DemoClass.h

#pragma once

#include <d3d9.h>

class Demo
{
protected:
	bool init_done;
public:
	Demo(): init_done(false) {};
	virtual ~Demo() {}

	virtual int do_init(LPDIRECT3D9 d3d, LPDIRECT3DDEVICE9 device)
	{
		device->SetRenderState(D3DRS_LIGHTING, FALSE);    // turn off the 3D lighting
		device->SetRenderState(D3DRS_CULLMODE, D3DCULL_CCW);
		device->SetRenderState(D3DRS_ZENABLE, FALSE);    // turn on the z-buffer

		init_done = true;

		return 0;
	}

	virtual int loop(LPDIRECT3D9 d3d, LPDIRECT3DDEVICE9 device)
	{
		if (init_done == false)
			if (0 != do_init(d3d, device))
				return -1;

		device->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 40, 100), 1.0f, 0);

		device->BeginScene();    // begins the 3D scene

		// do 3D rendering on the back buffer here

		device->EndScene();    // ends the 3D scene

		device->Present(NULL, NULL, NULL, NULL);    // displays the created frame

		return 0;
	}
};