Added class Trade::MeshObjectData, specialized for mesh instance types.

src/Trade/MeshObjectData.h

@@ -0,0 +1,58 @@
+#ifndef Magnum_Trade_MeshObjectData_h
+#define Magnum_Trade_MeshObjectData_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+/** @file
+ * @brief Class Magnum::Trade::MeshObjectData
+ */
+
+#include "ObjectData.h"
+
+namespace Magnum { namespace Trade {
+
+/**
+@brief %Mesh object data
+
+Provides access to material information for given mesh instance.
+*/
+class MAGNUM_EXPORT MeshObjectData: public ObjectData {
+    MeshObjectData(const MeshObjectData& other) = delete;
+    MeshObjectData(MeshObjectData&& other) = delete;
+    MeshObjectData& operator=(const MeshObjectData& other) = delete;
+    MeshObjectData& operator=(MeshObjectData&& other) = delete;
+
+    public:
+        /**
+         * @brief Constructor
+         * @param children          Child objects
+         * @param transformation    Transformation (relative to parent)
+         * @param instance          Instance ID
+         * @param material          Material ID
+         *
+         * Creates object with mesh instance type.
+         */
+        inline MeshObjectData(std::vector<size_t> children, const Matrix4& transformation, size_t instance, size_t material): ObjectData(children, transformation, InstanceType::Mesh, instance), _material(material) {}
+
+        /** @brief Material ID */
+        inline size_t material() { return _material; }
+
+    private:
+        size_t _material;
+};
+
+}}
+
+#endif

src/Trade/ObjectData.h

@@ -26,7 +26,8 @@ namespace Magnum { namespace Trade {
 /**
 @brief %Object data
 
-Provides access to object transformation and hierarchy.
+Provides access to object transformation and hierarchy. See also
+MeshObjectData, which is specialized for objects with mesh instance type.
 */
 class MAGNUM_EXPORT ObjectData {
     ObjectData(const ObjectData& other) = delete;
@@ -51,6 +52,9 @@ class MAGNUM_EXPORT ObjectData {
          */
         inline ObjectData(std::vector<size_t> children, const Matrix4& transformation, InstanceType instanceType, size_t instanceId): _children(children), _transformation(transformation), _instanceType(instanceType), _instanceId(instanceId) {}
 
+        /** @brief Destructor */
+        inline virtual ~ObjectData() {}
+
         /** @brief Child objects */
         inline std::vector<size_t>& children() { return _children; }
 
@@ -60,13 +64,16 @@ class MAGNUM_EXPORT ObjectData {
         /**
          * @brief Instance type
          * @return Type of instance held by this object
+         *
+         * If the instance is of type InstanceType::Mesh, the instance can be
+         * casted to MeshObjectData and provide more information.
          */
         inline InstanceType instanceType() const { return _instanceType; }
 
         /**
          * @brief Instance ID
          * @return ID of given camera / light / mesh etc., specified by
-         *      instance()
+         *      instanceType()
          */
         inline size_t instanceId() const { return _instanceId; }