Pixels rendering white (OpenGL)

Question

I'm trying to get non-shader per-pixel lighting in the background of my window. It's supposed to render completely white in the top-left corner and completely black in the bottom left corner, but instead it's white with black edges. For some reason, all pixels except the far right and far bottom edge are completely white (the edges are black)). Why isn't it rendering properly?

    glViewport(0, 0, Display.getWidth(), Display.getHeight());

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, 2000, 2000, 0, 1, -1);
    glMatrixMode(GL_MODELVIEW);

    if (lighting != 0)
        glDeleteLists(lighting, 1);

    lighting = glGenLists(1);

    glNewList(lighting, GL_COMPILE);

    glDisable(GL_TEXTURE_2D);

    glBegin(GL_POINTS);
    for (int x = 1; x <= 2000; x++)
    {
        for (int y = 1; y <= 2000; y++)
        {
            double dist = new Point(x, y).distance(new Point(0, 0));
            double brightness = 1 - (1 / 2000 * dist); //I tried just "1 / 2000 & dist" instead, but that just renders black everywhere

            glColor3d(brightness, brightness, brightness);

            glVertex2f(x, y);
        }
    }
    glEnd();

    glEndList();