summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/video/scotrsht.c
blob: ac395246af2b6c8eb2e600407aed1d502171db41 (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
#include "emu.h"
#include "includes/scotrsht.h"


/* Similar as Iron Horse */
PALETTE_INIT( scotrsht )
{
	int i;

	/* allocate the colortable */
	machine.colortable = colortable_alloc(machine, 0x100);

	/* create a lookup table for the palette */
	for (i = 0; i < 0x100; i++)
	{
		int r = pal4bit(color_prom[i + 0x000]);
		int g = pal4bit(color_prom[i + 0x100]);
		int b = pal4bit(color_prom[i + 0x200]);

		colortable_palette_set_color(machine.colortable, i, MAKE_RGB(r, g, b));
	}

	/* color_prom now points to the beginning of the lookup table */
	color_prom += 0x300;

	/* characters use colors 0x80-0xff, sprites use colors 0-0x7f */
	for (i = 0; i < 0x200; i++)
	{
		int j;

		for (j = 0; j < 8; j++)
		{
			UINT8 ctabentry = ((~i & 0x100) >> 1) | (j << 4) | (color_prom[i] & 0x0f);
			colortable_entry_set_value(machine.colortable, ((i & 0x100) << 3) | (j << 8) | (i & 0xff), ctabentry);
		}
	}
}

WRITE8_HANDLER( scotrsht_videoram_w )
{
	scotrsht_state *state = space->machine().driver_data<scotrsht_state>();

	state->m_videoram[offset] = data;
	tilemap_mark_tile_dirty(state->m_bg_tilemap, offset);
}

WRITE8_HANDLER( scotrsht_colorram_w )
{
	scotrsht_state *state = space->machine().driver_data<scotrsht_state>();

	state->m_colorram[offset] = data;
	tilemap_mark_tile_dirty(state->m_bg_tilemap, offset);
}

WRITE8_HANDLER( scotrsht_charbank_w )
{
	scotrsht_state *state = space->machine().driver_data<scotrsht_state>();

	if (state->m_charbank != (data & 0x01))
	{
		state->m_charbank = data & 0x01;
		tilemap_mark_all_tiles_dirty(state->m_bg_tilemap);
	}

	/* other bits unknown */
}

WRITE8_HANDLER( scotrsht_palettebank_w )
{
	scotrsht_state *state = space->machine().driver_data<scotrsht_state>();

	if (state->m_palette_bank != ((data & 0x70) >> 4))
	{
		state->m_palette_bank = ((data & 0x70) >> 4);
		tilemap_mark_all_tiles_dirty(state->m_bg_tilemap);
	}

	coin_counter_w(space->machine(), 0, data & 1);
	coin_counter_w(space->machine(), 1, data & 2);

	// data & 4 unknown
}


static TILE_GET_INFO( scotrsht_get_bg_tile_info )
{
	scotrsht_state *state = machine.driver_data<scotrsht_state>();
	int attr = state->m_colorram[tile_index];
	int code = state->m_videoram[tile_index] + (state->m_charbank << 9) + ((attr & 0x40) << 2);
	int color = (attr & 0x0f) + state->m_palette_bank * 16;
	int flag = 0;

	if(attr & 0x10)	flag |= TILE_FLIPX;
	if(attr & 0x20)	flag |= TILE_FLIPY;

	// data & 0x80 -> tile priority?

	SET_TILE_INFO(0, code, color, flag);
}

/* Same as Jailbreak + palette bank */
static void draw_sprites(running_machine &machine, bitmap_t *bitmap, const rectangle *cliprect )
{
	scotrsht_state *state = machine.driver_data<scotrsht_state>();
	UINT8 *spriteram = state->m_spriteram;
	int i;

	for (i = 0; i < state->m_spriteram_size; i += 4)
	{
		int attr = spriteram[i + 1];	// attributes = ?tyxcccc
		int code = spriteram[i] + ((attr & 0x40) << 2);
		int color = (attr & 0x0f) + state->m_palette_bank * 16;
		int flipx = attr & 0x10;
		int flipy = attr & 0x20;
		int sx = spriteram[i + 2] - ((attr & 0x80) << 1);
		int sy = spriteram[i + 3];

		if (flip_screen_get(machine))
		{
			sx = 240 - sx;
			sy = 240 - sy;
			flipx = !flipx;
			flipy = !flipy;
		}

		drawgfx_transmask(bitmap, cliprect, machine.gfx[1], code, color, flipx, flipy,
			sx, sy,
			colortable_get_transpen_mask(machine.colortable, machine.gfx[1], color, state->m_palette_bank * 16));
	}
}

VIDEO_START( scotrsht )
{
	scotrsht_state *state = machine.driver_data<scotrsht_state>();

	state->m_bg_tilemap = tilemap_create(machine, scotrsht_get_bg_tile_info, tilemap_scan_rows,  8, 8, 64, 32);

	tilemap_set_scroll_cols(state->m_bg_tilemap, 64);
}

SCREEN_UPDATE( scotrsht )
{
	scotrsht_state *state = screen->machine().driver_data<scotrsht_state>();
	int col;

	for (col = 0; col < 32; col++)
		tilemap_set_scrolly(state->m_bg_tilemap, col, state->m_scroll[col]);

	tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0);
	draw_sprites(screen->machine(), bitmap, cliprect);
	return 0;
}