//
//  KRViewport.h
//  Kraken Engine
//
//  Copyright 2022 Kearwood Gilbert. All rights reserved.
//  
//  Redistribution and use in source and binary forms, with or without modification, are
//  permitted provided that the following conditions are met:
//  
//  1. Redistributions of source code must retain the above copyright notice, this list of
//  conditions and the following disclaimer.
//  
//  2. Redistributions in binary form must reproduce the above copyright notice, this list
//  of conditions and the following disclaimer in the documentation and/or other materials
//  provided with the distribution.
//  
//  THIS SOFTWARE IS PROVIDED BY KEARWOOD GILBERT ''AS IS'' AND ANY EXPRESS OR IMPLIED
//  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
//  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KEARWOOD GILBERT OR
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//

#pragma once

#include "KREngine-common.h"

#include "aabb.h"

class KRLight;

class KRViewport
{
public:
  KRViewport();
  KRViewport(const Vector2& size, const Matrix4& matView, const Matrix4& matProjection);
  ~KRViewport();

  const Vector2& getSize() const;
  const Matrix4& getViewMatrix() const;
  const Matrix4& getProjectionMatrix() const;
  const Matrix4& getViewProjectionMatrix() const;
  const Matrix4& getInverseViewMatrix() const;
  const Matrix4& getInverseProjectionMatrix() const;
  const Vector3& getCameraDirection() const;
  const Vector3& getCameraPosition() const;
  const int* getFrontToBackOrder() const;
  const int* getBackToFrontOrder() const;
  void setSize(const Vector2& size);
  void setViewMatrix(const Matrix4& matView);
  void setProjectionMatrix(const Matrix4& matProjection);
  float getLODBias() const;
  void setLODBias(float lod_bias);

  // Overload assignment operator
  KRViewport& operator=(const KRViewport& v);

  unordered_map<AABB, int>& getVisibleBounds();

  const std::set<KRLight*>& getVisibleLights();
  void setVisibleLights(const std::set<KRLight*> visibleLights);

  bool visible(const AABB& b) const;
  float coverage(const AABB& b) const;

private:
  Vector2 m_size;
  Matrix4 m_matView;
  Matrix4 m_matProjection;

  float m_lodBias;

  // Derived values
  Matrix4 m_matViewProjection;
  Matrix4 m_matInverseView;
  Matrix4 m_matInverseProjection;
  Vector3 m_cameraDirection;
  Vector3 m_cameraPosition;

  int m_frontToBackOrder[8];
  int m_backToFrontOrder[8];

  void calculateDerivedValues();

  unordered_map<AABB, int> m_visibleBounds; // AABB's that output fragments in the last frame
};