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, 62 insertions, 0 deletions

diff --git a/source/blender/gpu/opengl/gl_index_buffer.cc b/source/blender/gpu/opengl/gl_index_buffer.cc
new file mode 100644
index 00000000000..03a9607a00b
--- /dev/null
+++ b/source/blender/gpu/opengl/gl_index_buffer.cc
@@ -0,0 +1,62 @@
+/*
+ * 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
+ */
+
+#include "gl_backend.hh"
+#include "gl_debug.hh"
+
+#include "gl_index_buffer.hh"
+
+namespace blender::gpu {
+
+GLIndexBuf::~GLIndexBuf()
+{
+  GLBackend::get()->buf_free(ibo_id_);
+}
+
+void GLIndexBuf::bind(void)
+{
+  if (is_subrange_) {
+    static_cast<GLIndexBuf *>(src_)->bind();
+    return;
+  }
+
+  if (ibo_id_ == 0) {
+    glGenBuffers(1, &ibo_id_);
+
+    if (data_ == nullptr) {
+      debug::raise_gl_error("Trying to use Index Buffer but the buffer contains no data");
+    }
+  }
+
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_id_);
+
+  if (data_ != nullptr) {
+    size_t size = this->size_get();
+    /* Sends data to GPU. */
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, size, data_, GL_STATIC_DRAW);
+    /* No need to keep copy of data in system memory. */
+    MEM_SAFE_FREE(data_);
+  }
+}
+
+}  // namespace blender::gpu
\ No newline at end of file