cpp-game-engine/graphics/include/game/graphics/renderer.hpp

//
//  renderer.hpp
//  graphics
//
//  Created by Sam Jaffe on 5/19/19.
//  Copyright © 2019 Sam Jaffe. All rights reserved.
//

#pragma once

#include <unordered_map>

#include "game/graphics/graphics_fwd.h"
#include "game/math/math_fwd.hpp"
#include "game/util/hash.hpp"
#include "matrix/matrix.hpp"
#include "vector/vector.hpp"

namespace graphics {
  struct renderer {
    virtual ~renderer() {}
    virtual std::shared_ptr<manager const> manager() const = 0;
    virtual void draw(object const & obj) = 0;
    virtual void draw(identity<material>, math::matr4 const &,
                      std::vector<vertex> const &) = 0;
    virtual void clear() = 0;
    virtual void flush() = 0;
  };

  enum class driver { openGL };

  class direct_renderer : public renderer {
  public:
    direct_renderer(driver d);
    std::shared_ptr<class manager const> manager() const override;
    void draw(object const & obj) override;
    void draw(identity<material>, math::matr4 const &,
              std::vector<vertex> const &) override;
    void clear() override;
    void flush() override;

  private:
    struct renderer_impl * pimpl;
  };

  class batch_renderer : public renderer {
  public:
    batch_renderer(renderer * impl, std::size_t batch_size = 0);
    batch_renderer(renderer * impl, math::matr4 const &,
                   std::size_t batch_size = 0);
    ~batch_renderer();
    std::shared_ptr<class manager const> manager() const override {
      return impl_->manager();
    }
    void draw(object const & obj) override;
    void draw(identity<material>, math::matr4 const &,
              std::vector<vertex> const &) override;
    void clear() override { impl_->clear(); }
    void flush() override;

  private:
    void check();
    void write();

  private:
    renderer * impl_;
    std::unordered_map<identity<material>, std::vector<vertex>> batches_;
    math::matr4 object_to_world_;
    std::size_t batch_size_;
    std::size_t elements_;
  };
}