View Full Version : Picture loads very slowly

09-06-2010, 09:17 AM
Hi all,

I've just started using opengl in visual studio. When i try to run my code, the picture draws very slowly (i noticed it seems to apply only to the ellipses as the other polygons show immediately).

I've tried running the code on other computers and the picture appears immediately. Hence tried reformatting and reinstalling VS2008 but nothing works.

Does anyone know what would the problem be?

Thanks in advance!

09-06-2010, 02:50 PM
Perhaps you should check you have a proper OpenGL driver installed. Often the shrinkwrapped drivers don't have a OpenGL driver and you end up with the Microsoft software driver. The very first thing you should do with OpenGL is read back the gl version once you have created the rendering context. It it says microshaft then you need new drivers!

09-06-2010, 09:36 PM
May i know what do you mean by read back the gl version?

09-06-2010, 11:11 PM
From: "Beginning OpenGL Game Programming" 1st ed page 37

Querying String Values
You can find out the details of the OpenGL implementation being used at runtime via the following function:

const GLubyte *glGetString(GLenum name);

The null-terminated string that is returned depends on the value passed as n a m e, which can be any of the following:

GL_VENDOR -return string is the vendor name of the current OpenGL version

GL_RENDERER -return string reflects the hardware being used (video card name as Windows sees it)

GL_VERSION -returns the OpenGl version (ex 2.1, 3.0, 3.1, 4.1, etc. along with the OS (Win2000.5, XP SP30,000, Vista SP2,000, etc)

GL_EXTENSIONS - returns the string containing a space-delimited list of all the OpenGL extensions(not sure if this is ALL extensions available to the version of OpenGL or all extensions supported by the specific video card(s) being used.)

- If you don't want to code the solution try this:
1. search "OpenGL Ext Viewer 3.16 from realtech VR" or their latest version
2. download the application. and run the install.
3. Once the program loads. It will show you system info: relating to your graphics setup, OpenGL info: OpenGL version & driver version, & last but not least DirectX Info: version & shader model version. This app should also show you download links for vendors for your specific video card. (& the application is free!)

09-07-2010, 03:28 AM
I've solved the problem.
Thanks for your help!

09-07-2010, 07:35 PM
was your problem a high segment count on circles/elipses?