Present line-generating algorithms

which include Bresenham algorithm

symmetrical algorithm and the algorithm based on the chain code theory of the line

are analyzed and compared in this paper. A property-based on the chain code theory of the line

are analyzed and compared in this paper. A property-based integrated line-generating algorithm

which is based on the Bresenham algorithm and makes full use of the symmetry

direction and continuity of the line

is presented to increase the speed of line generating. The results of our experiments have proved that the line-generating speed of the integrated algorithm is increased by more than 50 percent compared to that of Bresenham algorithm. The new algorithm is especially efficient for engineering drawings

in which the in- clinations of most lines are 0°

180°

±90°

±45°and±135°. In can be thought that the integrated line-generating algorithm has make great progress in the way to reach the minimum value of the operation time in generating a line. Existing CAD&CG algorithms must take into account the particularity and entireness of the object while the integrity and universality of the processing object is pursued. To handle the related algorithms in some special way according to the characteristics of engineering drawings is an effective method to improve present CAD&CG algorithms.