summaryrefslogtreecommitdiffstatshomepage
path: root/src/mess/video/pcw.c
blob: f4d18761636f013dd69efe382ee39851b04b60e3 (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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
// license:GPL-2.0+
// copyright-holders:Kevin Thacker
/***************************************************************************

  pcw.c

  Functions to emulate the video hardware of the Amstrad PCW.

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

#include "emu.h"
#include "includes/pcw.h"
#include "machine/ram.h"

inline void pcw_state::pcw_plot_pixel(bitmap_ind16 &bitmap, int x, int y, UINT32 color)
{
	bitmap.pix16(y, x) = (UINT16)color;
}

/***************************************************************************
  Start the video hardware emulation.
***************************************************************************/

void pcw_state::video_start()
{
	rectangle rect(0, PCW_PRINTER_WIDTH - 1, 0, PCW_PRINTER_HEIGHT - 1);

	m_prn_output = auto_bitmap_ind16_alloc(machine(),PCW_PRINTER_WIDTH,PCW_PRINTER_HEIGHT);
	m_prn_output->fill(1, rect);
}

#if 0
/* two colours */
static const unsigned short pcw_colour_table[PCW_NUM_COLOURS] =
{
	0, 1
};
#endif

/* black/white */
static const rgb_t pcw_palette[PCW_NUM_COLOURS] =
{
	rgb_t(0x000, 0x000, 0x000),
	rgb_t(0x0ff, 0x0ff, 0x0ff)
};


/* Initialise the palette */
PALETTE_INIT_MEMBER(pcw_state, pcw)
{
	palette.set_pen_colors(0, pcw_palette, ARRAY_LENGTH(pcw_palette));
}

/***************************************************************************
  Draw the game screen in the given bitmap_ind16.
  Do NOT call osd_update_display() from this function,
  it will be called by the main emulation engine.
***************************************************************************/
UINT32 pcw_state::screen_update_pcw(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	int x,y,b;
	unsigned short roller_ram_offs;
	unsigned char *roller_ram_ptr;
	int pen0,pen1;

	pen0 = 0;
	pen1 = 1;

	/* invert? */
	if (m_vdu_video_control_register & (1<<7))
	{
		/* yes */
		pen1^=1;
		pen0^=1;
	}

	/* video enable? */
	if ((m_vdu_video_control_register & (1<<6))!=0)
	{
		/* render top border */
		rectangle rect(0, PCW_SCREEN_WIDTH, 0, PCW_BORDER_HEIGHT);
		bitmap.fill(pen0, rect);

		/* render bottom border */
		rect.set(0, PCW_SCREEN_WIDTH, PCW_BORDER_HEIGHT + PCW_DISPLAY_HEIGHT, PCW_BORDER_HEIGHT + PCW_DISPLAY_HEIGHT + PCW_BORDER_HEIGHT);
		bitmap.fill(pen0, rect);

		/* offset to start in table */
		roller_ram_offs = (m_roller_ram_offset<<1);

		for (y=0; y<256; y++)
		{
			int by;
			unsigned short line_data;
			unsigned char *line_ptr;

			x = PCW_BORDER_WIDTH;

			roller_ram_ptr = m_ram->pointer() + m_roller_ram_addr + roller_ram_offs;

			/* get line address */
			/* b16-14 control which bank the line is to be found in, b13-3 the address in the bank (in 16-byte units), and b2-0 the offset. Thus a roller RAM address bbbxxxxxxxxxxxyyy indicates bank bbb, address 00xxxxxxxxxxx0yyy. */
			line_data = ((unsigned char *)roller_ram_ptr)[0] | (((unsigned char *)roller_ram_ptr)[1]<<8);

			/* calculate address of pixel data */
			line_ptr = m_ram->pointer() + ((line_data & 0x0e000)<<1) + ((line_data & 0x01ff8)<<1) + (line_data & 0x07);

			for (by=0; by<90; by++)
			{
				unsigned char byte;

				byte = line_ptr[0];

				for (b=0; b<8; b++)
				{
					if (byte & 0x080)
					{
						pcw_plot_pixel(bitmap,x+b, y+PCW_BORDER_HEIGHT, pen1);
					}
					else
					{
						pcw_plot_pixel(bitmap,x+b, y+PCW_BORDER_HEIGHT, pen0);

					}
					byte = byte<<1;
				}

				x = x + 8;


				line_ptr = line_ptr+8;
			}

			/* update offset, wrap within 512 byte range */
			roller_ram_offs+=2;
			roller_ram_offs&=511;

		}

		/* render border */
		/* 8 pixels either side of display */
		for (y=0; y<256; y++)
		{
			pcw_plot_pixel(bitmap, 0, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, 1, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, 2, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, 3, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, 4, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, 5, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, 6, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, 7, y+PCW_BORDER_HEIGHT, pen0);

			pcw_plot_pixel(bitmap, PCW_BORDER_WIDTH+PCW_DISPLAY_WIDTH+0, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, PCW_BORDER_WIDTH+PCW_DISPLAY_WIDTH+1, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, PCW_BORDER_WIDTH+PCW_DISPLAY_WIDTH+2, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, PCW_BORDER_WIDTH+PCW_DISPLAY_WIDTH+3, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, PCW_BORDER_WIDTH+PCW_DISPLAY_WIDTH+4, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, PCW_BORDER_WIDTH+PCW_DISPLAY_WIDTH+5, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, PCW_BORDER_WIDTH+PCW_DISPLAY_WIDTH+6, y+PCW_BORDER_HEIGHT, pen0);
			pcw_plot_pixel(bitmap, PCW_BORDER_WIDTH+PCW_DISPLAY_WIDTH+7, y+PCW_BORDER_HEIGHT, pen0);
		}
	}
	else
	{
		/* not video - render whole lot in pen 0 */
		rectangle rect(0, PCW_SCREEN_WIDTH, 0, PCW_SCREEN_HEIGHT);
		bitmap.fill(pen0, rect);
	}
	return 0;
}

UINT32 pcw_state::screen_update_pcw_printer(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	// printer output
	INT32 feed;
	rectangle rect(0, PCW_PRINTER_WIDTH - 1, 0, PCW_PRINTER_HEIGHT - 1);
	feed = -(m_paper_feed / 2);
	copyscrollbitmap(bitmap,*m_prn_output,0,NULL,1,&feed,rect);
	bitmap.pix16(PCW_PRINTER_HEIGHT-1, m_printer_headpos) = 0;
	bitmap.pix16(PCW_PRINTER_HEIGHT-2, m_printer_headpos) = 0;
	bitmap.pix16(PCW_PRINTER_HEIGHT-3, m_printer_headpos) = 0;
	bitmap.pix16(PCW_PRINTER_HEIGHT-1, m_printer_headpos-1) = 0;
	bitmap.pix16(PCW_PRINTER_HEIGHT-2, m_printer_headpos-1) = 0;
	bitmap.pix16(PCW_PRINTER_HEIGHT-1, m_printer_headpos+1) = 0;
	bitmap.pix16(PCW_PRINTER_HEIGHT-2, m_printer_headpos+1) = 0;
	return 0;
}