Removing polygons from the screen (OpenGL)?

Assuming the code is:

    glLoadIdentity();
    glTranslatef(-1.5f,0.0f,-6.0f);
glBegin(GL_TRIANGLES);
 开发者_JS百科       glVertex3f( 0.0f, 1.0f, 0.0f);
        glVertex3f(-1.0f,-1.0f, 0.0f);
        glVertex3f( 1.0f,-1.0f, 0.0f);
glEnd();

    glLoadIdentity();
    //Drawing another object...

How would I change the code to erase the object? I know that commenting out glTranslatef() will erase the triangle, but is that the formal way to do it?

---

If you put glClear at the start of the draw function (draw function is usually in a loop) you can simply choose not to redraw the triangle, drawing like that will leave no reference to your triangle.

Also, glTranslatef() wont remove your triangle, glTranslatef() is just a function to move the current matrix (in your case the matrix with your triangle is being moved into the camera view)

glClear()

http://www.khronos.org/opengles/documentation/opengles1_0/html/glClear.html

---

If you're asking how to make the triangle go away in subsequent frames, there's no need. Every frame time you're responsible for redrawing everything. OpenGL will not remember your triangle.

---

Putting an if around glBegin...glVertex...glEnd would be the most straightforward way.