This is part of a broader cleanup of some of the experimental Cogl API.
One of the reasons for this particular rename is to reduce the verbosity
of using the API. Another reason is that CoglVertexArray is going to be
renamed CoglAttributeBuffer and we want to help emphasize the
relationship between CoglAttributes and CoglAttributeBuffers.
We have a bunch of experimental convenience functions like
cogl_primitive_p2/p2t2 that have corresponding vertex structures but it
seemed a bit odd to have the vertex annotation e.g. "P2T2" be an infix
of the type like CoglP2T2Vertex instead of be a postfix like
CoglVertexP2T2. This switches them all to follow the postfix naming
style.
This adds convenience primitive constructors named like:
cogl_primitive_new_p3 or
cogl_primitive_new_p3c4 or
cogl_primitive_new_p3t2c4
where the letters correspond to the interleved vertex attributes layouts
such as CoglP3Vertex which is a struct with 3 float x,y,z members for
the [p]osition, or CoglP3T2C4Vertex which is a struct with 3 float x,y,z
members for the [p]osition, 2 float s,t members for the [t]exture
coordinates and 4 unsigned byte r,g,b,a members for the [c]olor.
The hope is that people will find these convenient enough to replace
cogl_polygon.
A CoglPrimitive is a retainable object for drawing a single primitive,
such as a triangle strip, fan or list.
CoglPrimitives build on CoglVertexAttributes and CoglIndices which
themselves build on CoglVertexArrays and CoglIndexArrays respectively.
A CoglPrimitive encapsulates enough information such that it can be
retained in a queue (e.g. the Cogl Journal, or renderlists in the
future) and drawn at some later time.
