TIP:            198
Title:          Image Command XPM Extension
Version:        $Revision: 1.6 $
Author:         R. Timothy Edwards <tim@stravinsky.jhuapl.edu>
Author:         Don Porter <dgp@users.sf.net>
Author:         Kevin Kenny <kennykb@acm.org>
State:          Draft
Type:           Project
Vote:           Pending
Created:        12-May-2004
Post-History:   
Tcl-Version:    8.7

~ Abstract

This TIP proposes an extension to the Tk '''image''' command to
incorporate color pixmap images based on the XPM format.  The format
is analogous to the '''bitmap''' option (''tkImgBmap.c'' in the Tk
source).

~Rationale

The "XPM" format has become more-or-less a standard, and is a nice
text-readable color alternative to the standard X11 bitmap format.
The runtime library for XPM is available in standard Linux
distributions and elsewhere.  Tk has a number of color '''photo'''
image formats, but these make various assumptions about rendering.
There is no color alternative to the simple pixel-based bitmap format.

~Specification

This TIP specifies the extension of the '''image''' command in the
following manner:

 > '''image create xpm''' ''name'' '''-file''' ''xpm_file''

It would probably be a nice idea to include in-line pixmap
specifications similar to that allowed for bitmaps by the BLT package.
However, at this time, the reference implementation does not include
such an extension.

~Reference Implementation

There is an implementation in the source for
XCircuit[http://xcircuit.ece.jhu.edu/].  The source file is
"tkPixmap.c".

~Comments

I'd like to see more justification in this proposal
as to why a new image type is needed, rather than
implementing a suitable format for either the existing
bitmap or photo image types.  

In fact, the Img extension already has XPM as a photo
image format.  I'm quite baffled as to the need for a new
image type.  Is this TIP better served by a request to
promote XPM to the core set of supported formats?

~Copyright

This document has been placed in the public domain.
