Well, a couple of days have gone by, so I assume that items (a) and (b)

in the freeglut_cursor.c file's "Open issues" comment are now satisfactor-
ily closed.

I also partially implemented some error-checking, using my limited
understanding of how Xlib users are supposed to do this.  (No one commented
about the lack of error-checking, pro or con.  Perhaps someone will care to
comment now?)

At present, it just will print out a warning, via fgWarning().  In part
because I'm not sure what is best to do, and in part because failure to
set the cursor type is probably not a fatal problem.


git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@327 7f0cb862-5218-0410-a997-914c9d46530a

freeglut/freeglut/src/freeglut_cursor.c

@@ -47,6 +47,35 @@
 
 /* -- INTERNAL FUNCTIONS --------------------------------------------------- */
 
+#if TARGET_HOST_UNIX_X11
+
+fgGetCursorError( Cursor cursor )
+{
+    int ret = 0;
+    char buf[ 256 ];
+    
+    switch( cursor )
+    {
+    case BadAlloc:
+    case BadFont:
+    case BadMatch:
+    case BadPixmap:
+    case BadValue:
+        XGetErrorText( fgDisplay.Display, cursor, buf, sizeof buf );
+        fgWarning( "Error in setting cursor:\n %s.", buf );
+        ret = cursor;
+        break;
+    default:
+        /* no error */
+        break;
+    }
+
+    return ret;
+}
+
+#endif
+
+
 /* -- INTERFACE FUNCTIONS -------------------------------------------------- */
 
 /*
@@ -60,20 +89,19 @@ void FGAPIENTRY glutSetCursor( int cursorID )
 #if TARGET_HOST_UNIX_X11
     /*
      * Open issues:
-     * (X) GLUT_CURSOR_NONE doesn't do what it should.  We can probably
+     * (a) Partial error checking.  Is that a problem?
-     *     build an empty pixmap for it, though, quite painlessly.
+     *     Is fgGetCursorError() correct?  Should we abort on errors?
-     * (X) Are we allocating resources, or causing X to do so?
+     *     Should there be a freeglut-wide X error handler?  Should
-     *     If yes, we should arrange to deallocate!
+     *     we use the X error-handler mechanism?
-     * (c) No error checking.  Is that a problem?
+     * (b) FULL_CROSSHAIR demotes to plain CROSSHAIR.  Old GLUT allows
-     * (d) FULL_CROSSHAIR demotes to plain CROSSHAIR.  Old GLUT allows
      *     for this, but if there is a system that easily supports a full-
      *     window (or full-screen) crosshair, we might consider it.
-     * (e) Out-of-range cursor-types are ignored.  Should we abort?
+     * (c) Out-of-range cursor-types generate warnings.  Should we abort?
-     *     Print a warning message?
      */
     {
         Cursor cursor;
         Pixmap no_cursor;  /* Used for GLUT_CURSOR_NONE */
+        int error = 0;
 
 #define MAP_CURSOR(a,b)                                     \
     case a:                                                 \
@@ -107,6 +135,7 @@ void FGAPIENTRY glutSetCursor( int cursorID )
                         XC_bottom_right_corner);
             MAP_CURSOR( GLUT_CURSOR_BOTTOM_LEFT_CORNER, XC_bottom_left_corner);
             /* MAP_CURSOR( GLUT_CURSOR_NONE,        XC_bogosity); */
+
         case GLUT_CURSOR_NONE:
         {
             static unsigned char no_cursor_bits[ 32 ];
@@ -130,10 +159,14 @@ void FGAPIENTRY glutSetCursor( int cursorID )
         
         case GLUT_CURSOR_INHERIT:
             break;
+
         default:
+            fgWarning( "Unknown cursor type: %d\n", cursorID );
             return;
         }
 
+        error = fgGetCursorError( cursor );
+
         if( GLUT_CURSOR_INHERIT == cursorID )
             XUndefineCursor( fgDisplay.Display,
                              fgStructure.Window->Window.Handle );