TY - THES
AU - Tran, Chan-Hung
PY - 1986
TI - Fast clipping algorithms for computer graphics
KW - Thesis/Dissertation
LA - eng
M3 - Text
AB - Interactive computer graphics allow achieving a high bandwidth man-machine communication only if the graphics system meets certain speed requirements. Clipping plays an important role in the viewing process, as well as in the functions zooming and panning; thus, it is desirable to develop a fast clipper. In this thesis, the intersection problem of a line segment against a convex polygonal object has been studied. Adaption of the the clip algorithms for parallel processing has also been investigated.
Based on the conventional parametric clipping algorithm, two families of 2-D generalized line clipping algorithms are proposed: the t-para method and the s-para method. Depending on the implementation both run either linearly in time using a sequential tracing or logarithmically in time by applying the numerical bisection method. The intersection problem is solved after the sector locations of the endpoints of a line segment are determined by a binary search. Three-dimensional clipping with a sweep-defined object using translational sweeping or conic sweeping is also discussed.
Furthermore, a mapping method is developed for rectangular clipping. The endpoints of a line segment are first mapped onto the clip boundaries by an interval-clip operation. Then a pseudo window is-defined and a set of conditions is derived for trivial acceptance and rejection.
The proposed algorithms are implemented and compared with the Liang-Barsky algorithm to estimate their practical efficiency. Vectorization of the 2-D and 3-D rectangular clipping algorithms on an array processor has also been attempted.
N2 - Interactive computer graphics allow achieving a high bandwidth man-machine communication only if the graphics system meets certain speed requirements. Clipping plays an important role in the viewing process, as well as in the functions zooming and panning; thus, it is desirable to develop a fast clipper. In this thesis, the intersection problem of a line segment against a convex polygonal object has been studied. Adaption of the the clip algorithms for parallel processing has also been investigated.
Based on the conventional parametric clipping algorithm, two families of 2-D generalized line clipping algorithms are proposed: the t-para method and the s-para method. Depending on the implementation both run either linearly in time using a sequential tracing or logarithmically in time by applying the numerical bisection method. The intersection problem is solved after the sector locations of the endpoints of a line segment are determined by a binary search. Three-dimensional clipping with a sweep-defined object using translational sweeping or conic sweeping is also discussed.
Furthermore, a mapping method is developed for rectangular clipping. The endpoints of a line segment are first mapped onto the clip boundaries by an interval-clip operation. Then a pseudo window is-defined and a set of conditions is derived for trivial acceptance and rejection.
The proposed algorithms are implemented and compared with the Liang-Barsky algorithm to estimate their practical efficiency. Vectorization of the 2-D and 3-D rectangular clipping algorithms on an array processor has also been attempted.
UR - https://open.library.ubc.ca/collections/831/items/1.0096928
ER - End of Reference