[mutter] clutter/stage-view: Move fb viewport and projection setting to here

[verdre <jonasd src gnome org>]

commit c4949b553df45b0ee03016c23f392003dcf40a4d
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Apr 30 21:51:10 2020 +0200

    clutter/stage-view: Move fb viewport and projection setting to here
    
    The stage would fetch the front framebuffer and set the viewport and
    projection matrix, but if we are going to more than one front buffer,
    that won't work, so let the stage just pass the viewport and projection
    matrix to the view and have the view deal with the framebuffer(s).
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1237

 clutter/clutter/clutter-stage-view-private.h |  9 +++++++++
 clutter/clutter/clutter-stage-view.c         | 29 ++++++++++++++++++++++++++++
 clutter/clutter/clutter-stage.c              | 14 ++++----------
 3 files changed, 42 insertions(+), 10 deletions(-)
---
diff --git a/clutter/clutter/clutter-stage-view-private.h b/clutter/clutter/clutter-stage-view-private.h
index 2e5ad4c537..6b445448e7 100644
--- a/clutter/clutter/clutter-stage-view-private.h
+++ b/clutter/clutter/clutter-stage-view-private.h
@@ -27,11 +27,20 @@ gboolean clutter_stage_view_is_dirty_viewport (ClutterStageView *view);
 void clutter_stage_view_set_dirty_viewport (ClutterStageView *view,
                                             gboolean          dirty);
 
+void clutter_stage_view_set_viewport (ClutterStageView *view,
+                                      float             x,
+                                      float             y,
+                                      float             width,
+                                      float             height);
+
 gboolean clutter_stage_view_is_dirty_projection (ClutterStageView *view);
 
 void clutter_stage_view_set_dirty_projection (ClutterStageView *view,
                                               gboolean          dirty);
 
+void clutter_stage_view_set_projection (ClutterStageView *view,
+                                        const CoglMatrix *matrix);
+
 void clutter_stage_view_add_redraw_clip (ClutterStageView            *view,
                                          const cairo_rectangle_int_t *clip);
 
diff --git a/clutter/clutter/clutter-stage-view.c b/clutter/clutter/clutter-stage-view.c
index 0aa92f3fbf..3ebe9c445c 100644
--- a/clutter/clutter/clutter-stage-view.c
+++ b/clutter/clutter/clutter-stage-view.c
@@ -363,6 +363,22 @@ clutter_stage_view_set_dirty_viewport (ClutterStageView *view,
   priv->dirty_viewport = dirty;
 }
 
+void
+clutter_stage_view_set_viewport (ClutterStageView *view,
+                                 float             x,
+                                 float             y,
+                                 float             width,
+                                 float             height)
+{
+  ClutterStageViewPrivate *priv =
+    clutter_stage_view_get_instance_private (view);
+  CoglFramebuffer *framebuffer;
+
+  priv->dirty_viewport = FALSE;
+  framebuffer = clutter_stage_view_get_framebuffer (view);
+  cogl_framebuffer_set_viewport (framebuffer, x, y, width, height);
+}
+
 gboolean
 clutter_stage_view_is_dirty_projection (ClutterStageView *view)
 {
@@ -382,6 +398,19 @@ clutter_stage_view_set_dirty_projection (ClutterStageView *view,
   priv->dirty_projection = dirty;
 }
 
+void
+clutter_stage_view_set_projection (ClutterStageView *view,
+                                   const CoglMatrix *matrix)
+{
+  ClutterStageViewPrivate *priv =
+    clutter_stage_view_get_instance_private (view);
+  CoglFramebuffer *framebuffer;
+
+  priv->dirty_projection = FALSE;
+  framebuffer = clutter_stage_view_get_framebuffer (view);
+  cogl_framebuffer_set_projection_matrix (framebuffer, matrix);
+}
+
 void
 clutter_stage_view_get_offscreen_transformation_matrix (ClutterStageView *view,
                                                         CoglMatrix       *matrix)
diff --git a/clutter/clutter/clutter-stage.c b/clutter/clutter/clutter-stage.c
index 9657dc8b59..310da1744b 100644
--- a/clutter/clutter/clutter-stage.c
+++ b/clutter/clutter/clutter-stage.c
@@ -3147,7 +3147,6 @@ _clutter_stage_maybe_setup_viewport (ClutterStage     *stage,
                                      ClutterStageView *view)
 {
   ClutterStagePrivate *priv = stage->priv;
-  CoglFramebuffer *fb = clutter_stage_view_get_framebuffer (view);
 
   if (clutter_stage_view_is_dirty_viewport (view))
     {
@@ -3174,19 +3173,14 @@ _clutter_stage_maybe_setup_viewport (ClutterStage     *stage,
       viewport_y = roundf (priv->viewport[1] * fb_scale - viewport_offset_y);
       viewport_width = roundf (priv->viewport[2] * fb_scale);
       viewport_height = roundf (priv->viewport[3] * fb_scale);
-      cogl_framebuffer_set_viewport (fb,
-                                     viewport_x, viewport_y,
-                                     viewport_width, viewport_height);
 
-      clutter_stage_view_set_dirty_viewport (view, FALSE);
+      clutter_stage_view_set_viewport (view,
+                                       viewport_x, viewport_y,
+                                       viewport_width, viewport_height);
     }
 
   if (clutter_stage_view_is_dirty_projection (view))
-    {
-      cogl_framebuffer_set_projection_matrix (fb, &priv->projection);
-
-      clutter_stage_view_set_dirty_projection (view, FALSE);
-    }
+    clutter_stage_view_set_projection (view, &priv->projection);
 }
 
 #undef _DEG_TO_RAD