読者です 読者をやめる 読者になる 読者になる

`(kakko ,man)

Find a guide into tomorrow by taking lessons from the past

Lisp Game Programming <Step12-1>

step12の最初はEnemyにshotがhitしたかどうかを判断するプログラム

enemyのstateを2(explosion)、shotのstateを0(dead)、爆発カウンターを0にセットして起動し、scoreを+100して、もしhighscoreよりscoreが大きくなったら、highscoreにscoreをセット

;; Step12 <Judge Shot Hit>
;; -----------------------------------------------------------------------------------------------
(defgeneric Enemy-hit-p (shot score foe))

(defmethod Enemy-hit-p (shot score foe)
  (when (= (state shot) 1) ; if shot state on
  (dolist (enemy (enemy-list foe))
    (when (and (= (state enemy) 1) ; if enemy is alive
                       (> (+ (x shot) 31) (x enemy))
                       (< (x shot) (+ (x enemy) 31))
                       (> (+ (y shot) 31) (y enemy))
                       (< (y shot) (+ (y enemy) 31)))
      (setf (state enemy) 2 ; enemy explosion
      (explode-cnt enemy) 0
      (state shot) 0) ; set shot state off
      (incf (score score) 100)))
      (when (> (score score) (highscore score))
        (setf (highscore score) (score score)))))