/*
* Copyright (C) 2023 Christopher J. Howard
*
* This file is part of Antkeeper source code.
*
* Antkeeper source code 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.
*
* Antkeeper source code 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 Antkeeper source code. If not, see .
*/
#ifndef ANTKEEPER_SCENE_DIRECTIONAL_LIGHT_HPP
#define ANTKEEPER_SCENE_DIRECTIONAL_LIGHT_HPP
#include
#include
#include
#include
#include
#include
namespace scene {
/**
* Light source with parallel rays and constant intensity.
*/
class directional_light: public light
{
public:
/// Creates a directional light.
directional_light();
/// Returns light_type::directional.
[[nodiscard]] inline light_type get_light_type() const noexcept override
{
return light_type::directional;
}
/// @name Light
/// @{
/**
* Sets the direction of the directional light.
*
* @param direction Unit-length light direction vector.
*/
void set_direction(const math::fvec3& direction);
/**
* Sets the color of the light.
*
* @param color Light color.
*/
inline void set_color(const math::fvec3& color) noexcept
{
m_color = color;
color_updated();
}
/**
* Sets the illuminance of the light on a surface perpendicular to the light direction.
*
* @param illuminance Illuminance on a surface perpendicular to the light direction.
*/
inline void set_illuminance(float illuminance) noexcept
{
m_illuminance = illuminance;
illuminance_updated();
}
/// Returns a unit vector pointing in the light direction.
[[nodiscard]] inline constexpr const math::fvec3& get_direction() const noexcept
{
return m_direction;
}
/// Returns the color of the light.
[[nodiscard]] inline constexpr const math::fvec3& get_color() const noexcept
{
return m_color;
}
/// Returns the illuminance of the light on a surface perpendicular to the light direction.
[[nodiscard]] inline constexpr float get_illuminance() const noexcept
{
return m_illuminance;
}
/// Returns the color-modulated illuminance of the light on a surface perpendicular to the light direction.
[[nodiscard]] inline constexpr const math::fvec3& get_colored_illuminance() const noexcept
{
return m_colored_illuminance;
}
/// @}
/// @name Shadow
/// @{
/**
* Enables or disables shadow casting.
*
* @param caster `true` if the light should cast shadows, `false` otherwise.
*/
void set_shadow_caster(bool caster) noexcept;
/**
* Sets the shadow map framebuffer.
*
* @param framebuffer Pointer to a shadow map framebuffer.
*/
void set_shadow_framebuffer(std::shared_ptr framebuffer) noexcept;
/**
* Sets the shadow bias factor for reducing self-shadowing.
*
* @param bias Shadow bias factor.
*/
void set_shadow_bias(float bias) noexcept;
/**
* Sets the number of shadow cascades.
*
* @param count Number of shadow cascades.
*/
void set_shadow_cascade_count(unsigned int count) noexcept;
/**
* Sets the shadow cascade coverage factor.
*
* @param factor Percentage of the view frustum clipping range covered by shadow cascades. A value of `1.0` results in full coverage of the view frustum clipping range, `0.5` results in coverage of half of the clipping range, etc.
*/
void set_shadow_cascade_coverage(float factor) noexcept;
/**
* Sets the shadow cascade distribution.
*
* @param weight Linear interpolation weight between uniform and logarithmic cascade distributions. A weight of `0.0` results in a uniform cascade distribution, while `1.0` results in a logarithmic distribution.
*/
void set_shadow_cascade_distribution(float weight) noexcept;
/// Returns `true` if the light casts shadows, `false` otherwise.
[[nodiscard]] inline bool is_shadow_caster() const noexcept
{
return m_shadow_caster;
}
/// Returns the shadow map framebuffer, of `nullptr` if no shadow map framebuffer is set.
[[nodiscard]] inline const std::shared_ptr& get_shadow_framebuffer() const noexcept
{
return m_shadow_framebuffer;
}
/// Returns the shadow bias factor.
[[nodiscard]] inline float get_shadow_bias() const noexcept
{
return m_shadow_bias;
}
/// Returns the number of shadow cascades.
[[nodiscard]] inline unsigned int get_shadow_cascade_count() const noexcept
{
return m_shadow_cascade_count;
}
/// Returns the shadow cascade coverage factor.
[[nodiscard]] inline float get_shadow_cascade_coverage() const noexcept
{
return m_shadow_cascade_coverage;
}
/// Returns the shadow cascade distribution weight.
[[nodiscard]] inline float get_shadow_cascade_distribution() const noexcept
{
return m_shadow_cascade_distribution;
}
/// Returns the array of shadow cascade far clipping plane distances.
/// @{
[[nodiscard]] inline constexpr std::span get_shadow_cascade_distances() const noexcept
{
return m_shadow_cascade_distances;
}
[[nodiscard]] inline constexpr std::span get_shadow_cascade_distances() noexcept
{
return m_shadow_cascade_distances;
}
/// @}
/// Returns the array of shadow cascade bias-scale matrices.
[[nodiscard]] inline constexpr std::span get_shadow_bias_scale_matrices() const noexcept
{
return m_shadow_bias_scale_matrices;
}
/// Returns the array of world-space to cascade texture-space transformation matrices.
/// @{
[[nodiscard]] inline constexpr std::span get_shadow_cascade_matrices() const noexcept
{
return m_shadow_cascade_matrices;
}
[[nodiscard]] inline constexpr std::span get_shadow_cascade_matrices() noexcept
{
return m_shadow_cascade_matrices;
}
/// @}
/// @}
private:
void transformed() override;
void color_updated();
void illuminance_updated();
void update_shadow_bias_scale_matrices();
math::fvec3 m_direction{0.0f, 0.0f, -1.0f};
math::fvec3 m_color{1.0f, 1.0f, 1.0f};
float m_illuminance{};
math::fvec3 m_colored_illuminance{};
bool m_shadow_caster{false};
std::shared_ptr m_shadow_framebuffer{nullptr};
float m_shadow_bias{0.001f};
unsigned int m_shadow_cascade_count{4};
float m_shadow_cascade_coverage{1.0f};
float m_shadow_cascade_distribution{0.8f};
std::vector m_shadow_cascade_distances;
std::vector m_shadow_cascade_matrices;
std::vector m_shadow_bias_scale_matrices;
};
} // namespace scene
#endif // ANTKEEPER_SCENE_DIRECTIONAL_LIGHT_HPP