Exhibit #0: Getting Info about Vertex Attributes

Vertex Attributes

There are 5 active vertex attributes.

Location	Name	Size	Type	Type Name
0	vert_position	1	35665	FLOAT_VEC3
1	vert_texCoord	1	35664	FLOAT_VEC2
2	vert_normal	1	35665	FLOAT_VEC3
3	vert_tangent	1	35666	FLOAT_VEC4
4	vert_size	1	5126	FLOAT

You can get the number of vertex attributes that are used with gl.getProgramParameter(program, gl.ACTIVE_ATTRIBUTES).
- The GLSL compiler will not include attributes that are declared but not used in your program.
You can get info about an attribute with gl.getActiveAttrib(program, <index-of-the-attribute>)
- Index goes from 0 to gl.getProgramParameter(program, gl.ACTIVE_ATTRIBUTES)-1
- You get an object that contains the name, size (always 1), and type of the attribute.
You can get the index of an attribute with the given name with gl.getAttribLocation(program, <attribute-name>)
Important: You need to check whether an attribute exist before enabling or binding something to it.
Hint: Use these commands to build better abstractions around vertex attributes.