EMBOSS: C2 Graphics Library

EMBOSS graphics currently uses a library called PLPLOT.

Original Library requirements

• Support for interactive graphics applications (not in PLPLOT)
• OpenGL or PHIGS standard preferred (not in PLPLOT)
• XWindows output seems most useful still
• GIF is needed for WWW interfaces (not directly in PLPLOT)
• Postscript seems best for quality printed output
• Meta files in some form would be useful for producing graphics in multiple forms, for example to the screen and to the printer.
• Must fit in with the restrictions of the GNU Lesser General Public License.

Issues:

1. Is PLPLOT good enough?
2. Is there a reasonable alternative to PLPLOT?
   • Mesa is an option, an OpenGL based library under public licence.
   • GTK (GIMPS Toolkit) has been suggested but seems to be a GUI library rather than something suitable for creating graphical output.
   • The Staden Package uses Tcl/Tk which remains an option.
   • Users have suggested other libraries
3. Can we use more than one graphics library?
4. Can we write our own graphics library?
5. Graphics code is tightly linked to the reast of the library, because ACD has a graph data type that makes cals to PLPLOT. We have been asked to separate the graphics (and ACD) from the rest of the library code. Is this a high priority?