[gimp] app: don't draw the grid if it covers the image entirely

[Michael Natterer <mitch src gnome org>]

commit 0c236cbc48ff53b18b4424cfcc1cec9400c35a2f
Author: Michael Natterer <mitch gimp org>
Date:   Sun Mar 4 20:16:14 2012 +0100

    app: don't draw the grid if it covers the image entirely
    
    Regardless of the elaborate discussion in bug #599267, as soon as the
    grid starts covering the image completely (when the is no more spacing
    between grid lines), it is entirely useless, so skip drawing it.

 app/display/gimpcanvasgrid.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/app/display/gimpcanvasgrid.c b/app/display/gimpcanvasgrid.c
index fbd6126..9f3304c 100644
--- a/app/display/gimpcanvasgrid.c
+++ b/app/display/gimpcanvasgrid.c
@@ -206,6 +206,13 @@ gimp_canvas_grid_draw (GimpCanvasItem   *item,
 
   g_return_if_fail (private->grid->xspacing > 0 && private->grid->yspacing > 0);
 
+  /*  skip grid drawing when the space between grid lines starts
+   *  disappearing, see bug #599267.
+   */
+  if (private->grid->xspacing * shell->scale_x < 2.0 ||
+      private->grid->yspacing * shell->scale_y < 2.0)
+    return;
+
   cairo_clip_extents (cr, &dx1, &dy1, &dx2, &dy2);
 
   x1 = floor (dx1);