fix crash when zooming in on audio regions

Fixes https://todo.sr.ht/~alextee/zrythm-bug/909.

inc/utils/gtk.h

@@ -1,21 +1,5 @@
-/*
- * Copyright (C) 2018-2022 Alexandros Theodotou <alex at zrythm dot org>
- *
- * This file is part of Zrythm
- *
- * Zrythm is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Zrythm 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 Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with Zrythm.  If not, see <https://www.gnu.org/licenses/>.
- */
+// SPDX-FileCopyrightText: © 2018-2022 Alexandros Theodotou <alex@zrythm.org>
+// SPDX-License-Identifier: LicenseRef-ZrythmLicense
 
 /**
  * \file
@@ -772,6 +756,9 @@ z_gtk_widget_find_child_of_type (
 void
 z_gtk_list_box_remove_all_children (GtkListBox * list_box);
 
+void
+z_graphene_rect_print (const graphene_rect_t * rect);
+
 /**
  * @}
  */

src/gui/widgets/region.c

@@ -856,7 +856,7 @@ draw_fade_part (
     }
 
   const int step = 1;
-  if (fade_in_px - start_px != 0)
+  if (vis_fade_in_px - vis_start_px > 0)
     {
       double local_px_diff = (double) (fade_in_px - start_px);
 
@@ -864,11 +864,11 @@ draw_fade_part (
       cairo_t * cr = NULL;
       if (use_cairo)
         {
-          cr = gtk_snapshot_append_cairo (
-            snapshot,
-            &GRAPHENE_RECT_INIT (
-              vis_start_px, 0, vis_fade_in_px - vis_start_px,
-              height));
+          graphene_rect_t grect = GRAPHENE_RECT_INIT (
+            vis_start_px, 0, vis_fade_in_px - vis_start_px,
+            height);
+          /*z_graphene_rect_print (&grect);*/
+          cr = gtk_snapshot_append_cairo (snapshot, &grect);
           cairo_set_source_rgba (cr, 0.2, 0.2, 0.2, 0.6);
           /*cairo_set_line_width (cr, 3);*/
         }
@@ -916,10 +916,11 @@ draw_fade_part (
             }
           else
             {
+              graphene_rect_t grect = GRAPHENE_RECT_INIT (
+                (float) i, 0, (float) step, draw_y_val);
+              /*z_graphene_rect_print (&grect);*/
               gtk_snapshot_append_color (
-                snapshot, &color,
-                &GRAPHENE_RECT_INIT (
-                  (float) i, 0, (float) step, draw_y_val));
+                snapshot, &color, &grect);
             }
         }
 
@@ -941,7 +942,7 @@ draw_fade_part (
   int visible_fade_out_px = MAX (fade_out_px, vis_offset_x);
   int visible_end_px = MIN (end_px, vis_offset_x + vis_width);
 
-  if (end_px - fade_out_px != 0)
+  if (visible_end_px - visible_fade_out_px > 0)
     {
       double local_px_diff = (double) (end_px - fade_out_px);
 
@@ -949,11 +950,11 @@ draw_fade_part (
       cairo_t * cr = NULL;
       if (use_cairo)
         {
-          cr = gtk_snapshot_append_cairo (
-            snapshot,
-            &GRAPHENE_RECT_INIT (
-              visible_fade_out_px, 0,
-              visible_end_px - visible_fade_out_px, height));
+          graphene_rect_t grect = GRAPHENE_RECT_INIT (
+            visible_fade_out_px, 0,
+            visible_end_px - visible_fade_out_px, height);
+          /*z_graphene_rect_print (&grect);*/
+          cr = gtk_snapshot_append_cairo (snapshot, &grect);
           cairo_set_source_rgba (cr, 0.2, 0.2, 0.2, 0.6);
           /*cairo_set_line_width (cr, 3);*/
         }
@@ -1001,10 +1002,11 @@ draw_fade_part (
           else
             {
               float draw_y_val = (float) (val * height);
+              graphene_rect_t grect = GRAPHENE_RECT_INIT (
+                (float) i, 0, 1, draw_y_val);
+              /*z_graphene_rect_print (&grect);*/
               gtk_snapshot_append_color (
-                snapshot, &color,
-                &GRAPHENE_RECT_INIT (
-                  (float) i, 0, 1, draw_y_val));
+                snapshot, &color, &grect);
             }
         }
 

src/utils/gtk.c

@@ -2154,3 +2154,13 @@ z_gtk_list_box_remove_all_children (GtkListBox * list_box)
       gtk_list_box_remove (list_box, GTK_WIDGET (row));
     }
 }
+
+void
+z_graphene_rect_print (const graphene_rect_t * rect)
+{
+  g_return_if_fail (rect->size.width >= 0);
+  g_return_if_fail (rect->size.height >= 0);
+  g_message (
+    "graphene rect: x %f y %f w %f h %f", rect->origin.x,
+    rect->origin.y, rect->size.width, rect->size.height);
+}