Untitled

I have a nice Scene class, which consists of a skybox and a list of items.

class SceneGraphScene
{
private:
	SceneGraph *m_pParentGraph;

	/*
	 * list of items to draw
	 */
	std::vector<SceneGraphItem*> m_SceneGraphItems;

	/*
	 * list of light sources to draw
	 */
	std::vector<LightSource> m_LightSources;

	/*
	 * list of texture ids necessary to draw the sky box
	 */
	std::vector<GLuint> m_iSkyBoxT;
	void drawSkyBox();

public:
//**

	virtual void RenderScene();
};

my item class should do the render-jobs for parts of the scene. for example for models.

class SceneGraphItem
{
//..

public:
//..

	void RenderItem() const  {draw1();}
};

my problem occurs when i try to draw via RenderItem() function in my scene. All i do is to draw a cube. if i write the same code in the renderfunction of my scene i get more than 1000 fps. but if i try to draw like in the example (down) i only have 16 frames and render problems with my skybox. there is no additional code in the render function of my item. i only run the draw1() function. this is my function:

void SceneGraphScene::RenderScene()
{
	// Lichter setzen
	for(unsigned int i = 0; i < m_LightSources.size(); i++) {
		if(i < GL_MAX_LIGHTS) {
			//std::cout<<"set up new light source"<<std::endl;
			glLightfv(GL_LIGHT0 + i, GL_AMBIENT, m_LightSources.at(i).fLightAmbient);
			glLightfv(GL_LIGHT0 + i, GL_DIFFUSE, m_LightSources.at(i).fLightDiffuse);
			glLightfv(GL_LIGHT0 + i, GL_POSITION, m_LightSources.at(i).fLightPosition);
			glEnable(GL_LIGHT0 + i);
		}
	}

	// Zeichne nun die Modelle
	for(unsigned int i = 0; i < m_SceneGraphItems.size(); i++) {
		m_SceneGraphItems.at(i)->RenderItem();
	}

	glColor4f(1.0f, 1.0f, 1.0f, 1.0f);// reset the color to white
}

inline void draw1()
{
    glPushMatrix();
    glBegin(GL_QUADS);
        // face v0-v1-v2-v3
        glNormal3f(0,0,1);
        glColor3f(1,1,1);
        glVertex3f(1,1,1);
        glColor3f(1,1,0);
        glVertex3f(-1,1,1);
        glColor3f(1,0,0);
        glVertex3f(-1,-1,1);
        glColor3f(1,0,1);
        glVertex3f(1,-1,1);

        // face v0-v3-v4-v6
        glNormal3f(1,0,0);
        glColor3f(1,1,1);
        glVertex3f(1,1,1);
        glColor3f(1,0,1);
        glVertex3f(1,-1,1);
        glColor3f(0,0,1);
        glVertex3f(1,-1,-1);
        glColor3f(0,1,1);
        glVertex3f(1,1,-1);

        // face v0-v5-v6-v1
        glNormal3f(0,1,0);
        glColor3f(1,1,1);
        glVertex3f(1,1,1);
        glColor3f(0,1,1);
        glVertex3f(1,1,-1);
        glColor3f(0,1,0);
        glVertex3f(-1,1,-1);
        glColor3f(1,1,0);
        glVertex3f(-1,1,1);

        // face  v1-v6-v7-v2
        glNormal3f(-1,0,0);
        glColor3f(1,1,0);
        glVertex3f(-1,1,1);
        glColor3f(0,1,0);
        glVertex3f(-1,1,-1);
        glColor3f(0,0,0);
        glVertex3f(-1,-1,-1);
        glColor3f(1,0,0);
        glVertex3f(-1,-1,1);

/..

    glPopMatrix();
}

How is this possible. The code is the same, why is the indirect call over the itemclass so slow ):