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

    Exidy Car Polo hardware

    driver by Zsolt Vasvari

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

#include "driver.h"
#include "carpolo.h"


UINT8 *carpolo_alpharam;
UINT8 *carpolo_spriteram;


/* the screen elements' priorties determine their color */
#define CHARSET_COLOR_BASE	(0x00)
#define BACKGROUND_PEN		((0x00 << 1) + 1)
#define FIELD_PEN			((0x01 << 1) + 1)
#define CAR1_COLOR			(0x02)
#define LINE_PEN			((0x03 << 1) + 1)
#define CAR4_COLOR			(0x04)
#define CAR3_COLOR			(0x05)
#define CAR2_COLOR			(0x06)
#define BALL_COLOR			(0x07)
#define NET_COLOR			(0x08)
#define LEFT_GOAL_COLOR		(0x09)
#define LEFT_GOAL_PEN		(0x18 + 0x08)
#define LEFT_SCORE_PEN		(0x18 + 0x06)
#define RIGHT_GOAL_COLOR	(0x0a)
#define RIGHT_GOAL_PEN		(0x18 + 0x18)
#define RIGHT_SCORE_PEN		(0x18 + 0x16)
#define SPECIAL_CHAR_COLOR	(0x0b)
#define ALPHA_COLOR_BASE	(0x0c)	/* 0x0c - 0x0f */

#define SPRITE_WIDTH		(16)
#define SPRITE_HEIGHT		(16)
#define GOAL_WIDTH			(16)
#define GOAL_HEIGHT			(64)

#define LEFT_GOAL_X			((2 * 16) - 8)
#define RIGHT_GOAL_X		((13 * 16) - 8)
#define GOAL_Y				(7 * 16)

#define TOP_BORDER			(16)
#define BOTTOM_BORDER		(255)
#define LEFT_BORDER			(0)
#define RIGHT_BORDER		(239)


static bitmap_t *sprite_sprite_collision_bitmap1;
static bitmap_t *sprite_sprite_collision_bitmap2;
static bitmap_t *sprite_goal_collision_bitmap1;
static bitmap_t *sprite_goal_collision_bitmap2;
static bitmap_t *sprite_border_collision_bitmap;


/***************************************************************************
 *
 *  Palette generation
 *
 *  The palette PROM is connected to the RGB output this way.
 *
 *  bit 0 -- 220 ohm resistor  -- BLUE (probably an error on schematics)
 *        -- 470 ohm resistor  -- BLUE (probably an error on schematics)
 *        -- 220 ohm resistor  -- GREEN
 *        -- 470 ohm resistor  -- GREEN
 *        -- 1  kohm resistor  -- GREEN
 *        -- 220 ohm resistor  -- RED
 *        -- 470 ohm resistor  -- RED
 *  bit 7 -- 1  kohm resistor  -- RED
 *
 **************************************************************************/

PALETTE_INIT( carpolo )
{
	int i;

	/* thanks to Jarek Burczynski for analyzing the circuit */
 /* static const float MAX_VOLTAGE = 6.9620f; */
	static const float MIN_VOLTAGE = 1.7434f;
	static const float MAX_VOLTAGE = 5.5266f;

	static const float r_voltage[] =
	{
		1.7434f, 2.1693f, 2.5823f, 3.0585f, 3.4811f, 4.0707f, 4.7415f, 5.4251f
	};

	static const float g_voltage[] =
	{
		1.7434f, 2.1693f, 2.5823f, 3.0585f, 3.4811f, 4.0707f, 4.7415f, 5.4251f
	 /* 4.7871f, 5.0613f, 5.3079f, 5.6114f, 5.7940f, 6.1608f, 6.5436f, 6.9620f */
	};

	static const float b_voltage[] =
	{
		1.9176f, 2.8757f, 3.9825f, 5.5266f
	};


	for (i = 0; i < machine->config->total_colors; i++)
	{
		UINT8 pen, r, g, b;
		int bit0, bit1, bit2;

		if (i < 0x18)
			/* sprites */
			pen = ((i - 0x00) & 0x01) ? CHARSET_COLOR_BASE + ((i - 0x00) >> 1) : 0;

		else if (i < 0x38)
			/* the bits in the goal gfx PROM are hooked up as follows (all active LO):
               D3 - goal post
               D2 - scoring area
               D1 - net
               D0 - n/c
               I am only filling in the colors actually used. */
			switch (i - 0x18)
			{
			case (0x00 | (0x07 ^ 0x0f)): pen = LEFT_GOAL_COLOR; break;
			case (0x00 | (0x0d ^ 0x0f)): pen = NET_COLOR; break;
			case (0x00 | (0x09 ^ 0x0f)): pen = NET_COLOR; break;  /* score */
			case (0x10 | (0x07 ^ 0x0f)): pen = RIGHT_GOAL_COLOR; break;
			case (0x10 | (0x0d ^ 0x0f)): pen = NET_COLOR; break;
			case (0x10 | (0x09 ^ 0x0f)): pen = NET_COLOR; break; /* score */
			default: pen = 0; break;
			}

		else
			/* alpha layer */
			pen = ((i - 0x38) & 0x01) ? ALPHA_COLOR_BASE   + ((i - 0x38) >> 1) : 0;

		/* red component */
		bit0 = (color_prom[pen] >> 7) & 0x01;
		bit1 = (color_prom[pen] >> 6) & 0x01;
		bit2 = (color_prom[pen] >> 5) & 0x01;
		r = ((r_voltage[(color_prom[pen] >> 5) & 0x07] - MIN_VOLTAGE) / (MAX_VOLTAGE - MIN_VOLTAGE)) * 255.;

		/* green component */
		bit0 = (color_prom[pen] >> 4) & 0x01;
		bit1 = (color_prom[pen] >> 3) & 0x01;
		bit2 = (color_prom[pen] >> 2) & 0x01;
		g = ((g_voltage[(color_prom[pen] >> 2) & 0x07] - MIN_VOLTAGE) / (MAX_VOLTAGE - MIN_VOLTAGE)) * 255.;

		/* blue component */
		bit0 = (color_prom[pen] >> 1) & 0x01;
		bit1 = (color_prom[pen] >> 0) & 0x01;
		b = ((b_voltage[(color_prom[pen] >> 0) & 0x03] - MIN_VOLTAGE) / (MAX_VOLTAGE - MIN_VOLTAGE)) * 255.;

		palette_set_color(machine, i, MAKE_RGB(r, g, b));
	}
}


/*************************************
 *
 *  Video system start
 *
 *************************************/

VIDEO_START( carpolo )
{
	bitmap_format format = video_screen_get_format(machine->primary_screen);

	sprite_sprite_collision_bitmap1 = auto_bitmap_alloc(machine, SPRITE_WIDTH*2, SPRITE_HEIGHT*2, format);
	sprite_sprite_collision_bitmap2 = auto_bitmap_alloc(machine, SPRITE_WIDTH*2, SPRITE_HEIGHT*2, format);

	sprite_goal_collision_bitmap1 = auto_bitmap_alloc(machine, SPRITE_WIDTH+GOAL_WIDTH, SPRITE_HEIGHT+GOAL_HEIGHT, format);
	sprite_goal_collision_bitmap2 = auto_bitmap_alloc(machine, SPRITE_WIDTH+GOAL_WIDTH, SPRITE_HEIGHT+GOAL_HEIGHT, format);

	sprite_border_collision_bitmap = auto_bitmap_alloc(machine, SPRITE_WIDTH, SPRITE_HEIGHT, format);

    state_save_register_global_bitmap(machine, sprite_sprite_collision_bitmap1);
    state_save_register_global_bitmap(machine, sprite_sprite_collision_bitmap2);
    state_save_register_global_bitmap(machine, sprite_goal_collision_bitmap1);
    state_save_register_global_bitmap(machine, sprite_goal_collision_bitmap2);
    state_save_register_global_bitmap(machine, sprite_border_collision_bitmap);
}


/*************************************
 *
 *  Core video refresh
 *
 *************************************/

static void draw_alpha_line(running_machine *machine, bitmap_t *bitmap, const rectangle *cliprect,
					   		int alpha_line, int video_line)
{
	int x;

	for (x = 0; x < 32; x++)
	{
		UINT8 code, col;

		code = carpolo_alpharam[alpha_line * 32 + x] >> 2;
		col  = carpolo_alpharam[alpha_line * 32 + x] & 0x03;

		drawgfx_transpen(bitmap,cliprect,machine->gfx[2],
				code,col,
				0,0,
				x*8,video_line*8,0);
	}
}


static void remap_sprite_code(running_machine *machine, int bank, int code, int *remapped_code, int *flipy)
{
	UINT8* PROM = memory_region(machine, "user1");

	code = (bank << 4) | code;
	*remapped_code = PROM[code] & 0x0f;
	*flipy = (PROM[code] & 0x10) >> 4;
}


static void draw_sprite(running_machine *machine, bitmap_t *bitmap, const rectangle *cliprect,
						UINT8 x, UINT8 y, int bank, int code, int col)
{
	int remapped_code, flipy;

	remap_sprite_code(machine, bank, code, &remapped_code, &flipy);

	x = 240 - x;
	y = 240 - y;

	drawgfx_transpen(bitmap,cliprect,machine->gfx[0],
			remapped_code, col,
			0, flipy,
			x, y,0);

	/* draw with wrap around */
	drawgfx_transpen(bitmap,cliprect,machine->gfx[0],
			remapped_code, col,
			0, flipy,
			(INT16)x - 256, y,0);
}


VIDEO_UPDATE( carpolo )
{
	/* draw the playfield elements in the correct priority order */

	/* score area - position determined by bit 4 of the vertical timing PROM */
	plot_box(bitmap,0,0,RIGHT_BORDER+1,TOP_BORDER,BACKGROUND_PEN);

	/* field */
	plot_box(bitmap,0,TOP_BORDER,RIGHT_BORDER+1,BOTTOM_BORDER-TOP_BORDER+1,FIELD_PEN);

	/* car 1 */
	draw_sprite(screen->machine, bitmap, cliprect,
				carpolo_spriteram[0x00], carpolo_spriteram[0x01],
				0, carpolo_spriteram[0x0c] & 0x0f, CAR1_COLOR);

	/* border - position determined by bit 4 and 7 of the vertical timing PROM */
	plot_box(bitmap,0,TOP_BORDER,   RIGHT_BORDER+1,1,LINE_PEN);
	plot_box(bitmap,0,BOTTOM_BORDER,RIGHT_BORDER+1,1,LINE_PEN);
	plot_box(bitmap,LEFT_BORDER,TOP_BORDER, 1,BOTTOM_BORDER-TOP_BORDER+1,LINE_PEN);
	plot_box(bitmap,RIGHT_BORDER,TOP_BORDER,1,BOTTOM_BORDER-TOP_BORDER+1,LINE_PEN);

	/* car 4 */
	draw_sprite(screen->machine, bitmap, cliprect,
				carpolo_spriteram[0x06], carpolo_spriteram[0x07],
				0, carpolo_spriteram[0x0d] >> 4, CAR4_COLOR);

	/* car 3 */
	draw_sprite(screen->machine, bitmap, cliprect,
				carpolo_spriteram[0x04], carpolo_spriteram[0x05],
				0, carpolo_spriteram[0x0d] & 0x0f, CAR3_COLOR);

	/* car 2 */
	draw_sprite(screen->machine, bitmap, cliprect,
				carpolo_spriteram[0x02], carpolo_spriteram[0x03],
				0, carpolo_spriteram[0x0c] >> 4, CAR2_COLOR);

	/* ball */
	draw_sprite(screen->machine, bitmap, cliprect,
				carpolo_spriteram[0x08], carpolo_spriteram[0x09],
				1, carpolo_spriteram[0x0e] & 0x0f, BALL_COLOR);

	/* left goal - position determined by bit 6 of the
       horizontal and vertical timing PROMs */
	drawgfxzoom_transpen(bitmap,cliprect,screen->machine->gfx[1],
				0,0,
				0,0,
				LEFT_GOAL_X,GOAL_Y,
				0x20000,0x20000,0);

	/* right goal */
	drawgfxzoom_transpen(bitmap,cliprect,screen->machine->gfx[1],
				0,1,
				1,0,
				RIGHT_GOAL_X,GOAL_Y,
				0x20000,0x20000,0);

	/* special char - bit 0 of 0x0f enables it,
                      bit 1 marked as WIDE, but never appears to be set */
	if (carpolo_spriteram[0x0f] & 0x02)
		popmessage("WIDE!\n");

	if (carpolo_spriteram[0x0f] & 0x01)
		draw_sprite(screen->machine, bitmap, cliprect,
					carpolo_spriteram[0x0a], carpolo_spriteram[0x0b],
					1, carpolo_spriteram[0x0e] >> 4, SPECIAL_CHAR_COLOR);


	/* draw the alpha layer */

	/* there are only 8 lines of text repeated 4 times
       and bit 3 of the vertical timing PROM controls in
       which quadrant the line will actually appear */

	draw_alpha_line(screen->machine, bitmap, cliprect, 0, (0*4+0)*2  );
	draw_alpha_line(screen->machine, bitmap, cliprect, 1, (0*4+0)*2+1);
	draw_alpha_line(screen->machine, bitmap, cliprect, 2, (3*4+1)*2  );
	draw_alpha_line(screen->machine, bitmap, cliprect, 3, (3*4+1)*2+1);
	draw_alpha_line(screen->machine, bitmap, cliprect, 4, (1*4+2)*2  );
	draw_alpha_line(screen->machine, bitmap, cliprect, 5, (1*4+2)*2+1);
	draw_alpha_line(screen->machine, bitmap, cliprect, 6, (0*4+3)*2  );
	draw_alpha_line(screen->machine, bitmap, cliprect, 7, (0*4+3)*2+1);

	return 0;
}


/*************************************
 *
 *  End of frame callback
 *
 *************************************/

static void normalize_coordinates(int *x1, int *y1, int *x2, int *y2)
{
	if (*x1 < *x2)
	{
		*x2 = *x2 - *x1;
		*x1 = 0;
	}
	else
	{
		*x1 = *x1 - *x2;
		*x2 = 0;
	}

	if (*y1 < *y2)
	{
		*y2 = *y2 - *y1;
		*y1 = 0;
	}
	else
	{
		*y1 = *y1 - *y2;
		*y2 = 0;
	}
}


static int check_sprite_sprite_collision(running_machine *machine,
										 int x1, int y1, int code1, int flipy1,
										 int x2, int y2, int code2, int flipy2,
										 int *col_x, int *col_y)
{
	int collided = 0;

	x1 = 240 - x1;
	y1 = 240 - y1;
	x2 = 240 - x2;
	y2 = 240 - y2;

	/* check if the two sprites are even within collision range */
	if ((abs(x1 - x2) < SPRITE_WIDTH) && (abs(y1 - y2) < SPRITE_HEIGHT))
	{
		int x,y;

		normalize_coordinates(&x1, &y1, &x2, &y2);

		bitmap_fill(sprite_sprite_collision_bitmap1, 0, 0);
		bitmap_fill(sprite_sprite_collision_bitmap2, 0, 0);

		drawgfx_opaque(sprite_sprite_collision_bitmap1,0,machine->gfx[0],
				code1,0,
				0,flipy1,
				x1,y1);

		drawgfx_opaque(sprite_sprite_collision_bitmap2,0,machine->gfx[0],
				code2,0,
				0,flipy2,
				x2,y2);

		for (x = x1; x < x1 + SPRITE_WIDTH; x++)
			for (y = y1; y < y1 + SPRITE_HEIGHT; y++)
				if ((*BITMAP_ADDR16(sprite_sprite_collision_bitmap1, y, x) == 1) &&
				    (*BITMAP_ADDR16(sprite_sprite_collision_bitmap2, y, x) == 1))
				{
					*col_x = (x1 + x) & 0x0f;
					*col_y = (y1 + y) & 0x0f;

					collided = 1;

					break;
				}
	}

	return collided;
}


/* returns 1 for collision with goal post,
   2 for collision with scoring area */
static int check_sprite_left_goal_collision(running_machine *machine, int x1, int y1, int code1, int flipy1, int goalpost_only)
{
	int collided = 0;

	x1 = 240 - x1;
	y1 = 240 - y1;

	/* check if the sprite is even within the range of the goal */
	if (((y1 + 16) > GOAL_Y) && (y1 < (GOAL_Y + GOAL_HEIGHT)) &&
	    ((x1 + 16) > LEFT_GOAL_X) && (x1 < (LEFT_GOAL_X + GOAL_WIDTH)))
	{
		int x,y;
		int x2,y2;


		x2 = LEFT_GOAL_X;
		y2 = GOAL_Y;

		normalize_coordinates(&x1, &y1, &x2, &y2);

		bitmap_fill(sprite_goal_collision_bitmap1, 0, 0);
		bitmap_fill(sprite_goal_collision_bitmap2, 0, 0);

		drawgfx_opaque(sprite_goal_collision_bitmap1,0,machine->gfx[0],
				code1,0,
				0,flipy1,
				x1,y1);

		drawgfxzoom_transpen(sprite_goal_collision_bitmap2,0,machine->gfx[1],
					0,0,
					0,0,
					x2,y2,
					0x20000,0x20000,0);

		for (x = x1; x < x1 + SPRITE_WIDTH; x++)
			for (y = y1; y < y1 + SPRITE_HEIGHT; y++)
				if ((*BITMAP_ADDR16(sprite_goal_collision_bitmap1, y, x) == 1))
				{
					pen_t pix = *BITMAP_ADDR16(sprite_goal_collision_bitmap2, y, x);

					if (pix == LEFT_GOAL_PEN)
					{
						collided = 1;
						break;
					}

					if (!goalpost_only && (pix == LEFT_SCORE_PEN))
					{
						collided = 2;
						break;
					}
				}
	}

	return collided;
}


static int check_sprite_right_goal_collision(running_machine *machine, int x1, int y1, int code1, int flipy1, int goalpost_only)
{
	int collided = 0;

	x1 = 240 - x1;
	y1 = 240 - y1;

	/* check if the sprite is even within the range of the goal */
	if (((y1 + 16) > GOAL_Y) && (y1 < (GOAL_Y + GOAL_HEIGHT)) &&
	    ((x1 + 16) > RIGHT_GOAL_X) && (x1 < (RIGHT_GOAL_X + GOAL_WIDTH)))
	{
		int x,y;
		int x2,y2;

		x2 = RIGHT_GOAL_X;
		y2 = GOAL_Y;

		normalize_coordinates(&x1, &y1, &x2, &y2);

		bitmap_fill(sprite_goal_collision_bitmap1, 0, 0);
		bitmap_fill(sprite_goal_collision_bitmap2, 0, 0);

		drawgfx_opaque(sprite_goal_collision_bitmap1,0,machine->gfx[0],
				code1,0,
				0,flipy1,
				x1,y1);

		drawgfxzoom_transpen(sprite_goal_collision_bitmap2,0,machine->gfx[1],
					0,1,
					1,0,
					x2,y2,
					0x20000,0x20000,0);

		for (x = x1; x < x1 + SPRITE_WIDTH; x++)
			for (y = y1; y < y1 + SPRITE_HEIGHT; y++)
				if ((*BITMAP_ADDR16(sprite_goal_collision_bitmap1, y, x) == 1))
				{
					pen_t pix = *BITMAP_ADDR16(sprite_goal_collision_bitmap2, y, x);

					if (pix == RIGHT_GOAL_PEN)
					{
						collided = 1;
						break;
					}

					if (!goalpost_only && (pix == RIGHT_SCORE_PEN))
					{
						collided = 2;
						break;
					}
				}
	}

	return collided;
}


/* returns 1 for collision with vertical border,
   2 for collision with horizontal border */
static int check_sprite_border_collision(running_machine *machine, UINT8 x1, UINT8 y1, int code1, int flipy1)
{
	UINT8 x,y;
	int collided = 0;

	x1 = 240 - x1;
	y1 = 240 - y1;

	drawgfx_opaque(sprite_border_collision_bitmap,0,machine->gfx[0],
			code1,0,
			0,flipy1,
			0,0);

	for (x = 0; x < SPRITE_WIDTH; x++)
		for (y = 0; y < SPRITE_HEIGHT; y++)
			if ((*BITMAP_ADDR16(sprite_border_collision_bitmap, y, x) == 1))
			{
				if (((UINT8)(x1 + x) == LEFT_BORDER) ||
					((UINT8)(x1 + x) == RIGHT_BORDER))
				{
					collided = 1;
					break;
				}

				if (((UINT8)(y1 + y) == TOP_BORDER) ||
					((UINT8)(y1 + y) == BOTTOM_BORDER))
				{
					collided = 2;
					break;
				}
			}

	return collided;
}


VIDEO_EOF( carpolo )
{
	int col_x, col_y;
	int car1_x, car2_x, car3_x, car4_x, ball_x;
	int car1_y, car2_y, car3_y, car4_y, ball_y;
	int car1_code, car2_code, car3_code, car4_code, ball_code;
	int car1_flipy, car2_flipy, car3_flipy, car4_flipy, ball_flipy;


	/* check car-car collision first */

	car1_x = carpolo_spriteram[0x00];
	car1_y = carpolo_spriteram[0x01];
	remap_sprite_code(machine, 0, carpolo_spriteram[0x0c] & 0x0f, &car1_code, &car1_flipy);

	car2_x = carpolo_spriteram[0x02];
	car2_y = carpolo_spriteram[0x03];
	remap_sprite_code(machine, 0, carpolo_spriteram[0x0c] >> 4,   &car2_code, &car2_flipy);

	car3_x = carpolo_spriteram[0x04];
	car3_y = carpolo_spriteram[0x05];
	remap_sprite_code(machine, 0, carpolo_spriteram[0x0d] & 0x0f, &car3_code, &car3_flipy);

	car4_x = carpolo_spriteram[0x06];
	car4_y = carpolo_spriteram[0x07];
	remap_sprite_code(machine, 0, carpolo_spriteram[0x0d] >> 4,   &car4_code, &car4_flipy);

	ball_x = carpolo_spriteram[0x08];
	ball_y = carpolo_spriteram[0x09];
	remap_sprite_code(machine, 1, carpolo_spriteram[0x0e] & 0x0f, &ball_code, &ball_flipy);


	/* cars 1 and 2 */
	if (check_sprite_sprite_collision(machine,
									  car1_x, car1_y, car1_code, car1_flipy,
									  car2_x, car2_y, car2_code, car2_flipy,
									  &col_x, &col_y))
		carpolo_generate_car_car_interrupt(machine, 0, 1);

	/* cars 1 and 3 */
	else if (check_sprite_sprite_collision(machine,
										   car1_x, car1_y, car1_code, car1_flipy,
										   car3_x, car3_y, car3_code, car3_flipy,
										   &col_x, &col_y))
		carpolo_generate_car_car_interrupt(machine, 0, 2);

	/* cars 1 and 4 */
	else if (check_sprite_sprite_collision(machine,
										   car1_x, car1_y, car1_code, car1_flipy,
										   car4_x, car4_y, car4_code, car4_flipy,
										   &col_x, &col_y))
		carpolo_generate_car_car_interrupt(machine, 0, 3);

	/* cars 2 and 3 */
	else if (check_sprite_sprite_collision(machine,
										   car2_x, car2_y, car2_code, car2_flipy,
										   car3_x, car3_y, car3_code, car3_flipy,
										   &col_x, &col_y))
		carpolo_generate_car_car_interrupt(machine, 1, 2);

	/* cars 2 and 4 */
	else if (check_sprite_sprite_collision(machine,
										   car2_x, car2_y, car2_code, car2_flipy,
										   car4_x, car4_y, car4_code, car4_flipy,
										   &col_x, &col_y))
		carpolo_generate_car_car_interrupt(machine, 1, 3);

	/* cars 3 and 4 */
	else if (check_sprite_sprite_collision(machine,
										   car3_x, car3_y, car3_code, car3_flipy,
										   car4_x, car4_y, car4_code, car4_flipy,
										   &col_x, &col_y))
		carpolo_generate_car_car_interrupt(machine, 2, 3);



	/* check car-ball collision */
	if (check_sprite_sprite_collision(machine,
									  car1_x, car1_y, car1_code, car1_flipy,
									  ball_x, ball_y, ball_code, ball_flipy,
									  &col_x, &col_y))
		carpolo_generate_car_ball_interrupt(machine, 0, col_x, col_y);

	else if (check_sprite_sprite_collision(machine,
										   car2_x, car2_y, car2_code, car2_flipy,
									  	   ball_x, ball_y, ball_code, ball_flipy,
										   &col_x, &col_y))
		carpolo_generate_car_ball_interrupt(machine, 1, col_x, col_y);

	else if (check_sprite_sprite_collision(machine,
										   car3_x, car3_y, car3_code, car3_flipy,
									  	   ball_x, ball_y, ball_code, ball_flipy,
										   &col_x, &col_y))
		carpolo_generate_car_ball_interrupt(machine, 2, col_x, col_y);

	else if (check_sprite_sprite_collision(machine,
										   car4_x, car4_y, car4_code, car4_flipy,
									  	   ball_x, ball_y, ball_code, ball_flipy,
										   &col_x, &col_y))
		carpolo_generate_car_ball_interrupt(machine, 3, col_x, col_y);


	/* check car-goal collision */
	if (check_sprite_left_goal_collision(machine, car1_x, car1_y, car1_code, car1_flipy, 1))
		carpolo_generate_car_goal_interrupt(machine, 0, 0);

	else if (check_sprite_right_goal_collision(machine, car1_x, car1_y, car1_code, car1_flipy, 1))
		carpolo_generate_car_goal_interrupt(machine, 0, 1);

	else if (check_sprite_left_goal_collision(machine, car2_x, car2_y, car2_code, car2_flipy, 1))
		carpolo_generate_car_goal_interrupt(machine, 1, 0);

	else if (check_sprite_right_goal_collision(machine, car2_x, car2_y, car2_code, car2_flipy, 1))
		carpolo_generate_car_goal_interrupt(machine, 1, 1);

	else if (check_sprite_left_goal_collision(machine, car3_x, car3_y, car3_code, car3_flipy, 1))
		carpolo_generate_car_goal_interrupt(machine, 2, 0);

	else if (check_sprite_right_goal_collision(machine, car3_x, car3_y, car3_code, car3_flipy, 1))
		carpolo_generate_car_goal_interrupt(machine, 2, 1);

	else if (check_sprite_left_goal_collision(machine, car4_x, car4_y, car4_code, car4_flipy, 1))
		carpolo_generate_car_goal_interrupt(machine, 3, 0);

	else if (check_sprite_right_goal_collision(machine, car4_x, car4_y, car4_code, car4_flipy, 1))
		carpolo_generate_car_goal_interrupt(machine, 3, 1);


	/* check ball collision with static screen elements */
	{
		int col;

		col = check_sprite_left_goal_collision(machine, ball_x, ball_y, ball_code, ball_flipy, 0);

		if (col == 1)  carpolo_generate_ball_screen_interrupt(machine, 0x05);
		if (col == 2)  carpolo_generate_ball_screen_interrupt(machine, 0x03);


		col = check_sprite_right_goal_collision(machine, ball_x, ball_y, ball_code, ball_flipy, 0);

		if (col == 1)  carpolo_generate_ball_screen_interrupt(machine, 0x05 | 0x08);
		if (col == 2)  carpolo_generate_ball_screen_interrupt(machine, 0x03 | 0x08);


		if (check_sprite_border_collision(machine, ball_x, ball_y, ball_code, ball_flipy))
			carpolo_generate_ball_screen_interrupt(machine, 0x06);
	}


	/* check car-border collision */
	{
		int col;

		col = check_sprite_border_collision(machine, car1_x, car1_y, car1_code, car1_flipy);

		if (col)
			carpolo_generate_car_border_interrupt(machine, 0, (col == 2));
		else
		{
			col = check_sprite_border_collision(machine, car2_x, car2_y, car2_code, car2_flipy);

			if (col)
				carpolo_generate_car_border_interrupt(machine, 1, (col == 2));
			else
			{
				col = check_sprite_border_collision(machine, car3_x, car3_y, car3_code, car3_flipy);

				if (col)
					carpolo_generate_car_border_interrupt(machine, 2, (col == 2));
				else
				{
					col = check_sprite_border_collision(machine, car4_x, car4_y, car4_code, car4_flipy);

					if (col)
						carpolo_generate_car_border_interrupt(machine, 3, (col == 2));
				}
			}
		}
	}
}
