I thought that GL commands were suppose to not function as expected (read, do nothing) when no RC was created or made current.
Im using glGetString and I think the other is gluGetString and both are for getting version numbers and they work.
glu I can understand, but why is the case for gl working?
PS: from time to time things screwed up (by itself, not my app!) and SetPixelFormat was causing my app to abort and return -1 to the OS. I think this was the problem but I cant be sure.
V-man
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Sig: http://glhlib.sourceforge.net
an open source GLU replacement library. Much more modern than GLU.
float matrix[16], inverse_matrix[16];
glhLoadIdentityf2(matrix);
glhTranslatef2(matrix, 0.0, 0.0, 5.0);
glhRotateAboutXf2(matrix, angleInRadians);
glhScalef2(matrix, 1.0, 1.0, -1.0);
glhQuickInvertMatrixf2(matrix, inverse_matrix);
glUniformMatrix4fv(uniformLocation1, 1, FALSE, matrix);
glUniformMatrix4fv(uniformLocation2, 1, FALSE, inverse_matrix);
Well those functions dont draw anything so they can work just fine without a valid Rendering Context. Now glVertex and stuff would not work of course with out a RC.
-SirKnight
-SirKnight
I don't think you should be able to call even glGetString() without a valid RC, at least there's no garantuee it will work afaik.
It can get confusing at times. I've recently discovered a minor issue with RC's and WGL_ARB_pixel_format :
With NVIDIA's drivers using WGL_ARB_pixel_format without a valid RC does not produce an error ( as I think it should ). On ATI drivers, a valid RC is required. NVIDIA's multisample application does not seem to have a valid RC when the pixelformat is selected ( it creates a context only to bind the functions ).
I have had the same problem with my app. It may only happen when I use the multisample extension to enable FSAA. The call to SetPixelFormat just exits the app with an exit code of -1; no errors listed; no crash; no nothing. I have to reboot in order to run any OpenGL apps after that.Originally posted by V-man:
PS: from time to time things screwed up (by itself, not my app!) and SetPixelFormat was causing my app to abort and return -1 to the OS. I think this was the problem but I cant be sure.
So you are saying that this is caused by calls to functions with no RC active? I'll have to look into that; when I use the pixel format extension to get a multisample pixel format, there is presumably no current RC.
Has anyone else run into this problem?
[This message has been edited by tcobbs (edited 05-10-2002).]
>>>It can get confusing at times. I've recently discovered a minor issue with RC's and WGL_ARB_pixel_format :<<<
It can definitly get confusing at times.
It would seem as if the reason why SetPixelFormat failed is not related. It happened today, and again quake 3 locks up.
Sometimes, it says there is an invalid op in kernel.dll Sometimes, I get GDI generic.
I really cant say what the cause is, but I am on win98, and that OS is crap. I will update the drivers to the latest and see (im on 23.11 now). Not using FSAA in any way
V-man
------------------------------
Sig: http://glhlib.sourceforge.net
an open source GLU replacement library. Much more modern than GLU.
float matrix[16], inverse_matrix[16];
glhLoadIdentityf2(matrix);
glhTranslatef2(matrix, 0.0, 0.0, 5.0);
glhRotateAboutXf2(matrix, angleInRadians);
glhScalef2(matrix, 1.0, 1.0, -1.0);
glhQuickInvertMatrixf2(matrix, inverse_matrix);
glUniformMatrix4fv(uniformLocation1, 1, FALSE, matrix);
glUniformMatrix4fv(uniformLocation2, 1, FALSE, inverse_matrix);
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