Cohen Sutherland Line Clipping Algorithm

The Cohen–Sutherland algorithm

is a computer graphics algorithm used for line clipping. The algorithm divides a two-dimensional space into 9 regions and then efficiently determines the lines and portions of lines that are visible in the center region of interest (the viewport).

We will use 4-bits to divide the entire region. These 4 bits represent the Top, Bottom, Right, and Left of the region as shown in the following figure. Here, the TOP and LEFT bit is set to 1 because it is the TOP-LEFT corner.

Viewport
Image Credits: Tutorials Point

There are 3 possibilities for the line to lie  −

• Line can be completely inside the window (This line should be visible).
• Line can be completely outside the window (This line should be rejected).
• Line can be partially inside the window (We find intersection point and draw only that portion of the line which lies inside the region).

Code:

If you can't see the code, then Enable JavaScript in you browser

Output:

Note: Just copy the files "CGA.bgi" & "EGAVGA.bgi" from bgi folder to bin. So, if you have copied these 2 files then you can skip writing "C:\\tc\\bgi" in initgraph with just ""(2 double quotes)