Making the check for a current window in "glutPostRedisplay" more stringent

[freeglut] / src / freeglut_display.c

diff --git a/src/freeglut_display.c b/src/freeglut_display.c
index 0626981..2ba0ec5 100644 (file)
--- a/src/freeglut_display.c
+++ b/src/freeglut_display.c
@@ -36,7 +36,12 @@
 void FGAPIENTRY glutPostRedisplay( void )
 {
     FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutPostRedisplay" );
-    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutPostRedisplay" );
+    if ( ! fgStructure.CurrentWindow )
+       {
+      fgError ( " ERROR:  Function <%s> called"
+                " with no current window defined.", "glutPostRedisplay" ) ;
+       }
+
     fgStructure.CurrentWindow->State.Redisplay = GL_TRUE;
 }
 
@@ -48,6 +53,10 @@ void FGAPIENTRY glutSwapBuffers( void )
     FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSwapBuffers" );
     FREEGLUT_EXIT_IF_NO_WINDOW ( "glutSwapBuffers" );
 
+    /*
+     * "glXSwapBuffers" already performs an implicit call to "glFlush". What
+     * about "SwapBuffers"?
+     */
     glFlush( );
     if( ! fgStructure.CurrentWindow->Window.DoubleBuffered )
         return;