Add world map region overlay dev tool

Using the existing 'World Map Location' dev tool, the world map can now
be given an overlay to show all the region boundaries and region ids.
This should make it easier to find out the region id of a specific
location.

One caveat is that this does not work with 'stitched' locations,
such as Motherlode Mine.

runelite-client/src/main/java/net/runelite/client/plugins/devtools/DevToolsPlugin.java

@@ -95,6 +95,9 @@ public class DevToolsPlugin extends Plugin
 	@Inject
 	private WorldMapLocationOverlay worldMapLocationOverlay;
 
+	@Inject
+	private WorldMapRegionOverlay mapRegionOverlay;
+
 	@Inject
 	private EventBus eventBus;
 
@@ -167,6 +170,7 @@ public class DevToolsPlugin extends Plugin
 		overlayManager.add(sceneOverlay);
 		overlayManager.add(cameraOverlay);
 		overlayManager.add(worldMapLocationOverlay);
+		overlayManager.add(mapRegionOverlay);
 
 		final DevToolsPanel panel = injector.getInstance(DevToolsPanel.class);
 
@@ -190,6 +194,7 @@ public class DevToolsPlugin extends Plugin
 		overlayManager.remove(sceneOverlay);
 		overlayManager.remove(cameraOverlay);
 		overlayManager.remove(worldMapLocationOverlay);
+		overlayManager.remove(mapRegionOverlay);
 		clientToolbar.removeNavigation(navButton);
 	}
 

runelite-client/src/main/java/net/runelite/client/plugins/devtools/WorldMapRegionOverlay.java

@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2018, Alex Kolpa <https://github.com/AlexKolpa>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package net.runelite.client.plugins.devtools;
+
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.FontMetrics;
+import java.awt.Graphics2D;
+import java.awt.Rectangle;
+import java.awt.geom.Rectangle2D;
+import javax.inject.Inject;
+import net.runelite.api.Client;
+import net.runelite.api.Point;
+import net.runelite.api.RenderOverview;
+import net.runelite.api.widgets.Widget;
+import net.runelite.api.widgets.WidgetInfo;
+import net.runelite.client.ui.overlay.Overlay;
+import net.runelite.client.ui.overlay.OverlayLayer;
+import net.runelite.client.ui.overlay.OverlayPosition;
+import net.runelite.client.ui.overlay.OverlayPriority;
+
+class WorldMapRegionOverlay extends Overlay
+{
+	private static final Color WHITE_TRANSLUCENT = new Color(255, 255, 255, 127);
+	private static final int LABEL_PADDING = 4;
+	private static final int REGION_SIZE = 1 << 6;
+	// Bitmask to return first coordinate in region
+	private static final int REGION_TRUNCATE = ~((1 << 6) - 1);
+	private final Client client;
+	private final DevToolsPlugin plugin;
+
+	@Inject
+	private WorldMapRegionOverlay(Client client, DevToolsPlugin plugin)
+	{
+		setPosition(OverlayPosition.DYNAMIC);
+		setPriority(OverlayPriority.HIGH);
+		setLayer(OverlayLayer.ALWAYS_ON_TOP);
+		this.client = client;
+		this.plugin = plugin;
+	}
+
+	@Override
+	public Dimension render(Graphics2D graphics)
+	{
+		if (!plugin.getWorldMapLocation().isActive())
+		{
+			return null;
+		}
+
+		drawRegionOverlay(graphics);
+		return null;
+	}
+
+	private void drawRegionOverlay(Graphics2D graphics)
+	{
+		RenderOverview ro = client.getRenderOverview();
+		Widget map = client.getWidget(WidgetInfo.WORLD_MAP_VIEW);
+		Float pixelsPerTile = ro.getWorldMapZoom();
+
+		if (map == null)
+		{
+			return;
+		}
+
+		Rectangle worldMapRect = map.getBounds();
+		graphics.setClip(worldMapRect);
+
+		int widthInTiles = (int) Math.ceil(worldMapRect.getWidth() / pixelsPerTile);
+		int heightInTiles = (int) Math.ceil(worldMapRect.getHeight() / pixelsPerTile);
+
+		Point worldMapPosition = ro.getWorldMapPosition();
+
+		// Offset in tiles from anchor sides
+		int yTileMin = worldMapPosition.getY() - heightInTiles / 2;
+		int xRegionMin = (worldMapPosition.getX() - widthInTiles / 2) & REGION_TRUNCATE;
+		int xRegionMax = ((worldMapPosition.getX() + widthInTiles / 2) & REGION_TRUNCATE) + REGION_SIZE;
+		int yRegionMin = (yTileMin & REGION_TRUNCATE);
+		int yRegionMax = ((worldMapPosition.getY() + heightInTiles / 2) & REGION_TRUNCATE) + REGION_SIZE;
+		int regionPixelSize = (int) Math.ceil(REGION_SIZE * pixelsPerTile);
+
+		for (int x = xRegionMin; x < xRegionMax; x += REGION_SIZE)
+		{
+			for (int y = yRegionMin; y < yRegionMax; y += REGION_SIZE)
+			{
+				graphics.setColor(WHITE_TRANSLUCENT);
+
+				int yTileOffset = -(yTileMin - y);
+				int xTileOffset = x + widthInTiles / 2 - worldMapPosition.getX();
+
+				int xPos = ((int) (xTileOffset * pixelsPerTile)) + (int) worldMapRect.getX();
+				int yPos = (worldMapRect.height - (int) (yTileOffset * pixelsPerTile)) + (int) worldMapRect.getY();
+				// Offset y-position by a single region to correct for drawRect starting from the top
+				yPos -= regionPixelSize;
+
+				graphics.drawRect(xPos, yPos, regionPixelSize, regionPixelSize);
+
+				int regionId = ((x >> 6) << 8) | (y >> 6);
+				String regionText = String.valueOf(regionId);
+				FontMetrics fm = graphics.getFontMetrics();
+				Rectangle2D textBounds = fm.getStringBounds(regionText, graphics);
+				int labelWidth = (int) textBounds.getWidth() + 2 * LABEL_PADDING;
+				int labelHeight = (int) textBounds.getHeight() + 2 * LABEL_PADDING;
+				graphics.fillRect(xPos, yPos, labelWidth, labelHeight);
+				graphics.setColor(Color.BLACK);
+				graphics.drawString(regionText, xPos + LABEL_PADDING, yPos + (int) textBounds.getHeight() + LABEL_PADDING);
+			}
+		}
+	}
+}