Hello,

I am writing my first shader in WebGL. I was wondering if the GLSL language has any way to evaluate if an attribute or a uniform is null. According to the specs it does not support to do something like

if (attributeX) {
dothis();
}  
else{ 
dothat():
}

And I think it would be a waste to write a bool attribute for each of these cases would be a waste.

Another question: what happen during rendering when you don't pass along the uniforms or attribs to the shader?

Thanks!