Point Clipping Algorithm in Computer Graphics

Clipping: In computer graphics our screen act as a 2-D coordinate system. it is not necessary that each and every point can be viewed on our viewing pane(i.e. our computer screen). We can view points, which lie in particular range (0,0) and (Xmax, Ymax). So, clipping is a procedure that identifies those portions of a picture that are either inside or outside of our viewing pane.
In case of point clipping, we only show/print points on our window which are in range of our viewing pane, others points which are outside the range are discarded.
Example

Input :
 clip 2
Output :
clip 3

Point Clipping Algorithm:

  1. Get the minimum and maximum coordinates of both viewing pane.
  2. Get the coordinates for a point.
  3. Check whether given input lies between minimum and maximum coordinate of viewing pane.
  4. If yes display the point which lies inside the region otherwise discard it.

C

filter_none

edit
close

play_arrow

link
brightness_4
code

// C program for point clipping Algorithm
#include<stdio.h>
//#include<graphics.h>
  
// Function for point clipping
void pointClip(int XY[][2], int n, int Xmin, int Ymin,
                                   int Xmax, int Ymax)
{
    /*************** Code for graphics view
    // initialize graphics mode
    detectgraph(&gm,&gr);
    initgraph(&gm,&gr,"d:\\tc\\BGI");
    for (int i=0; i<n; i++)
    {
    if ( (XY[i][0] >= Xmin) && (XY[i][0] <= Xmax))
    {
            if ( (XY[i][1] >= Ymin) && (XY[i][1] <= Ymax))
        putpixel(XY[i][0],XY[i][1],3);
    }
    }
    **********************/
    /**** Arithmetic view ****/
    printf ("Point inside the viewing pane:\n");
    for (int i=0; i<n; i++)
    {
        if ((XY[i][0] >= Xmin) && (XY[i][0] <= Xmax))
        {
            if ((XY[i][1] >= Ymin) && (XY[i][1] <= Ymax))
                printf ("[%d, %d] ", XY[i][0], XY[i][1]);
        }
    }
  
    // print point coordinate outside viewing pane
    printf ("\nPoint outside the viewing pane:\n");
    for (int i=0; i<n; i++)
    {
        if ((XY[i][0] < Xmin) || (XY[i][0] > Xmax))
            printf ("[%d, %d] ", XY[i][0], XY[i][1]);
        if ((XY[i][1] < Ymin) || (XY[i][1] > Ymax))
            printf ("[%d, %d] ", XY[i][0], XY[i][1]);
    }
}
  
// Driver code
int main()
{
    int XY[6][2] = {{10,10}, {-10,10}, {400,100},
                    {100,400}, {400,400}, {100,40}};
  
    // getmaxx() & getmaxy() will return Xmax, Ymax
    // value if graphics.h is included
    int Xmin = 0;
    int Xmax = 350;
    int Ymin = 0;
    int Ymax = 350;
    pointClip(XY, 6,  Xmin, Ymin, Xmax, Ymax);
    return 0;
}

chevron_right


Java

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java program for point clipping Algorithm
class GFG 
{
  
// Function for point clipping
static void pointClip(int XY[][], int n, 
                        int Xmin, int Ymin,
                        int Xmax, int Ymax)
{
    /*************** Code for graphics view
    // initialize graphics mode
    detectgraph(&gm,&gr);
    initgraph(&gm,&gr,"d:\\tc\\BGI");
    for (int i=0; i<n; i++)
    {
    if ( (XY[i][0] >= Xmin) && (XY[i][0] <= Xmax))
    {
            if ( (XY[i][1] >= Ymin) && (XY[i][1] <= Ymax))
        putpixel(XY[i][0],XY[i][1],3);
    }
    }
    **********************/
    /**** Arithmetic view ****/
    System.out.printf ("Point inside the viewing pane:\n");
    for (int i = 0; i < n; i++)
    {
        if ((XY[i][0] >= Xmin) && (XY[i][0] <= Xmax))
        {
            if ((XY[i][1] >= Ymin) && (XY[i][1] <= Ymax))
                System.out.printf ("[%d, %d] ", XY[i][0], XY[i][1]);
        }
    }
  
    // print point coordinate outside viewing pane
    System.out.printf ("\nPoint outside the viewing pane:\n");
    for (int i=0; i<n; i++)
    {
        if ((XY[i][0] < Xmin) || (XY[i][0] > Xmax))
            System.out.printf ("[%d, %d] ", XY[i][0], XY[i][1]);
        if ((XY[i][1] < Ymin) || (XY[i][1] > Ymax))
            System.out.printf ("[%d, %d] ", XY[i][0], XY[i][1]);
    }
}
  
// Driver code
public static void main(String[] args) 
{
        int XY[][] = {{10,10}, {-10,10}, {400,100},
                    {100,400}, {400,400}, {100,40}};
  
    // getmaxx() & getmaxy() will return Xmax, Ymax
    // value if graphics.h is included
    int Xmin = 0;
    int Xmax = 350;
    int Ymin = 0;
    int Ymax = 350;
    pointClip(XY, 6, Xmin, Ymin, Xmax, Ymax);
}
}
  
/* This code contributed by PrinciRaj1992 */

chevron_right


Python3

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python3 program for poclipping Algorithm
  
# Function for poclipping 
def pointClip(XY, n, Xmin, Ymin, Xmax, Ymax):
  
    """************** Code for graphics view 
    # initialize graphics mode 
    detectgraph(&gm, &gr) 
    initgraph(&gm, &gr, "d:\\tc\\BGI") 
    for (i=0 i<n i++) 
      
    if ((XY[i][0] >= Xmin) and 
        (XY[i][0] <= Xmax)) 
      
        if ((XY[i][1] >= Ymin) and 
            (XY[i][1] <= Ymax)) 
        putpixel(XY[i][0], XY[i][1], 3) 
      
    *********************"""
    """*** Arithmetic view ***"""
    print("Point inside the viewing pane:"
    for i in range(n):
        if ((XY[i][0] >= Xmin) and 
            (XY[i][0] <= Xmax)): 
            if ((XY[i][1] >= Ymin) and 
                (XY[i][1] <= Ymax)): 
                print("[", XY[i][0], ", ", XY[i][1], 
                      "]", sep = "", end = " ") 
          
    # prpocoordinate outside viewing pane 
    print("\n\nPoint outside the viewing pane:"
    for i in range(n):   
        if ((XY[i][0] < Xmin) or (XY[i][0] > Xmax)) :
            print("[", XY[i][0], ", ", XY[i][1],
                  "]", sep = "", end = " ") 
        if ((XY[i][1] < Ymin) or (XY[i][1] > Ymax)) :
            print("[", XY[i][0], ", ", XY[i][1], 
                  "]", sep = "", end = " ") 
  
# Driver Code
if __name__ == '__main__':
    XY = [[10, 10], [-10, 10], [400, 100], 
          [100, 400], [400, 400], [100, 40]] 
  
    # getmaxx() & getmaxy() will return Xmax, 
    # Ymax value if graphics.h is included 
    Xmin = 0
    Xmax = 350
    Ymin = 0
    Ymax = 350
    pointClip(XY, 6, Xmin, Ymin, Xmax, Ymax)
  
# This code is contributed by
# SHUBHAMSINGH10

chevron_right


C#

filter_none

edit
close

play_arrow

link
brightness_4
code

// C# program for point clipping Algorithm
using System;
  
class GFG 
{
  
// Function for point clipping
static void pointClip(int [,]XY, int n, 
                        int Xmin, int Ymin,
                        int Xmax, int Ymax)
{
    /*************** Code for graphics view
    // initialize graphics mode
    detectgraph(&gm,&gr);
    initgraph(&gm,&gr,"d:\\tc\\BGI");
    for (int i=0; i<n; i++)
    {
    if ( (XY[i,0] >= Xmin) && (XY[i,0] <= Xmax))
    {
            if ( (XY[i,1] >= Ymin) && (XY[i,1] <= Ymax))
        putpixel(XY[i,0],XY[i,1],3);
    }
    }
    **********************/
    /**** Arithmetic view ****/
    Console.Write("Point inside the viewing pane:\n");
    for (int i = 0; i < n; i++)
    {
        if ((XY[i, 0] >= Xmin) && (XY[i, 0] <= Xmax))
        {
            if ((XY[i, 1] >= Ymin) && (XY[i, 1] <= Ymax))
                Console.Write("[{0}, {1}] ", XY[i, 0], XY[i, 1]);
        }
    }
  
    // print point coordinate outside viewing pane
    Console.Write("\nPoint outside the viewing pane:\n");
    for (int i = 0; i < n; i++)
    {
        if ((XY[i, 0] < Xmin) || (XY[i, 0] > Xmax))
            Console.Write("[{0}, {1}] ", XY[i, 0], XY[i, 1]);
        if ((XY[i, 1] < Ymin) || (XY[i, 1] > Ymax))
            Console.Write("[{0}, {1}] ", XY[i, 0], XY[i, 1]);
    }
}
  
// Driver code
public static void Main(String[] args) 
{
        int [,]XY = {{10, 10}, {-10, 10}, {400, 100},
                    {100, 400}, {400, 400}, {100, 40}};
  
    // getmaxx() & getmaxy() will return Xmax, Ymax
    // value if graphics.h is included
    int Xmin = 0;
    int Xmax = 350;
    int Ymin = 0;
    int Ymax = 350;
    pointClip(XY, 6, Xmin, Ymin, Xmax, Ymax);
}
}
  
// This code contributed by Rajput-Ji

chevron_right


Output:

Point inside the viewing pane:
[10, 10] [100, 40] 

Point outside the viewing pane:
[-10, 10] [400, 100] [100, 400] [400, 400] [400, 400] 

Related Post :
Line Clipping | Set 1 (Cohen–Sutherland Algorithm)
Polygon Clipping | Sutherland–Hodgman Algorithm

This article is contributed by Shivam Pradhan (anuj_charm). If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.



My Personal Notes arrow_drop_up



Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.