BSL에서 브레이크 아웃 프로그래밍

Question

BSL에서 '브레이크 아웃'을 코딩하려고하는데, 은 내 코드에 환영 및 게임 오버 스크린을 추가하는 방법을 모르므로 막혀 있습니다. 게임이 시작 화면으로 시작한다고 가정하면 이고 화면에서 마우스로 클릭하면 일 때 실제 게임이 시작됩니다. 볼이 화면의 하단 가장자리와 충돌하면 game-over-screen 이 표시됩니다. 나는 어떤 조언을 주셔서 감사합니다!

(define WIDTH 200) 

    (define HEIGHT 200) 

(define BALL-RADIUS 10) 

(define BALL-IMG (circle BALL-RADIUS "solid" "red")) 

(define MT (empty-scene WIDTH HEIGHT)) 

    (define GAME-OVER 
    (place-image (text "Game-over" 30 "black") 
       100 100 
       MT)) 

    (define WELCOME 
     (place-image (text "Welcome" 30 "black") 
       100 100 
       MT)) 

    (define-struct vel (delta-x delta-y)) 
    ; a Vel is a structure: (make-vel Number Number) 
    ; interp. the velocity vector of a moving object 


    (define-struct ball (loc velocity)) 
    ; a Ball is a structure: (make-ball Posn Vel) 
    ; interp. the position and velocity of a object 

    (define RACKET (rectangle 30 10 "solid" "grey")) 
    (define-struct world-state (ball racket)) 
    ; A WorldState is a structure. (make-world-state Ball Location of 
    Racket) 
    ; interp. current velocity and location of ball, current location of 
    racket 


    ; Posn Vel -> Posn 
    ; applies q to p and simulates the movement in one clock tick 
    (check-expect (posn+vel (make-posn 5 6) (make-vel 1 2)) 
       (make-posn 6 8)) 
    (define (posn+vel p q) 
     (make-posn (+ (posn-x p) (vel-delta-x q)) 
      (+ (posn-y p) (vel-delta-y q)))) 


    ; Ball -> Ball 
    ; computes movement of ball in one clock tick 

    (define (move-ball ball) 
     (make-ball (posn+vel (ball-loc ball) 
         (ball-velocity ball)) 
      (ball-velocity ball))) 

    ; A Collision is either 
    ; - "top" 
    ; - "down" 
    ; - "left" 
    ; - "right" 
    ; - "racket" 
    ; - "none" 
    ; interp. the location where a ball collides with a wall 

    ; Posn -> Collision 
    ; detects with which of the walls (if any) or the racket the ball 
    collides 

    (define (collision world-state) 
     (cond 
     [(<= (posn-x (ball-loc (world-state-ball world-state))) BALL- 
    RADIUS) "left"] 
     [(<= (posn-y (ball-loc (world-state-ball world-state))) BALL- 
    RADIUS) "top"] 
     [(>= (posn-x (ball-loc (world-state-ball world-state))) (- WIDTH 
    BALL-RADIUS)) "right"] 
     [(>= (posn-y (ball-loc (world-state-ball world-state))) (- HEIGHT 
    BALL-RADIUS)) "down"] 
     [(and (>= (posn-y (ball-loc (world-state-ball world-state))) (- 
    HEIGHT BALL-RADIUS 10)) 
       (<= (- (posn-x (world-state-racket world-state)) 15) 
        (posn-x (world-state-racket world-state)) 
        (+ (posn-x (world-state-racket world-state)) 15))) 
    "racket"] 
     [else "none"])) 

    ; Vel Collision -> Vel 
    ; computes the velocity of an object after a collision 
    (define (bounce vel collision) 
     (cond [(or (string=? collision "left") 
       (string=? collision "right")) 
      (make-vel (- (vel-delta-x vel)) 
        (vel-delta-y vel))] 
      [(or (string=? collision "top") 
       (string=? collision "racket")) 
      (make-vel (vel-delta-x vel) 
         (- (vel-delta-y vel)))] 
     [else vel])) 


    ; render 

    ; WorldState -> Image 
    ; renders ball and 



    racket at their position 
    (check-expect (image? (render INITIAL-STATE)) #true) 
    (define (render world-state) 
     (place-image BALL-IMG 
        (posn-x (ball-loc (world-state-ball world-state))) 
        (posn-y (ball-loc (world-state-ball world-state))) 
        (place-image RACKET 
           (posn-x (world-state-racket world-state)) 
           195 
           (empty-scene WIDTH HEIGHT)))) 

    ;tick 

    ; WorldState -> WorldState 
    ; moves ball to its next location 
    (check-expect (tick INITIAL-STATE) (make-world-state (make-ball (make-posn 21 14) (make-vel 1 2)) (make-posn 20 195))) 

    (define (tick world-state) 
     (make-world-state (move-ball (make-ball (ball-loc (world-state-ball world-state)) 
          (bounce (ball-velocity (world-state-ball world-state)) 
            (collision world-state)))) 
         (world-state-racket world-state))) 



    ; A Location is a structure: (make-posn Number Number) 
    ; interp. x and y coordinate of a location on screen. 
    (define Loc (make-posn 1 1)) 

    ; A MouseEvent is one of 
    ; - "button-down" 
    ; - "button-up" 
    ; - "drag" 
    ; - "move" 
    ; - "enter" 
    ; - "leave" 
    ; interp. mouse events, e.g., mouse movements or mouse clicks 
    (define MOUSE-CLICK "button-down") 

    ; mouse 
    ; 
    ; Game Number Number MouseEvent -> WorldState 
    ; Update position of racket when the mouse moves 

    ;mouse-template 
    (define (mouse-template world-state mouse-loc-x mouse-loc-y MouseEvent) 
     (cond 
     ((string=? MouseEvent "button-down")...) 
     ((string=? MouseEvent "button-up")...) 
     ((string=? MouseEvent "drag")...) 
     ((string=? MouseEvent "move")...) 
     ((string=? MouseEvent "enter")...) 
     ((string=? MouseEvent "leave")...) 
     (else ...))) 



    (define (mouse world-state mouse-loc-x mouse-loc-y MouseEvent) 
     (cond 
     [(and (string=? MouseEvent "move") 
       (>= mouse-loc-y 180)) 
     (make-world-state (world-state-ball world-state) 
          (make-posn mouse-loc-x 195))] 
     [else world-state])) 


    (define INITIAL-BALL (make-ball (make-posn 20 12) 
            (make-vel 1 2))) 

    (define INITIAL-RACKET (make-posn 20 195)) 


    (define INITIAL-STATE (make-world-state INITIAL-BALL INITIAL-RACKET)) 


    ; WorldState -> WorldState 
    ; Starts the game 

    (define (main state) 
      (big-bang state 
       (on-tick tick 0.01) 
       (to-draw render) 
       (on-mouse mouse))) 

    ; start with INITIAL-STATE 

Answer 1

이제 세 가지 상태가 있습니다

• 는
게임 오버

지금까지 당신은 단지 "재생"있었다 재생

환영을 당신은 당신의 사용 그것을 대표하는 세계 구조.

이제 환영과 게임 오버의 두 가지 새로운 구조를 소개해야합니다.

이전 렌더 함수 이름을 render-world (또는 render-playing)으로 변경하십시오. 는 다음과 같이 쓰기 : 당신의 초기 상태는 환영의 인스턴스가되어야 물론

(define (render w) 
    (cond 
     [(welcome? w) (render-welcome w)] 
     [(world? w)  (render-world w)] 
     [(game-over? w) (render-game-over w)])) 

을, 당신은 세 가지 틱 기능이 필요합니다.