glBlendEquation error

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6 comments, last by kutraj 15 years, 3 months ago
Hi all. I was going through blending tutorial, and "glBlendEquation" seems not to be recognized by compiler. I am using c++, visual studio 2005 pro, windows vista. Any clue what I am missing ?. I can run other opengl applications, and tutorials like basic drawing and lighting, but not blending one. PS: How can I know which version of openGL i am running ? I have looked into gl.h file and at top it says some thing like this /*++ BUILD Version: 0004 and there is a #define as /* Version */ #define GL_VERSION_1_1 Any help will be appreciated. Regards.
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I believe it's glBlendFunc, not glBlendEquation.
Nops, its glBlendEquation(...).
Opengl redbook v2.1 page # 237
maybe this then?

Quote:
glBlendEquation is part of the GL_ARB_imaging subset. glBlendEquation is present only if GL_ARB_imaging is returned when glGetString is called with GL_EXTENSIONS as its argument.
I did something like this
const GLubyte* str = glGetString(GL_EXTENSIONS);
and it returns
"GL_EXT_bgra GL_WIN_swap_hint "
does this mean that I can not use "glBlendEquation" on my machine atall?

I am using vista home edition, nvidia geforce 8400m gt, visual studio 2005

Any help will be appreciated.
Regards
Quote:glBlendEquation is present only if GL_ARB_imaging is returned when glGetString is called with GL_EXTENSIONS as its argument.


I don't think so. You would probably use glBlendFunc. It's slightly more complicated, but it will do the job.
Quote:Original post by sfx81
I did something like this
const GLubyte* str = glGetString(GL_EXTENSIONS);
and it returns
"GL_EXT_bgra GL_WIN_swap_hint "
does this mean that I can not use "glBlendEquation" on my machine atall?

I am using vista home edition, nvidia geforce 8400m gt, visual studio 2005

Any help will be appreciated.
Regards


Have you downloaded the newest video drivers? It looks like you didn't. With GeForce 8400 you should have above a hundred of extensions.
Quote:

I don't think so. You would probably use glBlendFunc. It's slightly more complicated, but it will do the job.



glBlendFunc will only set the two constants (source and destination factors) in the blend equation itself, which is defined by glBlendEquation(...)

You cannot alter the equation (subtract instead of adding subsequent terms for instance) using glBlendFunc()

Update your drivers like rozz said and then try, it should work

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