region: Move RegionIterator to Mtk

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3501>

mtk/mtk/mtk-region.c

@@ -468,3 +468,50 @@ mtk_region_apply_matrix_transform_expand (const MtkRegion   *region,
 
   return transformed_region;
 }
+
+void
+mtk_region_iterator_init (MtkRegionIterator *iter,
+                          MtkRegion         *region)
+{
+  iter->region = region;
+  iter->i = 0;
+  iter->n_rectangles = mtk_region_num_rectangles (region);
+  iter->line_start = TRUE;
+
+  if (iter->n_rectangles > 1)
+    {
+      iter->rectangle = mtk_region_get_rectangle (region, 0);
+      iter->next_rectangle = mtk_region_get_rectangle (region, 1);
+
+      iter->line_end = iter->next_rectangle.y != iter->rectangle.y;
+    }
+  else if (iter->n_rectangles > 0)
+    {
+      iter->rectangle = mtk_region_get_rectangle (region, 0);
+      iter->line_end = TRUE;
+    }
+}
+
+gboolean
+mtk_region_iterator_at_end (MtkRegionIterator *iter)
+{
+  return iter->i >= iter->n_rectangles;
+}
+
+void
+mtk_region_iterator_next (MtkRegionIterator *iter)
+{
+  iter->i++;
+  iter->rectangle = iter->next_rectangle;
+  iter->line_start = iter->line_end;
+
+  if (iter->i + 1 < iter->n_rectangles)
+    {
+      iter->next_rectangle = mtk_region_get_rectangle (iter->region, iter->i + 1);
+      iter->line_end = iter->next_rectangle.y != iter->rectangle.y;
+    }
+  else
+    {
+      iter->line_end = TRUE;
+    }
+}

mtk/mtk/mtk-region.h

@@ -129,3 +129,50 @@ MtkRegion * mtk_region_apply_matrix_transform_expand (const MtkRegion   *region,
                                                       graphene_matrix_t *transform);
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (MtkRegion, mtk_region_unref)
+
+/**
+ * MtkRegionIterator:
+ * @region: region being iterated
+ * @rectangle: current rectangle
+ * @line_start: whether the current rectangle starts a horizontal band
+ * @line_end: whether the current rectangle ends a horizontal band
+ *
+ * MtkRegion is a yx banded region; sometimes its useful to iterate through
+ * such a region treating the start and end of each horizontal band in a distinct
+ * fashion.
+ *
+ * Usage:
+ *
+ * ```c
+ *  MtkRegionIterator iter;
+ *  for (mtk_region_iterator_init (&iter, region);
+ *       !mtk_region_iterator_at_end (&iter);
+ *       mtk_region_iterator_next (&iter))
+ *  {
+ *    [ Use iter.rectangle, iter.line_start, iter.line_end ]
+ *  }
+ *```
+ */
+typedef struct MtkaRegionIterator MtkRegionIterator;
+
+struct MtkaRegionIterator {
+  MtkRegion *region;
+  MtkRectangle rectangle;
+  gboolean line_start;
+  gboolean line_end;
+  int i;
+
+  /*< private >*/
+  int n_rectangles;
+  MtkRectangle next_rectangle;
+};
+
+MTK_EXPORT
+void mtk_region_iterator_init (MtkRegionIterator *iter,
+                               MtkRegion          *region);
+
+MTK_EXPORT
+gboolean mtk_region_iterator_at_end (MtkRegionIterator *iter);
+
+MTK_EXPORT
+void mtk_region_iterator_next (MtkRegionIterator *iter);

src/compositor/meta-shadow-factory.c

@@ -754,7 +754,7 @@ expand_region_inverse (MtkRegion *region,
                        gboolean   flip)
 {
   MetaRegionBuilder builder;
-  MetaRegionIterator iter;
+  MtkRegionIterator iter;
   MtkRectangle extents;
   int last_x;
 
@@ -775,9 +775,9 @@ expand_region_inverse (MtkRegion *region,
                      x_amount, y_amount, flip);
 
   last_x = extents.x;
-  for (meta_region_iterator_init (&iter, region);
+  for (mtk_region_iterator_init (&iter, region);
-       !meta_region_iterator_at_end (&iter);
+       !mtk_region_iterator_at_end (&iter);
-       meta_region_iterator_next (&iter))
+       mtk_region_iterator_next (&iter))
     {
       if (iter.rectangle.x > last_x)
         add_expanded_rect (&builder,

src/compositor/meta-window-shape.c

@@ -27,7 +27,7 @@
 
 #include <string.h>
 
-#include "compositor/region-utils.h"
+#include "mtk/mtk-region.h"
 
 struct _MetaWindowShape
 {
@@ -43,7 +43,7 @@ MetaWindowShape *
 meta_window_shape_new (MtkRegion *region)
 {
   MetaWindowShape *shape;
-  MetaRegionIterator iter;
+  MtkRegionIterator iter;
   MtkRectangle extents;
   int max_yspan_y1 = 0;
   int max_yspan_y2 = 0;
@@ -66,9 +66,9 @@ meta_window_shape_new (MtkRegion *region)
       return shape;
     }
 
-  for (meta_region_iterator_init (&iter, region);
+  for (mtk_region_iterator_init (&iter, region);
-       !meta_region_iterator_at_end (&iter);
+       !mtk_region_iterator_at_end (&iter);
-       meta_region_iterator_next (&iter))
+       mtk_region_iterator_next (&iter))
     {
       int max_line_xspan_x1 = -1;
       int max_line_xspan_x2 = -1;
@@ -117,9 +117,9 @@ meta_window_shape_new (MtkRegion *region)
   shape->rectangles = g_new (MtkRectangle, shape->n_rectangles);
 
   hash = 0;
-  for (meta_region_iterator_init (&iter, region);
+  for (mtk_region_iterator_init (&iter, region);
-       !meta_region_iterator_at_end (&iter);
+       !mtk_region_iterator_at_end (&iter);
-       meta_region_iterator_next (&iter))
+       mtk_region_iterator_next (&iter))
     {
       int x1, x2, y1, y2;
 

src/compositor/region-utils.c

@@ -126,56 +126,6 @@ meta_region_builder_finish (MetaRegionBuilder *builder)
   return result;
 }
 
-
-/* MetaRegionIterator */
-
-void
-meta_region_iterator_init (MetaRegionIterator *iter,
-                           MtkRegion          *region)
-{
-  iter->region = region;
-  iter->i = 0;
-  iter->n_rectangles = mtk_region_num_rectangles (region);
-  iter->line_start = TRUE;
-
-  if (iter->n_rectangles > 1)
-    {
-      iter->rectangle = mtk_region_get_rectangle (region, 0);
-      iter->next_rectangle = mtk_region_get_rectangle (region, 1);
-
-      iter->line_end = iter->next_rectangle.y != iter->rectangle.y;
-    }
-  else if (iter->n_rectangles > 0)
-    {
-      iter->rectangle = mtk_region_get_rectangle (region, 0);
-      iter->line_end = TRUE;
-    }
-}
-
-gboolean
-meta_region_iterator_at_end (MetaRegionIterator *iter)
-{
-  return iter->i >= iter->n_rectangles;
-}
-
-void
-meta_region_iterator_next (MetaRegionIterator *iter)
-{
-  iter->i++;
-  iter->rectangle = iter->next_rectangle;
-  iter->line_start = iter->line_end;
-
-  if (iter->i + 1 < iter->n_rectangles)
-    {
-      iter->next_rectangle = mtk_region_get_rectangle (iter->region, iter->i + 1);
-      iter->line_end = iter->next_rectangle.y != iter->rectangle.y;
-    }
-  else
-    {
-      iter->line_end = TRUE;
-    }
-}
-
 MtkRegion *
 meta_region_transform (const MtkRegion      *region,
                        MetaMonitorTransform  transform,

src/compositor/region-utils.h

@@ -26,41 +26,6 @@
 #include "clutter/clutter.h"
 #include "core/boxes-private.h"
 
-/**
- * MetaRegionIterator:
- * @region: region being iterated
- * @rectangle: current rectangle
- * @line_start: whether the current rectangle starts a horizontal band
- * @line_end: whether the current rectangle ends a horizontal band
- *
- * MtkRegion is a yx banded region; sometimes its useful to iterate through
- * such a region treating the start and end of each horizontal band in a distinct
- * fashion.
- *
- * Usage:
- *
- *  MetaRegionIterator iter;
- *  for (meta_region_iterator_init (&iter, region);
- *       !meta_region_iterator_at_end (&iter);
- *       meta_region_iterator_next (&iter))
- *  {
- *    [ Use iter.rectangle, iter.line_start, iter.line_end ]
- *  }
- */
-typedef struct _MetaRegionIterator MetaRegionIterator;
-
-struct _MetaRegionIterator {
-  MtkRegion *region;
-  MtkRectangle rectangle;
-  gboolean line_start;
-  gboolean line_end;
-  int i;
-
-  /*< private >*/
-  int n_rectangles;
-  MtkRectangle next_rectangle;
-};
-
 typedef struct _MetaRegionBuilder MetaRegionBuilder;
 
 #define META_REGION_BUILDER_MAX_LEVELS 16
@@ -87,11 +52,6 @@ void     meta_region_builder_add_rectangle (MetaRegionBuilder *builder,
                                             int                height);
 MtkRegion * meta_region_builder_finish (MetaRegionBuilder *builder);
 
-void     meta_region_iterator_init      (MetaRegionIterator *iter,
-                                         MtkRegion          *region);
-gboolean meta_region_iterator_at_end    (MetaRegionIterator *iter);
-void     meta_region_iterator_next      (MetaRegionIterator *iter);
-
 MtkRegion * meta_region_transform (const MtkRegion      *region,
                                    MetaMonitorTransform  transform,
                                    int                   width,