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

Video Hardware for Irem Games:
Battle Road, Lode Runner, Kid Niki, Spelunker

Tile/sprite priority system (for the Kung Fu Master M62 board):
- Tiles with color code >= N (where N is set by jumpers) have priority over
  sprites. Only bits 1-4 of the color code are used, bit 0 is ignored.

- Two jumpers select whether bit 5 of the sprite color code should be used
  to index the high address pin of the color PROMs, or to select high
  priority over tiles (or both, but is this used by any game?)

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

#include "driver.h"
#include "vidhrdw/generic.h"
#include "state.h"

data8_t *m62_tileram;
data8_t *m62_textram;
data8_t *horizon_scrollram;

static struct tilemap *m62_background;
static struct tilemap *m62_foreground;
static int flipscreen;
static const unsigned char *sprite_height_prom;
static int m62_background_hscroll;
static int m62_background_vscroll;

unsigned char *irem_textram;
size_t irem_textram_size;

static int kidniki_background_bank;
static int kidniki_text_vscroll;

static int spelunkr_palbank;

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

  Convert the color PROMs into a more useable format.

  Kung Fu Master has a six 256x4 palette PROMs (one per gun; three for
  characters, three for sprites).
  I don't know the exact values of the resistors between the RAM and the
  RGB output. I assumed these values (the same as Commando)

  bit 3 -- 220 ohm resistor  -- RED/GREEN/BLUE
        -- 470 ohm resistor  -- RED/GREEN/BLUE
        -- 1  kohm resistor  -- RED/GREEN/BLUE
  bit 0 -- 2.2kohm resistor  -- RED/GREEN/BLUE

***************************************************************************/
PALETTE_INIT( irem )
{
	int i;


	for (i = 0;i < Machine->drv->total_colors;i++)
	{
		int bit0,bit1,bit2,bit3,r,g,b;

		/* red component */
		bit0 = (color_prom[0] >> 0) & 0x01;
		bit1 = (color_prom[0] >> 1) & 0x01;
		bit2 = (color_prom[0] >> 2) & 0x01;
		bit3 = (color_prom[0] >> 3) & 0x01;
		r =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		/* green component */
		bit0 = (color_prom[Machine->drv->total_colors] >> 0) & 0x01;
		bit1 = (color_prom[Machine->drv->total_colors] >> 1) & 0x01;
		bit2 = (color_prom[Machine->drv->total_colors] >> 2) & 0x01;
		bit3 = (color_prom[Machine->drv->total_colors] >> 3) & 0x01;
		g =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		/* blue component */
		bit0 = (color_prom[2*Machine->drv->total_colors] >> 0) & 0x01;
		bit1 = (color_prom[2*Machine->drv->total_colors] >> 1) & 0x01;
		bit2 = (color_prom[2*Machine->drv->total_colors] >> 2) & 0x01;
		bit3 = (color_prom[2*Machine->drv->total_colors] >> 3) & 0x01;
		b =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;

		palette_set_color(i,r,g,b);

		color_prom++;
	}

	color_prom += 2*Machine->drv->total_colors;
	/* color_prom now points to the beginning of the sprite height table */

	sprite_height_prom = color_prom;	/* we'll need this at run time */
}

PALETTE_INIT( battroad )
{
	int i;


	for (i = 0;i < 512;i++)
	{
		int bit0,bit1,bit2,bit3,r,g,b;

		/* red component */
		bit0 = (color_prom[0] >> 0) & 0x01;
		bit1 = (color_prom[0] >> 1) & 0x01;
		bit2 = (color_prom[0] >> 2) & 0x01;
		bit3 = (color_prom[0] >> 3) & 0x01;
		r =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		/* green component */
		bit0 = (color_prom[512] >> 0) & 0x01;
		bit1 = (color_prom[512] >> 1) & 0x01;
		bit2 = (color_prom[512] >> 2) & 0x01;
		bit3 = (color_prom[512] >> 3) & 0x01;
		g =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		/* blue component */
		bit0 = (color_prom[2*512] >> 0) & 0x01;
		bit1 = (color_prom[2*512] >> 1) & 0x01;
		bit2 = (color_prom[2*512] >> 2) & 0x01;
		bit3 = (color_prom[2*512] >> 3) & 0x01;
		b =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;

		palette_set_color(i,r,g,b);

		color_prom++;
	}

	color_prom += 2*512;
	/* color_prom now points to the beginning of the character color prom */

	for (i = 0;i < 32;i++)
	{
		int bit0,bit1,bit2,r,g,b;


		bit0 = (color_prom[i] >> 0) & 0x01;
		bit1 = (color_prom[i] >> 1) & 0x01;
		bit2 = (color_prom[i] >> 2) & 0x01;
		r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
		bit0 = (color_prom[i] >> 3) & 0x01;
		bit1 = (color_prom[i] >> 4) & 0x01;
		bit2 = (color_prom[i] >> 5) & 0x01;
		g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
		bit0 = 0;
		bit1 = (color_prom[i] >> 6) & 0x01;
		bit2 = (color_prom[i] >> 7) & 0x01;
		b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;

		palette_set_color(i+512,r,g,b);
	}

	color_prom += 32;
	/* color_prom now points to the beginning of the sprite height table */

	sprite_height_prom = color_prom;	/* we'll need this at run time */
}

PALETTE_INIT( spelunk2 )
{
	int i;


	/* chars */
	for (i = 0;i < 512;i++)
	{
		int bit0,bit1,bit2,bit3,r,g,b;

		/* red component */
		bit0 = (color_prom[0] >> 0) & 0x01;
		bit1 = (color_prom[0] >> 1) & 0x01;
		bit2 = (color_prom[0] >> 2) & 0x01;
		bit3 = (color_prom[0] >> 3) & 0x01;
		r =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		/* green component */
		bit0 = (color_prom[0] >> 4) & 0x01;
		bit1 = (color_prom[0] >> 5) & 0x01;
		bit2 = (color_prom[0] >> 6) & 0x01;
		bit3 = (color_prom[0] >> 7) & 0x01;
		g =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		/* blue component */
		bit0 = (color_prom[2*256] >> 0) & 0x01;
		bit1 = (color_prom[2*256] >> 1) & 0x01;
		bit2 = (color_prom[2*256] >> 2) & 0x01;
		bit3 = (color_prom[2*256] >> 3) & 0x01;
		b =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;

		palette_set_color(i,r,g,b);

		color_prom++;
	}

	color_prom += 2*256;

	/* sprites */
	for (i = 0;i < 256;i++)
	{
		int bit0,bit1,bit2,bit3,r,g,b;

		/* red component */
		bit0 = (color_prom[0] >> 0) & 0x01;
		bit1 = (color_prom[0] >> 1) & 0x01;
		bit2 = (color_prom[0] >> 2) & 0x01;
		bit3 = (color_prom[0] >> 3) & 0x01;
		r =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		/* green component */
		bit0 = (color_prom[256] >> 0) & 0x01;
		bit1 = (color_prom[256] >> 1) & 0x01;
		bit2 = (color_prom[256] >> 2) & 0x01;
		bit3 = (color_prom[256] >> 3) & 0x01;
		g =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		/* blue component */
		bit0 = (color_prom[2*256] >> 0) & 0x01;
		bit1 = (color_prom[2*256] >> 1) & 0x01;
		bit2 = (color_prom[2*256] >> 2) & 0x01;
		bit3 = (color_prom[2*256] >> 3) & 0x01;
		b =  0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;

		palette_set_color(i+512,r,g,b);

		color_prom++;
	}

	color_prom += 2*256;


	/* color_prom now points to the beginning of the sprite height table */
	sprite_height_prom = color_prom;	/* we'll need this at run time */
}



static void register_savestate(void)
{
	state_save_register_int  ("video", 0, "flipscreen",              &flipscreen);
	state_save_register_int  ("video", 0, "kidniki_background_bank", &kidniki_background_bank);
	state_save_register_int  ("video", 0, "m62_background_hscroll", &m62_background_hscroll);
	state_save_register_int  ("video", 0, "m62_background_vscroll", &m62_background_vscroll);
	state_save_register_int  ("video", 0, "kidniki_text_vscroll",    &kidniki_text_vscroll);
	state_save_register_int  ("video", 0, "spelunkr_palbank",        &spelunkr_palbank);
	state_save_register_UINT8("video", 0, "irem_textram",            irem_textram,   irem_textram_size);
}

WRITE8_HANDLER( m62_flipscreen_w )
{
	/* screen flip is handled both by software and hardware */
	data ^= ~readinputport(4) & 1;

	flipscreen = data & 0x01;
	if (flipscreen)
		tilemap_set_flip(ALL_TILEMAPS, TILEMAP_FLIPX | TILEMAP_FLIPY);
	else
		tilemap_set_flip(ALL_TILEMAPS, 0);

	coin_counter_w(0,data & 2);
	coin_counter_w(1,data & 4);
}

WRITE8_HANDLER( m62_hscroll_low_w )
{
	m62_background_hscroll = ( m62_background_hscroll & 0xff00 ) | data;
}

WRITE8_HANDLER( m62_hscroll_high_w )
{
	m62_background_hscroll = ( m62_background_hscroll & 0xff ) | ( data << 8 );
}

WRITE8_HANDLER( m62_vscroll_low_w )
{
	m62_background_vscroll = ( m62_background_vscroll & 0xff00 ) | data;
}

WRITE8_HANDLER( m62_vscroll_high_w )
{
	m62_background_vscroll = ( m62_background_vscroll & 0xff ) | ( data << 8 );
}

WRITE8_HANDLER( m62_tileram_w )
{
	m62_tileram[ offset ] = data;
	tilemap_mark_tile_dirty( m62_background, offset >> 1 );
}

WRITE8_HANDLER( m62_textram_w )
{
	m62_textram[ offset ] = data;
	tilemap_mark_tile_dirty( m62_foreground, offset >> 1 );
}

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

  Draw the game screen in the given mame_bitmap.
  Do NOT call osd_update_display() from this function, it will be called by
  the main emulation engine.

***************************************************************************/
static void draw_sprites(struct mame_bitmap *bitmap, int colormask, int prioritymask, int priority)
{
	int offs;

	for (offs = 0;offs < spriteram_size;offs += 8)
	{
		int i,incr,code,col,flipx,flipy,sx,sy;

		if( ( spriteram[offs] & prioritymask ) == priority )
		{
			code = spriteram[offs+4] + ((spriteram[offs+5] & 0x07) << 8);
			col = spriteram[offs+0] & colormask;
			sx = 256 * (spriteram[offs+7] & 1) + spriteram[offs+6],
			sy = 256+128-15 - (256 * (spriteram[offs+3] & 1) + spriteram[offs+2]),
			flipx = spriteram[offs+5] & 0x40;
			flipy = spriteram[offs+5] & 0x80;

			i = sprite_height_prom[(code >> 5) & 0x1f];
			if (i == 1)	/* double height */
			{
				code &= ~1;
				sy -= 16;
			}
			else if (i == 2)	/* quadruple height */
			{
				i = 3;
				code &= ~3;
				sy -= 3*16;
			}

			if (flipscreen)
			{
				sx = 496 - sx;
				sy = 242 - i*16 - sy;	/* sprites are slightly misplaced by the hardware */
				flipx = !flipx;
				flipy = !flipy;
			}

			if (flipy)
			{
				incr = -1;
				code += i;
			}
			else incr = 1;

			do
			{
				drawgfx(bitmap,Machine->gfx[1],
						code + i * incr,col,
						flipx,flipy,
						sx,sy + 16 * i,
						&Machine->visible_area,TRANSPARENCY_PEN,0);

				i--;
			} while (i >= 0);
		}
	}
}

int m62_start( void (*tile_get_info)( int memory_offset ), int rows, int cols, int x1, int y1, int x2, int y2 )
{
	m62_background = tilemap_create( tile_get_info, tilemap_scan_rows, TILEMAP_TRANSPARENT, x1, y1, x2, y2 );
	if( !m62_background )
	{
		return 1;
	}

	m62_background_hscroll = 0;
	m62_background_vscroll = 0;

	register_savestate();

	if( rows != 0 )
	{
		tilemap_set_scroll_rows( m62_background, rows );
	}
	if( cols != 0 )
	{
		tilemap_set_scroll_cols( m62_background, cols );
	}

	return 0;
}

int m62_textlayer( void (*tile_get_info)( int memory_offset ), int rows, int cols, int x1, int y1, int x2, int y2 )
{
	m62_foreground = tilemap_create( tile_get_info, tilemap_scan_rows, TILEMAP_TRANSPARENT, x1, y1, x2, y2 );
	if( !m62_foreground )
	{
		return 1;
	}

	if( rows != 0 )
	{
		tilemap_set_scroll_rows( m62_foreground, rows );
	}
	if( cols != 0 )
	{
		tilemap_set_scroll_cols( m62_foreground, cols );
	}

	return 0;
}

WRITE8_HANDLER( kungfum_tileram_w )
{
	m62_tileram[ offset ] = data;
	tilemap_mark_tile_dirty( m62_background, offset & 0x7ff );
}

static void get_kungfum_bg_tile_info( int offs )
{
	int code;
	int color;
	int flags;
	code = m62_tileram[ offs ];
	color = m62_tileram[ offs + 0x800 ];
	flags = 0;
	if( ( color & 0x20 ) )
	{
		flags |= TILE_FLIPX;
	}
	SET_TILE_INFO( 0, code | ( ( color & 0xc0 ) << 2 ), color & 0x1f, flags );

	/* is the following right? */
	if( ( offs / 64 ) < 6 || ( ( color & 0x1f ) >> 1 ) > 0x0c )
	{
		tile_info.priority = 1;
	}
	else
	{
		tile_info.priority = 0;
	}
}

VIDEO_UPDATE( kungfum )
{
	int i;
	for( i = 0; i < 6; i++ )
	{
		tilemap_set_scrollx( m62_background, i, 0 );
	}
	for( i = 6; i < 32; i++ )
	{
		tilemap_set_scrollx( m62_background, i, m62_background_hscroll );
	}
	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x1f, 0x00, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_background, 1, 0 );
}

VIDEO_START( kungfum )
{
	return m62_start( get_kungfum_bg_tile_info, 32, 0, 8, 8, 64, 32 );
}


static void get_ldrun_bg_tile_info( int offs )
{
	int code;
	int color;
	int flags;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	flags = 0;
	if( ( color & 0x20 ) )
	{
		flags |= TILE_FLIPX;
	}
	SET_TILE_INFO( 0, code | ( ( color & 0xc0 ) << 2 ), color & 0x1f, flags );
	if( ( ( color & 0x1f ) >> 1 ) >= 0x04 )
	{
		tile_info.priority = 1;
	}
	else
	{
		tile_info.priority = 0;
	}
}

VIDEO_UPDATE( ldrun )
{
	tilemap_set_scrollx( m62_background, 0, m62_background_hscroll );
	tilemap_set_scrolly( m62_background, 0, m62_background_vscroll );

	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x0f, 0x10, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_background, 1, 0 );
	draw_sprites( bitmap, 0x0f, 0x10, 0x10 );
}

VIDEO_START( ldrun )
{
	return m62_start( get_ldrun_bg_tile_info, 1, 1, 8, 8, 64, 32 );
}


static void get_battroad_bg_tile_info( int offs )
{
	int code;
	int color;
	int flags;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	flags = 0;
	if( ( color & 0x20 ) )
	{
		flags |= TILE_FLIPX;
	}
	SET_TILE_INFO( 0, code | ( ( color & 0x40 ) << 3 ) | ( ( color & 0x10 ) << 4 ), color & 0x0f, flags );
	if( ( ( color & 0x0f ) >> 1 ) >= 0x04 )
	{
		tile_info.priority = 1;
	}
	else
	{
		tile_info.priority = 0;
	}
}

static void get_battroad_fg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_textram[ offs << 1 ];
	color = m62_textram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 2, code | ( ( color & 0x40 ) << 3 ) | ( ( color & 0x10 ) << 4 ), color & 0x0f, 0 );
}

VIDEO_UPDATE( battroad )
{
	tilemap_set_scrollx( m62_background, 0, m62_background_hscroll );
	tilemap_set_scrolly( m62_background, 0, m62_background_vscroll );
	tilemap_set_scrollx( m62_foreground, 0, 128 );
	tilemap_set_scrolly( m62_foreground, 0, 0 );
	tilemap_set_transparent_pen( m62_foreground, 0 );

	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x0f, 0x10, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_background, 1, 0 );
	draw_sprites( bitmap, 0x0f, 0x10, 0x10 );
	tilemap_draw( bitmap, cliprect, m62_foreground, 0, 0 );
}

VIDEO_START( battroad )
{
	return m62_start( get_battroad_bg_tile_info, 1, 1, 8, 8, 64, 32 ) ||
		m62_textlayer( get_battroad_fg_tile_info, 1, 1, 8, 8, 32, 32 );
}


/* almost identical but scrolling background, more characters, */
/* no char x flip, and more sprites */
static void get_ldrun4_bg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 0, code | ( ( color & 0xc0 ) << 2 ) | ( ( color & 0x20 ) << 5 ), color & 0x1f, 0 );
}

VIDEO_UPDATE( ldrun4 )
{
	tilemap_set_scrollx( m62_background, 0, m62_background_hscroll );

	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x1f, 0x00, 0x00 );
}

VIDEO_START( ldrun4 )
{
	return m62_start( get_ldrun4_bg_tile_info, 1, 0, 8, 8, 64, 32 );
}


static void get_lotlot_bg_tile_info( int offs )
{
	int code;
	int color;
	int flags;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	flags = 0;
	if( ( color & 0x20 ) )
	{
		flags |= TILE_FLIPX;
	}
	SET_TILE_INFO( 0, code | ( ( color & 0xc0 ) << 2 ), color & 0x1f, flags );
}

static void get_lotlot_fg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_textram[ offs << 1 ];
	color = m62_textram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 2, code | ( ( color & 0xc0 ) << 2 ), color & 0x1f, 0 );
}

VIDEO_UPDATE( lotlot )
{
	tilemap_set_scrollx( m62_background, 0, m62_background_hscroll - 64 );
	tilemap_set_scrolly( m62_background, 0, m62_background_vscroll + 32 );
	tilemap_set_scrollx( m62_foreground, 0, -64 );
	tilemap_set_scrolly( m62_foreground, 0, 32 );
	tilemap_set_transparent_pen( m62_foreground, 0 );

	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x1f, 0x00, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_foreground, 0, 0 );
}

VIDEO_START( lotlot )
{
	return m62_start( get_lotlot_bg_tile_info, 1, 1, 12, 10, 32, 64 ) ||
		m62_textlayer( get_lotlot_fg_tile_info, 1, 1, 12, 10, 32, 64 );
}


WRITE8_HANDLER( kidniki_text_vscroll_low_w )
{
	kidniki_text_vscroll = (kidniki_text_vscroll & 0xff00) | data;
}

WRITE8_HANDLER( kidniki_text_vscroll_high_w )
{
	kidniki_text_vscroll = (kidniki_text_vscroll & 0xff) | (data << 8);
}

WRITE8_HANDLER( kidniki_background_bank_w )
{
	if (kidniki_background_bank != (data & 1))
	{
		kidniki_background_bank = data & 1;
		memset(dirtybuffer,1,videoram_size);
	}
}

static void get_kidniki_bg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 0, code | ( ( color & 0xe0 ) << 3 ) | ( kidniki_background_bank << 11 ), color & 0x1f, 0 );
}

static void get_kidniki_fg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_textram[ offs << 1 ];
	color = m62_textram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 2, code | ( ( color & 0xc0 ) << 2 ), color & 0x1f, 0 );
}

VIDEO_UPDATE( kidniki )
{
	tilemap_set_scrollx( m62_background, 0, m62_background_hscroll );
	tilemap_set_scrollx( m62_foreground, 0, -64 );
	tilemap_set_scrolly( m62_foreground, 0, kidniki_text_vscroll + 128 );
	tilemap_set_transparent_pen( m62_foreground, 0 );

	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x1f, 0x00, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_foreground, 0, 0 );
}

VIDEO_START( kidniki )
{
	return m62_start( get_kidniki_bg_tile_info, 1, 0, 8, 8, 64, 32 ) ||
		m62_textlayer( get_kidniki_fg_tile_info, 1, 1, 12, 8, 32, 64 );
}


WRITE8_HANDLER( spelunkr_palbank_w )
{
	if (spelunkr_palbank != (data & 0x01))
	{
		spelunkr_palbank = data & 0x01;
		memset(dirtybuffer,1,videoram_size);
	}
}

static void get_spelunkr_bg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 0, code | ( ( color & 0x10 ) << 4 ) | ( ( color & 0x20 ) << 6 ) | ( ( color & 0xc0 ) << 3 ), ( color & 0x1f ) | ( spelunkr_palbank << 4 ), 0 );
}

static void get_spelunkr_fg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_textram[ offs << 1 ];
	color = m62_textram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 2, code | ( ( color & 0x10 ) << 4 ), ( color & 0x0f ) | ( spelunkr_palbank << 4 ), 0 );
}

VIDEO_UPDATE( spelunkr )
{
	tilemap_set_scrollx( m62_background, 0, m62_background_hscroll );
	tilemap_set_scrolly( m62_background, 0, m62_background_vscroll + 128 );
	tilemap_set_scrollx( m62_foreground, 0, -64 );
	tilemap_set_scrolly( m62_foreground, 0, 0 );
	tilemap_set_transparent_pen( m62_foreground, 0 );

	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x1f, 0x00, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_foreground, 0, 0 );
}

VIDEO_START( spelunkr )
{
	return m62_start( get_spelunkr_bg_tile_info, 1, 1, 8, 8, 64, 64 ) ||
		m62_textlayer( get_spelunkr_fg_tile_info, 1, 1, 12, 8, 32, 32 );
}


WRITE8_HANDLER( spelunk2_gfxport_w )
{
	m62_hscroll_high_w(0,(data&2)>>1);
	m62_vscroll_high_w(0,(data&1));
	if (spelunkr_palbank != ((data & 0x0c) >> 2))
	{
		spelunkr_palbank = (data & 0x0c) >> 2;
		memset(dirtybuffer,1,videoram_size);
	}
}

static void get_spelunk2_bg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 0, code | ( ( color & 0xf0 ) << 4 ), ( color & 0x0f ) | ( spelunkr_palbank << 4 ), 0 );
}

VIDEO_UPDATE( spelunk2 )
{
	tilemap_set_scrollx( m62_background, 0, m62_background_hscroll );
	tilemap_set_scrolly( m62_background, 0, m62_background_vscroll + 128 );
	tilemap_set_scrollx( m62_foreground, 0, -64 );
	tilemap_set_scrolly( m62_foreground, 0, 0 );
	tilemap_set_transparent_pen( m62_foreground, 0 );

	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x1f, 0x00, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_foreground, 0, 0 );
}

VIDEO_START( spelunk2 )
{
	return m62_start( get_spelunk2_bg_tile_info, 1, 1, 8, 8, 64, 64 ) ||
		m62_textlayer( get_spelunkr_fg_tile_info, 1, 1, 12, 8, 32, 32 );
}


static void get_youjyudn_bg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 0, code | ( ( color & 0x60 ) << 3 ), color & 0x1f, 0 );
	if( ( ( color & 0x1f ) >> 1 ) >= 0x08 )
	{
		tile_info.priority = 1;
	}
	else
	{
		tile_info.priority = 0;
	}
}

static void get_youjyudn_fg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_textram[ offs << 1 ];
	color = m62_textram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 2, code | ( ( color & 0xc0 ) << 2 ), ( color & 0x0f ), 0 );
}

VIDEO_UPDATE( youjyudn )
{
	tilemap_set_scrollx( m62_background, 0, m62_background_hscroll );
	tilemap_set_scrollx( m62_foreground, 0, -64 );
	tilemap_set_scrolly( m62_foreground, 0, 0 );
	tilemap_set_transparent_pen( m62_foreground, 0 );

	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x1f, 0x00, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_background, 1, 0 );
	tilemap_draw( bitmap, cliprect, m62_foreground, 0, 0 );
}

VIDEO_START( youjyudn )
{
	return m62_start( get_youjyudn_bg_tile_info, 1, 0, 8, 16, 64, 16 ) ||
		m62_textlayer( get_youjyudn_fg_tile_info, 1, 1, 12, 8, 32, 32 );
}


WRITE8_HANDLER( horizon_scrollram_w )
{
	horizon_scrollram[ offset ] = data;
}

static void get_horizon_bg_tile_info( int offs )
{
	int code;
	int color;
	code = m62_tileram[ offs << 1 ];
	color = m62_tileram[ ( offs << 1 ) | 1 ];
	SET_TILE_INFO( 0, code | ( ( color & 0xc0 ) << 2 ) | ( ( color & 0x20 ) << 5 ), color & 0x1f, 0 );
	if( ( ( color & 0x1f ) >> 1 ) >= 0x08 )
	{
		tile_info.priority = 1;
	}
	else
	{
		tile_info.priority = 0;
	}
}

VIDEO_UPDATE( horizon )
{
	int i;
	for( i = 0; i < 32; i++ )
	{
		tilemap_set_scrollx( m62_background, i, horizon_scrollram[ i << 1 ] | ( horizon_scrollram[ ( i << 1 ) | 1 ] << 8 ) );
	}
	tilemap_draw( bitmap, cliprect, m62_background, 0, 0 );
	draw_sprites( bitmap, 0x1f, 0x00, 0x00 );
	tilemap_draw( bitmap, cliprect, m62_background, 1, 0 );
}

VIDEO_START( horizon )
{
	return m62_start( get_horizon_bg_tile_info, 32, 0, 8, 8, 64, 32 );
}
