From: Carl Worth <cworth@cworth.org>
Date: Thu, 2 May 2013 21:33:12 +0000 (-0700)
Subject: Reduce code duplication with with new 'glwrap_lookup' function.
X-Git-Url: https://git.cworth.org/git?p=fips;a=commitdiff_plain;h=4ef9d74d4ff12afcc7e31bf13fe2a4993f06b987

Reduce code duplication with with new 'glwrap_lookup' function.

We already had two copies of 'lookup', (and were anticipating additional
modules which needed it as well). The DEFER macro is now also exported
as GLWRAP_DEFER for use in additional modules.
---

diff --git a/glwrap.c b/glwrap.c
index c37bae3..9537271 100644
--- a/glwrap.c
+++ b/glwrap.c
@@ -103,8 +103,8 @@ add_counter (void)
 	return counter->id;
 }
 
-static void *
-lookup (const char *name)
+void *
+glwrap_lookup (char *name)
 {
 	const char *libgl_filename = "libGL.so.1";
 	static void *libgl_handle = NULL;
@@ -121,20 +121,12 @@ lookup (const char *name)
 	return dlwrap_real_dlsym (libgl_handle, name);
 }
 
-/* Defer to the underlying, ''real'' function to do the real work. */
-#define DEFER(function,...) do {				\
-	static typeof(&function) real_ ## function;		\
-	if (! real_ ## function)				\
-		real_ ## function = lookup (#function);		\
-	real_ ## function(__VA_ARGS__); 			\
-} while (0);
-
 /* Execute a glBegineQuery/glEndQuery pair around an OpenGL call. */
 #define TIMED_DEFER(function,...) do {			\
 	unsigned counter;				\
 	counter = add_counter ();			\
 	glBeginQuery (GL_TIME_ELAPSED, counter);	\
-	DEFER(function, __VA_ARGS__);			\
+	GLWRAP_DEFER(function, __VA_ARGS__);		\
 	glEndQuery (GL_TIME_ELAPSED);			\
 } while (0);
 
@@ -436,7 +428,7 @@ glUseProgram (GLuint program)
 {
 	current_context.program = program;
 
-	DEFER(glUseProgram, program);
+	GLWRAP_DEFER(glUseProgram, program);
 }
 
 void
@@ -444,7 +436,7 @@ glUseProgramObjectARB (GLhandleARB programObj)
 {
 	current_context.program = programObj;
 
-	DEFER(glUseProgramObjectARB, programObj);
+	GLWRAP_DEFER(glUseProgramObjectARB, programObj);
 }
 
 static void
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).
  */
diff --git a/glxwrap.c b/glxwrap.c
index 78627d4..885f679 100644
--- a/glxwrap.c
+++ b/glxwrap.c
@@ -29,47 +29,10 @@
 
 #include "glwrap.h"
 
-typedef void (* fips_glXSwapBuffers_t)(Display *dpy, GLXDrawable drawable);
-
-static void *
-lookup (const char *name)
-{
-	const char *libgl_filename = "libGL.so.1";
-	static void *libgl_handle = NULL;
-
-	if (! libgl_handle) {
-		libgl_handle = dlwrap_real_dlopen (libgl_filename, RTLD_NOW | RTLD_DEEPBIND);
-		if (! libgl_handle) {
-			fprintf (stderr, "Error: Failed to dlopen %s\n",
-				 libgl_filename);
-			exit (1);
-		}
-	}
-
-	return dlwrap_real_dlsym (libgl_handle, name);
-}
-
-static void
-call_glXSwapBuffers (Display *dpy, GLXDrawable drawable)
-{
-	static fips_glXSwapBuffers_t real_glXSwapBuffers = NULL;
-	const char *name = "glXSwapBuffers";
-
-	if (! real_glXSwapBuffers) {
-		real_glXSwapBuffers = (fips_glXSwapBuffers_t) lookup (name);
-		if (! real_glXSwapBuffers) {
-			fprintf (stderr, "Error: Failed to find function %s.\n",
-				 name);
-			return;
-		}
-	}
-	real_glXSwapBuffers (dpy, drawable);
-}	
-
 void
 glXSwapBuffers (Display *dpy, GLXDrawable drawable)
 {
-	call_glXSwapBuffers (dpy, drawable);
+	GLWRAP_DEFER (glXSwapBuffers, dpy, drawable);
 
 	glwrap_end_frame ();
 }
@@ -81,10 +44,10 @@ glXGetProcAddressARB (const GLubyte *func)
 {
 	__GLXextFuncPtr ptr;
 	static fips_glXGetProcAddressARB_t real_glXGetProcAddressARB = NULL;
-	const char *name = "glXGetProcAddressARB";
+	char *name = "glXGetProcAddressARB";
 
 	if (! real_glXGetProcAddressARB) {
-		real_glXGetProcAddressARB = (fips_glXGetProcAddressARB_t) lookup (name);
+		real_glXGetProcAddressARB = glwrap_lookup (name);
 		if (! real_glXGetProcAddressARB) {
 			fprintf (stderr, "Error: Failed to find function %s.\n",
 				 name);