summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/video/pooyan.cpp
blob: cbe34704d3cc0a09554dae2bfe985952c5ed962f (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
188
189
// license:BSD-3-Clause
// copyright-holders:Allard van der Bas
/***************************************************************************

    Pooyan

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

#include "emu.h"
#include "video/resnet.h"
#include "includes/pooyan.h"

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

  Convert the color PROMs into a more useable format.

  Pooyan has one 32x8 palette PROM and two 256x4 lookup table PROMs
  (one for characters, one for sprites).
  The palette PROM is connected to the RGB output this way:

  bit 7 -- 220 ohm resistor  -- BLUE
        -- 470 ohm resistor  -- BLUE
        -- 220 ohm resistor  -- GREEN
        -- 470 ohm resistor  -- GREEN
        -- 1  kohm resistor  -- GREEN
        -- 220 ohm resistor  -- RED
        -- 470 ohm resistor  -- RED
  bit 0 -- 1  kohm resistor  -- RED

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

void pooyan_state::pooyan_palette(palette_device &palette) const
{
	const uint8_t *color_prom = memregion("proms")->base();
	static constexpr int resistances_rg[3] = { 1000, 470, 220 };
	static constexpr int resistances_b [2] = { 470, 220 };

	// compute the color output resistor weights
	double rweights[3], gweights[3], bweights[2];
	compute_resistor_weights(0, 255, -1.0,
			3, resistances_rg, rweights, 1000, 0,
			3, resistances_rg, gweights, 1000, 0,
			2, resistances_b,  bweights, 1000, 0);

	// create a lookup table for the palette
	for (int i = 0; i < 0x20; i++)
	{
		int bit0, bit1, bit2;

		// red component
		bit0 = BIT(color_prom[i], 0);
		bit1 = BIT(color_prom[i], 1);
		bit2 = BIT(color_prom[i], 2);
		int const r = combine_weights(rweights, bit0, bit1, bit2);

		// green component
		bit0 = BIT(color_prom[i], 3);
		bit1 = BIT(color_prom[i], 4);
		bit2 = BIT(color_prom[i], 5);
		int const g = combine_weights(gweights, bit0, bit1, bit2);

		// blue component
		bit0 = BIT(color_prom[i], 6);
		bit1 = BIT(color_prom[i], 7);
		int const b = combine_weights(bweights, bit0, bit1);

		palette.set_indirect_color(i, rgb_t(r, g, b));
	}

	// color_prom now points to the beginning of the lookup table
	color_prom += 0x20;

	// characters
	for (int i = 0; i < 0x100; i++)
	{
		uint8_t const ctabentry = (color_prom[i] & 0x0f) | 0x10;
		palette.set_pen_indirect(i, ctabentry);
	}

	// sprites
	for (int i = 0x100; i < 0x200; i++)
	{
		uint8_t const ctabentry = color_prom[i] & 0x0f;
		palette.set_pen_indirect(i, ctabentry);
	}
}



/*************************************
 *
 *  Tilemap info callback
 *
 *************************************/

TILE_GET_INFO_MEMBER(pooyan_state::get_bg_tile_info)
{
	int attr = m_colorram[tile_index];
	int code = m_videoram[tile_index];
	int color = attr & 0x0f;
	int flags = TILE_FLIPYX(attr >> 6);

	SET_TILE_INFO_MEMBER(0, code, color, flags);
}



/*************************************
 *
 *  Video startup
 *
 *************************************/

void pooyan_state::video_start()
{
	m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(pooyan_state::get_bg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32);
}



/*************************************
 *
 *  Memory write handlers
 *
 *************************************/

WRITE8_MEMBER(pooyan_state::videoram_w)
{
	m_videoram[offset] = data;
	m_bg_tilemap->mark_tile_dirty(offset);
}


WRITE8_MEMBER(pooyan_state::colorram_w)
{
	m_colorram[offset] = data;
	m_bg_tilemap->mark_tile_dirty(offset);
}


WRITE_LINE_MEMBER(pooyan_state::flipscreen_w)
{
	flip_screen_set(!state);
}



/*************************************
 *
 *  Sprite rendering
 *
 *************************************/

void pooyan_state::draw_sprites( bitmap_ind16 &bitmap, const rectangle &cliprect )
{
	for (int offs = 0x10; offs < 0x40; offs += 2)
	{
		int sx = m_spriteram[offs];
		int sy = 240 - m_spriteram2[offs + 1];

		int code = m_spriteram[offs + 1];
		int color = m_spriteram2[offs] & 0x0f;
		int flipx = ~m_spriteram2[offs] & 0x40;
		int flipy = m_spriteram2[offs] & 0x80;


			m_gfxdecode->gfx(1)->transmask(bitmap,cliprect,
			code,
			color,
			flipx, flipy,
			sx, sy,
			m_palette->transpen_mask(*m_gfxdecode->gfx(1), color, 0));
	}
}



/*************************************
 *
 *  Video update
 *
 *************************************/

uint32_t pooyan_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
	draw_sprites(bitmap, cliprect);
	return 0;
}