[gdl/pgriffis/meson-build: 1/2] Use more portable definition of PI G_PI

[Patrick Griffis <pgriffis src gnome org>]

commit 846f51c860627e181a6316a7117ce1525ae5b4da
Author: Patrick Griffis <pgriffis igalia com>
Date:   Mon Oct 18 10:57:20 2021 -0500

    Use more portable definition of PI G_PI

 gdl/gdl-dock-item-button-image.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/gdl/gdl-dock-item-button-image.c b/gdl/gdl-dock-item-button-image.c
index ebdd23c..301ebcc 100644
--- a/gdl/gdl-dock-item-button-image.c
+++ b/gdl/gdl-dock-item-button-image.c
@@ -68,13 +68,13 @@ gdl_dock_item_button_image_draw (GtkWidget      *widget,
 
     /* Draw the icon border */
     cairo_move_to (cr, 10.5, 2.5);
-    cairo_arc (cr, 10.5, 4.5, 2, -0.5 * M_PI, 0);
+    cairo_arc (cr, 10.5, 4.5, 2, -0.5 * G_PI, 0);
     cairo_line_to (cr, 12.5, 10.5);
-    cairo_arc (cr, 10.5, 10.5, 2, 0, 0.5 * M_PI);
+    cairo_arc (cr, 10.5, 10.5, 2, 0, 0.5 * G_PI);
     cairo_line_to (cr, 4.5, 12.5);
-    cairo_arc (cr, 4.5, 10.5, 2, 0.5 * M_PI, M_PI);
+    cairo_arc (cr, 4.5, 10.5, 2, 0.5 * G_PI, G_PI);
     cairo_line_to (cr, 2.5, 4.5);
-    cairo_arc (cr, 4.5, 4.5, 2, M_PI, 1.5 * M_PI);
+    cairo_arc (cr, 4.5, 4.5, 2, G_PI, 1.5 * G_PI);
     cairo_close_path (cr);
 
     cairo_stroke (cr);