bpp but with a 4-bit color granularity */
	machine->gfx[1]->color_granularity = 16;

	/* initialize the playfield */
	atarigen_playfield_tilemap = tilemap_create(machine, get_playfield_tile_info, tilemap_scan_cols,  8,8, 64,64);

	/* initialize the second playfield */
	atarigen_playfield2_tilemap = tilemap_create(machine, get_playfield2_tile_info, tilemap_scan_cols,  8,8, 64,64);
	tilemap_set_transparent_pen(atarigen_playfield2_tilemap, 0);

	/* initialize the motion objects */
	atarimo_init(machine, 0, &modesc);
}



/*************************************
 *
 *  Main refresh
 *
 *************************************/

VIDEO_UPDATE( relief )
{
	atarimo_rect_list rectlist;
	bitmap_t *mobitmap;
	int x, y, r;

	/* draw the playfield */
	bitmap_fill(priority_bitmap, cliprect, 0);
	tilemap_draw(bitmap, cliprect, atarigen_playfield_tilemap, 0, 0);
	tilemap_draw(bitmap, cliprect, atarigen_playfield2_tilemap, 0, 1);

	/* draw and merge the MO */
	mobitmap = atarimo_render(0, cliprect, &rectlist);
	for (r = 0; r < rectlist.numrects; r++, rectlist.rect++)
		for (y = rectlist.rect->min_y; y <= rectlist.rect->max_y; y++)
		{
			UINT16 *mo = (UINT16 *)mobitmap->base + mobitmap->rowpixels * y;
			UINT16 *pf = (UINT16 *)bitmap->base + bitmap->rowpixels * y;
			UINT8 *pri = (UINT8 *)priority_bitmap->base + priority_bitmap->rowpixels * y;
			for (x = rectlist.rect->min_x; x <= rectlist.rect->max_x; x++)
				if (mo[x])
				{
					/* verified from the GALs on the real PCB; equations follow
                     *
                     *      --- PF/M is 1 if playfield has priority, or 0 if MOs have priority
                     *      PF/M = PFXS
                     *
                     *      --- CS0 is set to 1 if the MO is transparent
                     *      CS0=!MPX0*!MPX1*!MPX2*!MPX3
                     *
                     *      --- CS1 is 1 to select playfield pixels or 0 to select MO pixels
                     *      !CS1=MPX5*MPX6*MPX7*!CS0
                     *          +!MPX4*MPX5*MPX6*MPX7
                     *          +PFXS*!CS0
                     *          +!MPX4*PFXS
                     *
                     *      --- CRA10 is the 0x200 bit of the color RAM index; set for the top playfield only
                     *      CRA10:=CS1*PFXS
                     *
                     *      --- CRA9 is the 0x100 bit of the color RAM index; set for MOs only
                     *      !CA9:=CS1
                     *
                     *      --- CRA8-1 are the low 8 bits of the color RAM index; set as expected
                     */
					int cs0 = 0;
					int cs1 = 1;

					/* compute the CS0 signal */
					cs0 = ((mo[x] & 0x0f) == 0);

					/* compute the CS1 signal */
					if ((!cs0 && (mo[x] & 0xe0) == 0xe0) ||
						((mo[x] & 0xf0) == 0xe0) ||
						(!pri[x] && !cs0) ||
						(!pri[x] && !(mo[x] & 0x10)))
						cs1 = 0;

					/* MO is displayed if cs1 == 0 */
					if (!cs1)
						pf[x] = mo[x];

					/* erase behind ourselves */
					mo[x] = 0;
				}
		}
	return 0;
}