+typedef GLint (*PFNGLGETATTRIBLOCATIONPROC) (GLuint program, const GLchar *name);
+PFNGLGETATTRIBLOCATIONPROC gl_GetAttribLocation;
+
+typedef void (*PFNGLVERTEXATTRIBPOINTERPROC)
+ (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride,
+ const GLvoid *pointer);
+PFNGLVERTEXATTRIBPOINTERPROC gl_VertexAttribPointer;
+
+typedef void (*PFNGLENABLEVERTEXATTRIBARRAYPROC) (GLuint index);
+PFNGLENABLEVERTEXATTRIBARRAYPROC gl_EnableVertexAttribArray;
+
+typedef GLint (*PFNGLGETUNIFORMLOCATIONPROC) (GLuint program, const GLchar *name);
+PFNGLGETUNIFORMLOCATIONPROC gl_GetUniformLocation;
+
+typedef void (*PFNGLUNIFORMMATRIX4FVPROC)
+ (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
+PFNGLUNIFORMMATRIX4FVPROC gl_UniformMatrix4fv;
+