feat(OpenGL): lab2 camera

OpenGL/lab2/include/camera.h

@@ -0,0 +1,154 @@
+#ifndef CAMERA_H
+#define CAMERA_H
+
+#include "glad/glad.h"
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <iostream>
+#include <vector>
+
+// 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, UP, DOWN };
+
+// 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;
+
+  bool firstMouse;
+  float lastX, lastY;
+
+  // constructor with vectors
+  Camera(float X, float Y, glm::vec3 position = glm::vec3(0.0f, 0.0f, 0.4f),
+         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) {
+    lastX = X;
+    lastY = Y;
+    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;
+    if (direction == UP) {
+      Position += Up * velocity;
+    if (direction == DOWN)
+      Position -= Up * velocity;
+    }
+    
+  }
+
+  // processes input received from a mouse input system. Expects the offset
+  // value in both the x and y direction.
+  void ProcessMouseMovement(float xpos, float ypos,
+                            GLboolean constrainPitch = true) {
+    if (firstMouse) {
+      lastX = xpos;
+      lastY = ypos;
+      firstMouse = false;
+    }
+
+    float xoffset = xpos - lastX;
+    float yoffset = lastY - ypos;
+    lastX = xpos;
+    lastY = ypos;
+
+    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

OpenGL/lab2/src/main.cpp

@@ -1,12 +1,18 @@
+#include "camera.h"
 #include "glad/glad.h"
 #include "shader.h"
 #include "stb_image.h"
 #include <GLFW/glfw3.h>
 #include <cmath>
-#include <iostream>
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 #include <glm/gtc/type_ptr.hpp>
+#include <iostream>
+
+// settings
+const unsigned int SCR_WIDTH = 600;
+const unsigned int SCR_HEIGHT = 600;
+
 
 // 四边形顶点
 float vertices[] = {
@@ -23,12 +29,13 @@ unsigned int indices[] = {
     1, 2, 3  // 第二个三角形
 };
 
+float deltaTime, lastTime;
+Camera camera = Camera(SCR_HEIGHT / 2.0f, SCR_HEIGHT / 2.0f);
+
 void framebuffer_size_callback(GLFWwindow *window, int width, int height);
 void processInput(GLFWwindow *window);
-
+void mouse_callback(GLFWwindow *window, double xpos, double ypos);
-// settings
+void scroll_callback(GLFWwindow *window, double xoffset, double yoffset);
-const unsigned int SCR_WIDTH = 600;
-const unsigned int SCR_HEIGHT = 600;
 
 int main() {
 
@@ -40,7 +47,8 @@ int main() {
   // glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
 
   // 创建窗口
-  GLFWwindow *window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
+  GLFWwindow *window =
+      glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
   if (window == NULL) {
     std::cout << "Failed to create GLFW window" << std::endl;
     glfwTerminate();
@@ -55,7 +63,10 @@ int main() {
   }
 
   // 设置视口
+  glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
   glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+  glfwSetCursorPosCallback(window, mouse_callback);
+  glfwSetScrollCallback(window, scroll_callback);
 
   // 创建着色器程序
   Shader shader = Shader("src/tex.vs", "src/tex.fs");
@@ -123,38 +134,55 @@ int main() {
   // 绑定纹理
   shader.setInt("tex", 0);
 
-  // 设置变换矩阵
+  // 开启深度测试
+  glEnable(GL_DEPTH_TEST);
 
   // 循环渲染
   while (!glfwWindowShouldClose(window)) {
+
+    // 计算帧时间差
+    float currentFrame = glfwGetTime();
+    deltaTime = currentFrame - lastTime;
+    lastTime = currentFrame;
+
     // 处理输入
     processInput(window);
 
-    // 设置为白色
+    // 初始化
-    glClearColor(1.0f, 1.0f, 1.0f, 0.0f);
+    glClearColor(0.3f, 0.3f, 0.3f, 0.3f);
-    glClear(GL_COLOR_BUFFER_BIT);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
     // 绑定纹理
     glActiveTexture(GL_TEXTURE0);
     glBindTexture(GL_TEXTURE_2D, texture);
 
+    glm::mat4 view = camera.GetViewMatrix();
+    glm::mat4 projection =
+        glm::perspective(glm::radians(camera.Zoom),
+                         (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
+
     // 绘制三角形
     shader.use();
     glBindVertexArray(VAO);
 
+    shader.setMat4("view", view);
+    shader.setMat4("projection", projection);
+
     glm::mat4 trans(1.0f);
-    trans = glm::rotate(trans, float(-sin((float)glfwGetTime())), glm::vec3(0.0, 1.0, 0.0));
+    trans = glm::rotate(trans, float(-sin((float)glfwGetTime())),
-    trans = glm::translate(trans,glm::vec3(-0.2,0.0,0.0));
+                        glm::vec3(0.0, 1.0, 0.0));
-    shader.setMat4("trans",trans);
+    trans = glm::translate(trans, glm::vec3(-0.2, 0.0, 0.0));
+    shader.setMat4("trans", trans);
     glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
 
     trans = glm::mat4(1.0f);
-    trans = glm::rotate(trans, float(-sin((float)glfwGetTime())), glm::vec3(0.0, 1.0, 0.0));
+    trans = glm::rotate(trans, float(sin((float)glfwGetTime())),
-    trans = glm::translate(trans,glm::vec3(0.2,0.0,0.0));
+                        glm::vec3(0.0, 1.0, 0.0));
-    trans = glm::rotate(trans,glm::radians(180.0f), glm::vec3(0.0, 1.0, 0.0));
+    trans = glm::translate(trans, glm::vec3(0.2, 0.0, 0.0));
-    // trans = glm::rotate(trans, (float)glfwGetTime(), glm::vec3(0.0, 0.5, 0.5));
+    trans = glm::rotate(trans, glm::radians(180.0f), glm::vec3(0.0, 1.0, 0.0));
-    // trans = glm::scale(trans, glm::vec3(0.5, 0.5, 0.5));
+    // trans = glm::rotate(trans, (float)glfwGetTime(), glm::vec3(0.0, 0.5,
-    shader.setMat4("trans",trans);
+    // 0.5)); trans = glm::scale(trans, glm::vec3(0.5, 0.5, 0.5));
+    shader.setMat4("trans", trans);
     glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
 
     // 检查并调用事件，交换缓冲
@@ -171,9 +199,30 @@ int main() {
 void processInput(GLFWwindow *window) {
   if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
     glfwSetWindowShouldClose(window, true);
+  if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
+    camera.ProcessKeyboard(FORWARD, deltaTime);
+  if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
+    camera.ProcessKeyboard(BACKWARD, deltaTime);
+  if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
+    camera.ProcessKeyboard(LEFT, deltaTime);
+  if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
+    camera.ProcessKeyboard(RIGHT, deltaTime);
+  if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_PRESS)
+    camera.ProcessKeyboard(UP, deltaTime);
+  if (glfwGetKey(window, GLFW_KEY_LEFT_SHIFT) == GLFW_PRESS)
+    camera.ProcessKeyboard(DOWN, deltaTime);
 }
 
+
 // 窗口大小改变时回调该函数
 void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
   glViewport(0, 0, width, height);
 }
+
+void mouse_callback(GLFWwindow *window, double xpos, double ypos) {
+  camera.ProcessMouseMovement(xpos, ypos);
+}
+
+void scroll_callback(GLFWwindow *window, double xoffset, double yoffset) {
+  camera.ProcessMouseScroll(yoffset);
+}

OpenGL/lab2/src/tex.vs

@@ -7,10 +7,13 @@ out vec3 ourColor;
 out vec2 TexCoord;
 
 uniform mat4 trans;
+uniform mat4 view; 
+uniform mat4 projection;
 
 void main()
 {
-    gl_Position = trans * vec4(aPos, 1.0);
+    gl_Position =  projection * view * trans * vec4(aPos, 1.0);
+    // gl_Position =  trans * vec4(aPos, 1.0);
     ourColor = aColor;
     TexCoord = aTexCoord;
 }