Some thoughts on Network Graphics (RFC0094)
Original Publication Date: 1971-Feb-03
Included in the Prior Art Database: 2001-Aug-15
Internet Society Requests For Comment (RFCs)
E. Harslem: AUTHOR [+2]
Network Working Group E. Harslem Request for Comments: 94 J. Heafner NIC: 5725 3 February 1971
Some Thoughts on Network Graphics
This note states some of our initial reactions to NWG/RFC #86, whose purpose was to provide a basis for discussion and development of Network graphics.
The method of operation described in Note 86 was to interpret data structures to produce graphic order codes for display. This method has proven satisfactory in the past and we favor this approach. The Note 86 proposal is directed toward a particular concept of operation (i.e., minimal graphics terminal connected to computational facilities at remote sites); our remarks embrace extended operations that include smart programs at each end of the connection as well as the minimal terminal.
The proposal in Note 86 should be broadened to include the description of more complex entities and it should be raised to a level of describing more general things. In this note, we first criticize the limitations imposed by the details of Note 86; then suggest some supplementary ingredients to extend its scope; and lastly, we suggest an alternate approach that reduces Network conversations (where possible) to symbol manipulation rather than gross detail.
Comments on the Detailed Restrictions of Note 86
The detailed constraints enumerated in Note 86 restrict many interesting features of the Rand display hardware that we consider necessary (from a human factors standpoint) to some current applications. They likewise restrict other nodes whose ARPA- sponsored research is dependent upon the use of sophisticated hardware. For example, the point, vector, and character capability of Note 86 excludes line type mode, intensity control, and many other attractive control operations; the maximum symbol sizes are too small for our large character size; the origin of all of our symbols is specified as the "centroid" of the symbol rather than the lower left corner of a virtual rectangle encompassing the symbol; under mode control for plotting purposes, the beam may not be advanced to the next character position; a 7-bit ASCII is insufficient; etc. In short, the five list items of Note 86 are not expressive enough; for example, there is nothing to allow one to position and open a graphic
Harslem, et. al. [Page 1]
RFC 94 Some Thoughts on Network Graphics February 1971
compare "window". The problem was not treated of supplying parameters identifying structure for match, etc. that are not actual display commands.
Perhaps some necessary information gathering (i.e., the display hardware descriptions and the characteristics of every node) is preliminary to the generation of a detailed specification. It is important that, without delay, a mechanism be defined for gathering and collating this information in such a way that it doesn't deter progress on Network graphics development.