Portal Mechanics (Closes #130)

src/main/java/net/glowstone/block/blocktype/BlockPortal.java

@@ -16,6 +16,24 @@
 
 public class BlockPortal extends BlockType {
 
+    /**
+     * Gets the Axis-specific bounding box of the specified block. Only works for Portal blocks.
+     *
+     * @param block the block to get the bounding box from.
+     * @return the resulting bounding box, axis alignment dependent.
+     */
+    public static BoundingBox getBoundingBox(GlowBlock block) {
+        boolean north = getFace(block.getData()) == BlockFace.NORTH;
+        Vector base = new Vector(north ? .375 : 0, 0, north ? 0 : .375);
+        Vector size = new Vector(north ? .25 : 1, 1, north ? 1 : .25);
+        return BoundingBox.fromPositionAndSize(block.getLocation().toVector().add(base), size);
+    }
+
+    private static BlockFace getFace(int blockData) {
+        int faceData = blockData & 3;
+        return faceData == 1 ? BlockFace.WEST : faceData == 2 ? BlockFace.NORTH : null;
+    }
+
     @Override
     public void onNearBlockChanged(final GlowBlock block, BlockFace face, GlowBlock changedBlock,
                                    Material oldType, byte oldData, Material newType, byte newData) {
@@ -28,24 +46,12 @@ public void onNearBlockChanged(final GlowBlock block, BlockFace face, GlowBlock
         }
         PortalShape shape = new PortalShape(block.getLocation(), left);
         if (shape.validate()
-                && shape.getPortalBlockCount() == shape.getHeight() * shape.getWidth()) {
+            && shape.getPortalBlockCount() == shape.getHeight() * shape.getWidth()) {
             return;
         }
         block.setType(Material.AIR);
     }
 
-    public static BoundingBox getBoundingBox(GlowBlock block) {
-        boolean north = getFace(block.getData()) == BlockFace.NORTH;
-        Vector base = new Vector(north ? .375 : 0, 0, north ? 0 : .375);
-        Vector size = new Vector(north ? .25 : 1, 1, north ? 1 : .25);
-        return BoundingBox.fromPositionAndSize(block.getLocation().toVector().add(base), size);
-    }
-
-    private static BlockFace getFace(int blockData) {
-        int faceData = blockData & 3;
-        return faceData == 1 ? BlockFace.WEST : faceData == 2 ? BlockFace.NORTH : null;
-    }
-
     @Override
     public void updateBlock(GlowBlock block) {
         // remove invalid portal blocks

src/main/java/net/glowstone/block/itemtype/ItemFlintAndSteel.java

@@ -15,7 +15,6 @@
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.util.Vector;
 
-
 public class ItemFlintAndSteel extends ItemTool {
 
     public ItemFlintAndSteel() {

src/main/java/net/glowstone/entity/GlowEntity.java

@@ -616,37 +616,47 @@ public void pulse() {
             }
         }
         GlowBlock block = world.getBlockAt(location);
+        // Nether portal handling
         if (block.getType().equals(Material.PORTAL)
             && BlockPortal.getBoundingBox(block).intersects(boundingBox)) {
             if (!isInPortal) {
+                //Entity just entered the Portal, fire EnterEvent
                 EventFactory.getInstance().callEvent(
                     new EntityPortalEnterEvent(this, block.getLocation()));
+                // prevent EnterEvent being fired again
                 isInPortal = true;
             }
+            // only try porting if the nether is enabled
             if (server.getAllowNether() && portalCooldown <= 0) {
-                GlowWorld w = getWorld().getEnvironment().equals(Environment.NETHER)
+                // determine destination world
+                GlowWorld destination = getWorld().getEnvironment().equals(Environment.NETHER)
                     ? server.getWorld("world") : server.getWorld("world_nether");
-                TravelAgent agent = w.getTravelAgent();
-                boolean destIsNether = w.getEnvironment().equals(Environment.NETHER);
+                TravelAgent agent = destination.getTravelAgent();
+                boolean destIsNether = destination.getEnvironment().equals(Environment.NETHER);
+                // Destination Coordinates: NetherX * 8 = OverworldX etc.
                 int destX = destIsNether ? location.getBlockX() / 8 : location.getBlockX() * 8;
                 int destY = destIsNether ? location.getBlockY() / 8 : location.getBlockY() * 8;
                 int destZ = destIsNether ? location.getBlockZ() / 8 : location.getBlockZ() * 8;
-                Location requested = new Location(w, destX, destY, destZ);
+                Location requested = new Location(destination, destX, destY, destZ);
                 if (agent.getCanCreatePortal() || agent.findPortal(requested) != null) {
                     Location teleportLocation = agent.findOrCreate(requested);
+                    //attempt teleportation: fire porting event, abort if cancelled
                     EntityPortalEvent p = EventFactory.getInstance().callEvent(
                         new EntityPortalEvent(this,
                             location.clone(), teleportLocation.clone(), agent));
                     if (!p.isCancelled()) {
+                        // if not, teleport the Entity to the location specified by the event
                         teleport(p.getTo());
                         setPortalCooldown(300);
+                        // change the velocity based on the portal exit event
                         setVelocity(EventFactory.getInstance().callEvent(
                             new EntityPortalExitEvent(this, previousLocation,
                                 location.clone(), velocity.clone(), new Vector())).getAfter());
                     }
                 }
             }
         } else {
+            // entity has left the portal
             isInPortal = false;
         }
 

src/main/java/net/glowstone/util/GlowTravelAgent.java

@@ -33,7 +33,7 @@ public class GlowTravelAgent implements TravelAgent {
      */
     public GlowTravelAgent(World world) {
         if (world.getEnvironment() == World.Environment.THE_END) {
-            throw new UnsupportedOperationException("Not supported yet.");
+            throw new UnsupportedOperationException("End Portals are not supported yet.");
         }
         this.world = world;
     }
@@ -316,9 +316,4 @@ public boolean createPortal(Location destination) {
         }
         return false;
     }
-
-    private boolean canBuildPortal(Location loc, BlockFace facing) {
-        // TODO: Need impl
-        return false;
-    }
 }

src/main/java/net/glowstone/util/pattern/PortalShape.java

@@ -15,6 +15,21 @@
  */
 public class PortalShape {
 
+    /**
+     * Max portal width or height.
+     */
+    private static final int MAX_PORTAL_WIDTH_HEIGHT = 21;
+
+    /**
+     * Min portal height.
+     */
+    private static final int MIN_PORTAL_HEIGHT = 3;
+
+    /**
+     * Min portal width.
+     */
+    private static final int MIN_PORTAL_WIDTH = 2;
+
     /**
      * The direction that is considered left.
      */
@@ -54,8 +69,8 @@ public PortalShape(Location buildLocation, BlockFace portalFace) {
         Location location = buildLocation.clone();
 
         // calculations start on the lower part, so we have to move down
-        while (location.getY() > buildLocation.getY() - 21 && location.getY() > 0 // validate y axis
-            && canBuildThrough(downImmutable(location).getBlock().getType())) {
+        while (location.getY() > buildLocation.getY() - MAX_PORTAL_WIDTH_HEIGHT
+            && location.getY() > 0 && canBuildThrough(downImmutable(location).getBlock().getType())) {
             // move downwards
             location.subtract(0, 1, 0);
         }
@@ -80,7 +95,7 @@ && canBuildThrough(downImmutable(location).getBlock().getType())) {
         width = getDistanceUntilEdge(bottomLeft, left.getOppositeFace()) + 1;
 
         // Portal too big / too small
-        if (width < 2 || width > 21) {
+        if (width < MIN_PORTAL_WIDTH || width > MAX_PORTAL_WIDTH_HEIGHT) {
             return;
         }
 
@@ -138,8 +153,8 @@ private int getDistanceUntilEdge(Location location, BlockFace face) {
         // Clone the location as Location objects are mutable
         Location destLoc = location.clone();
 
-        int i;
-        for (i = 0; i < 22; ++i) {
+        int distance;
+        for (distance = 0; distance <= MAX_PORTAL_WIDTH_HEIGHT; ++distance) {
             // Move onwards
             destLoc.add(face.getModX(), face.getModY(), face.getModZ());
             // Break if either an obstacle or the end of the obsidian "line" is reached
@@ -149,7 +164,7 @@ private int getDistanceUntilEdge(Location location, BlockFace face) {
             }
         }
         // If the target block is not obsidian, the portal is invalid.
-        return destLoc.getBlock().getType() == Material.OBSIDIAN ? i : -1;
+        return destLoc.getBlock().getType() == Material.OBSIDIAN ? distance : -1;
     }
 
     /**
@@ -158,7 +173,7 @@ private int getDistanceUntilEdge(Location location, BlockFace face) {
      * @return the height or 0 in case of failure
      */
     private int calculatePortalHeight() {
-        for (height = 0; height < 21; ++height) {
+        for (height = 0; height < MAX_PORTAL_WIDTH_HEIGHT; ++height) {
             boolean flag = false;
             for (int i = 0; i < width; ++i) {
                 Location location = offsetImmutable(bottomLeft, left.getOppositeFace(), i)
@@ -201,14 +216,15 @@ private int calculatePortalHeight() {
             }
         }
 
-        if (height <= 21 && height >= 3) {
+        if (height <= MAX_PORTAL_WIDTH_HEIGHT && height >= MIN_PORTAL_HEIGHT) {
             return height;
-        } else {
-            bottomLeft = null;
-            width = 0;
-            height = 0;
-            return 0;
         }
+
+        bottomLeft = null;
+        width = 0;
+        height = 0;
+        return 0;
+
     }
 
     /**
@@ -217,7 +233,8 @@ private int calculatePortalHeight() {
      * @return whether the portal shape is valid
      */
     public boolean validate() {
-        return bottomLeft != null && width >= 2 && width <= 21 && height >= 3 && height <= 21;
+        return bottomLeft != null && width >= MIN_PORTAL_WIDTH && width <= MAX_PORTAL_WIDTH_HEIGHT
+            && height >= MIN_PORTAL_HEIGHT && height <= MAX_PORTAL_WIDTH_HEIGHT;
     }
 
     /**
@@ -242,7 +259,6 @@ public void placePortalBlocks() {
                 block.setType(Material.PORTAL);
                 block.setData(meta);
             });
-
         }
     }
 }