读书笔记——使用模板缓冲区

标红的为关键代码

    glEnable(GL_STENCIL_TEST);
    glClearStencil(0);
    glClear(GL_COLOR_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
    glStencilFunc(GL_NEVER,0,0);
    glStencilOp(GL_INCR,GL_INCR,GL_INCR);

     ...
    glStencilFunc(GL_NOTEQUAL,1,1);
    glStencilOp(GL_KEEP,GL_KEEP,GL_KEEP);
    ...

GLfloat angle=0.0f;GLfloat radius=1.01f;glEnable(GL_STENCIL_TEST);glClearStencil(0);glClear(GL_COLOR_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);glColor3f(1.0f,0.0f,1.0f);glStencilFunc(GL_NEVER,0,0);glStencilOp(GL_INCR,GL_INCR,GL_INCR);glBegin(GL_LINE_STRIP);for (angle=0.0f;angle<400.0f;angle+=0.1){glVertex2f(radius*cos(angle),radius*sin(angle));radius*=1.002;}glEnd();glColor3f(1.0f,0.0f,0.0f);glStencilFunc(GL_NOTEQUAL,1,1);glStencilOp(GL_KEEP,GL_KEEP,GL_KEEP);glRectf(x,y,x+RectSize,y-RectSize);