程式碼 main.cpp
#include <iostream> #include <glad/glad.h> #include <glfw3.h> #include "Shader.h" #define STB_IMAGE_IMPLEMENTATION #include <stb_image.h> #include <glm/glm.hpp> #include <glm/gtc/matrix_transform.hpp> #include <glm/gtc/type_ptr.hpp> #include <chrono> #include <thread> using namespace std; // 回撥函式，每當視窗改變大小，視口大小也跟隨改變 void framebuffer_size_callback(GLFWwindow* window,int width,int height) { glViewport(0,0,width,height); } // 輸入 在GLFW中實現一些輸入控制 void processInput(GLFWwindow *window) { if(glfwGetKey(window,GLFW_KEY_ESCAPE) == GLFW_PRESS) // 是否按下了返回鍵(Esc) { glfwSetWindowShouldClose(window,true); // 把WindowShouldClose屬性設定為 true來關閉GLFW } } // ************** opengl 具體實現 ************ // 頂點資料 float vertices[] = { // ---- 位置 ---- - 紋理座標 - 0.5f, 0.5f, 0.0f, 1.0f, 1.0f, // 右上 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, // 右下 -0.5f, -0.5f, 0.0f, 0.0f, 0.0f, // 左下 -0.5f, 0.5f, 0.0f, 0.0f, 1.0f // 左上 }; // 紋理索引 unsigned int indices[] = { // 注意索引從0開始! // 此例的索引(0,1,2,3)就是頂點陣列vertices的下標， // 這樣可以由下標代表頂點組合成矩形 0, 1, 3, // 第一個三角形 1, 2, 3 // 第二個三角形 }; //****************************************** int main() { cout << "紋理" << endl; // GLFW (視窗) glfwInit(); // 初始化GLFW glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR,3); // 主版本號 glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR,3); // 次版本號 glfwWindowHint(GLFW_OPENGL_PROFILE,GLFW_OPENGL_CORE_PROFILE); // 使用核心模式 //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); Mac OS X系統 // 建立一個GLFW視窗物件 GLFWwindow* window = glfwCreateWindow(800,600,"texture",NULL,NULL); if(window == NULL) { std::cout<< "Failed to create GLFW window"<<std::endl; glfwTerminate(); return -1; } glfwMakeContextCurrent(window); // 視窗的上下文設定為當前執行緒的主上下文 // GLAD if(!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) // 初始化GLAD(初始化OpenGL函式指標) { std::cout<<"Failed to initialize GLAD"<<std::endl; return -1; } //*********** opengl 具體實現 ****************** // 著色器類 Shader shader("E:\\Project\\openglstudy2\\05_OpenglVector\\05_OpenglVector\\vertexSourceCode.vert", "E:\\Project\\openglstudy2\\05_OpenglVector\\05_OpenglVector\\fragmentSourceCode.frag"); // 頂點陣列物件 VAO unsigned int VAO; glGenVertexArrays(1,&VAO); // 建立頂點陣列物件 glBindVertexArray(VAO); // 繫結頂點陣列物件 // 頂點緩衝物件 VBO unsigned int VBO; glGenBuffers(1,&VBO); glBindBuffer(GL_ARRAY_BUFFER,VBO); // 繫結頂點緩衝物件 glBufferData(GL_ARRAY_BUFFER,sizeof(vertices),vertices,GL_STATIC_DRAW); // 把之前定義的頂點資料複製到緩衝的記憶體中 // 索引快取物件 EBO unsigned int EBO; glGenBuffers(1,&EBO); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,EBO); // 繫結索引緩衝物件 glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(indices),indices,GL_STATIC_DRAW); // 把之前定義的索引資料複製到索引緩衝的記憶體中 // 連結頂點屬性 （告訴 gpu 如何解析記憶體中的頂點資料） // 0 位置座標 glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,5 * sizeof(float),(void*)0); glEnableVertexAttribArray(0); // 1 紋理座標 glVertexAttribPointer(1,2,GL_FLOAT,GL_FALSE,5 * sizeof(float),(void*)(3*sizeof(float))); glEnableVertexAttribArray(1); unsigned int texture1,texture2; // 紋理物件1 texture1 glGenTextures(1,&texture1); glBindTexture(GL_TEXTURE_2D,texture1); // 設定紋理影像環繞方式 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); // 設定紋理過濾 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // 載入圖片 int width,height,nrChannels; unsigned char *data = stbi_load("E:\\Project\\openglstudy2\\resources\\textures\\container.jpg", &width,&height,&nrChannels,0); if(data) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data); glGenerateMipmap(GL_TEXTURE_2D); } else { std::cout << "Failed to load texture" << std::endl; } // 釋放掉影像資料 stbi_image_free(data); shader.use(); // 紋理物件2 texture2 glGenTextures(1,&texture2); glBindTexture(GL_TEXTURE_2D,texture2); // 設定紋理影像環繞方式 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); // 重複 // 設定紋理過濾 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // 載入圖片 stbi_set_flip_vertically_on_load(true); data = stbi_load("E:\\Project\\openglstudy2\\resources\\textures\\awesomeface.png", &width,&height,&nrChannels,0); if(data) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data); glGenerateMipmap(GL_TEXTURE_2D); } else { std::cout << "Failed to load texture" << std::endl; } // 釋放掉影像資料 stbi_image_free(data); // 設定取樣器對應的紋理單元（unform） shader.use(); shader.setInt("texture1",0); shader.setInt("texture2",1); // 變換 float scal = 0.1; bool flag = true; unsigned int transformLoc = glGetUniformLocation(shader.ID,"transform"); //************************** // 視口 glViewport(0,0,800,600); // 視口跟隨視窗大小改變 glfwSetFramebufferSizeCallback(window,framebuffer_size_callback); // 渲染迴圈 while(!glfwWindowShouldClose(window)) // 檢查GLFW是否被要求退出 { // 輸入 （使用者） processInput(window); // 輸入控制（自定義） //************** 渲染指令 （使用者）********** glClearColor(0.2f, 0.3f, 0.3f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture1); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, texture2); glBindVertexArray(VAO); // create transformations glm::mat4 transform; // make sure to initialize matrix to identity matrix first transform = glm::translate(transform, glm::vec3(0.5f, 0.5f, 0.0f)); auto gltime = (float)glfwGetTime(); transform = glm::rotate(transform, gltime*2, glm::vec3(0.0f, 0.0f, 1.0f)); transform = glm::scale(transform, glm::vec3(scal, scal, scal)); if(scal >= 1.0) // 自己實現的縮放效果 { flag = false; } else if(scal <= 0.1) { flag = true; } if(flag) { scal +=0.1; } else { scal -= 0.1; } // get matrix's uniform location and set matrix shader.use(); unsigned int transformLoc = glGetUniformLocation(shader.ID, "transform"); glUniformMatrix4fv(transformLoc, 1, GL_FALSE, glm::value_ptr(transform)); glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0); // create transformations glm::mat4 transform2; // make sure to initialize matrix to identity matrix first transform2 = glm::translate(transform2, glm::vec3(0.5f, -0.5f, 0.0f)); transform2 = glm::rotate(transform2, (float)glfwGetTime()*4, glm::vec3(0.0f, 0.0f, 1.0f)); float scaleAmount = static_cast<float>(sin(glfwGetTime())); transform2 = glm::scale(transform2, glm::vec3(scaleAmount, scaleAmount, scaleAmount)); // get matrix's uniform location and set matrix shader.use(); unsigned int transformLoc2 = glGetUniformLocation(shader.ID, "transform"); glUniformMatrix4fv(transformLoc2, 1, GL_FALSE, glm::value_ptr(transform2)); glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0); // create transformations glm::mat4 transform3; // make sure to initialize matrix to identity matrix first transform3 = glm::translate(transform3, glm::vec3(-0.5f, 0.5f, 0.0f)); transform3 = glm::rotate(transform3, (float)glfwGetTime()*6, glm::vec3(0.0f, 0.0f, 1.0f)); transform3 = glm::scale(transform3, glm::vec3(scaleAmount, scaleAmount, scaleAmount)); // get matrix's uniform location and set matrix shader.use(); unsigned int transformLoc3 = glGetUniformLocation(shader.ID, "transform"); glUniformMatrix4fv(transformLoc3, 1, GL_FALSE, glm::value_ptr(transform3)); glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0); // create transformations glm::mat4 transform4; // make sure to initialize matrix to identity matrix first transform4 = glm::translate(transform4, glm::vec3(-0.5f, -0.5f, 0.0f)); transform4 = glm::rotate(transform4, (float)glfwGetTime()*8, glm::vec3(0.0f, 0.0f, 1.0f)); transform4 = glm::scale(transform4, glm::vec3(scaleAmount, scaleAmount, scaleAmount)); // get matrix's uniform location and set matrix shader.use(); unsigned int transformLoc4 = glGetUniformLocation(shader.ID, "transform"); glUniformMatrix4fv(transformLoc4, 1, GL_FALSE, glm::value_ptr(transform4)); glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0); //*************************************** // 檢查並呼叫事件，交換緩衝 （預設操作） glfwSwapBuffers(window); // 交換顏色緩衝（它是一個儲存著GLFW視窗每一個畫素顏色值的大緩衝），它在這一迭代中被用來繪製，並且將會作為輸出顯示在螢幕上。 glfwPollEvents(); // 有沒有觸發什麼事件（比如鍵盤輸入、滑鼠移動等）、更新視窗狀態 } // 解綁 VAO VBO 著色器程式物件 glDeleteVertexArrays(1, &VAO); glDeleteBuffers(1, &VBO); // 當渲染迴圈結束後我們需要正確釋放/刪除之前的分配的所有資源 glfwTerminate(); return 0; }
著色器程式碼：
頂點著色器：
#version 330 core layout (location = 0) in vec3 aPos; layout (location = 1) in vec2 aTexCoord; out vec2 TexCoord; uniform mat4 transform; void main() { gl_Position = transform * vec4(aPos,1.0) ; TexCoord = vec2(aTexCoord.x, 1-aTexCoord.y); }
片段著色器：
#version 330 core out vec4 FragColor; in vec3 ourColor; in vec2 TexCoord; // 定義一個全域性的2D紋理取樣器 uniform sampler2D texture1; uniform sampler2D texture2; void main() { // GLSL內建的mix函式需要接受兩個值作為引數，並對它們根據第三個引數進行線性插值。 FragColor = mix(texture(texture1, TexCoord), texture(texture2, vec2(-TexCoord.x,TexCoord.y)), 0.2); }