模版测试似乎无能为力

问题描述

看来，无论我做什么，模板缓冲区都不会影响我正在绘制的内容。我正在绘制两个矩形，一个矩形绘制在另一个矩形的上方，略微偏离矩形。它们相交的部分是我唯一想要显示的东西。这样可以实现我想要的UI滚动区域。

这是我的抽奖电话：

void drawGL(sf::Window& i_Window)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glStencilOp(GL_KEEP,GL_KEEP,GL_REPLACE);
    glStencilFunc(GL_ALWAYS,1,0xFF);
    glStencilMask(0xFF);
    glUtil::DrawQuad(0.0f,0.0f,300,1.0f,1.0f);

    glStencilOp(GL_KEEP,GL_KEEP);
    glStencilFunc(GL_EQUAL,0xFF);
    glStencilMask(0x00);
    glUtil::DrawQuad(200.0f,200.0f,0.0f);
}

这是我初始化OpenGL的方式

void initGL(sf::Window& i_Window)
{
    glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_FASTEST);
    glShadeModel(GL_SMOOTH);
    glEnable(GL_CULL_FACE);
    glEnable(GL_TEXTURE_2D);
    glEnable(GL_BLEND);
    glEnable(GL_STENCIL_TEST);
    glDisable(GL_DEPTH_TEST);
    glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
    glEnableClientState(GL_VERTEX_ARRAY);
    //glEnableClientState(GL_TEXTURE_COORD_ARRAY);
    glLoadIdentity();
    glOrtho(0,i_Window.getSize().x,i_Window.getSize().y,10);
    glClearColor(0.0245f,0.1294f,0.27255f,1.0f);
}

我的DrawQuad()实现

    void DrawQuad(GLfloat i_fX,GLfloat i_fY,GLfloat i_fWidth,GLfloat i_fHeight,GLfloat i_fR,GLfloat i_fG,GLfloat i_fB,GLfloat i_fA = 1.0f)
    {
        GLfloat Vertices[18] = {};
        Vertices[0] = 0;            Vertices[1] = 0;            Vertices[2] = 0.0f;
        Vertices[3] = 0;            Vertices[4] = i_fHeight;    Vertices[5] = 0.0f;
        Vertices[6] = i_fWidth;     Vertices[7] = i_fHeight;    Vertices[8] = 0.0f;

        Vertices[9] = 0;            Vertices[10] = 0;           Vertices[11] = 0.0f;
        Vertices[12] = i_fWidth;    Vertices[13] = i_fHeight;   Vertices[14] = 0.0f;
        Vertices[15] = i_fWidth;    Vertices[16] = 0;           Vertices[17] = 0.0f;

        glPushMatrix();
        glTranslatef(i_fX,i_fY,0.0f);
        glColor4f(i_fR,i_fG,i_fB,i_fA);
        glVertexPointer(3,GL_FLOAT,Vertices);
        glDrawArrays(GL_TRIANGLES,6);
        glPopMatrix();
    }

还有我的main()函数，以防它对诊断有用...

int main()
{
    sf::Window window(sf::VideoMode(1200,720),"My window");
    initGL(window);

    sf::Event event;
    int nNumFrames = 0;
    while (window.isOpen())
    {
        while (window.pollEvent(event))
        {
            switch (event.type)
            {
            case sf::Event::Closed:
            case sf::Event::KeyPressed:
                window.close();
                break;
            case sf::Event::Resized:
                glViewport(0,window.getSize().x,window.getSize().y);
                glLoadIdentity();
                glOrtho(0,window.getSize().y,10);
                break;
            }
        }

        drawGL(window);
        window.display();

        ++nNumFrames;
    }

    return 0;
}

这是我得到的屏幕快照，无论我如何设置模板缓冲功能。我想看到的只是一个绿色的小盒子，白色和绿色的盒子相交。

解决方法

您的窗口（默认帧缓冲区）根本没有模板缓冲区。您必须使用sf::ContextSettings类来设置带有模板缓冲区的OpenGL窗口。

请参见Using OpenGL in a SFML window：

sf::ContextSettings settings;
settings.depthBits = 24;
settings.stencilBits = 8;
settings.antialiasingLevel = 4;
settings.majorVersion = 4;
settings.minorVersion = 6;

sf::Window window(sf::VideoMode(1200,720),"My window",sf::Style::Default,settings);