第五个OpenGL程序,vector 向量 (矩阵变换之 旋转,缩放)

效果:

 

CMakeLists.txt文件

cmake_minimum_required(VERSION 3.5)

project(05_OpenglVector LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

set(GLFW ${CMAKE_SOURCE_DIR}/../../../thirdParty/GLFW)
set(GLAD ${CMAKE_SOURCE_DIR}/../../../thirdParty/GLAD)
set(STB_IMAGE ${CMAKE_SOURCE_DIR}/../../../thirdParty/STB_IMAGE)
set(GLM ${CMAKE_SOURCE_DIR}/../../../thirdParty/GLM)

file(GLOB SOURCEFILE ./*cpp)
file(GLOB HEADERFILE ./*h)

# GLFW
include_directories(${GLFW}/include)
link_directories(${GLFW}/lib)
# GLAD
include_directories(${GLAD}/include)
# STB_IMAGE
include_directories(${STB_IMAGE}/include)
# GLM
include_directories(${GLM})

add_executable(${PROJECT_NAME} ${SOURCEFILE} ${HEADERFILE}
    Shader.h Shader.cpp
    vertexSourceCode.vert
    fragmentSourceCode.frag)

target_link_libraries(${PROJECT_NAME} PRIVATE glfw3)

include(GNUInstallDirs)
install(TARGETS ${PROJECT_NAME}
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)

 

代码 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>
using namespace std;

// 回调函数,每当窗口改变大小,视口大小也跟随改变
void framebuffer_size_callback(GLFWwindow* window,int width,int height)
{
    glViewport(0,0,width,height);
}

// 输入 在GLFW中实现一些输入控制
void processInput(GLFWwindow *window)
{
    if(glfwGetKey(window,GLFW_KEY_ESCAPE) == GLFW_PRESS)     // 是否按下了返回键(Esc)
    {
        glfwSetWindowShouldClose(window,true);               // 把WindowShouldClose属性设置为 true来关闭GLFW
    }
}
// ************** opengl 具体实现 ************
    // 顶点数据
float vertices[] = {
    //     ---- 位置 ----    - 纹理坐标 -
    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
};

    // 纹理索引
unsigned int indices[] = {
    // 注意索引从0开始!
    // 此例的索引(0,1,2,3)就是顶点数组vertices的下标,
    // 这样可以由下标代表顶点组合成矩形

    0, 1, 3, // 第一个三角形
    1, 2, 3  // 第二个三角形
};
//******************************************
int main()
{
    cout << "纹理" << endl;

// GLFW (窗口)
    glfwInit();                                                         // 初始化GLFW
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR,3);                       // 主版本号
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR,3);                       // 次版本号
    glfwWindowHint(GLFW_OPENGL_PROFILE,GLFW_OPENGL_CORE_PROFILE);       // 使用核心模式
    //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); Mac OS X系统

    // 创建一个GLFW窗口对象
    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);                              // 窗口的上下文设置为当前线程的主上下文

// GLAD
    if(!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))      // 初始化GLAD(初始化OpenGL函数指针)
    {
        std::cout<<"Failed to initialize GLAD"<<std::endl;
        return -1;
    }

//*********** opengl 具体实现 ******************
    // 着色器类
    Shader shader("E:\\Project\\openglstudy2\\05_OpenglVector\\05_OpenglVector\\vertexSourceCode.vert",
                  "E:\\Project\\openglstudy2\\05_OpenglVector\\05_OpenglVector\\fragmentSourceCode.frag");

    // 顶点数组对象 VAO
    unsigned int VAO;
    glGenVertexArrays(1,&VAO);   // 创建顶点数组对象
    glBindVertexArray(VAO);      // 绑定顶点数组对象
    // 顶点缓冲对象 VBO
    unsigned int VBO;
    glGenBuffers(1,&VBO);
    glBindBuffer(GL_ARRAY_BUFFER,VBO);                                       // 绑定顶点缓冲对象
    glBufferData(GL_ARRAY_BUFFER,sizeof(vertices),vertices,GL_STATIC_DRAW);  // 把之前定义的顶点数据复制到缓冲的内存中
    // 索引缓存对象 EBO
    unsigned int EBO;
    glGenBuffers(1,&EBO);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,EBO);                                       // 绑定索引缓冲对象
    glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(indices),indices,GL_STATIC_DRAW);  // 把之前定义的索引数据复制到索引缓冲的内存中

    // 链接顶点属性 (告诉 gpu 如何解析内存中的顶点数据)
    // 0 位置坐标
    glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,5 * sizeof(float),(void*)0);
    glEnableVertexAttribArray(0);
    // 1 纹理坐标
    glVertexAttribPointer(1,2,GL_FLOAT,GL_FALSE,5 * sizeof(float),(void*)(3*sizeof(float)));
    glEnableVertexAttribArray(1);

    unsigned int texture1,texture2;
    // 纹理对象1 texture1
    glGenTextures(1,&texture1);
    glBindTexture(GL_TEXTURE_2D,texture1);

    // 设置纹理图像环绕方式
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    // 设置纹理过滤
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    // 加载图片
    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;
    }
    // 释放掉图像数据
    stbi_image_free(data);

    shader.use();
    // 纹理对象2 texture2
    glGenTextures(1,&texture2);
    glBindTexture(GL_TEXTURE_2D,texture2);

    // 设置纹理图像环绕方式
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);    // 重复
    // 设置纹理过滤
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    // 加载图片
    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;
    }
    // 释放掉图像数据
    stbi_image_free(data);

    // 设置采样器对应的纹理单元(unform)
    shader.use();
    shader.setInt("texture1",0);
    shader.setInt("texture2",1);

    // 变换
    glm::mat4 trans;
    trans = glm::rotate(trans,glm::radians(90.0f),glm::vec3(0.0,0.0,1.0));
    trans = glm::scale(trans,glm::vec3(0.5,0.5,0.5));

    unsigned int transformLoc = glGetUniformLocation(shader.ID,"transform");
    glUniformMatrix4fv(transformLoc,1,GL_FALSE,glm::value_ptr(trans));  // 第二个参数代表要发送多少个矩阵

//**************************




// 视口
    glViewport(0,0,800,600);

// 视口跟随窗口大小改变
    glfwSetFramebufferSizeCallback(window,framebuffer_size_callback);

// 渲染循环
    while(!glfwWindowShouldClose(window))                            // 检查GLFW是否被要求退出
    {
        // 输入 (用户)
        processInput(window);                                        // 输入控制(自定义)

        //************** 渲染指令 (用户)**********

        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);
        shader.use();
        glBindVertexArray(VAO);
        glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0);

        //***************************************

        // 检查并调用事件,交换缓冲 (默认操作)
        glfwSwapBuffers(window);                                     // 交换颜色缓冲(它是一个储存着GLFW窗口每一个像素颜色值的大缓冲),它在这一迭代中被用来绘制,并且将会作为输出显示在屏幕上。
        glfwPollEvents();                                            // 有没有触发什么事件(比如键盘输入、鼠标移动等)、更新窗口状态
    }

    // 解绑 VAO  VBO 着色器程序对象
    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);


// 当渲染循环结束后我们需要正确释放/删除之前的分配的所有资源
    glfwTerminate();
    return 0;
}

 

着色器文件:
顶点着色器:

#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 = vec4(aPos,1.0) * transform;
   TexCoord = vec2(aTexCoord.x, -aTexCoord.y);
}

 

posted @ 2024-04-07 00:41  雾枫  阅读(8)  评论(0编辑  收藏  举报