wormlet.c

编译后直接运行的ＭＰ３播放器全部Ｃ语言源代码 一个包含FAT文件系统、系统引导 Boot、FLASH Driver等内容的

/**
 * Returns the index of the food that is closest to the point
 * specified by x, y. This index may be used in the foodx and 
 * foody arrays.
 * @param int x The x coordinate of the point
 * @param int y The y coordinate of the point
 * @return int A value usable as index in foodx and foody.
 */
static int get_nearest_food(int x, int y){
    int nearestfood = 0;
    int olddistance = FIELD_RECT_WIDTH + FIELD_RECT_HEIGHT;
    int deltax = 0;
    int deltay = 0;
    int foodindex;
    for (foodindex = 0; foodindex < MAX_FOOD; foodindex++) {
        int distance;
        deltax = foodx[foodindex] - x;
        deltay = foody[foodindex] - y;
        deltax = deltax > 0 ? deltax : deltax * (-1);
        deltay = deltay > 0 ? deltay : deltay * (-1);
        distance = deltax + deltay;

        if (distance < olddistance) {
            olddistance = distance;
            nearestfood = foodindex;
        }
    }
    return nearestfood;
}

/** 
 * Returns wether the specified position is next to the worm
 * and in the direction the worm looks. Use this method to 
 * test wether this position would be hit with the next move of 
 * the worm unless the worm changes its direction.
 * @param struct worm *w - The worm to be investigated
 * @param int x - The x coordinate of the position to test.
 * @param int y - The y coordinate of the position to test.
 * @return Returns true if the worm will hit the position unless
 * it change its direction before the next move.
 */
static bool is_in_front_of_worm(struct worm *w, int x, int y) {
    bool infront = false;
    int deltax = x - w->x[w->head];
    int deltay = y - w->y[w->head];

    if (w->dirx == 0) {
        infront = (w->diry * deltay) > 0;
    } else {
        infront = (w->dirx * deltax) > 0;
    }
    return infront;
}

/**
 * Returns true if the worm will collide with the next move unless
 * it changes its direction.
 * @param struct worm *w - The worm to be investigated.
 * @return Returns true if the worm will collide with the next move
 * unless it changes its direction.
 */
static bool will_worm_collide(struct worm *w) {
    int x = w->x[w->head] + w->dirx;
    int y = w->y[w->head] + w->diry;
    bool retVal = !is_in_field_rect(x, y);
    if (!retVal) {
        retVal = (argh_collision(x, y) != -1);
    }
    
    if (!retVal) {
        retVal = (worm_collision(w, x, y) != NULL);
    }
    return retVal;
}

/** 
 * This function
 * may be used to be stored in worm.fetch_worm_direction for
 * worms that are not controlled by humans but by artificial stupidity. 
 * A direction is searched that doesn't lead to collision but to the nearest
 * food - but not very intelligent. The direction is written to the specified
 * worm.
 * @param struct worm *w - The worm of which the direction 
 * is altered.
 */
static void virtual_player(struct worm *w) {
    bool isright;
    int plana, planb, planc;
    /* find the next lunch */
    int nearestfood = get_nearest_food(w->x[w->head], w->y[w->head]);

    /* determine in which direction it is */

    /* in front of me? */
    bool infront = is_in_front_of_worm(w, foodx[nearestfood], foody[nearestfood]);

    /* left right of me? */
    int olddir = get_worm_dir(w);
    set_worm_dir(w, (olddir + 1) % 4);
    isright = is_in_front_of_worm(w, foodx[nearestfood], foody[nearestfood]);
    set_worm_dir(w, olddir);

    /* detect situation, set strategy */
    if (infront) {
        if (isright) {
            plana = olddir;
            planb = (olddir + 1) % 4;
            planc = (olddir + 3) % 4;
        } else {
            plana = olddir;
            planb = (olddir + 3) % 4;
            planc = (olddir + 1) % 4;
        }
    } else {
        if (isright) {
            plana = (olddir + 1) % 4;
            planb = olddir;
            planc = (olddir + 3) % 4;
        } else {
            plana = (olddir + 3) % 4;
            planb = olddir;
            planc = (olddir + 1) % 4;
        }
    }

    /* test for collision */
    set_worm_dir(w, plana);
    if (will_worm_collide(w)){

        /* plan b */
        set_worm_dir(w, planb);

        /* test for collision */
        if (will_worm_collide(w)) {

            /* plan c */
            set_worm_dir(w, planc);
        }
    }
}

/**
 * prints out the score board with all the status information
 * about the game.
 */
static void score_board(void)
{
    char buf[15];
    char* buf2 = NULL;
    int i;
    int y = 0;
    rb->lcd_clearrect(FIELD_RECT_WIDTH + 2, 0, LCD_WIDTH - FIELD_RECT_WIDTH - 2, LCD_HEIGHT);
    for (i = 0; i < worm_count; i++) {
        int score = get_score(&worms[i]);
    
        /* high score */
        if (worms[i].fetch_worm_direction != virtual_player){
            if (highscore < score) {
                highscore = score;
            }
        }

        /* length */
        rb->snprintf(buf, sizeof (buf),"Len:%d", score);

        /* worm state */
        switch (check_collision(&worms[i])) {
            case COLLISION_NONE:  
                if (worms[i].growing > 0)
                    buf2 = "Growing";
                else {
                    if (worms[i].alive)
                        buf2 = "Hungry";
                    else
                        buf2 = "Wormed";
                }
                break;

            case COLLISION_WORM:  
                buf2 = "Wormed";
                break;

            case COLLISION_FOOD:  
                buf2 = "Growing";
                break;

            case COLLISION_ARGH:  
                buf2 = "Argh";
                break;

            case COLLISION_FIELD: 
                buf2 = "Crashed";
                break;
        }
        rb->lcd_putsxy(FIELD_RECT_WIDTH + 3, y  , buf);
        rb->lcd_putsxy(FIELD_RECT_WIDTH + 3, y+8, buf2);

        if (!worms[i].alive){
            rb->lcd_invertrect(FIELD_RECT_WIDTH + 2, y, 
                               LCD_WIDTH - FIELD_RECT_WIDTH - 2, 17);
        }
        y += 19;
    }
    rb->snprintf(buf , sizeof(buf), "Hs: %d", highscore);
#ifndef DEBUG_WORMLET
    rb->lcd_putsxy(FIELD_RECT_WIDTH + 3, LCD_HEIGHT - 8, buf);
#else
    rb->lcd_putsxy(FIELD_RECT_WIDTH + 3, LCD_HEIGHT - 8, debugout);
#endif
}

/**
 * Checks for collisions of the worm and its environment and
 * takes appropriate actions like growing the worm or killing it.
 * @return bool Returns true if the worm is dead. Returns
 * false if the worm is healthy, up and creeping.
 */
static bool process_collisions(struct worm *w)
{
    int index = -1;

    w->alive &= !field_collision(w);

    if (w->alive) {

        /* check if food was eaten */
        index = food_collision(w->x[w->head], w->y[w->head]);
        if (index != -1){
            int i;
            
            clear_food(index);
            make_food(index);
            draw_food(index);
            
            for (i = 0; i < ARGHS_PER_FOOD; i++) {
                argh_count++;
                if (argh_count > MAX_ARGH)
                    argh_count = MAX_ARGH;
                make_argh(argh_count - 1);
                draw_argh(argh_count - 1);
            }

            add_growing(w, WORM_PER_FOOD);

            draw_worm(w);
        }

        /* check if argh was eaten */
        else {
            index = argh_collision(w->x[w->head], w->y[w->head]);
            if (index != -1) {
                w->alive = false;
        }
            else {
                if (worm_collision(w, w->x[w->head], w->y[w->head]) != NULL) {
                    w->alive = false;
    }
            }
        }
    }
    return !w->alive;
}

/**
 * The main loop of the game.
 * @return bool Returns true if the game ended
 * with a dead worm. Returns false if the user
 * aborted the game manually.
 */ 
static bool run(void)
{
    int button = 0;
    int wormDead = false;

    /* ticks are counted to compensate speed variations */
    long cycle_start = 0, cycle_end = 0;
#ifdef DEBUG_WORMLET
    int ticks_to_max_cycle_reset = 20;
    long max_cycle = 0;
    char buf[20];
#endif

    /* initialize the board and so on */
    init_wormlet();

    cycle_start = *rb->current_tick;
    /* change the direction of the worm */
    while (button != BUTTON_OFF && ! wormDead)
    {
        int i;
        long cycle_duration ;
        switch (button) {
            case BUTTON_UP:
                if (players == 1 && !use_remote) {
                    player1_dir = NORTH;
                }
                break;

            case BUTTON_DOWN:
                if (players == 1 && !use_remote) {
                    player1_dir = SOUTH;
                }
                break;

            case BUTTON_LEFT:
                if (players != 1 || use_remote) {
                    player1_dir = (player1_dir + 3) % 4;
                } else {
                    player1_dir = WEST;
                }
                break;

            case BUTTON_RIGHT:
                if (players != 1 || use_remote) {
                    player1_dir = (player1_dir + 1) % 4;
                } else {
                    player1_dir = EAST;
                }
                break;

            case BUTTON_F2:
                player2_dir = (player2_dir + 3) % 4;
                break;

            case BUTTON_F3:
                player2_dir = (player2_dir + 1) % 4;
                break;

            case BUTTON_RC_VOL_UP:
                player3_dir = (player3_dir + 1) % 4;
                break;

            case BUTTON_RC_VOL_DOWN:
                player3_dir = (player3_dir + 3) % 4;
                break;

            case BUTTON_PLAY:
                do {
                    button = rb->button_get(true);
                } while (button != BUTTON_PLAY &&
                         button != BUTTON_OFF  &&
                         button != BUTTON_ON);
                break;
        }

        for (i = 0; i < worm_count; i++) {
            worms[i].fetch_worm_direction(&worms[i]);
        }

        wormDead = true;
        for (i = 0; i < worm_count; i++){
            struct worm *w = &worms[i];
            move_worm(w);
            wormDead &= process_collisions(w);
            draw_worm(w);
        }
        score_board();
        rb->lcd_update();
        if (button == BUTTON_ON) {
            wormDead = true;
        }

        /* here the wormlet game cycle ends
           thus the current tick is stored
           as end time */
        cycle_end = *rb->current_tick;

        /* The duration of the game cycle */
        cycle_duration = cycle_end - cycle_start;
        cycle_duration = MAX(0, cycle_duration);
        cycle_duration = MIN(SPEED -1, cycle_duration);


#ifdef DEBUG_WORMLET
        ticks_to_max_cycle_reset--;
        if (ticks_to_max_cycle_reset <= 0) {
            max_cycle = 0;
        }

        if (max_cycle < cycle_duration) {
            max_cycle = cycle_duration;
            ticks_to_max_cycle_reset = 20;
        }
        rb->snprintf(buf, sizeof buf, "ticks %d", max_cycle);
        set_debug_out(buf);
#endif
        /* adjust the number of ticks to wait for a button.
           This ensures that a complete game cycle including
           user input runs in constant time */
        button = rb->button_get_w_tmo(SPEED - cycle_duration);
        cycle_start = *rb->current_tick;
    }
    return wormDead;
}

#ifdef DEBUG_WORMLET

/**
 * Just a test routine that checks that worm_food_collision works
 * in some typical situations.
 */
static void test_worm_food_collision(void) {
    int collision_count = 0;
    int i;
    rb->lcd_clear_display();
    init_worm(&worms[0], 10, 10);
    add_growing(&worms[0], 10);
    set_worm_dir(&worms[0], EAST);
    for (i = 0; i < 10; i++) {
        move_worm(&worms[0]);
        draw_worm(&worms[0]);
    }

    set_worm_dir(&worms[0], SOUTH);
    for (i = 0; i < 10; i++) {
        move_worm(&worms[0]);
        draw_worm(&worms[0]);
    }

    foodx[0] = 15;
    foody[0] = 12;
    for (foody[0] = 20; foody[0] > 0; foody[0] --) {
        char buf[20];
        bool collision;
        draw_worm(&worms[0]);
        draw_food(0);
        collision = worm_food_collision(&worms[0], 0);
        if (collision) {
            collision_count++;
        }
        rb->snprintf(buf, sizeof buf, "collisions: %d", collision_count);
        rb->lcd_putsxy(0, LCD_HEIGHT -8, buf);
        rb->lcd_update();
    }
    if (collision_count != FOOD_SIZE) {
        rb->button_get(true);
    }


    foody[0] = 15;
    for (foodx[0] = 30; foodx[0] > 0; foodx[0] --) {
        char buf[20];
        bool collision;
        draw_worm(&worms[0]);
        draw_food(0);
        collision = worm_food_collision(&worms[0], 0);
        if (collision) {
            collision_count ++;
        }
        rb->snprintf(buf, sizeof buf, "collisions: %d", collision_count);
        rb->lcd_putsxy(0, LCD_HEIGHT -8, buf);
        rb->lcd_update();
    }
    if (collision_count != FOOD_SIZE * 2) {
        rb->button_get(true);
    }

}


static bool expensive_worm_in_rect(struct worm *w, int rx, int ry, int rw, int rh){
    int x, y;
    bool retVal = false;
    for (x = rx; x < rx + rw; x++){
        for (y = ry; y < ry + rh; y++) {
            if (specific_worm_collision(w, x, y) != -1) {
                retVal = true;
            }
        }
    }
    return retVal;
}

static void test_worm_argh_collision(void) {
    int i;
    int dir;
    int collision_count = 0;
    rb->lcd_clear_display();
    init_worm(&worms[0], 10, 10);
    add_growing(&worms[0], 40);
    for (dir = 0; dir < 4; dir++) {
        set_worm_dir(&worms[0], (EAST + dir) % 4);
        for (i = 0; i < 10; i++) {
            move_worm(&worms[0]);
            draw_worm(&worms[0]);
        }
    }

    arghx[0] = 12;
    for (arghy[0] = 0; arghy[0] < FIELD_RECT_HEIGHT - ARGH_SIZE; arghy[0]++){
        char buf[20];
        bool collision;
        draw_argh(0);
        collision = worm_argh_collision(&worms[0], 0);
        if (collision) {
            collision_count ++;
        }
        rb->snprintf(buf, sizeof buf, "collisions: %d", collision_count);
        rb->lcd_putsxy(0, LCD_HEIGHT -8, buf);
        rb->lcd_update();
    }
    if (collision_count != ARGH_SIZE * 2) {
        rb->button_get(true);