[mutter] monitor-tiled: Derive the dimension from what was configured

[Jonas Ådahl <jadahl src gnome org>]

commit 4cfcd4bce08926e4e9005cd912c81e83819194d5
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Mar 8 15:53:24 2017 +0800

    monitor-tiled: Derive the dimension from what was configured
    
    Previously, the size of the logical monitor was derived directly from
    the tiling information. This works fine until we add transformations,
    or set modes with a dimension different from the resulting resolution
    when tiled. Fix this by traversing the assigned CRTC rects, as these
    are already transformed by the configuration system.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=779745

 src/backends/meta-monitor.c |   22 +++++++++++-----------
 1 files changed, 11 insertions(+), 11 deletions(-)
---
diff --git a/src/backends/meta-monitor.c b/src/backends/meta-monitor.c
index 57eea84..f6eb227 100644
--- a/src/backends/meta-monitor.c
+++ b/src/backends/meta-monitor.c
@@ -702,11 +702,12 @@ meta_monitor_tiled_derive_dimensions (MetaMonitor   *monitor,
   MetaMonitorPrivate *monitor_priv =
     meta_monitor_get_instance_private (monitor);
   GList *l;
-  int width;
-  int height;
+  int min_x, min_y, max_x, max_y;
 
-  width = 0;
-  height = 0;
+  min_x = INT_MAX;
+  min_y = INT_MAX;
+  max_x = 0;
+  max_y = 0;
   for (l = monitor_priv->outputs; l; l = l->next)
     {
       MetaOutput *output = l->data;
@@ -714,15 +715,14 @@ meta_monitor_tiled_derive_dimensions (MetaMonitor   *monitor,
       if (!output->crtc)
         continue;
 
-      if (output->tile_info.loc_v_tile == 0)
-        width += output->crtc->rect.width;
-
-      if (output->tile_info.loc_h_tile == 0)
-        height += output->crtc->rect.height;
+      min_x = MIN (output->crtc->rect.x, min_x);
+      min_y = MIN (output->crtc->rect.y, min_y);
+      max_x = MAX (output->crtc->rect.x + output->crtc->rect.width, max_x);
+      max_y = MAX (output->crtc->rect.y + output->crtc->rect.height, max_y);
     }
 
-  *out_width = width;
-  *out_height = height;
+  *out_width = max_x - min_x;
+  *out_height = max_y - min_y;
 }
 
 static void