#include "Camera3D.hpp"

Camera3D::Camera3D(glm::vec3 position, glm::vec3 up, GLfloat yaw, GLfloat 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();
}

Camera3D::Camera3D(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 Camera3D::GetViewMatrix() {
    return glm::lookAt(this->Position, this->Position + this->Front, this->Up);
}

void Camera3D::ProcessKeyboard(Camera_Movement direction, GLfloat deltaTime) {
    GLfloat velocity = this->MovementSpeed * deltaTime;
    if (direction == FORWARD)
        this->Position += this->Front * velocity;
    if (direction == BACKWARD)
        this->Position -= this->Front * velocity;
    if (direction == LEFT)
        this->Position -= this->Right * velocity;
    if (direction == RIGHT)
        this->Position += this->Right * velocity;
}

void Camera3D::ProcessMouseMovement(GLfloat xoffset, GLfloat yoffset, GLboolean constrainPitch) {
    xoffset *= this->MouseSensitivity;
    yoffset *= this->MouseSensitivity;

    this->Yaw += xoffset;
    this->Pitch += yoffset;

    // Make sure that when pitch is out of bounds, screen doesn't get flipped
    if (constrainPitch) {
        if (this->Pitch > 89.0f)
            this->Pitch = 89.0f;
        if (this->Pitch < -89.0f)
            this->Pitch = -89.0f;
    }

    // Update Front, Right and Up Vectors using the updated Eular angles
    this->updateCameraVectors();
}

void Camera3D::ProcessMouseScroll(GLfloat yoffset) {
    if (this->Zoom >= 1.0f && this->Zoom <= 45.0f)
        this->Zoom -= yoffset/5.0f;
    if (this->Zoom <= 1.0f)
        this->Zoom = 1.0f;
    if (this->Zoom >= 45.0f)
        this->Zoom = 45.0f;
}

void Camera3D::updateCameraVectors() {
    // Calculate the new Front vector
    glm::vec3 front;
    front.x = cos(glm::radians(this->Yaw)) * cos(glm::radians(this->Pitch));
    front.y = sin(glm::radians(this->Pitch));
    front.z = sin(glm::radians(this->Yaw)) * cos(glm::radians(this->Pitch));
    this->Front = glm::normalize(front);
    // Also re-calculate the Right and Up vector
    this->Right = glm::normalize(glm::cross(this->Front,
                                            this->WorldUp));  // Normalize the vectors, because their length gets closer to 0 the more you look up or down which results in slower movement.
    this->Up = glm::normalize(glm::cross(this->Right, this->Front));
}