WebGL as a state machine: buffer manipulation

There is some information about the state of the rendering pipeline that we can retrieve when we are dealing with buffers with the functions: getParameter, getBufferParameter, and isBuffer.

Just like we did in the previous chapter, we will use getParameter(parameter) where parameter can have the following values:

• ARRAY_BUFFER_BINDING: It retrieves a reference to the currently-bound VBO

• ELEMENT_ARRAY_BUFFER_BINDING: It retrieves a reference to the currently-bound IBO

Also, we can enquire about the size and the usage of the currently-bound VBO and IBO using getBufferParameter(type, parameter) where type can have the following values:

• ARRAY_BUFFER: To refer to the currently bound VBO

• ELEMENT_ARRAY_BUFFER: To refer to the currently bound IBO

And parameter can be:

• BUFFER_SIZE: Returns the size of the requested buffer

• BUFFER_USAGE: Returns the usage of the requested buffer

Note

Your VBO and/or IBO needs to be bound when you enquire about the state of...