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Asked: 2026-06-08T15:48:21+00:00

Two questions: I am rendering elements in a large VBO with different shaders. In

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Two questions:

  1. I am rendering elements in a large VBO with different shaders. In GLSL 1.2 which I must use if I am correct as it is the most current version on OSX does not support uniform locations, which I assume means that the location of your attributes is wherever the compiler decides. Is there any way around this? For instance, as my VBO up with interleaved (x,y,z,nx,ny,nz,texU,texV), I need multiple shaders to be able to access these attributes in the same place every time. I am finding however that the compiler is giving them different locations leading to the location being the normals, and so on. I need their locations to be consistent with my VBO attribute location.

  2. I just got my first GLSL rendering completed and it looks exactly like I forgot to enable the depth test with various polygons rendered on top of one another. I enabled depth testing with:

    glEnable(GL_DEPTH_TEST);

    And the problem persists. Is there a different way to enable them with shaders? I thought the depth buffer took care of this?

    Problem 2 Solved. Turned out to be an SFML issue where I needed to specify the OpenGL settings when creating the window.

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  1. Editorial Team

    On OpenGL 3.3+ you have VAOs, when you use them, you do bind VBOs to it and you can define attributes in a custom order : http://www.opengl.org/sdk/docs/man3/xhtml/glEnableVertexAttribArray.xml (remember that attributes must be contiguous)

    A nice/easy implementation of this can be found on XNA : VertexDeclaration, you might want to see all the Vertex* types as well.

    Some hint on getting v3 to work with SFML :
    http://en.sfml-dev.org/forums/index.php?topic=6314.0

    An example on how to create and use VAOs : http://www.opentk.com/files/issues/HelloGL3.cs

    (It’s C# but I guess you’ll get it)

    Update :

    On v2.1 you have it too http://www.opengl.org/sdk/docs/man/xhtml/glEnableVertexAttribArray.xml, though you can’t create VAOs. Almost the same functionality can be achieved but you will have to bind attributes every time since it’ll be on the fixed pipeline.

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