Still problem with directional lighting, please help!

[BlackJack]

Ok, the problem is old, but still existing, so I post it again. I simply don't get this solved.

In this little testprogram all I want is the quad to have a normal of 0,0,1 and an infinite directional light lighting this quad. In my opinion it should be absolutely bright, after all both vectors are totally even, but instead it's dark. If I change both vectors (the one of the light and the poly) to 1,0,0 it is lighted... what's wrong on the code? Please help, thanks:

 
BOOL InitInstance( HINSTANCE hInstance, int nCmdShow )
{
	hInst = hInstance; // Instanzzugriffsnummer in unserer globalen Variable speichern
	hWnd = CreateWindow((char*)WinClass, "lp", WS_OVERLAPPEDWINDOW,
	  CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
 
	if( !hWnd ) 
	{
	  return FALSE;
	}
 
	SetWindowPos(hWnd,NULL,0,0,640,480,0);
 
	// -------------------- set up OpenGL -------------------------
 
	WinDC=GetDC(hWnd);
	memset(&Pfd,0,sizeof(Pfd));
 
	Pfd.nSize=sizeof(Pfd); Pfd.nVersion=1; Pfd.dwFlags=PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
	Pfd.iPixelType=PFD_TYPE_RGBA; Pfd.cColorBits=16; Pfd.cDepthBits=16; Pfd.iLayerType=PFD_MAIN_PLANE;	
	PixelFormat = ChoosePixelFormat(WinDC, &Pfd);
	SetPixelFormat(WinDC, PixelFormat, &Pfd);
 
	RC = wglCreateContext(WinDC);
	wglMakeCurrent(WinDC,RC);
	glClearColor(0.f,0.f,0.f,1.f);
	glDepthFunc(GL_LEQUAL);
	glDepthMask(true);
	glViewport(0,0,640,480);
	glEnable(GL_DEPTH_TEST);
 
	// --------------------------------------------------------------
 
	ShowWindow( hWnd, nCmdShow );
	UpdateWindow( hWnd );
 
	return TRUE;
}
 
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	switch( message ) 
	{
		case WM_PAINT:
 
			{
				wglMakeCurrent(WinDC,RC);
				glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
				glLoadIdentity();
 
				glMatrixMode(GL_MODELVIEW);
 
				float mfFrTop,mfFrRight,mfFrBottom,mfFrLeft;
				#define pi 3.141592653f
 
				//calculate and set the viewcone
				mfFrTop    = 10/*nearclip*/*(float)tan((60/*v. viewa.*//2.f)*(pi/180.f));
				mfFrRight  = mfFrTop*(90/*h. viewa.*//60/*v. viewa.*/);
				mfFrBottom = -mfFrTop;
				mfFrLeft   = -mfFrRight;
				glFrustum(mfFrLeft,mfFrRight,mfFrBottom,mfFrTop,10/*nearclip*/,1000/*farclip*/);		
 
				glEnable(GL_LIGHTING); //enable lighting
				glEnable(GL_LIGHT0); //enable light 0
				glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER,GL_FALSE); //local viewer shall not matter
				glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE); //two sided lighting plz
 
				//setup infinite directional light
				float lightpos[4] = {0.f,0.f,1.f,0.f};
				glLightfv(GL_LIGHT0,GL_POSITION,lightpos);
 
				glColor3f(1,1,1); //shared color for all vertices
				glNormal3f(0,0,1); //shared normal for all vertices
				glBegin(GL_QUADS);
					glVertex3f(-20,-20,-100);
					glVertex3f(20,-20,-100);
					glVertex3f(20,20,-100);
					glVertex3f(-20,20,-100);
				glEnd();
 
				SwapBuffers(WinDC);
			}
			break;
		case WM_DESTROY:
			PostQuitMessage( 0 );
			break;
		default:
			return DefWindowProc( hWnd, message, wParam, lParam );
   }
   return 0;
}

I also uploaded the zip with the source, so if anyone of you has some time, please check it in your compiler yourself... I have this problem since months and well... I slowly need to get it solved, thanks:
http://www.lyxion.com/lightprobs.zip

Michael

[PH]

Never use the modelview matrix for projection when using lighting. Load the frustum into GL_RPOJECTION and set modelview to identity ( then you'll see a bright quad ).

[BlackJack]

Aaaaaaaaaaah, finally . Thanks a lot.

BlackJack

Corrected code

 
				glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
				float mfFrTop,mfFrRight,mfFrBottom,mfFrLeft;
				#define pi 3.141592653f
 
				glMatrixMode(GL_PROJECTION);
				glLoadIdentity();
 
				//calculate and set the viewcone
				mfFrTop    = 10/*nearclip*/*(float)tan((60/*v. viewa.*//2.f)*(pi/180.f));
				mfFrRight  = mfFrTop*(90/*h. viewa.*//60/*v. viewa.*/);
				mfFrBottom = -mfFrTop;
				mfFrLeft   = -mfFrRight;
				glFrustum(mfFrLeft,mfFrRight,mfFrBottom,mfFrTop,10/*nearclip*/,1000/*farclip*/);		
 
				glEnable(GL_LIGHTING); //enable lighting
				glEnable(GL_LIGHT0); //enable light 0
				glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER,GL_FALSE); //local viewer shall not matter
				glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE); //two sided lighting plz
 
				//setup infinite directional light
				float lightpos[4] = {0.f,0.f,1.f,0.f};
				glLightfv(GL_LIGHT0,GL_POSITION,lightpos);
 
				glMatrixMode(GL_MODELVIEW);
				glLoadIdentity();
 
				int deg = (GetTickCount()/5) % 360;
 
				glColor3f(1,1,1); //shared color for all vertices
				glNormal3f(cos(deg*pi/180.f),0,sin(deg*pi/180.f)); //shared normal for all vertices
				glBegin(GL_QUADS);
					glVertex3f(-20,-20,-100);
					glVertex3f(20,-20,-100);
					glVertex3f(20,20,-100);
					glVertex3f(-20,20,-100);
				glEnd();				
 
				SwapBuffers(WinDC);

[zed]

also read the faq (the whole thing, right hand side of the www.opengl.org site)
itll only take an hours but can potentiually save time in the future

[BlackJack]

Well, have all in all readen days of GL doku already and am working with GL since more than 7 years, but.... never needed it's lighting, hehe. GLs lighting was compared to my own far slower, but well, now in the times of t&l of course not anymore ), so i started half a year ago a new engine from scratch to put the old big one... as soon as possible... onto a disc which will then "sleep" forever there . I think I even read that FAQ anytime, but well, my memory is no book... unfortunately , in any case thanks for the help.

Michael