Camera.h

#pragma once

// Std. Includes
#include <vector>

// GL Includes
#include <GL/glew.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>



// Defines several possible options for camera movement. Used as abstraction to stay away from window-system specific input methods
enum class Camera_Movement {
    FORWARD,
    BACKWARD,
    LEFT,
    RIGHT
};

// Default camera values
const GLfloat YAW = -90.0f;
const GLfloat PITCH = 0.0f;
const GLfloat SPEED = 7.0f;
const GLfloat SENSITIVTY = 0.05f;
const GLfloat ZOOM = 60.0f;


// An abstract camera class that processes input and calculates the corresponding Eular Angles, Vectors and Matrices for use in OpenGL
class Camera
{
public:

    GLfloat getZoom() const {
        return Zoom;
    }

    glm::vec3 getPosition() const {
        return Position;
    }


    Camera(glm::vec3 position = glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3 up = glm::vec3(0.0f, 1.0f, 0.0f), GLfloat yaw = YAW, GLfloat pitch = PITCH) : Front(glm::vec3(0.0f, 0.0f, -1.0f)), MovementSpeed(SPEED), MouseSensitivity(SENSITIVTY), Zoom(ZOOM)
    {
        this->Position = position;
        this->WorldUp = up;
        this->Yaw = yaw;
        this->Pitch = pitch;
        this->updateCameraVectors();
    }

    Camera(GLfloat posX, GLfloat posY, GLfloat posZ, GLfloat upX, GLfloat upY, GLfloat upZ, GLfloat yaw, GLfloat pitch) : Front(glm::vec3(0.0f, 0.0f, -1.0f)), MovementSpeed(SPEED), MouseSensitivity(SENSITIVTY), Zoom(ZOOM)
    {
        this->Position = glm::vec3(posX, posY, posZ);
        this->WorldUp = glm::vec3(upX, upY, upZ);
        this->Yaw = yaw;
        this->Pitch = pitch;
        this->updateCameraVectors();
    }

    glm::mat4 GetViewMatrix();

    void ProcessKeyboard(Camera_Movement direction, GLfloat deltaTime);
    void ProcessMouseMovement(GLfloat xoffset, GLfloat yoffset, GLboolean constrainPitch = true);
    void ProcessMouseScroll(GLfloat yoffset);

private:
    void updateCameraVectors();
    // Camera Attributes 
    glm::vec3 Position;
    glm::vec3 Front;
    glm::vec3 Up;
    glm::vec3 Right;
    glm::vec3 WorldUp;
    // Eular Angles
    GLfloat Yaw;
    GLfloat Pitch;
    // Camera options
    GLfloat MovementSpeed;
    GLfloat MouseSensitivity;
    GLfloat Zoom;
};