Create and have the sprite follow a path rather than explicitly

setting the sprite destination.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@152 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/sprite/Sprite.java

@@ -1,9 +1,10 @@
 //
-// $Id: Sprite.java,v 1.5 2001/08/02 18:59:00 shaper Exp $
+// $Id: Sprite.java,v 1.6 2001/08/02 20:43:03 shaper Exp $
 
 package com.threerings.miso.sprite;
 
 import java.awt.*;
+import java.util.Enumeration;
 
 import com.threerings.miso.Log;
 import com.threerings.miso.tile.Tile;
@@ -62,14 +63,11 @@ public class Sprite
         updateDrawPosition();
 
         _curFrame = 0;
-        _animDelay = -1;
+        _animDelay = ANIM_NONE;
         _numTicks = 0;
 
         setTiles(_tiles);
 
-        _dest = new Point();
-        _state = STATE_NONE;
-
         invalidate();
     }        
 
@@ -124,30 +122,53 @@ public class Sprite
     }
 
     /**
-     * Set the destination of the sprite in pixel coordinates.
+     * Set the sprite's active path and start moving it along its
+     * merry way.  If the sprite is already moving along a previous
+     * path the old path will be lost and the new path will begin to
+     * be traversed.
      *
-     * @param x the destination x-position.
-     * @param y the destination y-position.
+     * @param path the path to follow.
      */
-    public void setDestination (int x, int y)
+    public void move (Path path)
     {
-        // bail if we're already there
-        if (x == this.x && y == this.y) return;
+        // make sure following the path is a sensible thing to do
+        if (path == null || path.size() < 2) return;
 
-        // note our destination
-        _dest.setLocation(x, y);
+        // save an enumeration of the path nodes
+        _path = path.elements();
+
+        // skip the first node since it's our starting position.
+        // perhaps someday we'll do something with this.
+        _path.nextElement();
+
+        // start our meandering
+        moveAlongPath();
+    }
+
+    /**
+     * Start the sprite moving toward the next node in its path.
+     */
+    protected void moveAlongPath ()
+    {
+        // grab the next node in our path
+        _dest = (PathNode)_path.nextElement();
+
+        // if no more nodes remain, clear out our path and bail
+        if (_dest == null) {
+            _path = null;
+            return;
+        }
+
+        Log.info("moveAlongPath [dest=" + _dest + "].");
 
         // determine the horizontal/vertical move increments
-        float dist = MathUtil.distance(this.x, this.y, x, y);
-        _incx = (float)(x - this.x) / dist;
-        _incy = (float)(y - this.y) / dist;
+        float dist = MathUtil.distance(x, y, _dest.loc.x, _dest.loc.y);
+        _incx = (float)(_dest.loc.x - x) / dist;
+        _incy = (float)(_dest.loc.y - y) / dist;
 
         // init position data used to track fractional pixels
-        _movex = this.x;
-        _movey = this.y;
-
-        // and that we're moving toward it
-        _state = STATE_MOVING;
+        _movex = x;
+        _movey = y;
     }
 
     /**
@@ -157,13 +178,10 @@ public class Sprite
     {
         if (_curTile == null) return;
 
-        int xpos = x - (_curTile.width / 2);
-        int ypos = y - _curTile.height;
+        Rectangle dirty = new Rectangle(
+            _drawx, _drawy, _curTile.width, _curTile.height);
 
-        Rectangle dirty =
-            new Rectangle(xpos, ypos, _curTile.width, _curTile.height);
-
-//          Log.info("Sprite dirtying rect [x=" + dirty.x + ", y=" + dirty.y +
+//          Log.info("Sprite invalidate [x=" + dirty.x + ", y=" + dirty.y +
 //                   ", width=" + dirty.width + ", height=" + dirty.height + "].");
 
         _spritemgr.addDirtyRect(dirty);
@@ -176,40 +194,49 @@ public class Sprite
     public void tick ()
     {
         // increment the display tile if performing tile animation
-        if (_animDelay != -1 && (_numTicks++ == _animDelay)) {
+        if (_animDelay != ANIM_NONE && (_numTicks++ == _animDelay)) {
             _numTicks = 0;
             if (++_curFrame > _tiles.length - 1) _curFrame = 0;
             _curTile = _tiles[_curFrame];
+
+            // dirty our rectangle since we've altered our display tile
             invalidate();
         }
 
-        switch (_state) {
-        case STATE_MOVING:
-            // move the sprite incrementally toward its goal
-            x = (int)(_movex += _incx);
-            y = (int)(_movey += _incy);
-
-            // stop moving once we've reached our destination
-            if (_incx > 0 && x > _dest.x || _incx < 0 && x < _dest.x ||
-                _incy > 0 && y > _dest.y || _incy < 0 && y < _dest.y) {
-
-                // make sure we stop exactly where desired
-                x = _dest.x;
-                y = _dest.y;
-
-                // invalidate the sprite in its new location
-                invalidate();
-
-                // note our stoppage
-                _animDelay = -1;
-                _state = STATE_NONE;
-            }
-
-            updateDrawPosition();
-            break;
+        // move the sprite along toward its destination, if any 
+        if (_dest != null) {
+            handleMove();
         }
     }
 
+    /**
+     * Actually move the sprite's position toward its destination one
+     * display increment.
+     */
+    protected void handleMove ()
+    {
+        // move the sprite incrementally toward its goal
+        x = (int)(_movex += _incx);
+        y = (int)(_movey += _incy);
+
+        // stop moving once we've reached our destination
+        if (_incx > 0 && x > _dest.loc.x || _incx < 0 && x < _dest.loc.x ||
+            _incy > 0 && y > _dest.loc.y || _incy < 0 && y < _dest.loc.y) {
+
+            // make sure we stop exactly where desired
+            x = _dest.loc.x;
+            y = _dest.loc.y;
+
+            // dirty our rectangle since we've moved
+            invalidate();
+
+            // move further along the path if necessary
+            moveAlongPath();
+        }
+
+        updateDrawPosition();
+    }
+
     /**
      * Update the coordinates at which the sprite image is drawn to
      * reflect the sprite's current position.
@@ -238,9 +265,8 @@ public class Sprite
         return buf.append("]").toString();
     }
 
-    /** State constants. */
-    protected static final int STATE_NONE = 0;
-    protected static final int STATE_MOVING = 1;
+    /** Value used to denote that no tile animation is desired. */
+    protected static final int ANIM_NONE = -1;
 
     /** The tiles used to render the sprite. */
     protected Tile[] _tiles;
@@ -254,11 +280,11 @@ public class Sprite
     /** The coordinates at which the tile image is drawn. */
     protected int _drawx, _drawy;
 
-    /** The sprite's current state. */
-    protected int _state;
+    /** The PathNode objects describing the path the sprite is following. */
+    protected Enumeration _path;
 
-    /** When moving, the sprite's destination coordinates. */
-    protected Point _dest;
+    /** When moving, the sprite's destination path node. */
+    protected PathNode _dest;
 
     /** When moving, the sprite position including fractional pixels. */ 
     protected float _movex, _movey;

src/java/com/threerings/media/util/LineSegmentPath.java

@@ -1,5 +1,5 @@
 //
-// $Id: LineSegmentPath.java,v 1.1 2001/08/02 00:42:02 shaper Exp $
+// $Id: LineSegmentPath.java,v 1.2 2001/08/02 20:43:03 shaper Exp $
 
 package com.threerings.miso.sprite;
 
@@ -9,7 +9,9 @@ import java.util.Enumeration;
 /**
  * The Path class represents the path a sprite follows while
  * meandering about the screen.  There must be at least two nodes in
- * any worthwhile path.
+ * any worthwhile path.  The direction of the first node in the path
+ * is meaningless since the sprite begins at that node and will
+ * therefore never be heading towards it.
  */
 public class Path
 {
@@ -34,6 +36,15 @@ public class Path
         _nodes = new ArrayList();
     }
 
+    public Path (int x, int y)
+    {
+        _nodes = new ArrayList();
+
+        // add the starting node with an arbitrarily chosen direction
+        // since direction is meaningless here
+        addNode(x, y, DIR_NORTH);
+    }
+
     /**
      * Add a node to the path with the specified destination point and
      * facing direction.
@@ -47,6 +58,19 @@ public class Path
         _nodes.add(new PathNode(x, y, dir));
     }
 
+    /**
+     * Return the requested node index in the path, or null if no such
+     * index exists.
+     *
+     * @param idx the node index.
+     *
+     * @return the path node.
+     */
+    public PathNode getNode (int idx)
+    {
+        return (PathNode)_nodes.get(idx);
+    }
+
     /**
      * Return an enumeration of the PathNode objects in this path. 
      */
@@ -81,7 +105,7 @@ public class Path
 
         public Object nextElement ()
         {
-            return _nodes.get(_idx++);
+            return (_idx >= _nodes.size()) ? null : _nodes.get(_idx++);
         }
 
         protected ArrayList _nodes;

src/java/com/threerings/media/util/PathNode.java

@@ -1,5 +1,5 @@
 //
-// $Id: PathNode.java,v 1.1 2001/08/02 00:42:02 shaper Exp $
+// $Id: PathNode.java,v 1.2 2001/08/02 20:43:03 shaper Exp $
 
 package com.threerings.miso.sprite;
 
@@ -28,4 +28,16 @@ public class PathNode
         loc = new Point(x, y);
         this.dir = dir;
     }
+
+    /**
+     * Return a string representation of this path node.
+     */
+    public String toString ()
+    {
+        StringBuffer buf = new StringBuffer();
+        buf.append("[x=").append(loc.x);
+        buf.append(", y=").append(loc.y);
+        buf.append(", dir=").append(dir);
+        return buf.append("]").toString();
+    }
 }

src/java/com/threerings/miso/client/IsoSceneView.java

@@ -1,10 +1,10 @@
 //
-// $Id: IsoSceneView.java,v 1.22 2001/08/02 18:58:59 shaper Exp $
+// $Id: IsoSceneView.java,v 1.23 2001/08/02 20:43:03 shaper Exp $
 
 package com.threerings.miso.scene;
 
 import com.threerings.miso.Log;
-import com.threerings.miso.sprite.SpriteManager;
+import com.threerings.miso.sprite.*;
 import com.threerings.miso.tile.Tile;
 import com.threerings.miso.tile.TileManager;
 import com.threerings.miso.util.MathUtil;
@@ -69,6 +69,9 @@ public class IsoSceneView implements EditableSceneView
         // draw lines illustrating tracking of the mouse position
   	//paintMouseLines(gfx);
 
+        gfx.setColor(Color.yellow);
+        gfx.drawRect(0, 0, _model.bounds.width - 1, _model.bounds.height - 1);
+
 	// restore the original clipping region
 	gfx.setClip(oldclip);
     }
@@ -89,12 +92,12 @@ public class IsoSceneView implements EditableSceneView
             int[] dinfo = (int[])_dirty.remove(0);
             int tx = dinfo[0], ty = dinfo[1];
 
+            // get the tile's screen position
+            Polygon poly = getTilePolygon(tx, ty);
+
             // draw all layers at this tile position
             for (int kk = 0; kk < Scene.NUM_LAYERS; kk++) {
 
-                // get the tile's screen position
-                Polygon poly = getTilePolygon(tx, ty);
-
                 // get the tile at these coordinates and layer
                 Tile tile = _scene.tiles[tx][ty][kk];
                 if (tile == null) continue;
@@ -108,7 +111,7 @@ public class IsoSceneView implements EditableSceneView
             }
 
             // draw all sprites residing in the current tile
-            _spritemgr.renderSprites(gfx, getTilePolygon(tx, ty));
+            _spritemgr.renderSprites(gfx, poly);
         }
     }
 
@@ -386,6 +389,21 @@ public class IsoSceneView implements EditableSceneView
         _model.calculateXAxis();
     }
 
+    public Path getPath (Sprite sprite, int x, int y)
+    {
+        // make sure the destination point is within our bounds
+        if (x < 0 || x >= _model.bounds.width ||
+            y < 0 || y >= _model.bounds.height) {
+            return null;
+        }
+
+        // create path from current loc to destination
+        Path path = new Path(sprite.x, sprite.y);
+        path.addNode(x, y, Path.DIR_NORTH);
+
+        return path;
+    }
+
     /** The color to draw the highlighted tile. */
     protected static final Color HLT_COLOR = Color.green;
 

src/java/com/threerings/miso/client/SceneView.java

@@ -1,14 +1,16 @@
 //
-// $Id: SceneView.java,v 1.8 2001/08/02 00:42:02 shaper Exp $
+// $Id: SceneView.java,v 1.9 2001/08/02 20:43:03 shaper Exp $
 
 package com.threerings.miso.scene;
 
-import com.threerings.miso.tile.Tile;
-
 import java.awt.Component;
 import java.awt.Graphics;
 import java.util.ArrayList;
 
+import com.threerings.miso.sprite.Path;
+import com.threerings.miso.sprite.Sprite;
+import com.threerings.miso.tile.Tile;
+
 /**
  * The SceneView interface provides an interface to be implemented by
  * classes that provide a view of a given scene by drawing the scene
@@ -37,4 +39,17 @@ public interface SceneView
      * @param rects the list of <code>java.awt.Rectangle</code> objects.
      */
     public void invalidateRects (ArrayList rects);
+
+    /**
+     * Return a Path object detailing a valid path for the given
+     * sprite to take in the scene to get from its current position to
+     * the destination position.
+     *
+     * @param sprite the sprite to move.
+     * @param x the destination x-position in pixel coordinates.
+     * @param y the destination y-position in pixel coordinates.
+     *
+     * @return the sprite's path or null if no valid path exists.
+     */
+    public Path getPath (Sprite sprite, int x, int y);
 }

tests/src/java/com/threerings/miso/viewer/SceneViewPanel.java

@@ -1,5 +1,5 @@
 //
-// $Id: SceneViewPanel.java,v 1.6 2001/08/02 18:59:00 shaper Exp $
+// $Id: SceneViewPanel.java,v 1.7 2001/08/02 20:43:03 shaper Exp $
 
 package com.threerings.miso.viewer;
 
@@ -18,8 +18,9 @@ import com.threerings.miso.util.PerformanceMonitor;
 import com.threerings.miso.util.PerformanceObserver;
 
 /**
- * The SceneViewPanel class is responsible for managing a SceneView,
- * rendering it to the screen, and handling view-related UI events.
+ * The <code>SceneViewPanel</code> class is responsible for managing a
+ * <code>SceneView</code>, rendering it to the screen, and handling
+ * view-related UI events.
  */
 public class SceneViewPanel extends JPanel
     implements MouseListener, MouseMotionListener, PerformanceObserver
@@ -53,7 +54,7 @@ public class SceneViewPanel extends JPanel
         // load up the initial scene
         prepareStartingScene();
 
-        setDoubleBuffered(false);
+        //setDoubleBuffered(false);
 
         PerformanceMonitor.register(this, "paint", 1000);
     }
@@ -100,9 +101,6 @@ public class SceneViewPanel extends JPanel
 
 	_view.paint(g);
 
-        g.setColor(Color.yellow);
-        g.drawRect(0, 0, 600, 600);
-
         PerformanceMonitor.tick(this, "paint");
     }
 
@@ -113,34 +111,30 @@ public class SceneViewPanel extends JPanel
 
     /** MouseListener interface methods */
 
-    public void mouseClicked (MouseEvent e)
-    {
-        Log.info("mouseClicked [x=" + e.getX() + ", y=" + e.getY() + "].");
-    }
-
-    public void mouseEntered (MouseEvent e) { }
-
-    public void mouseExited (MouseEvent e) { }
-
     public void mousePressed (MouseEvent e)
     {
         int x = e.getX(), y = e.getY();
         Log.info("mousePressed [x=" + x + ", y=" + y + "].");
-        _sprite.setDestination(x, y);
+
+        // get the path from here to there
+        Path path = _view.getPath(_sprite, x, y);
+        if (path != null) {
+            _sprite.move(path);
+        }
+
+        // hackily highlight the tile that was clicked on for happy testing
         ((EditableSceneView)_view).setHighlightedTile(x, y);
     }
 
+    public void mouseClicked (MouseEvent e) { }
+    public void mouseEntered (MouseEvent e) { }
+    public void mouseExited (MouseEvent e) { }
     public void mouseReleased (MouseEvent e) { }
 
     /** MouseMotionListener interface methods */
 
-    public void mouseMoved (MouseEvent e)
-    {
-    }
-
-    public void mouseDragged (MouseEvent e)
-    {
-    }
+    public void mouseMoved (MouseEvent e) { }
+    public void mouseDragged (MouseEvent e) { }
 
     /** The config key to obtain the default scene filename. */
     protected static final String CFG_SCENE = "miso-viewer.default_scene";
@@ -148,6 +142,7 @@ public class SceneViewPanel extends JPanel
     /** The default scene to load and display. */
     protected static final String DEF_SCENE = "rsrc/scenes/default.xml";
 
+    /** The sprite we're manipulating within the view. */
     protected Sprite _sprite;
 
     /** The context object. */