#include "common.h"

/* modify a vecotor according to given type of bouncing */
void bounce_rand_vector (ball_t *in_b, uint8_t in_bouncetype);
void bounce_rand_vector (ball_t *in_b, uint8_t in_bouncetype)
{
	uint8_t rval = random8();
	
	switch (in_bouncetype)
	{
		case BOUNCE_NONE: /* don't touch the vector since nothing changed */
			return;

		case BOUNCE_BRICK:
			in_b->dir_x ^= (rval & 0x07);
			in_b->dir_y ^= (rval & 0x07);
			break;

		case BOUNCE_REBOUND: /* the rebound is rather percise */
			in_b->dir_x ^= (rval & 0x03);
			in_b->dir_y ^= (rval & 0x03);
			if (JOYISRIGHT || JOYISLEFT)
			{
				/* a moving rebond accelerates the ball by 1/8th */
				in_b->dir_y += (in_b->dir_y / 8);
				in_b->dir_x += (in_b->dir_x / 8);
			}
			break;

		default: /* walls */
			in_b->dir_x ^= (rval & 0x01);
			in_b->dir_y ^= (rval & 0x01);
	}
	if (!in_b->dir_x)
		in_b->dir_x = 213;
	
	if (!in_b->dir_y)
		in_b->dir_y = 217;
}

void ball_think (ball_t *b)
{
	int8_t proj_x, proj_y, bounce;
	
	/*
	if (!b->strength)
		return;
	*/
	
	/* projection of the new coordinates */
	proj_x = (b->x + (b->dir_x)) / 256;
	proj_y = (b->y + (b->dir_y)) / 256;
	
	/* falling out of the field */
	if (proj_y >= NUM_ROWS)
		ball_die (b);

	bounce = check_bounce (proj_x, b->y / 256);
	if (bounce & BOUNCE_UNDEF)
		bounce = (BOUNCE_X | bounce) & (BOUNCE_X | BOUNCE_Y);

	bounce |= check_bounce (b->x / 256, proj_y);
	if (bounce & BOUNCE_UNDEF)
		bounce = (BOUNCE_Y | bounce) & (BOUNCE_X | BOUNCE_Y);

	bounce |= check_bounce (proj_x, proj_y);
	if (bounce & BOUNCE_UNDEF)
		bounce = BOUNCE_X | BOUNCE_Y;

	bounce_rand_vector (b, bounce);

	/* bounce in x direction */
	if (bounce & (BOUNCE_X | BOUNCE_BRICK))
	{
		b->dir_x *= -1; /* invert x vector */

#if BOUNCE_SLOWDOWN
		if (b->dir_x < 0)
		{
			b->dir_x += BOUNCE_SLOWDOWN;
		} else
		{
			b->dir_x -= BOUNCE_SLOWDOWN;
		}
#endif
	}

	/* bounce in y direction */
	if (bounce & (BOUNCE_Y | BOUNCE_BRICK))
	{
		b->dir_y *= -1; /* invert y vector */

#if BOUNCE_SLOWDOWN
		if (b->dir_y < 0)
		{
			b->dir_y += BOUNCE_SLOWDOWN;
		} else
		{
			b->dir_y -= BOUNCE_SLOWDOWN;
		}
#endif
	}

	b->y += b->dir_y;
	b->x += b->dir_x;

	if (!b->dir_x || !b->dir_y)
	{
		printf("Ball stopped!\n");
	}
}
	
void ball_die (ball_t *in_b)
{
	in_b->strength--;

	/* respawn ball with random direction */
	if (in_b->strength)
	{
		print_ballsleft(in_b);
		ball_spawn_default (in_b);
	}
}

void ball_draw (ball_t *b)
{
	pixel p;
	p.x = (uint8_t) abs(b->x / 256);
	p.y = (uint8_t) abs(b->y / 256);

	setpixel (p, 3);
}

void ball_spawn (ball_t *in_ball, uint16_t in_x, uint16_t in_y, int16_t in_dir_x, int16_t in_dir_y)
{
	in_ball->x = in_x;
	in_ball->y = in_y;
	in_ball->dir_x = in_dir_x;
	in_ball->dir_y = in_dir_y;
}

void ball_spawn_default (ball_t *in_b)
{
	int16_t xdir;

	xdir = 128 + (random8() & 0x3F);
	if (random8() & 0x01)
		xdir *= -1;
	
	ball_spawn (in_b, (uint16_t) rebound_getpos() * 256, (NUM_ROWS -2) * 256,
		xdir, -131);
}