/* Vector
** Find_Required_Motion(Vector pt, FeaturePtr con)
** Returns the displacement required to make the pt satisfy the constraint.
*/
Vector
Find_Required_Motion(Vector pt, FeaturePtr con)
{
Vector result;
Vector temp_v;
switch ( con->f_type )
{
case plane_feature:
temp_v = Closest_Plane_Point(con->f_vector, con->f_point, pt);
break;
case line_feature:
temp_v = Closest_Line_Point(con->f_vector, con->f_point, pt);
break;
case point_feature:
temp_v = con->f_point;
break;
default: VNew(0, 0, 0, result);
}
VSub(temp_v, pt, result);
return result;
}
VAttrList VCreateAttrList (void)
{
VAttrList list;
list = VNew (VAttrRec);
list->next = list->prev = list->value = NULL;
list->repn = VUnknownRepn; /* not mistakable for an attribute */
list->name[0] = 0;
return list;
}
static VBoolean WriteAttr (FILE *f, VAttrListPosn *posn, int indent, VList *data_list, long *offset)
{
int i;
char *str;
VRepnKind repn;
VAttrList sublist;
VBundle b;
DataBlock *db;
VTypeMethods *methods;
size_t length;
VPointer value;
VBoolean result;
VAttrListPosn subposn;
/* Indent by the specified amount: */
for (i = 0; i < indent; i++)
FailTest (fputc ('\t', f));
indent++;
/* Output the attribute's name: */
FailTest (fprintf (f, "%s: ", VGetAttrName (posn)));
/* Ouput its value: */
switch (repn = VGetAttrRepn (posn)) {
case VAttrListRepn:
VGetAttrValue (posn, NULL, VAttrListRepn, (VPointer) & sublist);
result = WriteAttrList (f, sublist, indent, data_list, offset);
break;
case VBundleRepn:
VGetAttrValue (posn, NULL, VBundleRepn, (VBundle) & b);
if (! WriteString (f, b->type_name))
return FALSE;
FailTest (fputc (' ', f));
/* If it's a typed value with binary data... */
if (b->length > 0) {
/* Include "data" and "length" attributes in its attribute list: */
VPrependAttr (b->list, VLengthAttr, NULL, VLongRepn,
(VLong) b->length);
VPrependAttr (b->list, VDataAttr, NULL, VLongRepn,
(VLong) *offset);
/* Add it to the queue of binary data blocks to be written: */
*offset += b->length;
db = VNew (DataBlock);
db->posn = *posn;
db->list = b->list;
db->length = b->length;
VListAppend (*data_list, db);
}
/* Write the typed value's attribute list: */
result = WriteAttrList (f, b->list, indent, data_list, offset);
/* Remove the "data" and "length" attributes added earlier: */
if (b->length > 0) {
VFirstAttr (b->list, & subposn);
VDeleteAttr (& subposn);
VDeleteAttr (& subposn);
}
break;
case VStringRepn:
VGetAttrValue (posn, NULL, VStringRepn, (VPointer) & str);
result = WriteString (f, str);
break;
default:
if (! (methods = VRepnMethods (repn)) ||
! methods->encode_attr || ! methods->encode_data) {
VWarning ("VWriteFile: "
"%s attribute has unwriteable representation: %s",
VGetAttrName (posn), VRepnName (repn));
return FALSE;
}
/* Write the type name: */
if (! WriteString (f, VRepnName (repn)))
return FALSE;
FailTest (fputc (' ', f));
/* Invoke the object type's encode_attr method to obtain an
attribute list: */
VGetAttrValue (posn, NULL, repn, & value);
sublist = (methods->encode_attr) (value, & length);
/* If binary data is indicated... */
if (length > 0) {
/* Include "data" and "length" attributes in the attr list: */
VPrependAttr (sublist, VLengthAttr, NULL, VLongRepn,
(VLong) length);
VPrependAttr (sublist, VDataAttr, NULL, VLongRepn,
(VLong) *offset);
*offset += length;
}
/* Add the object to the queue of binary data blocks to be written: */
db = VNew (DataBlock);
db->posn = *posn;
db->list = sublist;
db->length = length;
VListAppend (*data_list, db);
/* Write the typed value's attribute list: */
result = WriteAttrList (f, sublist, indent, data_list, offset);
/* Remove the "data" and "length" attributes added earlier: */
if (length > 0) {
VFirstAttr (sublist, & subposn);
VDeleteAttr (& subposn);
VDeleteAttr (& subposn);
}
}
/* Output a trailing newline: */
if (result)
FailTest (fputc ('\n', f));
return result;
Fail:
VWarning ("VWriteFile: Write to stream failed");
return FALSE;
}
