C.a.R

http://mathsrv.ku-eichstaett.de/MGF/homes/grothmann/java/zirkel/

Here is C.a.R. (compass and ruler), a program, that simulates school geometry constructions with a pair of compasses and a straightedge (ruler).

The program uses Java, and runs on almost any modern platform.

The program is freeware, and the source is available and free by the GNU General Public License.

• Simulation of school geometry constructions in the plane.
• Runs on almost any modern platform, including Windows 95, NT or better, Linux, Mac OS, Mac OSX, Sun Solaris and other Unix
• Special graphical enhanced version for Java 1.3 (using e.g. anti-aliasing).
• Free source under GPL.
• HTML documentation.
• Context sensitive help integrated into the program.
• Modern intuitive interface, which follows the common interface rules.
• GUI in English, German, Italian, Portuguese or Spanish.
• Configurable toolbox.
• Visual mode of construction or descriptive mode, using commands.
• Programming language for constructions, including macros and macros called in macros.
• Uses the right mouse button for object properties and object movement as usual.
• Automatic generation of points on objects and intersections, with or without confirmation
• Lengths of segments and other sizes may be fixed. Fixed circles and angles can still be changed with the mouse, unless they are fixed by a composite expression.
• Partially visible circles and lines, which display only the relevant parts.
• Circles can be drawn as arcs.
• Arcs and angles can be kept acute.
• Hiding of construction details. Super-hiding with the hide tool and the control key.
• Colored construction objects.
• Think, normal or thick stroke for objects.
• Arrows.
• Display of object names, values or both.
• User controlled display accuracy for values.
• Construction tools for parallels, plumb lines and midpoints.
• Track of points while the user moves another point. Tracks of more than one point or line.
• Conic sections determined by 5 points.
• Tracks of curves from a set of tangents.
• Automatic tracks, while a point moves along a circle or a line. Tracks try to run through all construction states. Moved point turns, when it becomes invalid.
• Tracks or other constructions can be fixed as a background picture.
• Animation, and animated tracks.
• Macros to speed up construction steps and to make possible more complicate constructions.
• Optional prompt for values of angles, sizes of circles and expressions in macros.
• Assignments. Computer checks solution.
• Presentation of constructions in the Web.
• Automatic export into HTML, including style sheets, colors and other details.
• Use of the XML standard to store constructions.
• Constructions may be stored in compressed form.
• Fine printing.
• Arithmetic expression to display values and to fix object parameters (segment length, point position, angle size etc.). Expressions can be used in other expressions, and work in macros.
• Filled polygons with optional area display, transparent in Java 1.3., filled circles and angles.
• Multi line text.
• Replay of the construction.
• Optional grid with point snap.
• Background picture or tiled pattern.
• Save graphics to bitmap, in SVG, EPS or in FIG format.
• Constructions may be loaded in descriptive mode from a file, or edited in-line.