Texture binding and toggling screen mode

Started by Clueless December 27, 2004 07:25 PM

6 comments, last by Ruudje 19 years, 11 months ago

Author

185

December 27, 2004 07:25 PM

Hi. Apparently I'm relatively new to OpenGL programming. Right now I have to use the code below each frame. When I toggle between fullscreen/windowed mode and use the code below only once ... ( and glBindTexture(GL_TEXTURE_2D, m_TexId); each frame ) ... the texture disappears. I guess there is something seriously wrong with the design I chose? How is this usually done? Or does a program generally have to go through all the textures whenever the window has been killed and recreated?


        // create new texture
        glGenTextures(0, &m_TexId);
        // bind the texture
        glBindTexture(GL_TEXTURE_2D, m_TexId);
        // set texture stuff
        glTexParameteri(
            GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR );
        glTexParameteri(
            GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,
            GL_LINEAR_MIPMAP_NEAREST );
        gluBuild2DMipmaps(
            GL_TEXTURE_2D, m_Bpp, m_Width, m_Height, m_Type,
            GL_UNSIGNED_BYTE, m_pImageData );

Writing errors since 10/25/2003 2:25:56 AM

eSCHEn

394

December 27, 2004 08:27 PM

Unless it's just a typo, the line 'glGenTextures(0, &m_TexId);' should be 'glGenTextures(1, &m_TexId);'. If it is just a typo then you should check that your pixel data 'm_pImageData' is valid before the call to it.

In answer to your question, yes you do have to re-create your textures when you toggle from windowed to fullscreen. The reason is a little out of my knowledge but I suspect it has to do with the rendering context for OpenGL changing, therefore meaning you have to re-create your textures.

Hope this helped.

--
Cheers,
Darren Clark

dormlock

127

December 27, 2004 08:44 PM

I'm sure he may have this question too but what about resolution switching seems to me with the way the window is setup, to switch the resolution you'd hve to destroy the context and recreate it.

eSCHEn

394

December 27, 2004 10:49 PM

Yes, that's correct. To change resolution (NOT dimensions) you must destroy and re-create the window.

--
Cheers,
Darren Clark

Ruudje

100

December 28, 2004 02:58 AM

Ehm, why is that?

I usually set up a window of X x Y pixels and then change the resolution through the win32 api. I don not have to create a new window for that... I do have to resize it and pass that new size to opengl though. I have never run into this problem.

Look up

ChangeDisplaySettings(...)

on MSDN and see if you have use for it.

Clueless

Author

185

December 28, 2004 05:11 AM

Thank you very much for the replies.

It was not a typo btw. I did create 0 texture names.

I think ChangeDisplaySettings is used in the newer version of the basecode.
I'll just kill/recreate the window and tell the resource manager to recreate the textures.
Later I'll take a closer look at the Win32 specific rendering stuff.

Thanks again.

Writing errors since 10/25/2003 2:25:56 AM