dmabufformats: Add GdkDmabufFormatsBuilder

This is a utility object that helps in constructing GdkDmabufFormats.

gdk/gdkdmabufformats.c

@@ -207,3 +207,9 @@ gdk_dmabuf_formats_new (GdkDmabufFormat *formats,
 
   return self;
 }
+
+const GdkDmabufFormat *
+gdk_dmabuf_formats_peek_formats (GdkDmabufFormats *self)
+{
+  return self->formats;
+}

gdk/gdkdmabufformatsbuilder.c

@@ -0,0 +1,133 @@
+/* gdkdmabufformats.c
+ *
+ * Copyright 2023 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 <config.h>
+
+#include "gdkdmabufformatsbuilderprivate.h"
+
+#include "gdkdmabufformatsprivate.h"
+
+#define GDK_ARRAY_NAME gdk_dmabuf_formats_builder
+#define GDK_ARRAY_TYPE_NAME GdkDmabufFormatsBuilder
+#define GDK_ARRAY_ELEMENT_TYPE GdkDmabufFormat
+#define GDK_ARRAY_BY_VALUE 1
+#define GDK_ARRAY_PREALLOC 1024
+#define GDK_ARRAY_NO_MEMSET 1
+#include "gdk/gdkarrayimpl.c"
+
+/* NB: We keep duplicates in the list for ease of use. Only when creating the final
+ * GdkDmabufFormats do we actually remove duplicates.
+ */
+
+GdkDmabufFormatsBuilder *
+gdk_dmabuf_formats_builder_new (void)
+{
+  GdkDmabufFormatsBuilder *result = g_new (GdkDmabufFormatsBuilder, 1);
+
+  gdk_dmabuf_formats_builder_init (result);
+
+  return result;
+}
+
+static int
+gdk_dmabuf_format_compare (gconstpointer data_a,
+                           gconstpointer data_b)
+{
+  const GdkDmabufFormat *a = data_a;
+  const GdkDmabufFormat *b = data_b;
+
+  if (a->fourcc == b->fourcc)
+    return (a->modifier - b->modifier) >> 8 * (sizeof (gint64) - sizeof (gint));
+  else
+    return a->fourcc - b->fourcc;
+
+}
+
+static gboolean
+gdk_dmabuf_format_equal (gconstpointer data_a,
+                         gconstpointer data_b)
+{
+  const GdkDmabufFormat *a = data_a;
+  const GdkDmabufFormat *b = data_b;
+
+  return a->fourcc == b->fourcc
+      && a->modifier == b->modifier;
+}
+
+static void
+gdk_dmabuf_formats_builder_sort (GdkDmabufFormatsBuilder *self)
+{
+  qsort (gdk_dmabuf_formats_builder_get_data (self),
+         sizeof (GdkDmabufFormat),
+         gdk_dmabuf_formats_builder_get_size (self),
+         gdk_dmabuf_format_compare);
+}
+
+/* list must be sorted */
+static void
+gdk_dmabuf_formats_builder_remove_duplicates (GdkDmabufFormatsBuilder *self)
+{
+  gsize i, j;
+
+  for (i = 1, j = 0; i < gdk_dmabuf_formats_builder_get_size (self); i++)
+    {
+      if (gdk_dmabuf_format_equal (gdk_dmabuf_formats_builder_get (self, i),
+                                   gdk_dmabuf_formats_builder_get (self, j)))
+        continue;
+
+      j++;
+      if (i != j)
+        *gdk_dmabuf_formats_builder_index (self, j) = *gdk_dmabuf_formats_builder_index (self, i);
+    }
+}
+
+GdkDmabufFormats *
+gdk_dmabuf_formats_builder_free_to_formats (GdkDmabufFormatsBuilder *self)
+{
+  GdkDmabufFormats *formats;
+
+  gdk_dmabuf_formats_builder_sort (self);
+  gdk_dmabuf_formats_builder_remove_duplicates (self);
+
+  formats = gdk_dmabuf_formats_new (gdk_dmabuf_formats_builder_get_data (self),
+                                    gdk_dmabuf_formats_builder_get_size (self));
+  gdk_dmabuf_formats_builder_clear (self);
+  g_free (self);
+
+  return formats;
+}
+
+void
+gdk_dmabuf_formats_builder_add_format (GdkDmabufFormatsBuilder *self,
+                                       guint32                  fourcc,
+                                       guint64                  modifier)
+{
+  gdk_dmabuf_formats_builder_append (self, &(GdkDmabufFormat) { fourcc, modifier });
+}
+
+void
+gdk_dmabuf_formats_builder_add_formats (GdkDmabufFormatsBuilder *self,
+                                        GdkDmabufFormats        *formats)
+{
+  gdk_dmabuf_formats_builder_splice (self,
+                                     gdk_dmabuf_formats_builder_get_size (self),
+                                     0,
+                                     FALSE,
+                                     gdk_dmabuf_formats_peek_formats (formats),
+                                     gdk_dmabuf_formats_get_n_formats (formats));
+}

gdk/gdkdmabufformatsbuilderprivate.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "gdkdmabufformats.h"
+
+typedef struct GdkDmabufFormatsBuilder GdkDmabufFormatsBuilder;
+
+GdkDmabufFormatsBuilder *       gdk_dmabuf_formats_builder_new                  (void);
+GdkDmabufFormats *              gdk_dmabuf_formats_builder_free_to_formats      (GdkDmabufFormatsBuilder        *self);
+
+void                            gdk_dmabuf_formats_builder_add_format           (GdkDmabufFormatsBuilder        *self,
+                                                                                 guint32                         fourcc,
+                                                                                 guint64                         modifier);
+void                            gdk_dmabuf_formats_builder_add_formats          (GdkDmabufFormatsBuilder        *self,
+                                                                                 GdkDmabufFormats               *formats);

gdk/gdkdmabufformatsprivate.h

@@ -9,5 +9,7 @@ struct _GdkDmabufFormat
   guint64 modifier;
 };
 
-GdkDmabufFormats *gdk_dmabuf_formats_new (GdkDmabufFormat *formats,
-                                          gsize            n_formats);
+GdkDmabufFormats *      gdk_dmabuf_formats_new                  (GdkDmabufFormat  *formats,
+                                                                 gsize             n_formats);
+
+const GdkDmabufFormat * gdk_dmabuf_formats_peek_formats         (GdkDmabufFormats *self);

gdk/meson.build

@@ -18,6 +18,7 @@ gdk_public_sources = files([
   'gdkdisplay.c',
   'gdkdisplaymanager.c',
   'gdkdmabufformats.c',
+  'gdkdmabufformatsbuilder.c',
   'gdkdmabuftexture.c',
   'gdkdmabuftexturebuilder.c',
   'gdkdrag.c',