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

Atari Ultra Tank video emulation

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

#include "driver.h"
#include "ultratnk.h"
#include "audio/sprint4.h"

static tilemap* playfield;

static mame_bitmap* helper;

int ultratnk_collision[4];


PALETTE_INIT( ultratnk )
{
	palette_set_color(machine, 0, 0x00, 0x00, 0x00);
	palette_set_color(machine, 1, 0xa4, 0xa4, 0xa4);
	palette_set_color(machine, 2, 0x5b, 0x5b, 0x5b);
	palette_set_color(machine, 3, 0xff, 0xff, 0xff);

	colortable[0] = color_prom[0x00] & 3;
	colortable[2] = color_prom[0x00] & 3;
	colortable[4] = color_prom[0x00] & 3;
	colortable[6] = color_prom[0x00] & 3;
	colortable[8] = color_prom[0x00] & 3;

	colortable[1] = color_prom[0x01] & 3;
	colortable[3] = color_prom[0x02] & 3;
	colortable[5] = color_prom[0x04] & 3;
	colortable[7] = color_prom[0x08] & 3;
	colortable[9] = color_prom[0x10] & 3;
}


static void ultratnk_tile_info(int tile_index)
{
	UINT8 code = videoram[tile_index];

	if (code & 0x20)
	{
		SET_TILE_INFO(0, code, code >> 6, 0)
	}
	else
	{
		SET_TILE_INFO(0, code, 4, 0)
	}
}


VIDEO_START( ultratnk )
{
	helper = auto_bitmap_alloc(machine->screen[0].width, machine->screen[0].height, machine->screen[0].format);

	playfield = tilemap_create(ultratnk_tile_info, tilemap_scan_rows, TILEMAP_OPAQUE, 8, 8, 32, 32);

	return 0;
}


VIDEO_UPDATE( ultratnk )
{
	int i;

	tilemap_draw(bitmap, cliprect, playfield, 0, 0);

	for (i = 0; i < 4; i++)
	{
		int bank = 0;

		UINT8 horz = videoram[0x390 + 2 * i + 0];
		UINT8 attr = videoram[0x390 + 2 * i + 1];
		UINT8 vert = videoram[0x398 + 2 * i + 0];
		UINT8 code = videoram[0x398 + 2 * i + 1];

		if (code & 4)
		{
			bank = 32;
		}

		if (!(attr & 0x80))
		{
			drawgfx(bitmap, machine->gfx[1],
				(code >> 3) | bank,
				i,
				0, 0,
				horz - 15,
				vert - 15,
				cliprect, TRANSPARENCY_PEN, 0);
		}
	}

	return 0;
}


VIDEO_EOF( ultratnk )
{
	UINT16 BG = machine->gfx[0]->colortable[0];

	int i;

	/* check for sprite-playfield collisions */

	for (i = 0; i < 4; i++)
	{
		rectangle rect;

		int x;
		int y;

		int bank = 0;

		UINT8 horz = videoram[0x390 + 2 * i + 0];
		UINT8 vert = videoram[0x398 + 2 * i + 0];
		UINT8 code = videoram[0x398 + 2 * i + 1];

		rect.min_x = horz - 15;
		rect.min_y = vert - 15;
		rect.max_x = horz - 15 + machine->gfx[1]->width - 1;
		rect.max_y = vert - 15 + machine->gfx[1]->height - 1;

		sect_rect(&rect, &machine->screen[0].visarea);

		tilemap_draw(helper, &rect, playfield, 0, 0);

		if (code & 4)
		{
			bank = 32;
		}

		drawgfx(helper, machine->gfx[1],
			(code >> 3) | bank,
			4,
			0, 0,
			horz - 15,
			vert - 15,
			&rect, TRANSPARENCY_PEN, 1);

		for (y = rect.min_y; y <= rect.max_y; y++)
		{
			for (x = rect.min_x; x <= rect.max_x; x++)
			{
				if (read_pixel(helper, x, y) != BG)
				{
					ultratnk_collision[i] = 1;
				}
			}
		}
	}

	/* update sound status */

	discrete_sound_w(ULTRATNK_MOTOR_DATA_1, videoram[0x391] & 15);
	discrete_sound_w(ULTRATNK_MOTOR_DATA_2, videoram[0x393] & 15);
}


WRITE8_HANDLER( ultratnk_video_ram_w )
{
	if (data != videoram[offset])
	{
		tilemap_mark_tile_dirty(playfield, offset);
	}

	videoram[offset] = data;
}
