CLIPPING OPERATIONS

Any procedure that identifies those portions of a picture that is either inside or outside of a specified region of space

1.      Applied in World Coordinates

2.      Adapting Primitive Types

–Point

–Line

–Area (or Polygons)

–Curve, Text

Point Clipping:

1.      Assuming that the clip window is a rectangle in standard position

2.      Saving a point P=(x, y) for display

xw_min <=x<=xw_max

yw_min <=y<=yw_max

3.      Appling Fields  - Particles (explosion, sea foam)

1.      Parametric representation of Line segment with endpoints (x1, y1) and (x2, y2)

x = x_{1 +} u(x₂-x₁)

y = y_{1 +} u(y₂-y₁) ; 0<=u<=1

2.      Exterior of the window

– Intersection with outside the range u

3.      Interior of the window

– Intersection with inside the range u