summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/video/cchasm.c
blob: 0c4cfd926932f39b2b4af319e92e6d7764cb9717 (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
/***************************************************************************

    Cinematronics Cosmic Chasm hardware

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

#include "driver.h"
#include "video/vector.h"
#include "cchasm.h"

#define HALT   0
#define JUMP   1
#define COLOR  2
#define SCALEY 3
#define POSY   4
#define SCALEX 5
#define POSX   6
#define LENGTH 7

UINT16 *cchasm_ram;

static int xcenter, ycenter;

static TIMER_CALLBACK( cchasm_refresh_end )
{
    cpunum_set_input_line (0, 2, ASSERT_LINE);
}

static void cchasm_refresh (void)
{

	int pc = 0;
    int done = 0;
    int opcode, data;
    int currentx = 0, currenty = 0;
    int scalex = 0, scaley = 0;
    int color = 0;
    int total_length = 1;   /* length of all lines drawn in a frame */
    int move = 0;

	vector_clear_list();

	while (!done)
	{
        data = cchasm_ram[pc];
   		opcode = data >> 12;
        data &= 0xfff;
        if ((opcode > COLOR) && (data & 0x800))
          data |= 0xfffff000;

		pc++;

		switch (opcode)
		{
        case HALT:
            done=1;
            break;
        case JUMP:
            pc = data - 0xb00;
            logerror("JUMP to %x\n", data);
            break;
        case COLOR:
            color = VECTOR_COLOR444(data ^ 0xfff);
            break;
        case SCALEY:
            scaley = data << 5;
            break;
        case POSY:
            move = 1;
            currenty = ycenter + (data << 16);
            break;
        case SCALEX:
            scalex = data << 5;
            break;
        case POSX:
            move = 1;
            currentx = xcenter - (data << 16);
            break;
        case LENGTH:
            if (move)
            {
                vector_add_point (currentx, currenty, 0, 0);
                move = 0;
            }

            currentx -= data * scalex;
            currenty += data * scaley;

            total_length += abs(data);

            if (color)
                vector_add_point (currentx, currenty, color, 0xff);
            else
                move = 1;
            break;
        default:
            logerror("Unknown refresh proc opcode %x with data %x at pc = %x\n", opcode, data, pc-2);
            done = 1;
            break;
		}
	}
    /* Refresh processor runs with 6 MHz */
    timer_set (attotime_mul(ATTOTIME_IN_HZ(6000000), total_length), 0, cchasm_refresh_end);
}


WRITE16_HANDLER( cchasm_refresh_control_w )
{
	if (ACCESSING_MSB)
	{
		switch (data >> 8)
		{
		case 0x37:
			cchasm_refresh();
			break;
		case 0xf7:
			cpunum_set_input_line (0, 2, CLEAR_LINE);
			break;
		}
	}
}

VIDEO_START( cchasm )
{
	int xmin, xmax, ymin, ymax;

	xmin=machine->screen[0].visarea.min_x;
	ymin=machine->screen[0].visarea.min_y;
	xmax=machine->screen[0].visarea.max_x;
	ymax=machine->screen[0].visarea.max_y;

	xcenter=((xmax+xmin)/2) << 16;
	ycenter=((ymax+ymin)/2) << 16;

	video_start_vector(machine);
}