+ /** Resets all internal state and restarts rendering. There must be no
+ unpopped state in the stack. It is permissible to call begin() multiple
+ times without an intervening end(). */
+ void begin(const Camera *);
+
+ /** Replaces the Renderer's modelview matrix. */
+ void set_matrix(const Matrix &);
+
+ /** Applies a transform to the Renderer's modelview matrix. */
+ void transform(const Matrix &);
+
+ /** Returns the current modelview matrix. */
+ const Matrix &get_matrix() const { return state->modelview_matrix; }