Introduce a new convenience function to obtain the worldspawn

Locating the worldspawn node and converting it into an Entity pointer is a very
common operation, but so far has had to be done manually each time. Now there
is a convenience function map::current::getWorldspawn() which does this
automatically.

include/imap.h

@@ -114,3 +114,4 @@ inline IMap& GlobalMapModule() {
 	);
 	return _mapModule;
 }
+

libs/maplib.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "imap.h"
+#include "ientity.h"
+
+namespace map
+{
+
+namespace current
+{
+
+/// Convenience method to return the worldspawn entity pointer
+inline Entity* getWorldspawn()
+{
+    return Node_getEntity(GlobalMapModule().getWorldspawn());
+}
+
+}
+
+}

plugins/dm.difficulty/DifficultySettingsManager.cpp

@@ -4,6 +4,7 @@
 #include "itextstream.h"
 #include "entitylib.h"
 #include "gamelib.h"
+#include "maplib.h"
 #include "string/string.h"
 #include "registry/registry.h"
 #include "DifficultyEntity.h"
@@ -71,7 +72,7 @@ void DifficultySettingsManager::loadMapSettings() {
 void DifficultySettingsManager::loadDifficultyNames()
 {
     // Locate the worldspawn entity
-    Entity* worldspawn = Scene_FindEntityByClass("worldspawn");
+    Entity* worldspawn = map::current::getWorldspawn();
 
     // Try to locate the difficulty menu entity, where the default names are defined
     IEntityClassPtr menuEclass = GlobalEntityClassManager().findClass(

radiant/map/Map.h

@@ -23,6 +23,7 @@ namespace map
 class MapPositionManager;
 class StartupMapLoader;
 
+/// Main class representing the current map
 class Map :
 	public IMap,
 	public scene::Graph::Observer

radiant/map/MapPositionManager.cpp

@@ -1,5 +1,6 @@
 #include "MapPositionManager.h"
 
+#include "maplib.h"
 #include "ientity.h"
 #include "ieventmanager.h"
 #include "iregistry.h"
@@ -56,12 +57,7 @@ MapPositionManager::MapPositionManager()
 
 void MapPositionManager::loadPositions()
 {
-	// Find the worldspawn node
-	const scene::INodePtr& wsNode = GlobalMapModule().getWorldspawn();
-
-	if (!wsNode) return;
-
-	Entity* worldspawn = Node_getEntity(wsNode);
+	Entity* worldspawn = map::current::getWorldspawn();
 
 	if (worldspawn != nullptr) 
 	{
@@ -81,12 +77,7 @@ void MapPositionManager::loadPositions()
 
 void MapPositionManager::savePositions()
 {
-	// Find the worldspawn node
-	const scene::INodePtr& wsNode = GlobalMapModule().getWorldspawn();
-
-	if (!wsNode) return;
-
-	Entity* worldspawn = Node_getEntity(wsNode);
+    Entity* worldspawn = map::current::getWorldspawn();
 
 	for (unsigned int i = 1; i <= MAX_POSITIONS; ++i)
 	{
@@ -100,11 +91,7 @@ void MapPositionManager::savePositions()
 void MapPositionManager::removePositions()
 {
 	// Find the worldspawn node
-	const scene::INodePtr& wsNode = GlobalMapModule().getWorldspawn();
-
-	if (!wsNode) return;
-
-	Entity* worldspawn = Node_getEntity(wsNode);
+    Entity* worldspawn = map::current::getWorldspawn();
 
 	for (unsigned int i = 1; i <= MAX_POSITIONS; ++i) 
 	{

radiant/xyview/XYWnd.cpp

@@ -34,6 +34,7 @@
 #include "XYRenderer.h"
 #include "gamelib.h"
 #include "scenelib.h"
+#include "maplib.h"
 #include "render/frontend/RenderableCollectionWalker.h"
 
 #include <fmt/format.h>
@@ -939,14 +940,15 @@ void XYWnd::drawGrid()
 
 void XYWnd::drawBlockGrid()
 {
-    if (GlobalMap().getWorldspawn() == NULL) {
-        return; // no worldspawn yet
-    }
+    // Do nothing if there is no worldspawn yet
+    Entity* worldSpawn = map::current::getWorldspawn();
+    if (!worldSpawn)
+        return;
+
     // Set a default blocksize of 1024
     int blockSize = GlobalXYWnd().defaultBlockSize();
 
     // Check the worldspawn for a custom blocksize
-    Entity* worldSpawn = Node_getEntity(GlobalMap().getWorldspawn());
     assert(worldSpawn);
     std::string sizeVal = worldSpawn->getKeyValue("_blocksize");