[mutter] monitor: Fix tile coordinate calculation

[Jonas Ådahl <jadahl src gnome org>]

commit 21b8ae10b8d0ee0ba724941b10bc3f74a1fd1c5a
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Apr 14 21:11:28 2020 +0200

    monitor: Fix tile coordinate calculation
    
    Previously the tile coordinate was used to offset a CRTC scanout
    coordinate within a larger framebuffer. Since 3.36 we're always
    scanning out from (0, 0) as we always have one framebuffer per CRTC; we
    instead use the tile coordinate to calculate the coordinate the tile has
    in the stage view. Adapt calculation to fulfil this promise instead of
    the old one.
    
    This also corrects the tiled custom monitor test case.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1199

 src/backends/meta-monitor.c    | 8 ++++----
 src/tests/monitor-unit-tests.c | 3 ++-
 2 files changed, 6 insertions(+), 5 deletions(-)
---
diff --git a/src/backends/meta-monitor.c b/src/backends/meta-monitor.c
index f4d71f047..07857e00b 100644
--- a/src/backends/meta-monitor.c
+++ b/src/backends/meta-monitor.c
@@ -817,19 +817,19 @@ calculate_tile_coordinate (MetaMonitor         *monitor,
         case META_MONITOR_TRANSFORM_270:
         case META_MONITOR_TRANSFORM_FLIPPED_270:
           if (other_output->tile_info.loc_v_tile == output->tile_info.loc_v_tile &&
-              other_output->tile_info.loc_h_tile < output->tile_info.loc_h_tile)
+              other_output->tile_info.loc_h_tile > output->tile_info.loc_h_tile)
             y += other_output->tile_info.tile_w;
           if (other_output->tile_info.loc_h_tile == output->tile_info.loc_h_tile &&
-              other_output->tile_info.loc_v_tile < output->tile_info.loc_v_tile)
+              other_output->tile_info.loc_v_tile > output->tile_info.loc_v_tile)
             x += other_output->tile_info.tile_h;
           break;
         case META_MONITOR_TRANSFORM_90:
         case META_MONITOR_TRANSFORM_FLIPPED_90:
           if (other_output->tile_info.loc_v_tile == output->tile_info.loc_v_tile &&
-              other_output->tile_info.loc_h_tile > output->tile_info.loc_h_tile)
+              other_output->tile_info.loc_h_tile < output->tile_info.loc_h_tile)
             y += other_output->tile_info.tile_w;
           if (other_output->tile_info.loc_h_tile == output->tile_info.loc_h_tile &&
-              other_output->tile_info.loc_v_tile > output->tile_info.loc_v_tile)
+              other_output->tile_info.loc_v_tile < output->tile_info.loc_v_tile)
             x += other_output->tile_info.tile_h;
           break;
         }
diff --git a/src/tests/monitor-unit-tests.c b/src/tests/monitor-unit-tests.c
index ad0cdda62..883de1bd0 100644
--- a/src/tests/monitor-unit-tests.c
+++ b/src/tests/monitor-unit-tests.c
@@ -4828,12 +4828,13 @@ meta_test_monitor_custom_second_rotated_tiled_config (void)
           .current_mode = 1,
           .transform = META_MONITOR_TRANSFORM_90,
           .x = 1024,
-          .y = 400,
+          .y = 0,
         },
         {
           .current_mode = 1,
           .transform = META_MONITOR_TRANSFORM_90,
           .x = 1024,
+          .y = 400,
         }
       },
       .n_crtcs = 3,