8.qt使用opengl

三角形

main.cpp

#include <QMainWindow>
#include <QVBoxLayout>
#include <QPushButton>
#include <QApplication>
#include "TriangleWidget.h"

class MyWindow : public QMainWindow {
public:
    MyWindow() {
        // 创建容器和布局
        QWidget* centralWidget = new QWidget(this);
        QVBoxLayout* layout = new QVBoxLayout(centralWidget);

        // 插入我们的 OpenGL 控件
        TriangleWidget* glView = new TriangleWidget(this);
        layout->addWidget(glView);

        // 插入一个 Qt 原生按钮测试
        QPushButton* btn = new QPushButton("Reset Camera", this);
        layout->addWidget(btn);

        setCentralWidget(centralWidget);
        resize(1024, 768);
    }
};

int main(int argc, char* argv[]) {
    QApplication a(argc, argv);
    MyWindow w;
    w.show();
    return a.exec();
}

TriangleWidget.h

#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QOpenGLShaderProgram>
#include <QOpenGLBuffer>

class TriangleWidget : public QOpenGLWidget, protected QOpenGLFunctions {
public:
    using QOpenGLWidget::QOpenGLWidget;

protected:
    void initializeGL() override {
        initializeOpenGLFunctions(); // 初始化封装后的 GL 函数
        glClearColor(0.1f, 0.1f, 0.1f, 1.0f); // 设置背景深灰色

        // 1. 定义着色器代码
        const char* vsrc = R"(
            #version 330 core
            layout(location = 0) in vec3 pos;
            void main() { gl_Position = vec4(pos, 1.0); }
        )";
        const char* fsrc = R"(
            #version 330 core
            out vec4 color;
            void main() { color = vec4(1.0, 0.5, 0.2, 1.0); }
        )";

        // 2. 编译并链接着色器
        m_program = new QOpenGLShaderProgram();
        m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, vsrc);
        m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, fsrc);
        m_program->link();

        // 3. 准备三角形顶点数据
        float vertices[] = {
             0.0f,  0.5f, 0.0f, // 顶
            -0.5f, -0.5f, 0.0f, // 左下
             0.5f, -0.5f, 0.0f  // 右下
        };

        m_vbo.create();
        m_vbo.bind();
        m_vbo.allocate(vertices, sizeof(vertices));
    }

    void paintGL() override {
        glClear(GL_COLOR_BUFFER_BIT);

        m_program->bind();
        m_vbo.bind();

        // 绑定顶点属性
        m_program->enableAttributeArray(0);
        m_program->setAttributeBuffer(0, GL_FLOAT, 0, 3);

        glDrawArrays(GL_TRIANGLES, 0, 3);

        m_vbo.release();
        m_program->release();
    }

private:
    QOpenGLShaderProgram* m_program = nullptr;
    QOpenGLBuffer m_vbo;
};

CMakeLists.txt

cmake_minimum_required(VERSION 3.24.0)

# 设置项目名称和版本
project(DrawOpenGL VERSION 0.1 LANGUAGES CXX)

#系统变量中没有Qt目录需要添加路径
option(USE_STATIC_QT "是否使用静态Qt" OFF)

if(USE_STATIC_QT)
    #set(CMAKE_PREFIX_PATH "C:/D/Program/Qt/6.2.4/MSVC2022_x64_static_624_Release")
    #set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
else()
    #set(CMAKE_PREFIX_PATH "C:/D/Program/Qt/6.9.0/mingw_64")
endif()

# 查找 Qt 6 包
find_package(Qt6 REQUIRED COMPONENTS Core OpenGLWidgets)

# 设置 C++ 标准
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED True)

# 添加可执行文件
set(SOURCE main.cpp TriangleWidget.h)
add_executable(${PROJECT_NAME} ${SOURCE} )
# 输出到项目下的 bin 文件夹
set_target_properties(${PROJECT_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/bin")

# 链接 Qt 库
target_link_libraries(${PROJECT_NAME} PRIVATE Qt6::Core Qt6::OpenGLWidgets)

CMakePresets.json

{
  "version": 3,
  "configurePresets": [
    {
      "name": "base",
      "hidden": true,
      "generator": "Ninja",
      "binaryDir": "${sourceDir}/out/build/${presetName}",
      "cacheVariables": {
        "CMAKE_EXPORT_COMPILE_COMMANDS": "YES"
      }
    },
    {
      "name": "qt-static-release",
      "displayName": "Qt 6.2.4 MSVC Static Release",
      "inherits": "base",

      "architecture": { "value": "x64", "strategy": "external" },
      "toolset": { "value": "host=x64", "strategy": "external" },
      "cacheVariables": {
        "CMAKE_BUILD_TYPE": "Release",
        "CMAKE_C_COMPILER": "cl.exe",
        "CMAKE_CXX_COMPILER": "cl.exe",
        "CMAKE_PREFIX_PATH": "C:/D/Program/Qt/6.2.4/MSVC2022_x64_static_624_Release",
        "CMAKE_MSVC_RUNTIME_LIBRARY": "MultiThreaded"
      },
      "vendor": {
        "jetbrains.com/clion": {
          "toolchain": "MSVC"
        }
      }
    },
    {
      "name": "qt-mingw-dynamic",
      "displayName": "Qt 6.9.0 MinGW Dynamic",
      "inherits": "base",
      "cacheVariables": {
        "CMAKE_BUILD_TYPE": "Debug",
        "CMAKE_PREFIX_PATH": "C:/D/Program/Qt/6.9.0/mingw_64",
        "CMAKE_C_COMPILER": "gcc.exe",
        "CMAKE_CXX_COMPILER": "g++.exe"
      },
      "vendor": {
        "jetbrains.com/clion": {
          "toolchain": "Qt_Mingw"
        }
      }
    }
  ],
  "buildPresets": [
    { "name": "qt-debug", "configurePreset": "qt-mingw-dynamic" },
    { "name": "qt-release", "configurePreset": "qt-static-release" }
  ]
}

构建方法

方法一:vs2022打开CMakeLists.txt

方法二:命令行构建