adding experimental script to generate paletted images from RGB

tools/update-images.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+"""
+Find image files with magic expansion and convert them for use with stratagus.
+*-rgb.png: convert from RGB to stratagus palette
+*-big.png: shrink to half size, then convert from RGB as above
+TODO *.xcf: assumed to be the source of the same .png, print warning if newer
+
+Planned: What about something like this? Would this help?
+*-playercolor.png, *-unit.png: first is converted to gray, then puzzled together
+                               with the right palette entries
+"""
+
+import Image, ImageFilter
+import os, os.path
+import sys
+
+# where to find the other stratagus tools
+toolpath = os.path.dirname(sys.argv[0]) + '/'
+
+def convert(im):
+    "returns the Image im converted to stratagus palette"
+    im.convert('P', None, None, Image.ADAPTIVE, 227).save('delme.png')
+    print 'You can savely ignore the following warning:'
+    os.system(toolpath + 'png2stratagus delme.png delme2.png')
+    res = Image.open('delme2.png')
+    os.remove('delme.png')
+    os.remove('delme2.png')
+    return res
+
+def mustrebuild(srcfile, dstfile):
+    "check whether outfile needs to be rebuilt"
+    if not os.path.isfile(dstfile):
+        return 1
+    return os.stat(srcfile).st_mtime > os.stat(dstfile).st_mtime
+    
+if __name__ == '__main__':
+    if len(sys.argv) > 1:
+        print argv[0], 'works with the current directory, it takes no arguments.'
+        sys.exit(1)
+
+    filelist = os.listdir('.')
+    for infile in filelist:
+        ext = infile[-8:]
+        if ext in ['-big.png', '-rgb.png']:
+            outfile = infile[:-8] + '.png'
+            if mustrebuild(infile, outfile):
+                print 'generating', outfile, 'from', infile
+                im = Image.open(infile)
+                if im.mode == 'P':
+                    print 'warning:', infile, 'is already indexed, converting it to RGB first'
+                    im = im.convert('RGB')
+                if ext == '-big.png':
+                    (w, h) = im.size
+                    im = im.resize((w/2, h/2), Image.BILINEAR)
+                    convert(im).save(outfile)
+                elif ext == '-rgb.png':
+                    convert(im).save(outfile)
+    print 'done'