glVertexAttrib4f Interface to
OpenGL function glVertexAttrib4f
usage: glVertexAttrib4f( index, x, y, z, w )
C function: void glVertexAttrib4f(GLuint index, GLfloat x, GLfloat y, GLfloat z, GLfloat w)
Psychtoolbox/PsychOpenGL/MOGL/wrap/glVertexAttrib4f.m