Using legacy GLSL shaders

[slewicki]

I am currently working on porting over a legacy application that used an OpenGL renderer. I got BGFX working with our existing window and views, but some of our shaders have custom attributes. The shaders were compiled using the --raw flag and successfully loaded. I see that BGFX has some enumeration mapped attributes, but was wondering if we can use the attributes that already exist in our shader. Are the attributes mapped 1:1 (meaning that Position will always need to be specified as the first attribute)? Is it safe to use integer values to specify the attribute location? If yes then will there be any issues if we have more attributes in the shader then there are in the Attrib enum?

[slewicki]

As I look at the examples, I see that a lot extra attributes are using TEXCOORDX. Is this the approach to take and in the shader assign another variable to help specify what the variable is used for?