start fixing char->int enums use

oops was doing chart->int incorrectly for glib enums

TODO

@@ -1,3 +1,35 @@
+- try:
+
+	edvips --format=IM_BANDFMT_FLOAT babe.v
+
+  leaves it set to uchar
+
+  im_char2BandFmt() in vips7compat.c must allow old names as well
+
+
+- VIPS_ENUM_VALUE() returns a GEnumValue, see
+
+  	http://developer.gnome.org/gobject/stable/gobject-Enumeration-and-Flag-Types.html#GEnumValue
+
+  you need a ->value after it (after checking for a NULL result) to get the
+  int
+
+  check all uses ... seems to be only vips7compat, phew
+
+
+
+
+
+- turn wrap back on, with renames
+
+  	vips im_subtract
+
+  is the old vips7 interface
+
+  	vips subtract
+
+  is the new unfinished vips8 interface to the same function
+
 
 
 - revisit orc conv

libvips/deprecated/vips7compat.c

@@ -223,6 +223,25 @@ const char *im_dtype2char( VipsImageType n )
 const char *im_dhint2char( VipsDemandStyle style ) 
 	{ return( VIPS_ENUM_STRING( VIPS_TYPE_DEMAND_STYLE, style ) ); }
 
+/* enum string to int, try the GEnum first, then use a compat *char[] for old
+ * names.
+ */
+static int
+lookup_enum( GType type, char *names[], const char *name )
+{
+	GEnumValue *value;
+	int i;
+
+	if( (value = VIPS_ENUM_VALUE( type, name )) )
+		return( value->value );
+
+	for( i = 0; names[i]; i++ )
+		if( strcasecmp( names[i], name ) )
+			return( i );
+
+	return( -1 );
+}
+
 VipsInterpretation im_char2Type( const char *str ) 
 	{ return( VIPS_ENUM_VALUE( VIPS_TYPE_INTERPRETATION, str ) ); }
 VipsBandFormat im_char2BandFmt( const char *str )