Fix region clipping issues when using fractional scaling (#777)

* Fix region clipping issues

* Update libmuffin0.symbols

* clutter-stage-cogl: Fix uninitialized variable use_clipped_redraw

* clutter/stage-cogl: Avoid copying fb_clip_region

* Fix intents

Author: Sunderland93

clutter/clutter/clutter-damage-history.c

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2007,2008,2009,2010,2011  Intel Corporation.
+ * Copyright (C) 2020 Red Hat Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "clutter-build-config.h"
+
+#include "clutter-damage-history.h"
+
+#define DAMAGE_HISTORY_LENGTH 0x10
+
+struct _ClutterDamageHistory
+{
+    cairo_region_t *damages[DAMAGE_HISTORY_LENGTH];
+    int index;
+};
+
+ClutterDamageHistory *
+clutter_damage_history_new (void)
+{
+    ClutterDamageHistory *history;
+
+    history = g_new0 (ClutterDamageHistory, 1);
+
+    return history;
+}
+
+void
+clutter_damage_history_free (ClutterDamageHistory *history)
+{
+    int i;
+
+    for (i = 0; i < G_N_ELEMENTS (history->damages); i++)
+        g_clear_pointer (&history->damages[i], cairo_region_destroy);
+
+    g_free (history);
+}
+
+gboolean
+clutter_damage_history_is_age_valid (ClutterDamageHistory *history,
+                                     int                   age)
+{
+    if (age >= DAMAGE_HISTORY_LENGTH ||
+        age < 1)
+        return FALSE;
+
+    if (!clutter_damage_history_lookup (history, age))
+        return FALSE;
+
+    return TRUE;
+}
+
+void
+clutter_damage_history_record (ClutterDamageHistory *history,
+                               const cairo_region_t *damage)
+{
+    g_clear_pointer (&history->damages[history->index], cairo_region_destroy);
+    history->damages[history->index] = cairo_region_copy (damage);
+}
+
+static inline int
+step_damage_index (int current,
+                   int diff)
+{
+    return (current + diff) & (DAMAGE_HISTORY_LENGTH - 1);
+}
+
+void
+clutter_damage_history_step (ClutterDamageHistory *history)
+{
+    history->index = step_damage_index (history->index, 1);
+}
+
+const cairo_region_t *
+clutter_damage_history_lookup (ClutterDamageHistory *history,
+                               int                   age)
+{
+    return history->damages[step_damage_index (history->index, -age)];
+}

clutter/clutter/clutter-damage-history.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2007,2008,2009,2010,2011  Intel Corporation.
+ * Copyright (C) 2020 Red Hat Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef CLUTTER_DAMAGE_HISTORY_H
+#define CLUTTER_DAMAGE_HISTORY_H
+
+#include <cairo.h>
+#include <glib.h>
+
+typedef struct _ClutterDamageHistory ClutterDamageHistory;
+
+ClutterDamageHistory * clutter_damage_history_new (void);
+
+void clutter_damage_history_free (ClutterDamageHistory *history);
+
+gboolean clutter_damage_history_is_age_valid (ClutterDamageHistory *history,
+                                              int                   age);
+
+void clutter_damage_history_record (ClutterDamageHistory *history,
+                                    const cairo_region_t *damage);
+
+void clutter_damage_history_step (ClutterDamageHistory *history);
+
+const cairo_region_t * clutter_damage_history_lookup (ClutterDamageHistory *history,
+                                                      int                   age);
+
+#endif /* CLUTTER_DAMAGE_HISTORY_H */

clutter/clutter/clutter-stage-view-private.h

@@ -20,17 +20,28 @@
 
 #include "clutter/clutter-stage-view.h"
 
-void clutter_stage_view_after_paint (ClutterStageView *view);
+void clutter_stage_view_after_paint (ClutterStageView *view,
+                                     cairo_region_t   *redraw_clip);
+
+void clutter_stage_view_before_swap_buffer (ClutterStageView     *view,
+                                            const cairo_region_t *swap_region);
 
 gboolean clutter_stage_view_is_dirty_viewport (ClutterStageView *view);
 
-void clutter_stage_view_set_dirty_viewport (ClutterStageView *view,
-                                            gboolean          dirty);
+void clutter_stage_view_invalidate_viewport (ClutterStageView *view);
+
+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_invalidate_projection (ClutterStageView *view);
+
+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);
@@ -43,4 +54,11 @@ const cairo_region_t * clutter_stage_view_peek_redraw_clip (ClutterStageView *vi
 
 cairo_region_t * clutter_stage_view_take_redraw_clip (ClutterStageView *view);
 
+
+void clutter_stage_view_transform_rect_to_onscreen (ClutterStageView            *view,
+                                                    const cairo_rectangle_int_t *src_rect,
+                                                    int                          dst_width,
+                                                    int                          dst_height,
+                                                    cairo_rectangle_int_t       *dst_rect);
+
 #endif /* __CLUTTER_STAGE_VIEW_PRIVATE_H__ */