docs: public void apply(GL2 gl) {
      // 3D projection
      gl.glMatrixMode(GL2.GL_PROJECTION);
      gl.glLoadIdentity();
      // Perspective.
      glu.gluPerspective(35, ratio, 1, 1000);
      glu.gluLookAt(distance * sinZ, distance * -cosZ, height, // pos
          0, 0, .5, // center
          0, 0, 1 // up
      );
      // Change back to model view matrix.
      gl.glMatrixMode(GL2.GL_MODELVIEW);
      gl.glLoadIdentity();
  
      // Store the matrixes for reference.
      gl.glGetIntegerv(GL.GL_VIEWPORT, viewp, 0);
      gl.glGetDoublev(GLMatrixFunc.GL_MODELVIEW_MATRIX, modelview, 0);
      gl.glGetDoublev(GLMatrixFunc.GL_PROJECTION_MATRIX, projection, 0);
    }