#define S64 long long
SFIXED RFXSWF_SP(SFIXED a1,SFIXED a2,SFIXED b1,SFIXED b2)
{ S64 a;
- a = (S64)a1*(S64)b1+(S64)a2*(S64)b2;
- return (SFIXED)(a>>16);
+ a = ((S64)a1*(S64)b1+(S64)a2*(S64)b2)>>16;
+ SFIXED result = (SFIXED)(a);
+ if(a!=result)
+ fprintf(stderr, "Warning: overflow in matrix multiplication");
+ return result;
}
SFIXED RFXSWF_QFIX(int zaehler,int nenner) // bildet Quotient von zwei INTs in SFIXED
{ S64 z = zaehler<<16;
if (!s1) return (s2)?(MATRIX *)memcpy(d,s2,sizeof(MATRIX)):NULL;
if (!s2) return (MATRIX *)memcpy(d,s1,sizeof(MATRIX));
- d->tx = RFXSWF_SP(s1->sx,s1->r1,s2->tx,s2->ty);
- d->ty = RFXSWF_SP(s1->r0,s1->sy,s2->tx,s2->ty);
+ d->tx = s1->tx + RFXSWF_SP(s1->sx,s1->r1,s2->tx,s2->ty);
+ d->ty = s1->ty + RFXSWF_SP(s1->r0,s1->sy,s2->tx,s2->ty);
d->sx = RFXSWF_SP(s1->sx,s1->r1,s2->sx,s2->r0);
d->r0 = RFXSWF_SP(s1->r0,s1->sy,s2->sx,s2->r0);