Convex Hull 2

How to use Convex_Hull_2 Demo

Main Functionality

- Reset application
- Creating a new window
- Print
- Close the current window
- Quit the application

Editing

- Generate points
- Insert new points in the list
- Remove points from the list
- Modify the coordinates of the points in the list

Reset application

Press Ctrl+N combination keys or go to File menu and choose "New". The points list will be erased, the window's visible area will be set to default. (-1, 1, -1, 1)

Create a new window

Press Ctrl+W combination keys or go to File menu and choose "New Window". A new window will appear, modifying the visible area to make the points list fit in the new window.

Print

Press Ctrl+P combination keys or go to File menu and choose "Print". The visible area on the screen will be outputed to the print device of your choice.

Close the current window

Press Ctrl+X combination keys or go to File menu and choose "Close". You may do it for any window other than the initial one, this operation will close only the one you have choosen. If you do this for the initial parent window, it will close the others too.

Quit the application

Press Ctrl+Q combination keys or go to File menu and choose "Quit". When you quit the application, all the windows you have created will be destroyed.

Generate points

To generate points, go to Draw menu and choose "Generate points" or press Ctrl+G combination keys. This action will generate random points uniformly distributed in the open disc with radius 1. Each time you do this action, new points will be added to the list, the old set of point being updated and not erased.

Insert new points in the list

Left click on the "Input point" layer. Be sure there is no layer activated in standard toolbar that eat events. To be sure, press the arrow button situated on the standard toolbar. Left Click anywhere on the application's drawing area (the black rectangle) to insert the point. The new point is inserted in the list and the convex hull is recomputed. To insert more than one point, keep clicking on the rectangle without deactivating the "Input point" layer. To deactivate this layer, just press the arrow button situated on the same toolbar.

Remove points from the list

(1)Left click on the "Move/Delete point" layer. If the "Input point" layer was active, it will deactivate itself. (2)Right click on the drawing area (the black rectangle) near an existing point. A popup menu will apear and the nearest point will be highlighted. If the popup doesn't appear, press the arrow button on the "standard toolbar" to deactivate all layers that could eat the events. (3)Choose "Delete". The point will be removed from the list. To delete more than one point, repeat the process from (2) to (3). To deactivate this layer, just press the arrow button situated on the same toolbar.

Modify the coordinates of the points in the list

(1)Left click on the "Move/Delete point" layer. If the "Input point" layer was active, it will deactivate itself. (2)Right click on the drawing area (the black rectangle) near an existing point. A popup menu will apear and the nearest point will be highlighted. (3)Choose "Move". From this moment, the point will move as you move the mouse. The convex hull will reflect the changes. (4)Left click on the drawing area will position the point at the mouse coordinates. You may repeat the process from the step (2) to (4). To deactivate this layer, just press the arrow button situated on the same toolbar.

Last modified: Fri May 16 14:31:39 MEST 2003