#include "camera.hpp"
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

glm::mat4 Camera::look_at() {
  return glm::lookAt(position, position + front, up);
}

void Camera::forward() {
  dirty = true;
  position += speed * front;
}

void Camera::back() {
  dirty = true;
  position -= speed * front;
}

void Camera::left() {
  dirty = true;
  position -= glm::normalize(glm::cross(front, up)) * speed;
}

void Camera::right() {
  dirty = true;
  position += glm::normalize(glm::cross(front, up)) * speed;
}

void Camera::update(float deltaTime) {
  speed = movement_speed * deltaTime;
}

void Camera::mouse_move(double xpos, double ypos) {
  dirty = true;

  if(firstMouse) {
    lastX = xpos;
    lastY = ypos;
    firstMouse = false;
  }

  float xoffset = xpos - lastX;
  float yoffset = lastY - ypos;
  lastX = xpos;
  lastY = ypos;

  const float sensitivity = 0.1f;
  xoffset *= sensitivity;
  yoffset *= sensitivity;

  yaw += xoffset;
  pitch += yoffset;

  if(pitch > 89.0f) pitch = 89.0f;
  if(pitch < -89.0f) pitch = -89.0f;

  direction.x = cos(glm::radians(yaw)) * cos(glm::radians(pitch));
  direction.y = sin(glm::radians(pitch));
  direction.z = sin(glm::radians(yaw)) * cos(glm::radians(pitch));

  front = glm::normalize(direction);
}

void Camera::mouse_scroll(double xoffset, double yoffset) {
  dirty = true;
  fov -= (float)yoffset;

  if(fov < 1.0f) fov = 1.0f;
  if(fov > 90.0f) fov = 90.0f;
}