Print Page - Null Pointer at glClear()

Title: Null Pointer at glClear()
Post by: Atridas on January 07, 2008, 01:05:41

Hello, I'm trying to write some king of java 3d game engine (starting at tetris : - P ) But I've got a really intreaging problem...

Well in short, when I call "GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GLL11.GL_DEPTH_BUFFER_BIT)" my aplication crashes and throws a NullPointerException...

Edit:

Code Select

// troba quin es el bpp actual
			int bpp = 
				Display.getDisplayMode().getBitsPerPixel();
			
			//trobar el mode que busquem
			DisplayMode[] modes = 
				Display.getAvailableDisplayModes();
			
			DisplayMode mode = null;
			
			for (int i=0;i<modes.length;i++) {
				if ((modes[i].getBitsPerPixel() == bpp) 
						|| (mode == null)) 
				{
					if ((modes[i].getWidth() == width) 
							&& (modes[i].getHeight() == height))
						mode = modes[i];
				}
			}
			
			if (mode==null)
				throw new Arexception("no s'ha trobat " +
						"un mode de renderitzat adecuat");
			

			Display.setTitle(titol);
			Display.setDisplayMode(mode);
			Display.setFullscreen(fullscreen);
			
			Display.create();
			
			
			//inicialitzacions OpenGL
			GL11.glShadeModel(GL11.GL_SMOOTH);
			GL11.glClearColor(0.3f, 0.3f, 0.2f, 0.0f);
			
			GL11.glClearDepth(1.0f);						
			GL11.glEnable(GL11.GL_DEPTH_TEST);				
			GL11.glDepthFunc(GL11.GL_LEQUAL);
			
			GL11.glDisable(GL11.GL_CULL_FACE);
			
			GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT, GL11.GL_NICEST);

Code Select

GL11.glMatrixMode(GL11.GL_PROJECTION);						// Select The Projection Matrix
		GL11.glLoadIdentity();							// Reset The Projection Matrix
	
		// Calculate The Aspect Ratio Of The Window
		float ratio =((float)width)/((float)height);
		GLU.gluPerspective(45.0f,ratio,1.0f,100.0f);
	
		GL11.glMatrixMode(GL11.GL_MODELVIEW);						// Select The Modelview Matrix
		GL11.glLoadIdentity();

Do I miss anything?

Title: Re: Null Pointer at glClear()
Post by: Matzon on January 07, 2008, 06:48:13

are you doing Display.create in the same thread as GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GLL11.GL_DEPTH_BUFFER_BIT)?

is it only GL11.glClear that crashes ?

Title: Re: Null Pointer at glClear()
Post by: Atridas on January 07, 2008, 11:31:23

Quoteare you doing Display.create in the same thread as GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GLL11.GL_DEPTH_BUFFER_BIT)?

well... no I'm not...

I'm trying some kind of multithreated engine... and initialitzation is done in another thread... so... I see it may be a bad idea... I'll change it to the render thread

Edit:

It worked, so thanks

From now on, I s'pose that I should move every single GL call to the same thread, nop?

Title: Re: Null Pointer at glClear()
Post by: Matzon on January 07, 2008, 12:40:07

either that - or make sure to release and aquire the context as needed - tho it can be tricky to get right.

Title: Re: Null Pointer at glClear()
Post by: Atridas on January 07, 2008, 12:59:13

Every gl call at one thread, and no problems...

except from input xDDDDDD I works OK in debug mode, but not when I run it (using eclipse, BTW)

LWJGL Forum

Programming => OpenGL => Topic started by: Atridas on January 07, 2008, 01:05:41