/****************************************************************************

    AstroMenace
    Hardcore 3D space scroll-shooter with spaceship upgrade possibilities.
    Copyright (c) 2006-2019 Mikhail Kurinnoi, Viewizard


    AstroMenace is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    AstroMenace 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 AstroMenace. If not, see <https://www.gnu.org/licenses/>.


    Website: https://viewizard.com/
    Project: https://github.com/viewizard/astromenace
    E-mail: viewizard@viewizard.com

*****************************************************************************/

// TODO class cLight should use encapsulation

#ifndef CORE_LIGHT_LIGHT_H
#define CORE_LIGHT_LIGHT_H

#include "../base.h"
#include "../math/math.h"

namespace viewizard {

struct sVECTOR3D;

enum class eLightType {
    Directional,    // located far (sun, stars, etc)
    Point           // located close (engines, weapon flashes, etc)
};

class cLight {
    friend std::weak_ptr<cLight> vw_CreateLight(eLightType Type);

public:
    // Activate and setup for proper light type (OpenGL-related).
    bool Activate(int CurrentLightNum, const float (&Matrix)[16]);
    // Deactivate (OpenGL-related).
    void DeActivate();
    // Set location.
    void SetLocation(sVECTOR3D NewLocation);

    // Light's color.
    float Diffuse[4]{0.0f, 0.0f, 0.0f, 1.0f};
    float Specular[4]{0.0f, 0.0f, 0.0f, 1.0f};
    float Ambient[4]{0.0f, 0.0f, 0.0f, 1.0f};
    // Maximum color (for color deviation calculations).
    float DiffuseMax[4];
    float SpecularMax[4];
    // Attenuations.
    float ConstantAttenuation{0.0f};
    float LinearAttenuation{0.0f};
    float QuadraticAttenuation{0.0f};
    // Attenuations base (for particle system effects).
    float LinearAttenuationBase{0.0f};
    float QuadraticAttenuationBase{0.0f};
    // Direction.
    sVECTOR3D Direction{0.0f, 0.0f, 0.0f};
    // Location (for point lights only).
    sVECTOR3D Location{0.0f, 0.0f, 0.0f};
    // On/Off switch, in this case Off mean On=false.
    bool On{true};

private:
    // OpenGL-related.
    int RealLightNum{-1};
    // Store LightType for fast access (we also use it as key for LightsMap).
    eLightType LightType{eLightType::Point};

    // Don't allow direct new/delete usage in code, only vw_CreateLight()
    // allowed for light creation and release setup (deleter must be provided).
    cLight() = default;
    ~cLight() = default;
};


// Activate proper lights for particular object (presented by location and radius^2).
void vw_CheckAndActivateAllLights(const sVECTOR3D &Location, float Radius2, int DirLimit,
                                  int PointLimit, const float (&Matrix)[16]);
// Calculate affected lights counter and create sorted map with affected lights.
int vw_CalculateAllPointLightsAttenuation(const sVECTOR3D &Location, float Radius2,
                                          std::multimap<float, cLight*> *AffectedLightsMap);
// Deactivate all lights.
void vw_DeActivateAllLights();
// Release light.
void vw_ReleaseLight(std::weak_ptr<cLight> &Light);
// Release all lights.
void vw_ReleaseAllLights();
// Create light.
std::weak_ptr<cLight> vw_CreateLight(eLightType Type);
// Create point light with initialization.
std::weak_ptr<cLight> vw_CreatePointLight(const sVECTOR3D &Location,
                                          float R, float G, float B,
                                          float Linear, float Quadratic);
// Get main direct light. Usually, first one is the main.
bool vw_GetMainDirectLight(std::weak_ptr<cLight> &Light);

} // viewizard namespace

#endif // CORE_LIGHT_LIGHT_H
