early implementation of geometry bank, partial replacement of math classes with glm

openglgeometrybank.h

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+/*
+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 <vector>
+#include <glm/glm.hpp>
+#include <glm/gtc/type_ptr.hpp>
+#include "GL/glew.h"
+#ifdef _WINDOWS
+#include "GL/wglew.h"
+#endif
+
+struct basic_vertex {
+    glm::vec3 position; // 3d space
+    glm::vec3 normal; // 3d space
+    glm::vec2 texture; // uv space
+
+    void serialize( std::ostream& );
+    void deserialize( std::istream& );
+};
+
+typedef std::vector<basic_vertex> vertex_array;
+
+// generic geometry bank class, allows storage, update and drawing of geometry chunks
+
+typedef std::size_t geometrychunk_handle;
+
+class geometry_bank {
+
+public:
+// types:
+
+// constructors:
+
+// destructor:
+    virtual
+        ~geometry_bank() { ; }
+
+// methods:
+    // creates a new geometry chunk of specified type from supplied vertex data. returns: handle to the chunk or NULL
+    virtual
+    geometrychunk_handle
+        create( vertex_array &Vertices, int const Datatype );
+    // replaces data of specified chunk with the supplied vertex data, starting from specified offset
+    virtual
+    bool
+        replace( vertex_array &Vertices, geometrychunk_handle const Chunk, std::size_t const Offset = 0 );
+    // draws geometry stored in specified chunk
+    virtual
+    void
+        draw( geometrychunk_handle const Chunk ) = 0;
+    // draws geometry stored in supplied list of chunks
+    template <typename _Iterator>
+    void
+        draw( _Iterator First, _Iterator Last ) { while( First != Last ) { draw( *First ); ++First; } }
+    vertex_array &
+        data( geometrychunk_handle const Chunk );
+
+protected:
+// types:
+    struct geometry_chunk {
+        int type; // kind of geometry used by the chunk
+        vertex_array vertices; // geometry data
+
+        geometry_chunk( vertex_array &Vertices, int const Datatype ) :
+                            vertices( Vertices ),   type( Datatype )
+        {}
+    };
+
+    typedef std::vector<geometry_chunk> geometrychunk_sequence;
+
+// members:
+    geometrychunk_sequence m_chunks;
+
+};
+
+// opengl vbo-based variant of the geometry bank
+
+class opengl_vbogeometrybank : public geometry_bank {
+
+public:
+// methods:
+    // creates a new geometry chunk of specified type from supplied vertex data. returns: handle to the chunk or NULL
+    geometrychunk_handle
+        create( vertex_array &Vertices, int const Datatype );
+    // replaces data of specified chunk with the supplied vertex data, starting from specified offset
+    bool
+        replace( vertex_array &Vertices, geometrychunk_handle const Chunk, std::size_t const Offset = 0 );
+    // draws geometry stored in specified chunk
+    void
+        draw( geometrychunk_handle const Chunk );
+
+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:
+    void
+        bind_buffer();
+    void
+        delete_buffer();
+
+// members:
+    static GLuint m_activebuffer; // buffer bound currently on the opengl end, if any
+    GLuint m_buffer{ NULL }; // id of the buffer holding data on the opengl end
+    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
+
+};