Camera.hpp

//
// Created by iak on 14.01.17.
//

#pragma once

#include <vector>

#define GLEW_STATIC
#define GLEW_NO_GLU

#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 Camera_Movement {
    FORWARD,
    BACKWARD,
    LEFT,
    RIGHT
};

// Default camera values
extern const GLfloat YAW;
extern const GLfloat PITCH;
extern const GLfloat SPEED;
extern const GLfloat SENSITIVTY;
extern const GLfloat ZOOM;


// An abstract camera class that processes input and calculates the corresponding Euler Angles, Vectors and Matrices for use in OpenGL
// Note that angles are represented in degrees whereas GLM functions operate radians
class Camera
{
public:
    // Constructor with vectors
    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);

    // Constructor with scalar values
    Camera(GLfloat posX, GLfloat posY, GLfloat posZ,
           GLfloat upX, GLfloat upY, GLfloat upZ,
           GLfloat yaw, GLfloat pitch);

    // Returns the view matrix calculated using Euler Angles and the LookAt Matrix
    glm::mat4 GetViewMatrix();

    // Processes input received from any keyboard-like input system. Accepts input parameter in the form of camera defined ENUM (to abstract it from windowing systems)
    void ProcessKeyboard(Camera_Movement direction, GLfloat deltaTime);

    // Processes input received from a mouse input system. Expects the offset value in both the x and y direction.
    void ProcessMouseMovement(GLfloat xoffset, GLfloat yoffset, GLboolean constrainPitch = true);

    // Processes input received from a mouse scroll-wheel event. Only requires input on the vertical wheel-axis
    void ProcessMouseScroll(GLfloat yoffset);

    // Camera Attributes
    glm::vec3 Position;
    glm::vec3 Front;
    glm::vec3 Up;
    glm::vec3 Right;
    glm::vec3 WorldUp;
    // Euler Angles
    GLfloat Yaw;
    GLfloat Pitch;
    // Camera options
    GLfloat MovementSpeed;
    GLfloat MouseSensitivity;
    GLfloat Zoom;

private:
    // Calculates the front vector from the Camera's (updated) Eular Angles
    void updateCameraVectors();
};