public Point FindNextPixel(IntField image, int cx, int cy)
{
int dist = 0;
while (dist < (image.Width / 2 + image.Height / 2 + 2))
{
for (int x = dist, y = 0; x > 0; x--, y++)
{
if (image.GetWrapped(cx + x, cy + y) != 0)
{
return(new Point(x, y));
}
}
for (int x = 0, y = dist; y > 0; x--, y--)
{
if (image.GetWrapped(cx + x, cy + y) != 0)
{
return(new Point(x, y));
}
}
for (int x = -dist, y = 0; x < 0; x++, y--)
{
if (image.GetWrapped(cx + x, cy + y) != 0)
{
return(new Point(x, y));
}
}
for (int x = 0, y = -dist; y < 0; x++, y++)
{
if (image.GetWrapped(cx + x, cy + y) != 0)
{
return(new Point(x, y));
}
}
dist++;
}
return(new Point(0, 0));
}
public override void Encode(IntField image, Stream output)
{
// Predictive transform
image.ArgbTo4c();
image.PredictionEnTransformXor(Seer);
int px = 0, py = 0;
List <int> dxs = new List <int>();
List <int> dys = new List <int>();
List <int> clr = new List <int>();
List <Point> jumps = new List <Point>();
IntField vis = new IntField(image.Width, image.Height);
int vis_ctr = 0;
while (true)
{
Point pt = FindNextPixel(image, px, py);
px += pt.X;
py += pt.Y;
int c = image.GetWrapped(px, py);
if (c == 0)
{
break;
}
if (Math.Abs(pt.X) > 5 || Math.Abs(pt.Y) > 5)
{
jumps.Add(pt);
}
else
{
dxs.Add(pt.X);
dys.Add(pt.Y);
}
clr.Add(c);
image.SetWrapped(px, py, 0);
if (vis_ctr % 1000 == 0)
{
AddImageGrayscale(image, "progress.{0:00000}".Fmt(vis_ctr));
}
vis.SetWrapped(px, py, ++vis_ctr);
}
SetCounter("jumps", jumps.Count);
AddIntDump("xs", dxs);
AddIntDump("ys", dys);
AddIntDump("cs", clr);
AddImageGrayscale(vis, "seq-global");
vis.Data = vis.Data.Select(val => val % 512).ToArray();
AddImageGrayscale(vis, "seq-local");
var xs = CodecUtil.InterleaveNegatives(dxs.ToArray());
var ys = CodecUtil.InterleaveNegatives(dxs.ToArray());
var cs = clr.ToArray();
List <ulong[]> xps = new List <ulong[]>();
List <ulong[]> yps = new List <ulong[]>();
List <ulong> xpts = new List <ulong>();
List <ulong> ypts = new List <ulong>();
for (int given = 0; given <= 10; given++)
{
if (given < 10)
{
xps.Add(CodecUtil.GetNextProbsGiven(xs, given));
yps.Add(CodecUtil.GetNextProbsGiven(ys, given));
}
else
{
xps.Add(CodecUtil.GetNextProbsGivenGreater(xs, given - 1));
yps.Add(CodecUtil.GetNextProbsGivenGreater(ys, given - 1));
}
AddIntDump("xp-{0}".Fmt(given), xps.Last().Select(var => (int)var));
AddIntDump("yp-{0}".Fmt(given), yps.Last().Select(var => (int)var));
xpts.Add(xps.Last().Aggregate((tot, val) => tot + val));
ypts.Add(yps.Last().Aggregate((tot, val) => tot + val));
}
List <ulong[]> cps = new List <ulong[]>();
cps.Add(new ulong[4] {
0, 1, 1, 1
});
for (int given = 1; given <= 3; given++)
{
cps.Add(CodecUtil.GetNextProbsGiven(cs, given));
AddIntDump("cp-{0}".Fmt(given), cps.Last().Select(var => (int)var));
}
ulong[] cpts = new ulong[4];
for (int i = 0; i < cps.Count; i++)
{
cpts[i] = cps[i].Aggregate((tot, val) => tot + val);
}
ArithmeticWriter aw = new ArithmeticWriter(output, null);
int prev;
//prev = 0;
//for (int i = 0; i < cs.Length; i++)
//{
// aw.Probs = cps[prev];
// aw.TotalProb = cpts[prev];
// aw.WriteSymbol(cs[i]);
// prev = cs[i];
//}
//aw.Flush();
// For comparison: normal arithmetic 5846, shifting probs 3270
//ulong[] probs = CodecUtil.CountValues(cs);
//AddIntDump("cp-overall", probs.Select(val => (int)val));
//ArithmeticWriter aw = new ArithmeticWriter(output, probs);
//for (int i = 0; i < cs.Length; i++)
// aw.WriteSymbol(cs[i]);
//aw.Flush();
prev = 0;
for (int i = 0; i < xs.Length; i++)
{
if (prev > 10)
{
prev = 10;
}
aw.Probs = xps[prev];
aw.TotalProb = xpts[prev];
aw.WriteSymbol(xs[i]);
prev = xs[i];
}
aw.Flush();
//prev = 0;
//for (int i = 0; i < ys.Length; i++)
//{
// if (prev > 10) prev = 10;
// aw.Probs = yps[prev];
// aw.TotalProb = ypts[prev];
// aw.WriteSymbol(ys[i]);
// prev = ys[i];
//}
//aw.Flush();
}