Line Drawing - Points and lines
Line drawing is accomplished through computing the intermediate point coordinates along the line path between two given end points. Since, screen pixels are referred along with integer values, plotted positions may only around the calculated coordinates that is pixels that are intensified are those such lie very near to the line path if not precisely on the line path that is in the case of absolutely horizontal, vertical or 45° lines merely.
Figure: Stair case effect
Standard algorithms are accessible to find out which pixels provide the best approximation to the desired line. Screen resolution conversely, is a large factor towards enhancing the approximation. In a high resolution system such adjacent pixels are very closely spaced which the approximated line-pixels lay extremely close to the real line path and thus, the plotted lines appear to be vary smoother; mostly like straight lines drawn upon paper. In a low resolution system, the similar approximation technique causes lines to be shown with a "stair-step appearance" that is not smooth as demonstrated in following figure; the effect is termed as the stair case effect.