void quaternion::slerp(const quaternion &p, const quaternion &q, float time, quaternion &result)
{
if (time <= 0.0f)
{
result = p;
return;
}
if (time >= 1.0f)
{
result = q;
return;
}
float cos_omega = p.s * q.s + p.x * q.x + p.y * q.y + p.z * q.z;
quaternion temp = q;
if (cos_omega < 0.0f)
{
temp = -temp;
cos_omega = -cos_omega;
}
/*
// I really dont think this is faster, but I'll check it out later
float sin_omega = sqrt(1.0f - cos_omega * cos_omega);
float omega = atan2(sin_omega, cos_omega);
float inv_sin = 1.0f / sin_omega;
float k0 = sin((1.0f - time) * omega) * inv_sin;
float k1 = sin(time * omega) * inv_sin;
result = p * k0 + temp * k1;
*/
float omega = (float)facos(p.s * q.s + p.x * q.x + p.y * q.y + p.z * q.z);
result = ((p * ((float)fsin(omega * (1.0f - time))) + (q * (float)fsin(omega*time)))) / (float)fsin(omega);
}
static BOOL act(int p,int q)
{ /* act on selected key */
int k,n,c;
aprint(PRESSED,4+5*p,6+3*q,keys[q][p]);
switch(p+7*q)
{
case 0: if (degrees) fmul(x,radeg,x);
if (hyp) fsinh(x,x);
else fsin(x,x);
newx=TRUE;
break;
case 1: if (degrees) fmul(x,radeg,x);
if (hyp) fcosh(x,x);
else fcos(x,x);
newx=TRUE;
break;
case 2: if (degrees) fmul(x,radeg,x);
if (hyp) ftanh(x,x);
else ftan(x,x);
newx=TRUE;
break;
case 3: if (lgbase>0)
{
n=size(x);
if (abs(n)<MR_TOOBIG)
{
convert(lgbase,x);
if (n<0) frecip(x,x);
fpower(x,abs(n),x);
newx=TRUE;
break;
}
if (lgbase==2) fmul(x,loge2,x);
if (lgbase==10) fmul(x,loge10,x);
}
fexp(x,x);
newx=TRUE;
break;
case 4: mip->RPOINT=!mip->RPOINT;
newx=TRUE;
break;
case 5: clrall();
newx=TRUE;
break;
case 6: return TRUE;
case 7: if (hyp) fasinh(x,x);
else fasin(x,x);
if (degrees) fdiv(x,radeg,x);
newx=TRUE;
break;
case 8: if (hyp) facosh(x,x);
else facos(x,x);
if (degrees) fdiv(x,radeg,x);
newx=TRUE;
break;
case 9: if (hyp) fatanh(x,x);
else fatan(x,x);
if (degrees) fdiv(x,radeg,x);
newx=TRUE;
break;
case 10: flog(x,x);
if (lgbase==2) fdiv(x,loge2,x);
if (lgbase==10) fdiv(x,loge10,x);
newx=TRUE;
break;
case 11: newx=TRUE;
k=3;
forever
{
aprint(INVER,2+stptr[k],2,settings[k][option[k]]);
curser(2+stptr[k],2);
c=arrow(gethit());
if (c==1)
{
if (option[k]==nops[k]) option[k]=0;
else option[k]+=1;
continue;
}
aprint(STATCOL,2+stptr[k],2,settings[k][option[k]]);
if (c==0 || c==2) break;
if (c==4 && k>0) k--;
if (c==3 && k<3) k++;
}
setopts();
break;
case 12: chekit(7);
break;
case 13: result=FALSE;
if (ipt==0) break;
ipt--;
mybuff[ipt]='\0';
if (ipt==0) clr();
just(mybuff);
cinstr(x,mybuff);
newx=TRUE;
break;
case 14: if (!next('7')) putchar(BELL);
break;
case 15: if (!next('8')) putchar(BELL);
break;
case 16: if (!next('9')) putchar(BELL);
break;
case 17: chekit(6);
break;
case 18: chekit(5);
break;
case 19: chekit(4);
break;
case 20: copy(m,x);
newx=TRUE;
break;
case 21: if (!next('4')) putchar(BELL);
break;
case 22: if (!next('5')) putchar(BELL);
break;
case 23: if (!next('6')) putchar(BELL);
break;
case 24: fmul(x,x,x);
newx=TRUE;
break;
case 25: froot(x,2,x);
newx=TRUE;
break;
case 26: chekit(3);
break;
case 27: brkt=0;
chekit(0);
flag=OFF;
fadd(m,x,m);
newx=TRUE;
break;
case 28: if (!next('1')) putchar(BELL);
break;
case 29: if (!next('2')) putchar(BELL);
break;
case 30: if (!next('3')) putchar(BELL);
break;
case 31: frecip(x,x);
newx=TRUE;
break;
case 32: fpi(x);
newx=TRUE;
break;
case 33: chekit(2);
break;
case 34: negify(x,x);
newx=TRUE;
break;
case 35: if (!next('0')) putchar(BELL);
break;
case 36: if (!next('/')) putchar(BELL);
break;
case 37: if (!next('.')) putchar(BELL);
break;
case 38: if (ipt>0)
{
putchar(BELL);
result=FALSE;
}
else
{
zero(x);
brkt+=1;
newx=TRUE;
}
break;
case 39: if (brkt>0)
{
chekit(0);
brkt-=1;
}
else
{
putchar(BELL);
result=FALSE;
}
break;
case 40: chekit(1);
break;
case 41: brkt=0;
equals(0);
flag=OFF;
break;
}
return FALSE;
}