Java Shooter Game - FiledDirector :: findClosestEnemy - http://tibor-simon.com/programming/auto-aiming-logic-for-games/

FiledDirector_findClosestEnemy.java

private boolean findClosestEnemy() {
        if (enemyList.isEmpty()) {
            targetEnemy = null;
            System.out.println("Target enemy NOT found!");
            return false;
        }
        if (enemyList.size() == 1) {
            targetEnemy = enemyList.get(0);
            // System.out.println("Target enemy found!");
            return true;
        }

        int targetIndex = 0;
        float min = 800.0f;
        Circle pC = playerCircle();
        float px = pC.getCenterX();
        float py = pC.getCenterY();

        for (int i = 0; i < enemyList.size(); i++) {
            Enemy enemy = enemyList.get(i);
            Circle eC = enemy.outline();
            float ex = eC.getCenterX();
            float ey = eC.getCenterY();
            float tempMin = (float) Math.sqrt(Math.pow(Math.abs(ex - px), 2)
                    + Math.pow(Math.abs(ey - py), 2));
            if (tempMin < min) {
                min = tempMin;
                targetIndex = i;
            }
        }

        targetEnemy = enemyList.get(targetIndex);
        // System.out.println("Target enemy found!");
        return true;
}