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OpenGL resolution settings?

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How can I make OpenGL run with certain resolution settings? If I need to get them from windows settings how can I temporarily change them to a certain setting? I think I''ve sorta made myself clear... Thanks Uni

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You''re probably looking for glViewport() if you want to get OpenGL to run with a specific resolution. You can change it if you want (for render to texture or whatever). You should probably have the window dimensions left over from when you created the window. Hope that helps.

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Actually, the solution to this suprised me, since I was initally working with Direct3D, which has separate initialisation for full-screen mode.

In OpenGL, you just make a popup-style window (i.e. with no borders) and place it in the top-left corner of the screen (0,0).

Then you have to change the windows desktop resolution to fit the window:

// Example for 640x480x32 mode

DEVMODE dmScreenSettings;

dmScreenSettings.dmPelsWidth = 640;
dmScreenSettings.dmPelsHeight = 480;
dmScreenSettings.dmBitsPerPel = 32;

ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN);

CDS_FULLSCREEN is to hide the status bar at the bottom

And when you want to get out of full-screen mode, just do:

ChangeDisplaySettings(NULL, 0);

After Direct3D, this is soooooo much easier eh


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Summit is still up...when I increase the resolution i.e. make


higher values isn't the image (in this case a triangle) meant to decrease in size due to more pixels being on screen? Mine ain't it just stays the same size.

here's the code if it helps:

RECT windowRect;

int width = 800;
int height = 600;
int bits = 32;

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

if(fsval == true)
DEVMODE dmScreenSettings; // device mode
dmScreenSettings.dmSize = sizeof(dmScreenSettings);
dmScreenSettings.dmPelsWidth = width; // screen width
dmScreenSettings.dmPelsHeight = height; // screen height
dmScreenSettings.dmBitsPerPel = bits; // bits per pixel

I think that is the code that is needed.


[edited by - Unimatrix_001 on June 5, 2002 6:22:34 PM]

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The triangle should appear to be the same size. Images are placed on the screen as fractions of the screen width. Higher resolution just gives more detail.

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