# CirclePack 'disp' commands

Routine displays of circles and other geometric object are available with mouse and menu operations in CirclePack, and display options can be adjusted via the Screen -> Display Options menu.
To generate more sophisticated and flexible visual displays, you will want to use the underlying commands display and Display (abbr: disp) and their various flag options.
Calls can be very simple: disp -w -c -f will clear the canvas of the active packing, then draw the packing circles and carrier faces. More complicated calls overload the command with numerous options for objects, colors, line thicknesses, etc.
Overall Structure: The basic format is illustrated here:
disp -w -cf a(1 10) -df b -gt5c40
The disp is followed by any number of flag/data segments. A 'flag' string is a contiguous string of characters starting with '-', a code for the type of object, and then optional modifiers. Following the flag string there may be a 'data' string indicating which of these objects to display. See the List Specs tab for the data string format information. For example, '-cf a(1 10)' is a flag/data segment calling for display of the filled circles numbered 1 through 10.
Flag strings can also carried compact coding for color and thickness, as in the flag '-gt5c40'. The '-g' calls for drawing the current 'closed path' (a global path maintained by CirclePack), the 't5' specifies line thickness 5 (default is 1) and the 'c40' indicates color code 40 (medium blue).
Notes:
The full range of options described here can also be prescribed as the default via the "set_disp_text" command.
The 'post' command for generating PostScript images of the canvasses is parallel to the 'disp' command in nearly all features.
Simple Commands: disp -c, disp - Overall Structure: A sample command