Simple animation that renders rain drops for a specified period of time.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@869 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/animation/RainAnimation.java

@@ -0,0 +1,104 @@
+//
+// $Id: RainAnimation.java,v 1.1 2002/01/18 16:22:23 shaper Exp $
+
+package com.threerings.media.animation;
+
+import java.awt.Color;
+import java.awt.Graphics2D;
+import java.awt.Rectangle;
+
+import com.threerings.media.util.RandomUtil;
+
+/**
+ * An animation that displays raindrops spattering across an image.
+ */
+public class RainAnimation extends Animation
+{
+    /**
+     * Constructs a rain animation with reasonable defaults for the number
+     * of raindrops and their dimensions.
+     *
+     * @param bounds the bounding rectangle for the animation.
+     * @param delay the number of seconds the animation should last.
+     */
+    public RainAnimation (Rectangle bounds, long delay)
+    {
+        super(bounds);
+
+        init(delay, DEFAULT_COUNT, DEFAULT_WIDTH, DEFAULT_HEIGHT);
+    }
+
+    /**
+     * Constructs a rain animation.
+     *
+     * @param bounds the bounding rectangle for the animation.
+     * @param delay the number of seconds the animation should last.
+     * @param count the number of raindrops to render in each frame.
+     * @param wid the width of a raindrop's bounding rectangle.
+     * @param hei the height of a raindrop's bounding rectangle.
+     */
+    public RainAnimation (
+        Rectangle bounds, long delay, int count, int wid, int hei)
+    {
+        super(bounds);
+        init(delay, count, wid, hei);
+    }
+
+    protected void init (long delay, int count, int wid, int hei)
+    {
+        // save things off
+        _count = count;
+        _wid = wid;
+        _hei = hei;
+
+        // create the raindrop array
+        _drops = new int[count];
+
+        // calculate ending time
+        _end = System.currentTimeMillis() + delay;
+    }
+
+    // documentation inherited
+    public void tick (long timestamp)
+    {
+        _finished = (timestamp >= _end);
+        _animmgr.addDirtyRect(new Rectangle(_bounds));
+
+        // calculate the latest raindrop locations
+        for (int ii = 0; ii < _count; ii++) {
+            int x = RandomUtil.getInt(_bounds.width);
+            int y = RandomUtil.getInt(_bounds.height);
+            _drops[ii] = (x << 16 | y);
+        }
+    }
+
+    // documentation inherited
+    public void paint (Graphics2D gfx)
+    {
+        gfx.setColor(Color.white);
+        for (int ii = 0; ii < _count; ii++) {
+            int x = _drops[ii] >> 16;
+            int y = _drops[ii] & 0xFFFF;
+            gfx.drawLine(x, y, x + _wid, y + _hei);
+        }
+    }
+
+    /** The number of raindrops. */
+    protected static final int DEFAULT_COUNT = 300;
+
+    /** The raindrop streak dimensions. */
+    protected static final int DEFAULT_WIDTH = 13;
+    protected static final int DEFAULT_HEIGHT = 10;
+
+    /** The number of raindrops. */
+    protected int _count;
+
+    /** The dimensions of each raindrop's bounding rectangle. */
+    protected int _wid, _hei;
+
+    /** The raindrop locations. */
+    protected int[] _drops;
+
+    /** The ending animation time. */
+    protected long _end;
+}