Partial implementation of sendMap (#605)

Fixes #572

Author: Pr0methean

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

@@ -61,6 +61,7 @@
 import net.glowstone.inventory.InventoryMonitor;
 import net.glowstone.inventory.crafting.PlayerRecipeMonitor;
 import net.glowstone.io.PlayerDataService.PlayerReader;
+import net.glowstone.map.GlowMapCanvas;
 import net.glowstone.net.GlowSession;
 import net.glowstone.net.message.play.entity.AnimateEntityMessage;
 import net.glowstone.net.message.play.entity.DestroyEntitiesMessage;
@@ -73,6 +74,7 @@
 import net.glowstone.net.message.play.game.ExperienceMessage;
 import net.glowstone.net.message.play.game.HealthMessage;
 import net.glowstone.net.message.play.game.JoinGameMessage;
+import net.glowstone.net.message.play.game.MapDataMessage;
 import net.glowstone.net.message.play.game.MultiBlockChangeMessage;
 import net.glowstone.net.message.play.game.NamedSoundEffectMessage;
 import net.glowstone.net.message.play.game.PlayEffectMessage;
@@ -2404,7 +2406,9 @@ public void sendBlockEntityChange(Location location, GlowBlockEntity type, Compo
 
     @Override
     public void sendMap(MapView map) {
-        throw new UnsupportedOperationException("Not supported yet.");
+        GlowMapCanvas mapCanvas = GlowMapCanvas.createAndRender(map, this);
+        session.send(new MapDataMessage(map.getId(), map.getScale().ordinal(), Collections.emptyList(),
+            mapCanvas.toSection()));
     }
 
     @Override

src/main/java/net/glowstone/map/GlowMapCanvas.java

@@ -1,9 +1,13 @@
 package net.glowstone.map;
 
 import java.awt.Image;
+import net.glowstone.net.message.play.game.MapDataMessage.Section;
+import org.bukkit.entity.Player;
 import org.bukkit.map.MapCanvas;
 import org.bukkit.map.MapCursorCollection;
 import org.bukkit.map.MapFont;
+import org.bukkit.map.MapRenderer;
+import org.bukkit.map.MapView;
 
 /**
  * Represents a canvas for drawing to a map. Each canvas is associated with a specific {@link org.bukkit.map.MapRenderer} and represents that renderer's layer on the map.
@@ -12,16 +16,25 @@ public final class GlowMapCanvas implements MapCanvas {
 
     public static final int MAP_SIZE = 128;
     private final byte[] buffer = new byte[MAP_SIZE * MAP_SIZE];
-    private final GlowMapView mapView;
+    private final MapView mapView;
     private MapCursorCollection cursors = new MapCursorCollection();
     private byte[] base;
 
-    protected GlowMapCanvas(GlowMapView mapView) {
+    public static GlowMapCanvas createAndRender(MapView mapView, Player player) {
+        GlowMapCanvas out = new GlowMapCanvas(mapView);
+        for (MapRenderer renderer : mapView.getRenderers()) {
+            renderer.initialize(mapView);
+            renderer.render(mapView, out, player);
+        }
+        return out;
+    }
+
+    protected GlowMapCanvas(MapView mapView) {
         this.mapView = mapView;
     }
 
     @Override
-    public GlowMapView getMapView() {
+    public MapView getMapView() {
         return mapView;
     }
 
@@ -80,4 +93,7 @@ public void drawText(int x, int y, MapFont font, String text) {
         throw new UnsupportedOperationException("Not supported yet.");
     }
 
+    public Section toSection() {
+        return new Section(MAP_SIZE, MAP_SIZE, mapView.getCenterX(), mapView.getCenterZ(), buffer.clone());
+    }
 }

src/main/java/net/glowstone/map/GlowMapView.java

@@ -4,7 +4,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import net.glowstone.GlowWorld;
 import net.glowstone.entity.GlowPlayer;
 import org.bukkit.World;
 import org.bukkit.map.MapRenderer;
@@ -21,9 +20,9 @@ public final class GlowMapView implements MapView {
     private final short id;
     private Scale scale;
     private int x, z;
-    private GlowWorld world;
+    private World world;
 
-    protected GlowMapView(GlowWorld world, short id) {
+    protected GlowMapView(World world, short id) {
         this.world = world;
         this.id = id;
         x = world.getSpawnLocation().getBlockX();
@@ -76,13 +75,13 @@ public void setCenterZ(int z) {
     }
 
     @Override
-    public GlowWorld getWorld() {
+    public World getWorld() {
         return world;
     }
 
     @Override
     public void setWorld(World world) {
-        this.world = (GlowWorld) world;
+        this.world = world;
     }
 
     @Override