QOpenGLWidget 绘制YUV和空心矩形,给出代码

以下是一个简单的 QOpenGLWidget 绘制 YUV 和空心矩形的示例代码：

void MyOpenGLWidget::initializeGL()
{
    initializeOpenGLFunctions();
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
}

void MyOpenGLWidget::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT);

    // 绘制 YUV 图像
    glBindTexture(GL_TEXTURE_2D, yuvTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, yData);
    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, uvTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RG, width / 2, height / 2, 0, GL_RG, GL_UNSIGNED_BYTE, uvData);
    glUniform1i(yuvSamplerLoc, 0);
    glUniform1i(uvSamplerLoc, 1);
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

    // 绘制空心矩形
    glUseProgram(rectProgram);
    glBindVertexArray(rectVAO);
    glUniform4f(rectColorLoc, 1.0f, 0.0f, 0.0f, 1.0f);
    glDrawArrays(GL_LINE_LOOP, 0, 4);
}

void MyOpenGLWidget::resizeGL(int w, int h)
{
    glViewport(0, 0, w, h);
}

void MyOpenGLWidget::createYUVTexture()
{
    glGenTextures(1, &yuvTexture);
    glBindTexture(GL_TEXTURE_2D, yuvTexture);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
}

void MyOpenGLWidget::createUVTexture()
{
    glGenTextures(1, &uvTexture);
    glBindTexture(GL_TEXTURE_2D, uvTexture);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
}

void MyOpenGLWidget::createRectProgram()
{
    rectProgram = glCreateProgram();
    GLuint vs = glCreateShader(GL_VERTEX_SHADER);
    GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
    const char* vsSource = "#version 330 core\n"
        "layout (location = 0) in vec2 aPos;\n"
        "void main()\n"
        "{\n"
        "    gl_Position = vec4(aPos, 0.0, 1.0);\n"
        "}\n";
    const char* fsSource = "#version 330 core\n"
        "uniform vec4 color;\n"
        "out vec4 FragColor;\n"
        "void main()\n"
        "{\n"
        "    FragColor = color;\n"
        "}\n";
    glShaderSource(vs, 1, &vsSource, NULL);
    glCompileShader(vs);
    glShaderSource(fs, 1, &fsSource, NULL);
    glCompileShader(fs);
    glAttachShader(rectProgram, vs);
    glAttachShader(rectProgram, fs);
    glLinkProgram(rectProgram);
    glDeleteShader(vs);
    glDeleteShader(fs);
    rectColorLoc = glGetUniformLocation(rectProgram, "color");
}

void MyOpenGLWidget::createRectVAO()
{
    GLfloat vertices[] = {
        -0.5f,  0.5f,
         0.5f,  0.5f,
         0.5f, -0.5f,
        -0.5f, -0.5f
    };
    glGenVertexArrays(1, &rectVAO);
    glBindVertexArray(rectVAO);
    GLuint rectVBO;
    glGenBuffers(1, &rectVBO);
    glBindBuffer(GL_ARRAY_BUFFER, rectVBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), (void*)0);
    glEnableVertexAttribArray(0);
}

其中，yuvTexture 和 uvTexture 是 YUV 图像的纹理 ID，yData 和 uvData 是 YUV 图像的数据，width 和 height 是图像的宽度和高度。rectProgram 是绘制空心矩形的着色器程序 ID，rectVAO 是空心矩形的顶点数组对象 ID，rectColorLoc 是颜色 uniform 变量的位置。在 paintGL 函数中，首先绑定 YUV 纹理和 UV 纹理，然后绘制 YUV 图像，最后绘制空心矩形。在 createYUVTexture、createUVTexture、createRectProgram 和 createRectVAO 函数中，分别创建 YUV 纹理、UV 纹理、着色器程序和顶点数组对象。