Screencast DrGeo
From OFSET Community Wiki
Contents |
Introduction
These videos demonstrate most of the DrGeo features: basic manipulations, simple construction, use of the advanced integrated programming tools.
Note: In some video, halo are used, to show a halo surrounding graphic elements of the user interface, depending on your platform you need to press the right mouse button, or combination of key like Alt+clic. See Squeak, un Smalltalk libre multimédia.
Starting with Dr. Geo II
In the following video, I show basic operations with DrGeo.
- Opening a figure
- Recording in the 'Do' menu a DrGeo command to open it
- More fun recording a DrGeo command in the Do menu
- Zooming, moving an example figure
- Contextual menu from the drawing background menu
- Persisting contextual menu
- Extraction item from the contextual menu
- Halo menu
- Asking buttons to Dr. Geo
Basic tools
Point tools
- Free point, point on curve
- Intersection point
- Middle of two points
- Middle of a segment
- Point define by coordinates
Curve tools
- Line
- Ray
- Segment
- Vector
- Circle defined by two points
- Circle defined by center and radius
- Arc
- Polygon
- Locus
Transformation tools
- Parallel line
- Perpendicular line
- Central symmetry
- Axial symmetry
- Translation
- Rotation with angle in radian
- Rotation with geometric angle in degree
- Rotation with oriented angle in degree
- Scale
Numeric tools
- Distance : distance between two points, a point and a line, segment length, vector norm, arc length, circle perimeter, line slope
- Geometric angle
- Oriented angle
- Free value you can change at will
Other tools
- Undo/redo commands
- Erase
- Style on object: change aspect, edit object name, edit value. Demonstrated for the various item categories
- Griding
- Create multiple mode
- Default position and scale
Advanced tools
Etoys viewer
- Open the Point viewer
- Manipulate with the viewer a free point
- Manipulate with the viewer a free point on a curve
- EToys script to move a point
- EToys script to control a point with a joystick
Macro-construction
Smalltalk programmed figure
It is a progressive collection of screencasts. You should view all once in the listed order bellow.
- Demonstration of Smalltalk programmed figure
- Write a programmed triangle
- Write a programmed triangle with randomized summit
- Write programmed recursive triangles
Smalltalk script
- Write and use a script without any argument
- Write and use a script with one argument
- Write and use a script with two arguments
- Write and use a script returning a Point instance
Misc examples
Several misc examples of use can be view at ftp://ftp.ofset.org/squeak/drgeo. Beware these screencasts are based on earlier version of DrGeoII and the video quality is not as good as the previous ones.
Morphic integration
To be continued...
- Inserting text in DrGeo figure
- Inserting image in DrGeo figure
- Connecting media with connector
- Inserting DrGeo figure in book media
Technical note
If you want to collaborate on that page, just write to hilaire@ofset.org, I create an account for you.
The video are encoded with the maximum quality, at a screen resolution not higher to the PAL DVD format (720x576). However it can be at a lower screen resolution.
To produce the screencast, I use recordmydesktop with the maximum video quality at 8 fps and no sound:
recordmydesktop --no-sound -windowid 0x3800002 -fps 8 -o 003-advanced-record-in-menu.ogg
With some of these screencasts we produced a video clip presenting Dr. Geo II.

