If only one of -T and -F transforms given, invert it to find the other.

And, in partiview version, make sure to *use* o2d/d2o if provided!

src/warp.c

@@ -197,6 +197,20 @@ void windup( struct warpstuff *ws, Point *out, CONST Point *in )
     out->x[2] = x*s + z*c;
 }
 
+void dvtfmpoint( Point *dst, CONST Point *src, CONST double T[16] )
+{
+  int i;
+  for(i = 0; i < 3; i++)
+    dst->x[i] = src->x[0]*T[i] + src->x[1]*T[i+4] + src->x[2]*T[i+8] + T[i+12];
+}
+
+void windup_o2d( struct warpstuff *ws, Point *out, CONST Point *in ) {
+    Point tin, tout;
+
+    dvtfmpoint( &tin, in, ws->o2d );
+    windup( ws, &tout, &tin );
+    dvtfmpoint( out, &tout, ws->d2o );
+}
 
 void warpspecks( struct warpstuff *ws,
 		 struct stuff *st,
@@ -212,7 +226,10 @@ void warpspecks( struct warpstuff *ws,
   osp = osl->specks;
   sp = sl->specks;
   for(i = 0; i < n; i++) {
-    windup( ws, &sp->p, &osp->p );
+    if(ws->has_o2d)
+	windup_o2d( ws, &sp->p, &osp->p );
+    else
+	windup( ws, &sp->p, &osp->p );
     osp = NextSpeck(osp, osl, 1);
     sp = NextSpeck(sp, sl, 1);
   }
@@ -354,6 +371,27 @@ float fastsin2pi( float v ) {
   return sintbl[i] + (v - i)*(sintbl[i+1]-sintbl[i]);
 }
 
+void deucinv( double dst[16], CONST double src[16] )
+{
+    int i, j;
+    double s = src[0]*src[0] + src[1]*src[1] + src[2]*src[2];
+    Point trans;
+    double t[16];
+    if(src == dst) {
+	memcpy( t, src, sizeof(t) );
+	src = t;
+    }
+    for(i = 0; i < 3; i++) {
+	for(j = 0; j < 3; j++)
+	    dst[i*4+j] = src[j*4+i] / s;
+	dst[i*4+3] = 0;
+    }
+    for(i = 0; i < 3; i++)
+	dst[3*4+i] = -(src[3*4+0]*dst[0*4+i] + src[3*4+1]*dst[1*4+i] + src[3*4+2]*dst[2*4+i]);
+    dst[3*4+3] = 1;
+}
+
+
 #ifndef STANDALONE
 
 int warp_parse_args( struct dyndata *dd, struct stuff *st, int argc, char **argv )
@@ -441,8 +479,16 @@ warp_get_parti( struct dyndata *dd, struct stuff *st, double realtime )
   ws->tfrac = warpfrac(ws, realtime * 30);
   if(ws->has_zerotime)
     ws->tfrac -= warpfrac(ws, ws->zerotime);
-   if(ws->has_trange && ws->period0 != 0)
-	ws->tfrac *= (ws->tto - ws->tfrom) / ws->period0;
+  if(ws->has_trange && ws->period0 != 0)
+    ws->tfrac *= (ws->tto - ws->tfrom) / ws->period0;
+
+  if(ws->has_o2d && !ws->has_d2o) {
+    deucinv( ws->d2o, ws->o2d );
+    ws->has_d2o = -1;
+  } else if(!ws->has_o2d && ws->has_d2o) {
+    deucinv( ws->o2d, ws->d2o );
+    ws->has_o2d = -1;
+  }
 
 
   if(getenv("WDBG")) printf("%g %g %g # rt frac frac(rt)\n", realtime, ws->tfrac, warpfrac(ws, realtime*30));
@@ -571,7 +617,6 @@ void dwindup( struct warpstuff *ws, float *xyzout, float *dxyzout, CONST float *
    dxyzout[2] = dtheta * (x*c - z*s);
 }
 
-
 void dwindup_o2d( struct warpstuff *ws, float *xyzout, float *dxyzout, CONST float *xyz )
 {
     float v[3], w[3], dw[3];