153 lines
2.9 KiB
C
153 lines
2.9 KiB
C
#include "common.h"
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/* modify a vecotor according to given type of bouncing */
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void bounce_rand_vector (ball_t *in_b, uint8_t in_bouncetype);
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void bounce_rand_vector (ball_t *in_b, uint8_t in_bouncetype)
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{
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uint8_t rval = random8();
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switch (in_bouncetype)
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{
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case BOUNCE_NONE: /* don't touch the vector since nothing changed */
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return;
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case BOUNCE_BRICK:
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in_b->dir_x ^= (rval & 0x07);
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in_b->dir_y ^= (rval & 0x07);
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break;
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case BOUNCE_REBOUND: /* the rebound is rather percise */
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in_b->dir_x ^= (rval & 0x03);
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in_b->dir_y ^= (rval & 0x03);
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if (JOYISRIGHT || JOYISLEFT)
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{
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/* a moving rebond accelerates the ball by 1/8th */
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in_b->dir_y += (in_b->dir_y / 8);
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in_b->dir_x += (in_b->dir_x / 8);
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}
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break;
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default: /* walls */
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in_b->dir_x ^= (rval & 0x01);
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in_b->dir_y ^= (rval & 0x01);
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}
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if (!in_b->dir_x)
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in_b->dir_x = 213;
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if (!in_b->dir_y)
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in_b->dir_y = 217;
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}
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void ball_think (ball_t *b)
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{
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int8_t proj_x, proj_y, bounce;
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/*
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if (!b->strength)
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return;
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*/
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/* projection of the new coordinates */
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proj_x = (b->x + (b->dir_x)) / 256;
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proj_y = (b->y + (b->dir_y)) / 256;
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/* falling out of the field */
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if (proj_y >= NUM_ROWS)
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ball_die (b);
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bounce = check_bounce (proj_x, b->y / 256);
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if (bounce & BOUNCE_UNDEF)
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bounce = (BOUNCE_X | bounce) & (BOUNCE_X | BOUNCE_Y);
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bounce |= check_bounce (b->x / 256, proj_y);
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if (bounce & BOUNCE_UNDEF)
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bounce = (BOUNCE_Y | bounce) & (BOUNCE_X | BOUNCE_Y);
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bounce |= check_bounce (proj_x, proj_y);
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if (bounce & BOUNCE_UNDEF)
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bounce = BOUNCE_X | BOUNCE_Y;
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bounce_rand_vector (b, bounce);
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/* bounce in x direction */
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if (bounce & (BOUNCE_X | BOUNCE_BRICK))
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{
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b->dir_x *= -1; /* invert x vector */
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#if BOUNCE_SLOWDOWN
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if (b->dir_x < 0)
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{
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b->dir_x += BOUNCE_SLOWDOWN;
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} else
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{
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b->dir_x -= BOUNCE_SLOWDOWN;
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}
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#endif
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}
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/* bounce in y direction */
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if (bounce & (BOUNCE_Y | BOUNCE_BRICK))
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{
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b->dir_y *= -1; /* invert y vector */
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#if BOUNCE_SLOWDOWN
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if (b->dir_y < 0)
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{
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b->dir_y += BOUNCE_SLOWDOWN;
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} else
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{
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b->dir_y -= BOUNCE_SLOWDOWN;
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}
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#endif
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}
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b->y += b->dir_y;
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b->x += b->dir_x;
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if (!b->dir_x || !b->dir_y)
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{
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printf("Ball stopped!\n");
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}
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}
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void ball_die (ball_t *in_b)
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{
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in_b->strength--;
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/* respawn ball with random direction */
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if (in_b->strength)
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{
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print_ballsleft(in_b);
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ball_spawn_default (in_b);
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}
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}
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void ball_draw (ball_t *b)
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{
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pixel p;
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p.x = (uint8_t) abs(b->x / 256);
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p.y = (uint8_t) abs(b->y / 256);
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setpixel (p, 3);
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}
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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)
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{
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in_ball->x = in_x;
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in_ball->y = in_y;
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in_ball->dir_x = in_dir_x;
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in_ball->dir_y = in_dir_y;
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}
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void ball_spawn_default (ball_t *in_b)
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{
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int16_t xdir;
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xdir = 128 + (random8() & 0x3F);
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if (random8() & 0x01)
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xdir *= -1;
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ball_spawn (in_b, (uint16_t) rebound_getpos() * 256, (NUM_ROWS -2) * 256,
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xdir, -131);
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}
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