Date: Monday May 26, 2003 @ 0:49
Author: sunshine
Update of /cvsroot/crystal/CS/plugins/mesh/spr3d/object
In directory sc8-pr-cvs1:/tmp/cvs-serv1472/plugins/mesh/spr3d/object
Modified Files:
spr3d.mak
Added Files:
spr3d.csplugin
Log Message:
Eric Sunshine performed Phase One of the elimination of the monolithic
scf.cfg:
-*- Plugin modules are now self-describing. This information can be
queried at run-time without having to actually load the module.
-*- The plugin maintainer now manages the plugin's meta-information in an
external .csplugin file, rather than hard-coding the information into
the plugin's source code. The mechanism by which the meta-information
is bound to the plugin is platform-dependent. Presently, all
platforms simply lay down the meta-information in a plain text file
alongside the plugin itself; with the same basename and extension
.csplugin. This may change in the future. For example, on MacOS/X,
the meta-information will probably be encapsulated within the plugin's
bundle wrapper.
-*- Plugin meta-information is now maintained in XML format. Here is an
example:
<?xml version="1.0"?>
<!-- gl3d.csplugin -->
<plugin>
<name>gl3d</name>
<scf>
<classes>
<class>
<name>crystalspace.graphics3d.opengl</name>
<description>OpenGL 3D graphics driver</description>
<requires>
<class>crystalspace.font.server.</class>
</requires>
</class>
</classes>
</scf>
</plugin>
-*- Since meta-information is now extensible, maintainers can choose to
publish supplementary information about plugins (in addition to the
SCF information already published). For example, image loading
plugins could publish "image indendification" information which would
allow the image loading multiplexor to selectively request image
loading plugins on-demand, rather than requesting all plugins
unconditionally, even if they are not needed. Here is an example of a
possible meta-information table for the PNG loader:
<?xml version="1.0"?>
<!-- cspngimg.csplugin -->
<plugin>
<name>cspngimg</name>
<scf>...</scf>
<imageloader>
<imagetype>
<class>crystalspace.graphic.image.io.png</class>
<identify>
<mimetype>image/png</mimetype>
<extension>png</extension>
<extension>PNG</extension>
<scan length="4" bytes="\0x89PNG"/>
</identify>
</imagetype>
</imageloader>
</plugin>
In this example, the PNG loader meta-information tells the multiplexor
several different ways to identify a PNG image: by checking file
extension, if available; by checking MIME type, if available; by
checking for the magic-string "\0x89PNG" in the raw image data. If
the multiplexor identifies the image as PNG, only then will it
actually request the PNG loader.
-*- Added the --meta-file directive to msvcgen.pl to allow specification
of the meta-information file for a module. The value of this option
is interpolated into template files via the new %metafile% variable.
msvcgen.mak now utilizes this flag with the value of the new
INC.PROJECT makefile variable. Augmented the MSVC6 and MSVC7 plugin
template files (plugin.tpl) to make use of %metafile%.
-*- Changed the file extension for plugins on MacOS/X from .csplugin to
.csbundle to avoid conflict with new meta-information resource which
uses the extension .csplugin.
-*- Still To-Do:
- Augment SCF to utilize the new meta-information resources, and to
understand the new XML format. Presently, these resources are
ignored at run-time.
- Add platform-specific function to scan and locate plugins
automatically, rather than relying upon a monolithic registry such
as scf.cfg.
- Add platform-specific function to query a plugin's meta-information.
- Eliminate the monolithic scf.cfg.
- Augment static linking to work with the new facility.
- Eliminate the hard-coded SCF registration information in each
plugin's source code.
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