GPUIndexBuf: GL backend Isolation

This is part of the Vulkan backend task T68990.

There is no real change, only making some code re-organisation.
This also make the IndexBuf completely abstract from outside the
GPU module.

1 files changed, 68 insertions, 0 deletions

diff --git a/source/blender/gpu/opengl/gl_index_buffer.hh b/source/blender/gpu/opengl/gl_index_buffer.hh
new file mode 100644
index 00000000000..b84934bb77f
--- /dev/null
+++ b/source/blender/gpu/opengl/gl_index_buffer.hh
@@ -0,0 +1,68 @@
+/*
+ * 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 2
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ */
+
+#pragma once
+
+#include "MEM_guardedalloc.h"
+
+#include "gpu_index_buffer_private.hh"
+
+#include "glew-mx.h"
+
+namespace blender::gpu {
+
+class GLIndexBuf : public IndexBuf {
+  friend class GLBatch;
+  friend class GLDrawList;
+
+ private:
+  GLuint ibo_id_ = 0;
+
+ public:
+  ~GLIndexBuf();
+
+  void bind(void);
+
+  void *offset_ptr(uint additional_vertex_offset) const
+  {
+    additional_vertex_offset += index_start_;
+    if (index_type_ == GPU_INDEX_U32) {
+      return (GLuint *)0 + additional_vertex_offset;
+    }
+    return (GLushort *)0 + additional_vertex_offset;
+  }
+
+  GLuint restart_index(void) const
+  {
+    return (index_type_ == GPU_INDEX_U16) ? 0xFFFFu : 0xFFFFFFFFu;
+  }
+
+  MEM_CXX_CLASS_ALLOC_FUNCS("GLIndexBuf")
+};
+
+static inline GLenum to_gl(GPUIndexBufType type)
+{
+  return (type == GPU_INDEX_U32) ? GL_UNSIGNED_INT : GL_UNSIGNED_SHORT;
+}
+
+}  // namespace blender::gpu