1 files changed, 82 insertions, 0 deletions
diff --git a/gsk/gl/gskglbufferprivate.h b/gsk/gl/gskglbufferprivate.h
new file mode 100644
index 0000000000..3f783898f0
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+++ b/gsk/gl/gskglbufferprivate.h
@@ -0,0 +1,82 @@
+/* gskglbufferprivate.h
+ *
+ * Copyright 2020 Christian Hergert <chergert@redhat.com>
+ *
+ * This file 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 file 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 General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef __GSK_GL_BUFFER_PRIVATE_H__
+#define __GSK_GL_BUFFER_PRIVATE_H__
+
+#include "gskgltypesprivate.h"
+
+G_BEGIN_DECLS
+
+typedef struct _GskGLBuffer
+{
+  guint8 *buffer;
+  gsize   buffer_pos;
+  gsize   buffer_len;
+  guint   count;
+  GLenum  target;
+  gsize   element_size;
+} GskGLBuffer;
+
+void   gsk_gl_buffer_init    (GskGLBuffer *self,
+                              GLenum       target,
+                              guint        element_size);
+void   gsk_gl_buffer_destroy (GskGLBuffer *buffer);
+GLuint gsk_gl_buffer_submit  (GskGLBuffer *buffer);
+
+static inline gpointer
+gsk_gl_buffer_advance (GskGLBuffer *buffer,
+                       guint         count)
+{
+  gpointer ret;
+  gsize to_alloc = count * buffer->element_size;
+
+  if G_UNLIKELY (buffer->buffer_pos + to_alloc > buffer->buffer_len)
+    {
+      while (buffer->buffer_pos + to_alloc > buffer->buffer_len)
+        buffer->buffer_len *= 2;
+      buffer->buffer = g_realloc (buffer->buffer, buffer->buffer_len);
+    }
+
+  ret = buffer->buffer + buffer->buffer_pos;
+
+  buffer->buffer_pos += to_alloc;
+  buffer->count += count;
+
+  return ret;
+}
+
+static inline void
+gsk_gl_buffer_retract (GskGLBuffer *buffer,
+                       guint        count)
+{
+  buffer->buffer_pos -= count * buffer->element_size;
+  buffer->count -= count;
+}
+
+static inline guint
+gsk_gl_buffer_get_offset (GskGLBuffer *buffer)
+{
+  return buffer->count;
+}
+
+G_END_DECLS
+
+#endif /* __GSK_GL_BUFFER_PRIVATE_H__ */