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ViperG

OpenGL Glscissors / window resize.

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Never noticed this until now. When i resize my opengl window by calling...
		ReSizeGLScene(width, height);
	
		SetWindowLong( hWnd, WS_EX_APPWINDOW, WS_POPUP | WS_CLIPSIBLINGS | WS_CLIPCHILDREN );
		SetWindowPos( hWnd, HWND_TOP, 0, 0, width, height, SWP_SHOWWINDOW );




GLvoid ReSizeGLScene(GLsizei width, GLsizei height)		
{
	if (height==0)										
	{
		height=1;										
	}
	glViewport(0,0,width,height);						
	glMatrixMode(GL_PROJECTION);						
	glLoadIdentity();									
	glOrtho( -screenx/2, screenx/2,-screeny/2, screeny/2, 1, -1);  //sets the middle of the screen as center.
	glMatrixMode(GL_MODELVIEW);							
	glLoadIdentity();									

}




and modify the resolution, increase or decrease, it permanently shifts my glscissors coordinates up and to the right by about 5-20 pixels so it doesn't work correctly. Everything else works, just glscissors now fails sorta once i resize my window just once. I might have a bug somehwere else that is causing this. ill look into it later but not sure why resizing the opengl etc would make my glscissor test have some offset amount...

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Alright i was able to fix it with this


ReSizeGLScene(width, height);

WindowRect.left=(long)0; // Set Left Value To 0
WindowRect.right=(long)width; // Set Right Value To Requested Width
WindowRect.top=(long)0; // Set Top Value To 0
WindowRect.bottom=(long)height; // Set Bottom Value To Requested Height

AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle); // Adjust Window To True Requested Size

SetWindowLong( hWnd, dwStyle, dwExStyle);

SetWindowPos( hWnd, HWND_TOP, 0, 0, WindowRect.right-WindowRect.left, WindowRect.bottom-WindowRect.top, SWP_SHOWWINDOW );







Now glcissors is working except at the maximum resolution. it's a few pixels off in the y axis. I'm thinking its because of the title bar. When you request a maximum sized window in windowed mode, you go off the screen because of the title bar and the border. only thing i can think of for now is to detect the difference at maximum resolution and apply a minor offset. When i create the window it works fine, even at full resolution. It's just when you call setWindowsPos that it messes up when you request maximum resolution (and windows is running in this resolution etc.)

[edit] ah ok, it's not actually letting me create a window beyond the windows resolution, and even when your set it to maximum resolution, you are not really getting a client area of that resolution (whatever windows is running at). So i just need a diff function or something to allow me to create a window beyond the boundries of windows current resolution.

[edit2] Ok looks like i have 2 options. I can disallow maximum resolution in windowed mode, or i can adjust the opengl width and height to equal the actual client size of the window that windows will allow when you are maxed out...

[edit3] Apparently i fixed the problem by calling my resize opengl function after i setwindowspos, now everything works... not exactly sure why it makes a difference...

[Edited by - ViperG on August 16, 2009 2:39:10 PM]

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