struct xobject *t1_Xform(
register struct xobject *obj, /* object to transform */
register DOUBLE M[2][2]) /* transformation matrix */
{
if (obj == NULL)
return(NULL);
if (obj->type == FONTTYPE) {
register struct font *F = (struct font *) obj;
F = UniqueFont(F);
return((struct xobject*)F);
}
if (obj->type == PICTURETYPE) {
/*
In the case of a picture, we choose both to update the picture's
transformation matrix and keep the handles up to date.
*/
register struct picture *P = (struct picture *) obj;
register struct segment *handles; /* temporary path to transform handles */
P = UniquePicture(P);
handles = PathSegment(LINETYPE, P->origin.x, P->origin.y);
handles = Join(handles,
PathSegment(LINETYPE, P->ending.x, P->ending.y) );
handles = (struct segment *)Xform((struct xobject *) handles, M);
P->origin = handles->dest;
P->ending = handles->link->dest;
KillPath(handles);
return((struct xobject *)P);
}
if (ISPATHTYPE(obj->type)) {
struct XYspace pseudo; /* local temporary space */
PseudoSpace(&pseudo, M);
return((struct xobject *) PathTransform((struct segment *)obj, &pseudo));
}
if (obj->type == SPACETYPE) {
register struct XYspace *S = (struct XYspace *) obj;
/* replaced ISPERMANENT(S->flag) with S->references > 1 3-26-91 PNM */
if (S->references > 1)
S = CopySpace(S);
else
S->ID = NEXTID;
MatrixMultiply(S->tofract.normal, M, S->tofract.normal);
/*
* mark inverted matrix invalid:
*/
S->flag &= ~HASINVERSE(ON);
FillOutFcns(S);
return((struct xobject *) S);
}
return(ArgErr("Untransformable object", obj, obj));
}
void
QuerySpace(struct XYspace *S, /* space asked about */
double *cxxP, double *cyxP, /* where to put answer */
double *cxyP, double *cyyP)
{
double M[2][2]; /* temp matrix to build user's answer */
if (S->type != SPACETYPE) {
ArgErr("QuerySpace: not a space", S, NULL);
return;
}
MatrixMultiply(S->tofract.normal, IDENTITY->tofract.inverse, M);
*cxxP = M[0][0];
*cxyP = M[1][0];
*cyxP = M[0][1];
*cyyP = M[1][1];
}
/*
:h3.KillPath() - Destroying a Path
Destroying a path is simply a matter of freeing each segment in the
linked list. Again, we let the experts handle text.
*/
void
KillPath(struct segment *p) /* path to destroy */
{
register struct segment *linkp; /* temp register holding next segment*/
/* return conditional based on reference count 3-26-91 PNM */
if ( (--(p->references) > 1) ||
( (p->references == 1) && !ISPERMANENT(p->flag) ) )
return;
while (p != NULL) {
if (!ISPATHTYPE(p->type)) {
ArgErr("KillPath: bad segment", p, NULL);
return;
}
linkp = p->link;
if (p->type == TEXTTYPE)
KillText(p);
else
Free(p);
p = linkp;
}
}