/*
 * This file is part of the Colobot: Gold Edition source code
 * Copyright (C) 2001-2023, Daniel Roux, EPSITEC SA & TerranovaTeam
 * http://epsitec.ch; http://colobot.info; http://github.com/colobot
 *
 * This program 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.
 *
 * This program 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://gnu.org/licenses
 */

/**
 * \file graphics/core/light.h
 * \brief Light struct and related enums
 */

#pragma once


#include "graphics/core/color.h"

#include "math/const.h"

#include <glm/glm.hpp>


// Graphics module namespace
namespace Gfx
{

/**
 * \enum LightType
 * \brief Type of light in 3D scene
 */
enum LightType
{
    LIGHT_POINT,
    LIGHT_SPOT,
    LIGHT_DIRECTIONAL
};

/**
 * \struct Light
 * \brief Properties of light in 3D scene
 *
 * This structure was created as analog to DirectX's D3DLIGHT.
 */
struct Light
{
    //! Type of light source
    LightType  type = LIGHT_POINT;
    //! Color of ambient light
    Color      ambient = Color(0.4f, 0.4f, 0.4f);
    //! Color of diffuse light
    Color      diffuse = Color(0.8f, 0.8f, 0.8f);
    //! Color of specular light
    Color      specular = Color(1.0f, 1.0f, 1.0f);
    //! Position in world space (for point & spot lights)
    glm::vec3    position = glm::vec3(0.0f, 0.0f, 0.0f);
    //! Direction in world space (for directional & spot lights)
    glm::vec3    direction = glm::vec3(0.0f, 0.0f, 1.0f);
    //! Constant attenuation factor
    float           attenuation0 = 1.0f;
    //! Linear attenuation factor
    float           attenuation1 = 0.0f;
    //! Quadratic attenuation factor
    float           attenuation2 = 0.0f;
    //! Angle of spotlight cone (0-PI/2 radians)
    float           spotAngle = Math::PI/2.0f;
    //! Intensity of spotlight (0 = uniform; 128 = most intense)
    float           spotIntensity = 0.0f;

    //! Loads default values
    void LoadDefault()
    {
        *this = Light();
    }
};


} // namespace Gfx