Liang Barsky Line Clipping Algorithm in C
The Liang Barsky line clipping algorithm is a method used in computer graphics to efficiently determine the portion of a line segment that lies within a specified clipping window. It is more efficient than Cohen Sutherland algorithm because It clips the line with more efficient parametric equations. This algorithm was developed by You-Dong Liang and Brian A. Barsky in 1984. This method is particularly effective for lines predominantly inside or outside the window.
Program Code of Liang Barsky Line Clipping Algorithm in C
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 | //Liang Barsky Line Clipping Algorithm in C #include<graphics.h> #include<conio.h> #include<stdio.h> void main() { int i,gd=DETECT,gm; int x1,y1,x2,y2,xmin,xmax,ymin,ymax,xx1,xx2,yy1,yy2,dx,dy; float t1,t2,p[4],q[4],temp; xmin=150; xmax=450; ymin=100; ymax=350; initgraph(&gd,&gm,"c:\\turboc3\\bgi"); rectangle(xmin,ymin,xmax,ymax); printf("Enter starting point of line : "); scanf("%d%d",&x1,&y1); printf("Enter ending point of line : "); scanf("%d%d",&x2,&y2); printf("Line before clipping:"); line(x1,y1,x2,y2); getch(); cleardevice(); printf("Line after clipping:"); rectangle(xmin,ymin,xmax,ymax); //Line Clipping process dx=x2-x1; dy=y2-y1; p[0]=-dx; p[1]=dx; p[2]=-dy; p[3]=dy; q[0]=x1-xmin; q[1]=xmax-x1; q[2]=y1-ymin; q[3]=ymax-y1; for(i=0;i<4;i++) { if(p[i]==0) { if(q[i]>=0) { if(i<2) { if(y1<ymin) { y1=ymin; } if(y2>ymax) { y2=ymax; } line(x1,y1,x2,y2); } if(i>1) { if(x1<xmin) { x1=xmin; } if(x2>xmax) { x2=xmax; } line(x1,y1,x2,y2); } } } } t1=0; t2=1; for(i=0;i<4;i++) { temp=q[i]/p[i]; if(p[i]<0) { if(t1<=temp) t1=temp; } else { if(t2>temp) t2=temp; } } if(t1<t2) { xx1 = x1 + t1 * p[1]; xx2 = x1 + t2 * p[1]; yy1 = y1 + t1 * p[3]; yy2 = y1 + t2 * p[3]; line(xx1,yy1,xx2,yy2); } getch(); closegraph(); } |
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