point clipping - 2-d viewing and clippingpoint

Question

Point clipping - 2-d viewing and clipping

Point clipping is the method related to suitable display of points in the scene, though this type of clipping is utilized less frequently in comparison to the other types, that is, line and polygon clipping. Although, in several situations, for example: the scenes that involve particle movements as explosion, dust and so on, this is quite helpful. For the sake of simplicity, suppose that the clip window is rectangular in shape. Consequently, the minimum and maximum coordinate value, that is, (Xw_max, Yw_max) and (Xw_min, Yw_min) are sufficient to identify window size and any point (X,Y), that can be displayed or shown should satisfy the subsequent inequalities. Or else, the point will not be visible. Hence, the point will be clipped or not can be determined on the basis of subsequent inequalities.

   Yw_max

≤ X ≤ Xw Xw_{min  max}

≤ Y ≤ Yw Yw_{min  max}

     Yw_min 

Xw      Xw _{min max}

Figure: Point Clipping

This is to be noticed that (Xw_max, Yw_max) and (Xw_min, Yw_min) can be either world coordinate window boundary or viewport boundary. Additionally, if any one of these four inequalities is not satisfied then the point is clipped that is not saved for display.