public static Block Encode(List <RGB> colors)
{
// regular case: just try our best to compress and minimise Error
var bestsolns = new SolutionSet();
foreach (var flip in new[] { false, true })
{
var pixels = new[] { 0, 1 }.Select(i => colors.Where((c, j) => (j / (flip ? 2 : 8)) % 2 == i).ToArray()).ToArray();
foreach (var diff in new[] { false, true }) // let's again just assume no diff
{
var solns = new Solution[2];
var limit = diff ? 32 : 16;
int i;
for (i = 0; i < 2; i++)
{
var errorThreshold = bestsolns.TotalError;
if (i == 1)
{
errorThreshold -= solns[0].Error;
}
var opt = new Optimizer(pixels[i], limit, errorThreshold);
if (i == 1 && diff)
{
opt._baseColor = solns[0].BlockColor;
if (!opt.ComputeDeltas(-4, -3, -2, -1, 0, 1, 2, 3))
{
break;
}
}
else
{
if (!opt.ComputeDeltas(-4, -3, -2, -1, 0, 1, 2, 3, 4))
{
break;
}
// Fix fairly arbitrary/unrefined thresholds that control how far away to scan for potentially better solutions.
if (opt._bestSln.Error > 9000)
{
if (opt._bestSln.Error > 18000)
{
opt.ComputeDeltas(-8, -7, -6, -5, 5, 6, 7, 8);
}
else
{
opt.ComputeDeltas(-5, 5);
}
}
}
if (opt._bestSln.Error >= errorThreshold)
{
break;
}
solns[i] = opt._bestSln;
}
if (i != 2)
{
continue;
}
var solnset = new SolutionSet(flip, diff, solns[0], solns[1]);
if (solnset.TotalError < bestsolns.TotalError)
{
bestsolns = solnset;
}
}
}
return(bestsolns.ToBlock());
}
// TODO: This is currently still very brute-forcey. Can be improved in the future
public static bool RepackEtc1CompressedBlock(List <RGB> colors, out Block block)
{
foreach (var flip in new[] { false, true })
{
var allpixels0 = colors.Where((c, j) => (j / (flip ? 2 : 8)) % 2 == 0).ToArray();
var pixels0 = allpixels0.Distinct().ToArray();
if (pixels0.Length > 4)
{
continue;
}
var allpixels1 = colors.Where((c, j) => (j / (flip ? 2 : 8)) % 2 == 1).ToArray();
var pixels1 = allpixels1.Distinct().ToArray();
if (pixels1.Length > 4)
{
continue;
}
foreach (var diff in new[] { false, true })
{
if (!diff)
{
var tables0 = Enumerable.Range(0, 8).Where(i => pixels0.All(c => _lookup16[i][c.R] && _lookup16[i][c.G] && _lookup16[i][c.B])).ToList();
if (!tables0.Any())
{
continue;
}
var tables1 = Enumerable.Range(0, 8).Where(i => pixels1.All(c => _lookup16[i][c.R] && _lookup16[i][c.G] && _lookup16[i][c.B])).ToList();
if (!tables1.Any())
{
continue;
}
var opt0 = new Optimizer(allpixels0, 16, 1);
Solution soln0 = null;
foreach (var ti in tables0)
{
var rs = Enumerable.Range(0, 16).Where(a => pixels0.All(c => _lookup16big[ti][a].Contains(c.R))).ToArray();
var gs = Enumerable.Range(0, 16).Where(a => pixels0.All(c => _lookup16big[ti][a].Contains(c.G))).ToArray();
var bs = Enumerable.Range(0, 16).Where(a => pixels0.All(c => _lookup16big[ti][a].Contains(c.B))).ToArray();
soln0 = opt0.FindExactMatches(from r in rs from g in gs from b in bs select new RGB(r, g, b), Constants.Modifiers[ti]).FirstOrDefault();
if (soln0 != null)
{
break;
}
}
if (soln0 == null)
{
continue;
}
var opt1 = new Optimizer(allpixels1, 16, 1);
foreach (var ti in tables1)
{
var rs = Enumerable.Range(0, 16).Where(a => pixels1.All(c => _lookup16big[ti][a].Contains(c.R))).ToArray();
var gs = Enumerable.Range(0, 16).Where(a => pixels1.All(c => _lookup16big[ti][a].Contains(c.G))).ToArray();
var bs = Enumerable.Range(0, 16).Where(a => pixels1.All(c => _lookup16big[ti][a].Contains(c.B))).ToArray();
var soln1 = opt1.FindExactMatches(from r in rs from g in gs from b in bs select new RGB(r, g, b), Constants.Modifiers[ti]).FirstOrDefault();
if (soln1 != null)
{
block = new SolutionSet(flip, false, soln0, soln1).ToBlock();
return(true);
}
}
}
else
{
var tables0 = Enumerable.Range(0, 8).Where(i => pixels0.All(c => _lookup32[i][c.R] && _lookup32[i][c.G] && _lookup32[i][c.B])).ToList();
if (!tables0.Any())
{
continue;
}
var tables1 = Enumerable.Range(0, 8).Where(i => pixels1.All(c => _lookup32[i][c.R] && _lookup32[i][c.G] && _lookup32[i][c.B])).ToList();
if (!tables1.Any())
{
continue;
}
var opt0 = new Optimizer(allpixels0, 32, 1);
var solns0 = new List <Solution>();
foreach (var ti in tables0)
{
var rs = Enumerable.Range(0, 32).Where(a => pixels0.All(c => _lookup32big[ti][a].Contains(c.R))).ToArray();
var gs = Enumerable.Range(0, 32).Where(a => pixels0.All(c => _lookup32big[ti][a].Contains(c.G))).ToArray();
var bs = Enumerable.Range(0, 32).Where(a => pixels0.All(c => _lookup32big[ti][a].Contains(c.B))).ToArray();
solns0.AddRange(opt0.FindExactMatches(from r in rs from g in gs from b in bs select new RGB(r, g, b), Constants.Modifiers[ti]));
}
if (!solns0.Any())
{
continue;
}
var opt1 = new Optimizer(allpixels1, 32, 1);
foreach (var ti in tables1)
{
var rs = Enumerable.Range(0, 32).Where(a => pixels1.All(c => _lookup32big[ti][a].Contains(c.R))).ToArray();
var gs = Enumerable.Range(0, 32).Where(a => pixels1.All(c => _lookup32big[ti][a].Contains(c.G))).ToArray();
var bs = Enumerable.Range(0, 32).Where(a => pixels1.All(c => _lookup32big[ti][a].Contains(c.B))).ToArray();
foreach (var soln0 in solns0)
{
var q = (from r in rs
let dr = r - soln0.BlockColor.R
where dr >= -4 && dr < 4
from g in gs
let dg = g - soln0.BlockColor.G
where dg >= -4 && dg < 4
from b in bs
let db = b - soln0.BlockColor.B
where db >= -4 && db < 4
select new RGB(r, g, b));
var soln1 = opt1.FindExactMatches(q, Constants.Modifiers[ti]).FirstOrDefault();
if (soln1 != null)
{
block = new SolutionSet(flip, true, soln0, soln1).ToBlock();
return(true);
}
}
}
}
}
}
block = new Block();
return(false);
}