Initial source commit

minorGems/graphics/3d/Primitive3DFactory.h

@@ -0,0 +1,129 @@
+/*
+ * Modification History
+ *
+ * 2001-March-14   Jason Rohrer
+ * Created.
+ *
+ * 2001-April-1   Jason Rohrer
+ * Added subreal entity vane class to factory. 
+ */
+
+#ifndef PRIMITIVE_3D_FACTORY_INCLUDED
+#define PRIMITIVE_3D_FACTORY_INCLUDED 
+
+#include "Primitive3D.h"
+
+// Run-time type identification interface (RTTI)
+#include <typeinfo>
+
+
+// include these primitives only if we are part of subreal
+#ifdef SUBREAL
+#include "subreal/entity/EntityBodyPrimitive3D.h"
+#define FACTORY_ENTITY_BODY_PRIMITIVE_FLAG 1
+#include "subreal/entity/EntityVanePrimitive3D.h"
+#define FACTORY_ENTITY_VANE_PRIMITIVE_FLAG 2
+
+#endif
+
+// the default flag
+#define FACTORY_DEFAULT_PRIMITIVE_FLAG 0
+
+
+/**
+ * Class that maps Primitive3D integer subclass type flags to Primitive3D
+ * subclass instances.
+ *
+ * Motivation for this class:
+ * We want to extend Object3D to support subclass typed serialization
+ * and deserialization without placing too much of a burden on
+ * future Object3D subclasses.  For instance, we don't want subclasses
+ * to have to write their own de/serialization functions so that
+ * particular Primitive3D subclasses are serialized correctly.
+ * We can avoid this burden by writing the base Object3D serialization
+ * code so that it uses this factory to transmit subclasses with
+ * type informaton.
+ *
+ * @author Jason Rohrer
+ */
+class Primitive3DFactory {
+	public:
+
+		/**
+		 * Finds an integer subclass type flag for a primitive instance.
+		 *
+		 * @param inPrimitive the primitive to determine a flag for.  Must
+		 *   be destroyed by the caller.
+		 *
+		 * @return a type flag for inObject.  0 (the default Object3D
+		 *   baseclass flag) will be returned if subclass determination fails.
+		 */
+		static int primitive3DToInt( Primitive3D *inPrimitive );
+
+		
+		/**
+		 * Constructs a new, unitialized Primitive3D (in other words,
+		 * an Primitive3D ready for deserialization) of a subclass
+		 * type matching inTypeFlag.
+		 *
+		 * @param inTypeFlag the type flag specifying the class
+		 *   of the returned primitive.
+		 *
+		 * @return an (unitialized) Primitive3D class instance with a
+		 *   subclass type corresponding to inTypeFlag.  If no
+		 *   matching class is found, a default Primitive3D baseclass
+		 *   instance is returned.  Must be destroyed by the caller. 
+		 */
+		static Primitive3D *intToPrimitive3D( int inTypeFlag );
+		
+	};
+
+
+
+inline int Primitive3DFactory::primitive3DToInt( Primitive3D *inPrimitive ) {
+
+	// use RTTI to determine type of inPrimitive
+	
+#ifdef SUBREAL
+	if( typeid( *inPrimitive ) == typeid( EntityBodyPrimitive3D ) ) {
+		return FACTORY_ENTITY_BODY_PRIMITIVE_FLAG;
+		}
+	else if( typeid( *inPrimitive ) == typeid( EntityVanePrimitive3D ) ) {
+		return FACTORY_ENTITY_VANE_PRIMITIVE_FLAG;
+		}
+#endif
+
+	// else return the default flag
+	return FACTORY_DEFAULT_PRIMITIVE_FLAG;
+	}
+
+
+
+inline Primitive3D *Primitive3DFactory::intToPrimitive3D( int inTypeFlag ) {
+	switch( inTypeFlag ) {
+		case FACTORY_DEFAULT_PRIMITIVE_FLAG:
+			return new Primitive3D();
+			break;
+
+			/* these primitives are only defined if
+			 * we are part of subreal
+			 */
+#ifdef SUBREAL
+		case FACTORY_ENTITY_BODY_PRIMITIVE_FLAG:
+			return new EntityBodyPrimitive3D();
+			break;
+		case FACTORY_ENTITY_VANE_PRIMITIVE_FLAG:
+			return new EntityVanePrimitive3D();
+			break;
+#endif
+
+		default:
+			// unknown primitive flag type
+			return new Primitive3D();
+			break;
+		}
+			
+	}
+
+
+#endif