drawable.h

/********************************************************************
 * Copyright (C) 2015 Liangliang Nan <liangliang.nan@gmail.com>
 * https://3d.bk.tudelft.nl/liangliang/
 *
 * This file is part of Easy3D. If it is useful in your research/work,
 * I would be grateful if you show your appreciation by citing it:
 * ------------------------------------------------------------------
 *      Liangliang Nan.
 *      Easy3D: a lightweight, easy-to-use, and efficient C++ library
 *      for processing and rendering 3D data.
 *      Journal of Open Source Software, 6(64), 3255, 2021.
 * ------------------------------------------------------------------
 *
 * Easy3D is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 3
 * as published by the Free Software Foundation.
 *
 * Easy3D 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, see <http://www.gnu.org/licenses/>.
 ********************************************************************/
 
#ifndef EASY3D_RENDERER_DRAWABLE_H
#define EASY3D_RENDERER_DRAWABLE_H
 
#include <string>
#include <vector>
#include <functional>
 
#include <easy3d/core/types.h>
#include <easy3d/renderer/state.h>
 
namespace easy3d {
 
    class Model;
    class Camera;
    class Manipulator;
    class VertexArrayObject;
 
    class Drawable : public State {
    public:
        // three types of drawables
        enum Type {
            DT_POINTS = 0x0000,     // == GL_POINTS
            DT_LINES = 0x0001,      // == GL_LINES
            DT_TRIANGLES = 0x0004   // == GL_TRIANGLES
        };
 
    public:
        // a drawable can be stand-alone or attached to a model
        explicit Drawable(const std::string &name = "unknown", Model *model = nullptr);
        ~Drawable() override;
 
        virtual Type type() const = 0;
 
        const std::string &name() const { return name_; }
        void set_name(const std::string& n) { name_ = n; }
 
        Model *model() { return model_; }
        const Model *model() const { return model_; }
        void set_model(Model *m) { model_ = m; }
 
        const Box3 &bounding_box() const;
 
        State& state() { return *this; };
        const State& state() const { return *this; };
        void set_state(const State& s) { state() = s; };
 
        void buffer_stats(std::ostream &output) const;
 
        unsigned int vertex_buffer() const { return vertex_buffer_; }
        unsigned int color_buffer() const { return color_buffer_; }
        unsigned int normal_buffer() const { return normal_buffer_; }
        unsigned int texcoord_buffer() const { return texcoord_buffer_; }
        unsigned int element_buffer() const { return element_buffer_; }
 
        void update_vertex_buffer(const std::vector<vec3> &vertices, bool dynamic = false);
        void update_color_buffer(const std::vector<vec3> &colors, bool dynamic = false);
        void update_normal_buffer(const std::vector<vec3> &normals, bool dynamic = false);
        void update_texcoord_buffer(const std::vector<vec2> &texcoords, bool dynamic = false);
        void update_element_buffer(const std::vector<unsigned int> &elements);
        void update_element_buffer(const std::vector< std::vector<unsigned int> > &elements);
 
        void disable_element_buffer();
 
 
        std::size_t num_vertices() const { return num_vertices_; }
 
 
        virtual void draw(const Camera *camera) const = 0;
 
        void gl_draw() const;
 
        void update();
 
        void set_update_func(const std::function<void(Model*, Drawable*)>& func) { update_func_ = func; }
 
 
 
        Manipulator* manipulator();
        const Manipulator* manipulator() const;
 
        void set_manipulator(Manipulator* manip) { manipulator_ = manip; }
 
        mat4 manipulated_matrix() const;
 
        VertexArrayObject *vao() { return vao_; }
        const VertexArrayObject *vao() const { return vao_; }
 
    protected:
        // actual update of the rendering buffers are here
        virtual void update_buffers_internal();
 
        void clear();
 
    protected:
        std::string name_;
        Model *model_;
        Box3 bbox_;
 
        // vertex array object
        VertexArrayObject *vao_;
 
        std::size_t num_vertices_;
        std::size_t num_indices_;
 
        bool update_needed_;
        std::function<void(Model*, Drawable*)> update_func_;
 
        unsigned int vertex_buffer_;
        unsigned int color_buffer_;
        unsigned int normal_buffer_;
        unsigned int texcoord_buffer_;
        unsigned int element_buffer_;
 
        // drawables not attached to a model can also be manipulated
        Manipulator* manipulator_;   // for manipulation
    };
 
}
 
 
#endif  // EASY3D_RENDERER_DRAWABLE_H