Java version of Kinema

52 Kinema/java/src/Kinema.java

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+import java.util.Arrays;
+import java.util.Scanner;
+
+/**
+ * Game of Kinema
+ * <p>
+ * Based on the Basic game of Kinema here
+ * https://github.com/coding-horror/basic-computer-games/blob/main/52%20Kinema/kinema.bas
+ * <p>
+ * Note:  The idea was to create a version of the 1970's Basic game in Java, without introducing
+ * new features - no additional text, error checking, etc has been added.
+ */
+public class Kinema {
+
+    // Used for keyboard input
+    private final Scanner kbScanner;
+
+    private enum GAME_STATE {
+        STARTUP,
+        INIT,
+        HOW_HIGH,
+        SECONDS_TILL_IT_RETURNS,
+        ITS_VELOCITY,
+        RESULTS,
+        GAME_OVER
+    }
+
+    // Current game state
+    private GAME_STATE gameState;
+
+    private int numberAnswersCorrect;
+
+    // How many meters per second a ball is thrown
+    private int velocity;
+
+    public Kinema() {
+        kbScanner = new Scanner(System.in);
+
+        gameState = GAME_STATE.STARTUP;
+    }
+
+    /**
+     * Main game loop
+     */
+    public void play() {
+
+        double playerAnswer;
+        double correctAnswer;
+        do {
+            switch (gameState) {
+
+                case STARTUP:
+                    intro();
+                    gameState = GAME_STATE.INIT;
+                    break;
+
+                case INIT:
+                    numberAnswersCorrect = 0;
+
+                    // calculate a random velocity for the player to use in the calculations
+                    velocity = 5 + (int) (35 * Math.random());
+                    System.out.println("A BALL IS THROWN UPWARDS AT " + velocity + " METERS PER SECOND.");
+                    gameState = GAME_STATE.HOW_HIGH;
+                    break;
+
+                case HOW_HIGH:
+
+                    playerAnswer = displayTextAndGetNumber("HOW HIGH WILL IT GO (IN METERS)? ");
+
+                    // Calculate the correct answer to how high it will go
+                    correctAnswer = 0.05 * Math.pow(velocity, 2);
+                    if (calculate(playerAnswer, correctAnswer)) {
+                        numberAnswersCorrect++;
+                    }
+                    gameState = GAME_STATE.ITS_VELOCITY;
+                    break;
+
+                case ITS_VELOCITY:
+
+                    playerAnswer = displayTextAndGetNumber("HOW LONG UNTIL IT RETURNS (IN SECONDS)? ");
+
+                    // Calculate current Answer for how long until it returns to the ground in seconds
+                    correctAnswer = (double) velocity / 5;
+                    if (calculate(playerAnswer, correctAnswer)) {
+                        numberAnswersCorrect++;
+                    }
+                    gameState = GAME_STATE.SECONDS_TILL_IT_RETURNS;
+                    break;
+
+                case SECONDS_TILL_IT_RETURNS:
+
+                    // Calculate random number of seconds for 3rd question
+                    double seconds = 1 + (Math.random() * (2 * velocity)) / 10;
+
+                    // Round to one decimal place.
+                    double scale = Math.pow(10, 1);
+                    seconds = Math.round(seconds * scale) / scale;
+
+                    playerAnswer = displayTextAndGetNumber("WHAT WILL ITS VELOCITY BE AFTER " + seconds + " SECONDS? ");
+
+                    // Calculate the velocity after the given number of seconds
+                    correctAnswer = velocity - (10 * seconds);
+                    if (calculate(playerAnswer, correctAnswer)) {
+                        numberAnswersCorrect++;
+                    }
+                    gameState = GAME_STATE.RESULTS;
+                    break;
+
+                case RESULTS:
+                    System.out.println(numberAnswersCorrect + " RIGHT OUT OF 3");
+                    if (numberAnswersCorrect > 1) {
+                        System.out.println(" NOT BAD.");
+                    }
+                    gameState = GAME_STATE.STARTUP;
+                    break;
+            }
+        } while (gameState != GAME_STATE.GAME_OVER);
+    }
+
+    private void intro() {
+        System.out.println(simulateTabs(33) + "KINEMA");
+        System.out.println(simulateTabs(15) + "CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY");
+        System.out.println();
+    }
+
+    private boolean calculate(double playerAnswer, double correctAnswer) {
+
+        boolean gotItRight = false;
+
+        if (Math.abs((playerAnswer - correctAnswer) / correctAnswer) < 0.15) {
+            System.out.println("CLOSE ENOUGH");
+            gotItRight = true;
+        } else {
+            System.out.println("NOT EVEN CLOSE");
+        }
+        System.out.println("CORRECT ANSWER IS " + correctAnswer);
+        System.out.println();
+
+        return gotItRight;
+    }
+
+    /*
+     * Print a message on the screen, then accept input from Keyboard.
+     * Converts input to a Double
+     *
+     * @param text message to be displayed on screen.
+     * @return what was typed by the player.
+     */
+    private double displayTextAndGetNumber(String text) {
+        return Double.parseDouble(displayTextAndGetInput(text));
+    }
+
+    /*
+     * Print a message on the screen, then accept input from Keyboard.
+     *
+     * @param text message to be displayed on screen.
+     * @return what was typed by the player.
+     */
+    private String displayTextAndGetInput(String text) {
+        System.out.print(text);
+        return kbScanner.next();
+    }
+
+    /**
+     * Simulate the old basic tab(xx) command which indented text by xx spaces.
+     *
+     * @param spaces number of spaces required
+     * @return String with number of spaces
+     */
+    private String simulateTabs(int spaces) {
+        char[] spacesTemp = new char[spaces];
+        Arrays.fill(spacesTemp, ' ');
+        return new String(spacesTemp);
+    }
+
+}

52 Kinema/java/src/KinemaGame.java

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+public class KinemaGame {
+    public static void main(String[] args) {
+
+        Kinema kinema = new Kinema();
+        kinema.play();
+    }
+}