X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=glaze-gl.c;h=e7dd728c058b53f31b2ba2f0f73fdb128781512d;hb=acb1372fca12d1df8bead92eb2ab16dbc98b9c6c;hp=453d4606f2be1320b009630bf1e041960b190afc;hpb=f427658599546afd1fa19c31f25001ada8c0667d;p=glaze

diff --git a/glaze-gl.c b/glaze-gl.c
index 453d460..e7dd728 100644
--- a/glaze-gl.c
+++ b/glaze-gl.c
@@ -31,6 +31,8 @@
 void *libgl_handle;
 void *wrapper_handle;
 
+#define STRNCMP_LITERAL(str, literal) strncmp (str, literal, sizeof (literal) - 1)
+
 static void
 open_libgl_handle (void)
 {
@@ -78,7 +80,7 @@ open_wrapper_handle (void)
 
 	path = getenv ("GLAZE_WRAPPER");
 	if (path == NULL) {
-		fprintf (stderr, "GLAZE_WRAPPER unset. Please set to path of real libGL.so under glaze.\n");
+		fprintf (stderr, "GLAZE_WRAPPER unset. Please set to path of Glaze-using wrapper library.\n");
 		exit (1);
 	}
 
@@ -104,8 +106,29 @@ glaze_init (void)
 static void *
 resolve (const char *name)
 {
+	static int before_first_gl_call = 1;
 	void *symbol;
 
+	if (before_first_gl_call &&
+	    STRNCMP_LITERAL (name, "gl") == 0 &&
+	    STRNCMP_LITERAL (name, "glX") != 0)
+	{
+		char *callback_name = getenv ("GLAZE_FIRST_GL_CALL_CALLBACK");
+		if (callback_name) {
+			void (*callback) (void) = dlsym (wrapper_handle,
+							 callback_name);
+			if (callback) {
+				(callback) ();
+			} else {
+				fprintf (stderr,
+					 "Error: Failed to find function %s "
+					 "in GLAZE_WRAPPER library.\n",
+					 callback_name);
+			}
+		}
+		before_first_gl_call = 0;
+	}
+
 	/* The wrapper gets first choice on all symbols. */
 	symbol = dlsym (wrapper_handle, name);
 	if (symbol)
@@ -114,6 +137,84 @@ resolve (const char *name)
 	return dlsym (libgl_handle, name);
 }
 
+void
+(*glXGetProcAddress (const unsigned char *name))(void);
+
+void
+(*glXGetProcAddress (const unsigned char *name))(void)
+{
+	static int first_call = 1;
+	static typeof (&glXGetProcAddress) wrapper_glXGetProcAddress;
+	static typeof (&glXGetProcAddress) libgl_glXGetProcAddress;
+	void *symbol;
+
+	/* On the first call, check if the wrapper provides an
+	 * implementation of this function. */
+	if (first_call) {
+		wrapper_glXGetProcAddress = dlsym (wrapper_handle,
+						   "glXGetProcAddress");
+		libgl_glXGetProcAddress = dlsym (libgl_handle,
+						 "glXGetProcAddress");
+		first_call = 0;
+	}
+
+	/* If the wrapper implements glXGetProcAddress itself, then it
+	 * had better know best what to do. Just let it. */
+	if (wrapper_glXGetProcAddress)
+		return wrapper_glXGetProcAddress (name);
+
+	/* Otherwise, we need to resolve the name.
+	 *
+	 * The wrapper gets first choice on all symbols. */
+	symbol = dlsym (wrapper_handle, (char *) name);
+	if (symbol)
+		return symbol;
+
+	/* The wrapper doesn't care, so defer to the underlying
+	 * glXGetProcAddress */
+	return libgl_glXGetProcAddress (name);
+
+}
+
+void
+(*glXGetProcAddressARB (const unsigned char *name))(void);
+
+void
+(*glXGetProcAddressARB (const unsigned char *name))(void)
+{
+	static int first_call = 1;
+	static typeof (&glXGetProcAddressARB) wrapper_glXGetProcAddressARB;
+	static typeof (&glXGetProcAddressARB) libgl_glXGetProcAddressARB;
+	void *symbol;
+
+	/* On the first call, check if the wrapper provides an
+	 * implementation of this function. */
+	if (first_call) {
+		wrapper_glXGetProcAddressARB = dlsym (wrapper_handle,
+						      "glXGetProcAddressARB");
+		libgl_glXGetProcAddressARB = dlsym (libgl_handle,
+						    "glXGetProcAddressARB");
+		first_call = 0;
+	}
+
+	/* If the wrapper implements glXGetProcAddressARB itself, then
+	 * it had better know best what to do. Just let it. */
+	if (wrapper_glXGetProcAddressARB)
+		return wrapper_glXGetProcAddressARB (name);
+
+	/* Otherwise, we need to resolve the name.
+	 *
+	 * The wrapper gets first choice on all symbols. */
+	symbol = dlsym (wrapper_handle, (char *) name);
+	if (symbol)
+		return symbol;
+
+	/* The wrapper doesn't care, so defer to the underlying
+	 * glXGetProcAddressARB */
+	return libgl_glXGetProcAddressARB (name);
+
+}
+
 #define GLAZE_API(name)							\
 void * name() __attribute__((ifunc(#name "_resolver")));		\
 static void *								\