X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=glwrap.h;fp=glwrap.h;h=2dc18383c0c864e40e5b033ce67f2f209fe895dd;hb=4ef9d74d4ff12afcc7e31bf13fe2a4993f06b987;hp=81e1e34c9f0ccc11980de3e70caf42366dd501c2;hpb=385fae6dca60b9b41e91c9b8bfe1a05a4eb18240;p=fips

diff --git a/glwrap.h b/glwrap.h
index 81e1e34..2dc1838 100644
--- a/glwrap.h
+++ b/glwrap.h
@@ -22,6 +22,21 @@
 #ifndef GLWRAP_H
 #define GLWRAP_H
 
+/* Lookup a function named 'name' in the underlying, real, libGL.so */
+void *
+glwrap_lookup (char *name);
+
+/* Defer to the real 'function' (from libGL.so) to do the real work.
+ * The symbol is looked up once and cached in a static variable for
+ * future uses.
+ */
+#define GLWRAP_DEFER(function,...) do {				\
+	static typeof(&function) real_ ## function;		\
+	if (! real_ ## function)				\
+		real_ ## function = glwrap_lookup (#function);	\
+	real_ ## function(__VA_ARGS__); 			\
+} while (0);
+
 /* Should be called at the end of ever function wrapper for an OpenGL
  * function that ends a frame, (glXSwapBuffers and similar).
  */