Camera.h

// Copyright 2022 ShenMian
// License(Apache-2.0)
 
#pragma once
 
#include <math/math.hpp>
 
class Camera
{
public:
    enum class Type
    {
        Perspective, // 透视投影
        Orthographic // 正交投影
    };
 
    Camera(Type type);
 
    void set_perspective(float vFOV, float aspectRatio, float near, float far);
 
    void set_orthographic(float width, float height, float near, float far);
 
    Type get_type() const;
 
    float get_vfov() const;
 
    float get_hfov() const;
 
    float get_aspect_ratio() const;
 
    float get_near() const;
 
    float get_far() const;
 
    void set_position(const Vector3f& pos);
 
    const Vector3f& get_position() const;
 
    void set_rotation(const Vector3f& rot);
 
    const Vector3f& get_rotation() const;
 
    Vector3f get_front() const;
    Vector3f get_right() const;
    Vector3f get_up() const;
 
    const Matrix4& get_view() const;
 
    const Matrix4& get_projection() const;
 
protected:
    void update_projection_matrix() const;
 
    void update_view_matrix() const;
 
    struct Perspective
    {
        float vFOV;
        float aspectRatio;
        float near;
        float far;
    };
 
    struct Orthographic
    {
        float width;
        float height;
        float near;
        float far;
    };
 
    union {
        Perspective  perspective_;
        Orthographic orthographic_;
    };
 
    Type type_;
 
    Vector3f position_;
    Vector3f rotation_;
    Vector3f up_ = -Vector3f({0.f, 1.f, 0.f}); // TODO
 
    mutable Matrix4 projection_;
    mutable bool    projection_dirty_ = true;
    mutable Matrix4 view_;
    mutable bool    view_dirty_ = true;
};