X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=glaze.c;h=0c2eada8d458ea1ca672a1e9a90df365032909ce;hb=adf4faac47e4136b879913b6ae9e2018de64af93;hp=af2aade6cbe0f2312cfb00368b3ab240b826f9e1;hpb=5341dd2062919031591f197abab8d2e44fa5d191;p=glaze

diff --git a/glaze.c b/glaze.c
index af2aade..0c2eada 100644
--- a/glaze.c
+++ b/glaze.c
@@ -26,6 +26,7 @@
 #include <stdlib.h>
 
 void *libgl_handle;
+void *wrapper_handle;
 
 static void
 open_libgl_handle (void)
@@ -48,6 +49,27 @@ open_libgl_handle (void)
 	}
 }
 
+static void
+open_wrapper_handle (void)
+{
+	const char *path;
+
+	if (wrapper_handle)
+		return;
+
+	path = getenv ("GLAZE_WRAPPER");
+	if (path == NULL) {
+		fprintf (stderr, "GLAZE_WRAPPER unset. Please set to path of real libGL.so under glaze.\n");
+		exit (1);
+	}
+
+	wrapper_handle = dlopen (path, RTLD_LAZY);
+	if (wrapper_handle == NULL) {
+		fprintf (stderr, "Error: Failed to dlopen %s\n", path);
+		exit (1);
+	}
+}
+
 static void
 glaze_init (void) __attribute__((constructor));
 
@@ -55,11 +77,19 @@ static void
 glaze_init (void)
 {
 	open_libgl_handle ();
+	open_wrapper_handle ();
 }
 
 static void *
 resolve (const char *name)
 {
+	void *symbol;
+
+	/* The wrapper gets first choice on all symbols. */
+	symbol = dlsym (wrapper_handle, name);
+	if (symbol)
+		return symbol;
+
 	return dlsym (libgl_handle, name);
 }