Add GskStroke

A GskStroke struct collects the parameters that are
needed for stroking a path.

gsk/gskstrokeprivate.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * 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 2.1 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/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+
+#pragma once
+
+#include "gskstroke.h"
+
+G_BEGIN_DECLS
+
+struct _GskStroke
+{
+  float line_width;
+  GskLineCap line_cap;
+  GskLineJoin line_join;
+  float miter_limit;
+
+  float *dash;
+  gsize n_dash;
+  float dash_length; /* sum of all dashes in the array */
+  float dash_offset;
+};
+
+static inline void
+gsk_stroke_init_copy (GskStroke       *stroke,
+                      const GskStroke *other)
+{
+  *stroke = *other;
+
+  stroke->dash = g_memdup (other->dash, stroke->n_dash * sizeof (float));
+}
+
+static inline void
+gsk_stroke_clear (GskStroke *stroke)
+{
+  g_clear_pointer (&stroke->dash, g_free);
+  stroke->n_dash = 0; /* better safe than sorry */
+}
+
+float gsk_stroke_get_join_width (GskStroke);
+
+G_END_DECLS