Move source code examples to Antora examples directoryantora

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

1 files changed, 106 insertions, 0 deletions

diff --git a/docs/modules/ROOT/examples/spacewar/SpaceObject.java b/docs/modules/ROOT/examples/spacewar/SpaceObject.java
new file mode 100644
index 000000000..ee3afabcc
--- /dev/null
+++ b/docs/modules/ROOT/examples/spacewar/SpaceObject.java
@@ -0,0 +1,106 @@
+/*
+
+Copyright (c) Xerox Corporation 1998-2002.  All rights reserved.
+
+Use and copying of this software and preparation of derivative works based
+upon this software are permitted.  Any distribution of this software or
+derivative works must comply with all applicable United States export control
+laws.
+
+This software is made available AS IS, and Xerox Corporation makes no warranty
+about the software, its performance or its conformity to any specification.
+
+|<---            this code is formatted to fit into 80 columns             --->|
+|<---            this code is formatted to fit into 80 columns             --->|
+|<---            this code is formatted to fit into 80 columns             --->|
+
+
+SpaceObject.java
+Part of the Spacewar system.
+
+*/
+
+package spacewar;
+
+
+/**
+ * SpaceObjects are objects that float around in space.  They support the
+ * minimal SpaceObject protocol, having to do with position, velocity,
+ * size and liveness.  They are constructed with game, position, velocity
+ * and size.  When constructed, a spaceobject adds itself to the registry.
+ *
+ * When it dies, a spaceobject removes itself from the registry.  But note
+ * that it doesn't decide when to die, subclasses do that.
+ *
+ * The display aspects actually draw the space object on the screen and say
+ * how much space it takes up there.
+ */
+abstract class SpaceObject {
+
+    private Game    game;
+    private double  xPos, yPos, oldXPos, oldYPos, xVel, yVel;
+    private boolean alive;
+
+    SpaceObject (Game theGame, double xP, double yP, double xV, double yV) {
+        game = theGame;
+        xPos = xP;
+        yPos = yP;
+        oldXPos = xP;
+        oldYPos = yP;
+        xVel = xV;
+        yVel = yV;
+
+        alive = true;
+        getGame().getRegistry().register(this);
+    }
+
+    Game getGame()      { return game; }
+
+    double getXPos()    { return xPos; }
+    double getYPos()    { return yPos; }
+
+    double getOldXPos() { return oldXPos; }
+    double getOldYPos() { return oldYPos; }
+
+    double getXVel()    { return xVel; }
+    double getYVel()    { return yVel; }
+
+    void setXVel (double n) { xVel = n; }
+    void setYVel (double n) { yVel = n; }
+
+    boolean isAlive()          { return alive; }
+    void setIsAlive(boolean n) { alive = n; }
+
+
+    /**
+     * Move 1 unit of time's worth of distance.  I.e. increment xPos by xVel
+     * and yPos by yVel.  If we move off an edge of the screen move us back
+     * in the opposite edge.
+     */
+    void clockTick() {
+        oldXPos = xPos;
+        oldYPos = yPos;
+        xPos = (xPos + xVel) % getGame().getWidth();
+        if(xPos < 0)
+            xPos += getGame().getWidth();
+        yPos = (yPos + yVel) % getGame().getHeight();
+        if(yPos < 0)
+            yPos += getGame().getHeight();
+    }
+
+    void accelerate(double dXVel, double dYVel) {
+        xVel += dXVel;
+        yVel += dYVel;
+    }
+
+    void die() {
+        getGame().getRegistry().unregister(this);
+    }
+
+    abstract int getSize();
+
+    /** resolve the effects of colliding with a space object.
+     *  @param obj the space object that this object is colliding with.
+     */
+    abstract void handleCollision(SpaceObject obj);
+}