Initial revision

intern/python/modules/vrml/loader.py

@@ -0,0 +1,97 @@
+# The VRML loader
+# supports gzipped files
+# 
+# TODO: better progress monitoring
+
+import parser 
+
+def quiet(txt):
+	pass
+
+debug = quiet
+
+def debug1(txt):
+	print "Loader:", txt
+
+g_last = 0
+
+def getFileType(file):
+	"returns the file type string from 'file'"
+	file.seek(0)
+	magic = file.readline()
+	if magic[:3] == '\037\213\010':
+		file.seek(0)
+		return "gzip"
+	elif magic[:10] == '#VRML V2.0':
+		file.seek(0)
+		return "vrml"
+	else:
+		file.seek(0)
+		return ""
+
+class Loader:
+	def __init__(self, url, progress = None):
+		self.url = url
+		self.debug = debug
+		self.fail = debug
+		self.monitor = debug
+		self.progress = progress
+		self.nodes = 0 # number of nodes parsed
+
+	def getGzipFile(self, file):
+		'''Return gzip file (only called when gzip type is recognised)'''
+		# we now have the local filename and the headers
+		# read the first few bytes, check for gzip magic number
+		self.monitor( "gzip-encoded file... loading gzip library")
+		try:
+			import gzip
+			file = gzip.open(file,"rb")
+			return file
+		except ImportError, value:
+			self.fail("Gzip library unavailable, compressed file cannot be read")
+		except:
+			self.fail("Failed to open Gzip file")
+
+		return None
+
+	def load(self):
+		self.debug("try: load file from %s" % self.url)
+		url = self.url
+
+		# XXX
+		try:
+			file = open(url, 'rb')
+		except IOError, val:
+			self.debug("couldn't open file %s" % url)
+			return None
+
+		if getFileType(file) == 'gzip':
+			file.close()
+			file = self.getGzipFile(url)
+		try:
+			data = file.read()
+		except MemoryError, value:
+			self.fail("Insufficient memory to load file as string", value)
+			return None
+		except IOError, value:
+				self.fail("I/O Error while reading data from file %s "% url)
+		p = parser.Parser(data)
+		if self.progress:
+			scenegraph = p.parse(self.progress)
+			print "progress"
+		else:
+			scenegraph = p.parse()
+			
+		self.nodes = p.progresscount # progress
+		del p
+		return scenegraph
+
+
+def load(url, progress = None):
+	l = Loader(url, progress)
+	return l.load()
+	
+def test(name = None):	
+	if not name:
+		name = '/tmp/gna.wrl'
+	return load(name)