public ClusterFit(ColourSet colours, SquishFlags flags, float?metric)
: base(colours, flags)
{
// set the iteration count
m_iterationCount = ((m_flags & SquishFlags.kColourIterativeClusterFit) != 0 ? 8 : 1);
// initialise the metric (old perceptual = 0.2126f, 0.7152f, 0.0722f)
if (metric != null)
{
//m_metric = Vec4( metric[0], metric[1], metric[2], 1.0f );
}
else
{
m_metric = new Vector4(1.0f);
}
// initialise the best error
m_besterror = new Vector4(float.MaxValue);
// cache some values
int count = m_colours.Count;
Vector3[] values = m_colours.Points;
// get the covariance matrix
Sym3x3 covariance = Sym3x3.ComputeWeightedCovariance(count, values, m_colours.Weights);
// compute the principle component
m_principle = Sym3x3.ComputePrincipleComponent(covariance);
}
public RangeFit(ColourSet colours, SquishFlags flags, float?metric)
: base(colours, flags)
{
// initialise the metric (old perceptual = 0.2126f, 0.7152f, 0.0722f)
if (metric != null)
{
//m_metric = new Vector3( metric[0], metric[1], metric[2] );
}
else
{
m_metric = new Vector3(1.0f);
}
// initialise the best error
m_besterror = float.MaxValue;
// cache some values
int count = m_colours.Count;
Vector3[] values = m_colours.Points;
float[] weights = m_colours.Weights;
// get the covariance matrix
Sym3x3 covariance = Sym3x3.ComputeWeightedCovariance(count, values, weights);
// compute the principle component
Vector3 principle = Sym3x3.ComputePrincipleComponent(covariance);
// get the min and max range as the codebook endpoints
Vector3 start = new Vector3(0.0f);
Vector3 end = new Vector3(0.0f);
if (count > 0)
{
float min, max;
// compute the range
start = end = values[0];
min = max = Vector3.Dot(values[0], principle);
for (int i = 1; i < count; ++i)
{
float val = Vector3.Dot(values[i], principle);
if (val < min)
{
start = values[i];
min = val;
}
else if (val > max)
{
end = values[i];
max = val;
}
}
}
// clamp the output to [0, 1]
Vector3 one = new Vector3(1.0f);
Vector3 zero = new Vector3(0.0f);
start = Vector3.Min(one, Vector3.Max(zero, start));
end = Vector3.Min(one, Vector3.Max(zero, end));
// clamp to the grid and save
Vector3 grid = new Vector3(31.0f, 63.0f, 31.0f);
Vector3 gridrcp = new Vector3(1.0f / 31.0f, 1.0f / 63.0f, 1.0f / 31.0f);
Vector3 half = new Vector3(0.5f);
m_start = Helpers.Truncate(grid * start + half) * gridrcp;
m_end = Helpers.Truncate(grid * end + half) * gridrcp;
}
