Pdf an efficient algorithm for line clipping in computer. Three new algorithms for twodimensional line clipping. This performance comparison is machineindependent, based on an analysis of the number of arithmetic operations and comparisons required by the different algorithms. Replace with i and repeat the algorithm questions 1 use. The ideas for clipping line of liang barsky and cyrusbeck are the same. The liangbarsky algorithm is a line clipping algorithm. This algorithm is considered to be the faster parametric line clipping algorithm.
Write a program to fill a circle using flood fill algorithm. Be semesterv it question bank computer graphics and. Liang barsky line clipping algorithm is faster line clipper algorithm based on analysis of the parametric equation of a line segment. I also guide them in doing their final year projects. The algorithm is very different to the other line clipping algorithms.
This paper proposes a new line clipping algorithm for 3d space against a cuboid which is not generated based on cohensutherland or liang barsky line clipping algorithms. The next step we consider if tvalue is entering or exiting by using inner product. Cohen sutherland midpoint subdivision, liang barsky. The liang barsky algorithm uses the parametric equation of a line and inequalities describing the range of the clipping window to determine the intersections between the line and the clipping window. The performance of this algorithm is shown to be consistently better than existing algorithms, including the cohensutherland and liang barsky algorithms. The liangbarsky algorithm uses the parametric equation of a line and. Identify line clipping algorithms from the following a cohen sutherland algorithm b liang barsky clipping c nichollleenicholl clipping dall of the above ans. The only difference is liang barsky algorithm has been optimized for an upright rectangular clip window. This is a part of mumbai university mca colleges computer graphics cg mca sem 2. The inequalities describing the range of the clipping window which is used to determine the intersections between the line and the clip window. What are the other 10 display file structures used. Get answer set up a detailed algorithm for the nicholl.
This algorithm is more efficient than cohensutherland line clipping algorithm and can be extended to 3dimensional clipping. Cyrus beck line clipping liang and barsky any convex region as window parametric line input line ab. Liang barsky line clipping algorithm free download as pdf file. Line clipping 2d transformations computer science department. Liangbarsky algorithm cg programs and notes for mca. A explain the cohensutherland line clipping algorithm with suitable example. Write a program to fill a circle using boundary fill algorithm. Because of unifying approach to the clipping problem solution algorithms are simple. In computer graphics, the liangbarsky algorithm is a line clipping algorithm. Compare the number of arithmetic operations performed in the nln algorithm to both the cohensutherland and liang barsky line clipping algorithms, for several different line orientations relative to a clipping window. The algorithm divides a twodimensional space into 9 regions and then efficiently determines the lines and portions of lines that are visible in the central region of interest the viewport. Liang and barsky 1984 algorithm efficient in clipping upright 2d3d clipping regions cyrus beck may be reduced to more efficient liang barsky case based on parametric form of a line line. Liang barsky algorithm cg this program is for implementing liang barsky algorithm.
In the algorithm, first of all, it is detected whether line lies inside the screen or it is outside the screen. Basic transformations, matrix representations and homogeneous coordinates, composite transformations, clipping and windowing. Program to show the implementation of liangbarsky line. Simple comparisons used to find actual intersection points. Compare the number of arithmetic operations performed in the cohensutherland and the liang barsky line clipping algorithms for several different line orientations relative to a clipping window. Pdf most of the line clipping algorithms are based on cohensutherland. Line clipping computer science university of north texas. Indeed, converting a pdf to word or an rtf file isnt that obvious. Few questions about liangbarsky line clipping algorithm.
Need for clipping and windowing, line clipping algorithms. I have 4 years of hands on experience on helping student in completing their homework. Pdf an efficient line clipping algorithm for 3d space. Weiler atherton three dimensional object representations, geometric transformations and 3d viewing boundary representation and space. Liang barsky line clipping algorithm is faster line clipper. It employs parametric line representation and simple dot products. Algorithms for line clipping and their complexity computer. Fast, destructive implemetation of liangbarsky line clipping algorithm. Algorithms were derived from the cohensutherlands and liangbarsky s. Cohensutherland line clipping and liang barsky line clipping algorithm by shilpa.
Liang barsky algorithm in computer graphics, the liang barsky algorithm named after you dong liang and brian a. Complete implementation of liang barsky line clipping algorithm in opengl. Liang and barsky 1984 algorithm efficient in clipping. This algorithm is more efficient than cohensutherland algorithm. For the line segments that cannot be identified as completely inside or outside the window by simple testings, this algorithm applies affine transformations the shearing.
Clipping operations point clipping, line clipping algorithms. Explain sutherland hodgman polygon clipping algorithm. In computer graphics, the liang barsky algorithm named after youdong liang and brian a. Almost two decades ago, liang and barsky developed a fast and efficient parametric line clipping algorithm. Q 2 a explain bresenham line drawing algorithm with proper mathematical analysis and identify the pixel positions along a line between a10,10 and b18,16 using it. The algorithm divides a 2d space into 9 regions, of which only the middle part viewport is visible. It is performed by using the line clipping algorithm. Suppose that the open gl window is 500 x 50 pixels and the clipping window is a unit square with the origin at the lower left corner.
Clipping polygons n cohensutherland and liang barsky clip line segments against each window in turn n polygons can be fragmented into several polygons during clipping n may need to add edges n need more sophisticated algorithms to handle polygons. Hello friends, i am free lance tutor, who helped student in completing their homework. New algorithms for 2d line clipping against convex and nonconvex windows. Write a complete program to implement the liang barsky line clipping algorithm. Easy tutor author of program to show the implementation of liang barsky line clipping algorithm is from united states. The liang barsky algorithm uses the parametric equation of a line and inequalities describing the range of the clipping window to determine the intersections between the line and the clip window. Easy tutor author of program of liang barsky algorithm for line clipping is from united states. Over 10 million scientific documents at your fingertips. Taking input from user on mouse clicks and then taking window coordinates on mouse click.
Cohen sutherland line clipping algorithm the cohensutherland algorithm is a computergraphics algorithm used for line clipping. Discuss the request mode, sample mode and event modes with the figures wherever required. Day queensland university of technology, school of computing science, gpo box 2434, brisbane 4001, australia abstracta new algorithm for clipping. Clipping cyrus beck line clipping liang and barsky p n q implicit line window edge. All lines come under any one of the following categories. The line clipping algorithm basing on affine transformation. Liang barsky line clipping algorithm applied mathematics. The region is defined by edges e i having outward pointing normals n i. Few questions about liang barsky line clipping algorithm.
Technical section an algorithm for clipping lines in object and image space j. Liang and barsky have created an algorithm that uses floatingpoint arithmetic but finds the appropriate end points with. Liangbarsky line clipping algorithm cohen sutherland line clipping algorithm. What is the fraction of the total refresh time per frame.
A new algorithm for clipping line segments by a rectangular window on rectangular coordinate system is presented in this paper. Mathematics stack exchange is a question and answer site for people studying math at any level and professionals in related fields. Pdf an efficient algorithm for line clipping in computer graphics. The liang barsky algorithm uses the parametric equation of a line and inequalities describing the range of the clipping window to determine the intersections between the line and the. Consider a noninterlaced raster system with resolution of 1280 by 1024, a refresh rate of 60 hz, a horizontal retrace time of 5 microseconds and a vertical retrace time of 500. The liang barsky algorithm is a line clipping algorithm. With these intersections it knows which portion of the line should be drawn. Write a program to implement liang barsky line clipping algorithm. A given the obtained r 2 value i think the features that i chose for the linear. This algorithm is more efficient than cohen sutherland line clipping algorithm and can be extended to 3dimensional clipping. Given a line segment clipped against e i the intersection point is.
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