GPUBatch: Move allocator to backend

source/blender/gpu/opengl/gl_backend.hh

@@ -27,6 +27,7 @@
 
 #include "BLI_vector.hh"
 
+#include "gl_batch.hh"
 #include "gl_context.hh"
 #include "gl_drawlist.hh"
 
@@ -43,6 +44,11 @@ class GLBackend : public GPUBackend {
     return new GLContext(ghost_window, shared_orphan_list_);
   };
 
+  Batch *batch_alloc(void)
+  {
+    return new GLBatch();
+  };
+
   DrawList *drawlist_alloc(int list_length)
   {
     return new GLDrawList(list_length);

source/blender/gpu/opengl/gl_batch.cc

@@ -0,0 +1,50 @@
+/*
+ * 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) 2016 by Mike Erwin.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ *
+ * GL implementation of GPUBatch.
+ * The only specificity of GL here is that it caches a list of
+ * Vertex Array Objects based on the bound shader interface.
+ */
+
+#include "BLI_assert.h"
+
+#include "glew-mx.h"
+
+#include "gpu_batch_private.hh"
+#include "gpu_primitive_private.h"
+
+#include "gl_batch.hh"
+
+using namespace blender::gpu;
+
+GLBatch::GLBatch(void)
+{
+}
+
+GLBatch::~GLBatch()
+{
+}
+
+void GLBatch::draw(int v_first, int v_count, int i_first, int i_count)
+{
+  UNUSED_VARS(v_first, v_count, i_first, i_count);
+}

source/blender/gpu/opengl/gl_batch.hh

@@ -0,0 +1,84 @@
+/*
+ * 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.
+ *
+ * Copyright 2020, Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ *
+ * GPU geometry batch
+ * Contains VAOs + VBOs + Shader representing a drawable entity.
+ */
+
+#pragma once
+
+#include "MEM_guardedalloc.h"
+
+#include "gpu_batch_private.hh"
+
+#include "glew-mx.h"
+
+#include "GPU_shader_interface.h"
+
+namespace blender {
+namespace gpu {
+
+#define GPU_BATCH_VAO_STATIC_LEN 3
+
+class GLVaoCache {
+  /* Vao management: remembers all geometry state (vertex attribute bindings & element buffer)
+   * for each shader interface. Start with a static number of vaos and fallback to dynamic count
+   * if necessary. Once a batch goes dynamic it does not go back. */
+  bool is_dynamic_vao_count = false;
+  union {
+    /** Static handle count */
+    struct {
+      const GPUShaderInterface *interfaces[GPU_BATCH_VAO_STATIC_LEN];
+      GLuint vao_ids[GPU_BATCH_VAO_STATIC_LEN];
+    } static_vaos;
+    /** Dynamic handle count */
+    struct {
+      uint count;
+      const GPUShaderInterface **interfaces;
+      GLuint *vao_ids;
+    } dynamic_vaos;
+  };
+
+  GLuint search(const GPUShaderInterface *interface);
+  void insert(GLuint vao_id, const GPUShaderInterface *interface);
+  void clear(void);
+  void interface_remove(const GPUShaderInterface *interface);
+};
+
+class GLBatch : public Batch {
+ private:
+  /** Cached values (avoid dereferencing later). */
+  GLuint vao_id;
+  /** All vaos corresponding to all the GPUShaderInterface this batch was drawn with. */
+  GLVaoCache vaos;
+
+ public:
+  GLBatch();
+  ~GLBatch();
+
+  void draw(int v_first, int v_count, int i_first, int i_count) override;
+
+  MEM_CXX_CLASS_ALLOC_FUNCS("GLBatch");
+};
+
+}  // namespace gpu
+}  // namespace blender