Colour Colour::asRGB()
{
Colour c(this);
switch (space)
{
case RGB:
c.space = RGB;
break;
case XYZ:
c.space = RGB;
c.x = 3.240479 * x - 1.537150 * y - 0.498535 * z;
c.y = - 0.969256 * x + 1.875991 * y + 0.041556 * z;
c.z = 0.055648 * x - 0.204043 * y + 1.057311 * z;
break;
case HSV:
c.space = HSV;
// H is given on [0, 6] or UNDEFINED. S and V are given on [0, 1].
// RGB are each returned on [0, 1].
float m, n, f;
int i;
if(x == -1 ) {c.x=c.y=c.z=z;}
i = (int)floorf(x);
f = x - i;
if(!(i & 1)) f = 1 - f; // if i is even
m = z * (1 - y);
n = z * (1 - y * f);
switch (i)
{
case 6:
case 0: c.x=z; c.y=n; c.z=m;
break;
case 1: c.x=n; c.y=z; c.z=m;
break;
case 2: c.x=m, c.y=z; c.z=n;
break;
case 3: c.x=m, c.y=n; c.z=z;
break;
case 4: c.x=n, c.y=m; c.z=z;
break;
case 5: c.x=z, c.y=m; c.z=n;
break;
}
break;
case xyY:
// FIXME do this directly
Colour xyz = asXYZ();
c = xyz.asRGB();
break;
}
return c;
}