BatchedMesh: Add deleteGeometry function (#29523)

* Add support for "deleteGeometry"

* Add docs, fix mistype

docs/api/en/objects/BatchedMesh.html

@@ -260,7 +260,13 @@
 		<p>
 			Adds the given geometry to the [name] and returns the associated geometry id referring to it to be used in other functions.
 		</p>
-
+		<h3>
+			[method:Integer deleteGeometry]( [param:Integer geometryId] )
+		</h3>
+		<p>
+			[page:Integer geometryId]: The id of a geometry to remove from the [name] that was previously added via "addGeometry". Any instances referencing
+			this geometry will also be removed as a side effect.
+		</p>
 		<h3>
 			[method:Integer addInstance]( [param:Integer geometryId] )
 		</h3>

src/objects/BatchedMesh.js

@@ -145,8 +145,9 @@ class BatchedMesh extends Mesh {
 		// stores visible, active, and geometry id per object
 		this._drawInfo = [];
 
-		// instance ids that have been set as inactive, and are available to be overwritten
+		// instance, geometry ids that have been set as inactive, and are available to be overwritten
 		this._availableInstanceIds = [];
+		this._availableGeometryIds = [];
 
 		// geometry information
 		this._drawRanges = [];
@@ -400,13 +401,6 @@ class BatchedMesh extends Mesh {
 
 		this._validateGeometry( geometry );
 
-		// ensure we're not over geometry
-		if ( this._drawInfo.length >= this._maxInstanceCount ) {
-
-			throw new Error( 'BatchedMesh: Maximum item count reached.' );
-
-		}
-
 		// get the necessary range fo the geometry
 		const reservedRange = {
 			vertexStart: - 1,
@@ -481,23 +475,40 @@ class BatchedMesh extends Mesh {
 
 		}
 
-		// update id
-		const geometryId = this._geometryCount;
-		this._geometryCount ++;
-
 		// add the reserved range and draw range objects
-		reservedRanges.push( reservedRange );
-		drawRanges.push( {
+		const drawRange = {
 			start: hasIndex ? reservedRange.indexStart : reservedRange.vertexStart,
-			count: - 1
-		} );
-		bounds.push( {
+			count: - 1,
+			active: true,
+		};
+
+		const boundsInfo = {
 			boxInitialized: false,
 			box: new Box3(),
 
 			sphereInitialized: false,
 			sphere: new Sphere()
-		} );
+		};
+
+		// update id
+		let geometryId;
+		if ( this._availableGeometryIds.length > 0 ) {
+
+			geometryId = this._availableGeometryIds.pop();
+			reservedRanges[ geometryId ] = reservedRange;
+			drawRanges[ geometryId ] = drawRange;
+			bounds[ geometryId ] = boundsInfo;
+
+
+		} else {
+
+			geometryId = this._geometryCount;
+			this._geometryCount ++;
+			reservedRanges.push( reservedRange );
+			drawRanges.push( drawRange );
+			bounds.push( boundsInfo );
+
+		}
 
 		// update the geometry
 		this.setGeometryAt( geometryId, geometry );
@@ -617,13 +628,34 @@ class BatchedMesh extends Mesh {
 
 	}
 
-	/*
 	deleteGeometry( geometryId ) {
 
-		// TODO: delete geometry and associated instances
+		const drawRanges = this._drawRanges;
+		if ( geometryId >= drawRanges.length || drawRanges[ geometryId ].active === false ) {
+
+			return this;
+
+		}
+
+		// delete any instances associated with this geometry
+		const drawInfo = this._drawInfo;
+		for ( let i = 0, l = drawInfo.length; i < l; i ++ ) {
+
+			if ( drawInfo[ i ].geometryIndex === geometryId ) {
+
+				this.deleteInstance( i );
+
+			}
+
+		}
+
+		drawRanges[ geometryId ].active = false;
+		this._availableGeometryIds.push( geometryId );
+		this._visibilityChanged = true;
+
+		return this;
 
 	}
-	*/
 
 	deleteInstance( instanceId ) {