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
PseudoSpace(struct XYspace *S, /* coordinate space structure to fill out */
double M[2][2]) /* matrix that will become 'tofract.normal' */
{
S->type = SPACETYPE;
S->flag = ISPERMANENT(ON) + ISIMMORTAL(ON);
S->references = 2; /* 3-26-91 added PNM */
S->tofract.normal[0][0] = M[0][0];
S->tofract.normal[1][0] = M[1][0];
S->tofract.normal[0][1] = M[0][1];
S->tofract.normal[1][1] = M[1][1];
FillOutFcns(S);
}
void InitSpaces(void)
{
IDENTITY->type = SPACETYPE;
FillOutFcns(IDENTITY);
contexts[NULLCONTEXT].normal[1][0]
= contexts[NULLCONTEXT].normal[0][1]
= contexts[NULLCONTEXT].inverse[1][0]
= contexts[NULLCONTEXT].inverse[0][1] = 0.0;
contexts[NULLCONTEXT].normal[0][0]
= contexts[NULLCONTEXT].normal[1][1]
= contexts[NULLCONTEXT].inverse[0][0]
= contexts[NULLCONTEXT].inverse[1][1] = 1.0;
USER->flag |= ISIMMORTAL(ON);
CoerceInverse(USER);
}
