opengl 3.3 renderer integration, minor renderer tweaks

opengl33geometrybank.h

@@ -0,0 +1,72 @@
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+#pragma once
+
+#include "geometrybank.h"
+#include "gl/buffer.h"
+#include "gl/vao.h"
+
+namespace gfx {
+
+// opengl vao/vbo-based variant of the geometry bank
+
+class opengl33_vaogeometrybank : public geometry_bank {
+
+public:
+// constructors:
+    opengl33_vaogeometrybank() = default;
+// destructor
+    ~opengl33_vaogeometrybank() {
+        delete_buffer(); }
+// methods:
+    static
+    void
+        reset() {;}
+
+private:
+// types:
+    struct chunk_record{
+        std::size_t offset{ 0 }; // beginning of the chunk data as offset from the beginning of the last established buffer
+        std::size_t size{ 0 }; // size of the chunk in the last established buffer
+        bool is_good{ false }; // true if local content of the chunk matches the data on the opengl end
+    };
+
+    typedef std::vector<chunk_record> chunkrecord_sequence;
+
+// methods:
+    // create() subclass details
+    void
+        create_( gfx::geometry_handle const &Geometry ) override;
+    // replace() subclass details
+    void
+        replace_( gfx::geometry_handle const &Geometry ) override;
+    // draw() subclass details
+    void
+        draw_( gfx::geometry_handle const &Geometry, gfx::stream_units const &Units, unsigned int const Streams ) override;
+    // release() subclass details
+    void
+        release_() override;
+    void
+        setup_buffer();
+    void
+        delete_buffer();
+
+// members:
+	std::optional<gl::buffer> m_buffer; // buffer data on the opengl end
+	std::optional<gl::vao> m_vao;
+    std::size_t m_buffercapacity{ 0 }; // total capacity of the last established buffer
+    chunkrecord_sequence m_chunkrecords; // helper data for all stored geometry chunks, in matching order
+    // vectors for glMultiDrawArrays in class scope
+    // to don't waste time on reallocating
+    std::vector<GLint> m_offsets;
+    std::vector<GLsizei> m_counts;
+};
+
+} // namespace gfx