lib: create scaffolding for DMA-BUF texture

This will eventually be used with two copies of the texture, and then
swap between them.

lib/mks-dmabuf-texture-private.h

@@ -0,0 +1,37 @@
+/*
+ * mks-dmabuf-texture-private.h
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <gdk/gdk.h>
+
+G_BEGIN_DECLS
+
+GdkTexture *mks_dmabuf_texture_new (int        dmabuf_fd,
+                                    guint      width,
+                                    guint      height,
+                                    guint      stride,
+                                    guint      fourcc,
+                                    guint64    modifier,
+                                    gboolean   y0_top,
+                                    GError   **error);
+
+G_END_DECLS

lib/mks-dmabuf-texture.c

@@ -0,0 +1,57 @@
+/*
+ * mks-dmabuf-texture.c
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include "mks-dmabuf-texture-private.h"
+
+GdkTexture *
+mks_dmabuf_texture_new (int        dmabuf_fd,
+                        guint      width,
+                        guint      height,
+                        guint      stride,
+                        guint      fourcc,
+                        guint64    modifier,
+                        gboolean   y0_top,
+                        GError   **error)
+{
+  if G_UNLIKELY (dmabuf_fd < 0)
+    {
+      g_set_error_literal (error,
+                           G_IO_ERROR,
+                           G_IO_ERROR_INVALID_ARGUMENT,
+                           "Invalid FD for DMA-BUF");
+      return NULL;
+    }
+
+  if G_UNLIKELY (width == 0 || height == 0 || stride == 0)
+    {
+      g_set_error_literal (error,
+                           G_IO_ERROR,
+                           G_IO_ERROR_INVALID_ARGUMENT,
+                           "Invalid width/height/stride");
+      return NULL;
+    }
+
+  /* TODO: use dmabuf importing code here */
+
+  return NULL;
+}