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Spongebob
10-31-2008, 12:01 PM
Hello all :)
The last days I've been asked to make a project in OpenGL. I haven't touch OpenGL since 2005. I was looking an OpenGL Engine of mine from the past and I realized that I was passing some vertex data to the VertexBufferObject using glTexCoordPointer() (tangents and bitangents) instead of glVertexAttribPointer(). But I can't remember why! :P
So.. now I want to use VBO for a mesh with this data structure:


struct VertexTBN
{
vector3 pos;
vector2 texCoord;
vector3 normal;
vector3 tangent;
vector3 bitangent;
};


What is better to use for Tagnents and Bitangents? glTexCoordPointer()? or glVertexAttribPointer()?

I guess for pos, texCoord and normal is best to use glVertexPointer(), glTexCoordPointer(), glNormalPointer() respectively. right?

If I try to glDrawElements() that VBO without a glsl shader will it work?(skiping the tangent and bitangent ofc). or it will fail?

Thanks for your time!

Korval
10-31-2008, 12:45 PM
You can only use generic attributes (defined through glVertexAttribPointer) if you're using glslang (or ARB_vertex_program). So if you have need of the fixed-function pipeline, you'll need to use glTexCoordPointer.