This is a demo on how JavaScript can be used for drawing graphics objects
like lines and circles with mouse. The objects are drawn by adding points
to the drawing area. For lines we use the classic Bresenham's algorithm.
For circles we just use its equation. The origin of the coordinate system is
in the top left corner of the area below. Only a part of a line/circle inside
the drawing area is displayed. The previously plotted line/circle is
erased.
Click, drag, and release the mouse within the drawing area to draw.
JavaScript is slooowww, wait several seconds for an object to appear
before drawing the next one.
The script is designed for a W3C compliant browser, e.g.
Firefox.
Input coordinates:
| Lines (x1,y1,x2,y2) | Circles (x,y,r) |
|---|---|