public override bool RenderMultiThreaded(Float128 xmin, Float128 xmax, Float128 ymin, Float128 ymax, Float128 step, int maxIterations)
{
Float128 HALF = new Float128(0.5);
//Parallel.For(0, (int)(((ymax - ymin) / step) + .5M), (yp) =>
Parallel.For(0, ymax.SubFast(ymin).Div(step).AddFast(HALF).IntValue(), (yp) =>
{
if (Abort)
{
return;
}
Float128 y = ymin.AddFast(step.Mul(yp));
int xp = 0;
for (Float128 x = xmin; x.SubFast(xmax).Hi < 0; x = x.AddFast(step), xp++)
{
Float128 accumx = x;
Float128 accumy = y;
int iters = 0;
Float128 sqabs = new Float128(0);
do
{
Float128 naccumx = accumx.Sqr().SubFast(accumy.Sqr());
Float128 naccumy = accumx.Mul(accumy).MulPwrOf2(2);
accumx = naccumx.AddFast(x);
accumy = naccumy.AddFast(y);
iters++;
sqabs = accumx.Sqr().AddFast(accumy.Sqr());
} while (sqabs.SubFast(limit).Hi < 0 && iters < maxIterations);
DrawPixel(xp, yp, iters);
}
});
return(!Abort);
}
public override bool RenderSingleThreaded(Float128 xmin, Float128 xmax, Float128 ymin, Float128 ymax, Float128 step, int maxIterations)
{
int yp = 0;
for (Float128 y = ymin; y.SubFast(ymax).Hi < 0 && !Abort; y = y.AddFast(step), yp++)
{
if (Abort)
{
return(false);
}
int xp = 0;
for (Float128 x = xmin; x.SubFast(xmax).Hi < 0; x = x.AddFast(step), xp++)
{
Float128 accumx = x;
Float128 accumy = y;
int iters = 0;
Float128 sqabs = new Float128(0);
do
{
Float128 naccumx = accumx.Sqr().SubFast(accumy.Sqr());
Float128 naccumy = accumx.Mul(accumx).MulPwrOf2(2);
accumx = naccumx.AddFast(x);
accumy = naccumy.AddFast(y);
iters++;
sqabs = accumx.Sqr().AddFast(accumy.Sqr());
} while (sqabs.SubFast(limit).Hi < 0 && iters < maxIterations);
DrawPixel(xp, yp, iters);
}
}
return(true);
}
private static int to_digits(this Float128 dd, char[] s, int precision, int intBase)
{
int halfBase = (intBase + 1) >> 1;
if (dd.Hi == 0.0)
{
// Assume dd.lo == 0.
for (int i = 0; i < s.Length; ++i)
{
s[i] = '0';
}
return(0);
}
// First determine the (approximate) exponent.
Float128 temp = dd.Abs();
int exp = (int)Math.Floor(Math.Log(temp.Hi) / Math.Log(intBase));
Float128 p = new Float128(intBase);
if (exp < -300)
{
temp.MulSelf(p.Pow(150));
p.PowSelf(-exp - 150);
temp.MulSelf(p);
}
else
{
p.PowSelf(-exp);
temp.MulSelf(p);
}
// Fix roundoff errors. (eg. floor(log10(1e9))=floor(8.9999~)=8)
if (temp.Hi >= intBase)
{
exp++;
temp.Hi /= intBase;
temp.Lo /= intBase;
}
else if (temp.Hi < 1)
{
exp--;
temp.Hi *= intBase;
temp.Lo *= intBase;
}
if (temp.Hi >= intBase || temp.Hi < 1)
{
throw new Exception("Can't compute exponent.");
}
// Handle one digit more. Used afterwards for rounding.
int numDigits = precision + 1;
// Extract the digits.
for (int i = 0; i < numDigits; i++)
{
int val = (int)temp.Hi;
temp = temp.Sub(val);
temp = temp.Mul(intBase);
s[i] = (char)val;
}
if (s[0] <= 0)
{
throw new Exception("Negative leading digit.");
}
// Fix negative digits due to roundoff error in exponent.
for (int i = numDigits - 1; i > 0; i--)
{
if (s[i] >= 32768)
{
s[i - 1]--;
s[i] += (char)intBase;
}
}
// Round, handle carry.
if (s[precision] >= halfBase)
{
s[precision - 1]++;
int i = precision - 1;
while (i > 0 && s[i] >= intBase)
{
s[i] -= (char)intBase;
s[--i]++;
}
}
s[precision] = (char)0;
// If first digit became too high, shift right.
if (s[0] >= intBase)
{
exp++;
for (int i = precision; i >= 1;)
{
s[i] = s[--i];
}
}
// Convert to ASCII.
for (int i = 0; i < precision; i++)
{
s[i] = Float128.BASE_36_TABLE[s[i]];
}
// If first digit became zero, and exp > 0, shift left.
if (s[0] == '0' && exp < 32768)
{
exp--;
for (int i = 0; i < precision;)
{
s[i] = s[++i];
}
}
return(exp);
}
