daily update

lighting-colors/camera.hh

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+
+#ifndef CAMERA_H
+#define CAMERA_H
+
+#include <glad/glad.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
+const float YAW = -90.0f;
+const float PITCH = 0.0f;
+const float SPEED = 2.5f;
+const float SENSITIVITY = 0.1f;
+const float ZOOM = 45.0f;
+
+// An abstract camera class that processes input and calculates the
+// corresponding Euler Angles, Vectors and Matrices for use in OpenGL
+class Camera {
+public:
+  // camera Attributes
+  glm::vec3 Position;
+  glm::vec3 Front;
+  glm::vec3 Up;
+  glm::vec3 Right;
+  glm::vec3 WorldUp;
+  // euler Angles
+  float Yaw;
+  float Pitch;
+  // camera options
+  float MovementSpeed;
+  float MouseSensitivity;
+  float Zoom;
+
+  // 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), float yaw = YAW,
+         float pitch = PITCH)
+      : Front(glm::vec3(0.0f, 0.0f, -1.0f)), MovementSpeed(SPEED),
+        MouseSensitivity(SENSITIVITY), Zoom(ZOOM) {
+    Position = position;
+    WorldUp = up;
+    Yaw = yaw;
+    Pitch = pitch;
+    updateCameraVectors();
+  }
+  // constructor with scalar values
+  Camera(float posX, float posY, float posZ, float upX, float upY, float upZ,
+         float yaw, float pitch)
+      : Front(glm::vec3(0.0f, 0.0f, -1.0f)), MovementSpeed(SPEED),
+        MouseSensitivity(SENSITIVITY), Zoom(ZOOM) {
+    Position = glm::vec3(posX, posY, posZ);
+    WorldUp = glm::vec3(upX, upY, upZ);
+    Yaw = yaw;
+    Pitch = pitch;
+    updateCameraVectors();
+  }
+
+  // returns the view matrix calculated using Euler Angles and the LookAt Matrix
+  glm::mat4 GetViewMatrix() {
+    return glm::lookAt(Position, Position + Front, Up);
+  }
+
+  // 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, float deltaTime) {
+    float velocity = MovementSpeed * deltaTime;
+    if (direction == FORWARD)
+      Position += Front * velocity;
+    if (direction == BACKWARD)
+      Position -= Front * velocity;
+    if (direction == LEFT)
+      Position -= Right * velocity;
+    if (direction == RIGHT)
+      Position += Right * velocity;
+  }
+
+  // processes input received from a mouse input system. Expects the offset
+  // value in both the x and y direction.
+  void ProcessMouseMovement(float xoffset, float yoffset,
+                            GLboolean constrainPitch = true) {
+    xoffset *= MouseSensitivity;
+    yoffset *= MouseSensitivity;
+
+    Yaw += xoffset;
+    Pitch += yoffset;
+
+    // make sure that when pitch is out of bounds, screen doesn't get flipped
+    if (constrainPitch) {
+      if (Pitch > 89.0f)
+        Pitch = 89.0f;
+      if (Pitch < -89.0f)
+        Pitch = -89.0f;
+    }
+
+    // update Front, Right and Up Vectors using the updated Euler angles
+    updateCameraVectors();
+  }
+
+  // processes input received from a mouse scroll-wheel event. Only requires
+  // input on the vertical wheel-axis
+  void ProcessMouseScroll(float yoffset) {
+    Zoom -= (float)yoffset;
+    if (Zoom < 1.0f)
+      Zoom = 1.0f;
+    if (Zoom > 45.0f)
+      Zoom = 45.0f;
+  }
+
+private:
+  // calculates the front vector from the Camera's (updated) Euler Angles
+  void updateCameraVectors() {
+    // calculate the new Front vector
+    glm::vec3 front;
+    front.x = cos(glm::radians(Yaw)) * cos(glm::radians(Pitch));
+    front.y = sin(glm::radians(Pitch));
+    front.z = sin(glm::radians(Yaw)) * cos(glm::radians(Pitch));
+    Front = glm::normalize(front);
+    // also re-calculate the Right and Up vector
+    Right = glm::normalize(glm::cross(
+        Front, WorldUp)); // normalize the vectors, because their length gets
+                          // closer to 0 the more you look up or down which
+                          // results in slower movement.
+    Up = glm::normalize(glm::cross(Right, Front));
+  }
+};
+#endif