Add function glaze_set_first_gl_call_callback

[glaze] / glaze-gl.c

diff --git a/glaze-gl.c b/glaze-gl.c
index 453d4606f2be1320b009630bf1e041960b190afc..7248876b75da4940ee83e71430b9647f41ef801d 100644 (file)
--- 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)
 {
@@ -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)