/// <summary>
/// Compute the alpha parameter using (1.0-t)*m_tf1 + t*m_tf2
/// </summary>
/// <param name="values">The values to compute the color. Must be between 0.0f and 1.0f</param>
/// <returns>The alpha t parameter. Negative values when errors occure (e.g array too large)</returns>
public override float ComputeAlpha(float[] values)
{
float tf1Val;
float tf2Val;
uint dim = GetDimension();
//We need to rearrange "values" because of the gradient of the lowest dimension object
//Check tf1
if (m_tf1.GetDimension() < dim && m_tf1.HasGradient())
{
float temp = values[m_tf1.GetDimension() - 1];
values[m_tf1.GetDimension() - 1] = values[dim - 1];
tf1Val = m_tf1.ComputeAlpha(values);
values[m_tf1.GetDimension() - 1] = temp;
}
else
{
tf1Val = m_tf1.ComputeAlpha(values);
}
//Check tf2
if (m_tf2.GetDimension() < dim && m_tf2.HasGradient())
{
float temp = values[m_tf2.GetDimension() - 1];
values[m_tf2.GetDimension() - 1] = values[dim - 1];
tf2Val = m_tf2.ComputeAlpha(values);
values[m_tf2.GetDimension() - 1] = temp;
}
else
{
tf2Val = m_tf2.ComputeAlpha(values);
}
return((1.0f - m_t) * tf1Val + m_t * tf2Val);
}
/// <summary>
/// Compute the Texture pixels
/// </summary>
/// <param name="values">Array of values to send to the Transfer Function. Size : texelSize.x*texelSize.y</param>
/// <param name="padding">The padding in the array between each values</param>
/// <returns>Return true on success, false on failure</returns>
public bool ComputeTexture(float[] values, uint padding)
{
if (values.Length / padding != m_dimensions.x * m_dimensions.y)
{
return(false);
}
float[] v = new float[padding];
m_colors = new byte[4 * values.Length / padding];
for (int i = 0; i < m_colors.Length / 4; i++)
{
Array.Copy(values, padding * i, v, 0, padding);
Color iCol = m_tf.ComputeColor(v);
m_colors[4 * i] = (byte)(iCol.r * 255);
m_colors[4 * i + 1] = (byte)(iCol.g * 255);
m_colors[4 * i + 2] = (byte)(iCol.b * 255);
m_colors[4 * i + 3] = (byte)(m_tf.ComputeAlpha(v) * 255);
}
return(true);
}
private short[] ComputeTFColor(TransferFunction tf)
{
VTKDataset vtk = (VTKDataset)m_subDataset.Parent;
int hasGradient = (tf.HasGradient() ? 1 : 0);
if (vtk.IsLoaded == false || tf == null || tf.GetDimension() - hasGradient > vtk.PointFieldDescs.Count ||
(m_subDataset.OwnerID != -1 && m_subDataset.OwnerID != m_dataProvider.GetHeadsetID())) //Not a public subdataset
{
return(null);
}
int t1 = (int)Math.Floor(tf.Timestep);
int t2 = (int)Math.Ceiling(tf.Timestep);
int[] times = new int[] { t1, t2 };
unsafe
{
int[] indices = new int[vtk.PointFieldDescs.Count];
for (int i = 0; i < indices.Length; i++)
{
indices[i] = i;
}
Datasets.Gradient gradient = vtk.GetGradient(indices);
short[] colors = new short[m_dimensions.x * m_dimensions.y * m_dimensions.z]; //short because RGBA4444 == 2 bytes -> short
float frac = tf.Timestep - (float)Math.Truncate(tf.Timestep);
List <PointFieldDescriptor> ptDescs = m_subDataset.Parent.PointFieldDescs;
Parallel.For(0, m_dimensions.z, new ParallelOptions {
MaxDegreeOfParallelism = 8
},
(k, state) =>
{
float[] partialResT1 = new float[indices.Length + hasGradient];
float[] partialResT2 = new float[indices.Length + hasGradient];
fixed(short *pcolors = colors)
{
//int maxOldK = Math.Max(10 * (curK + 1), m_dimensions.z);
//for(int k = 10*curK; k < maxOldK; k++)
{
UInt64 ind = (UInt64)(k * m_dimensions.x * m_dimensions.y);
UInt64 readIntK = (UInt64)(m_descPts.Size[0] * m_descPts.Size[1] * (k * m_descPts.Size[2] / m_dimensions.z));
for (int j = 0; j < m_dimensions.y; j++)
{
//Pre compute the indice up to J--K coordinate
UInt64 readIntJK = (UInt64)(m_descPts.Size[0] * (j * m_descPts.Size[1] / m_dimensions.y)) + readIntK;
for (int i = 0; i < m_dimensions.x; i++)
{
UInt64 readInd = (UInt64)(i * m_descPts.Size[0] / m_dimensions.x) + readIntJK;
if (vtk.MaskValue != null && ((byte *)(vtk.MaskValue.Value))[readInd] == 0 ||
(m_subDataset.EnableVolumetricMask && m_subDataset.GetVolumetricMaskAt((int)readInd) == false))
{
pcolors[ind] = 0;
}
else
{
float[][] partialRes = new float[][] { partialResT1, partialResT2 };
for (int p = 0; p < 2; p++)
{
//Determine transfer function coordinates
for (int l = 0; l < indices.Length; l++)
{
int ids = indices[l];
if (ptDescs[ids].NbValuesPerTuple == 1)
{
partialRes[p][ids] = (ptDescs[ids].Value[times[p]].ReadAsFloat(readInd) - ptDescs[ids].MinVal) / (ptDescs[ids].MaxVal - ptDescs[ids].MinVal);
}
else
{
partialRes[p][ids] = (ptDescs[ids].ReadMagnitude(readInd, times[p]) - ptDescs[ids].MinVal) / (ptDescs[ids].MaxVal - ptDescs[ids].MinVal);
}
}
if (tf.HasGradient())
{
if (gradient != null)
{
partialRes[p][partialRes[p].Length - 1] = gradient.Values[times[p]][readInd]; //In case we need the gradient
}
else
{
partialRes[p][partialRes[p].Length - 1] = 0.0f;
}
}
}
//Linear interpolation
Color c = (1.0f - frac) * tf.ComputeColor(partialResT1) + frac * tf.ComputeColor(partialResT2);
float a = (1.0f - frac) * tf.ComputeAlpha(partialResT1) + frac * tf.ComputeAlpha(partialResT2);
byte r = (byte)(16 * c.r);
if (r > 15)
{
r = 15;
}
byte g = (byte)(16 * c.g);
if (g > 15)
{
g = 15;
}
byte b = (byte)(16 * c.b);
if (b > 15)
{
b = 15;
}
byte _a = (byte)(16 * a);
if (_a > 15)
{
_a = 15;
}
pcolors[ind] = (short)((r << 12) + (g << 8) + //RGBA4444 color format
(b << 4) + _a);
}
ind += 1;
}
}
}
}
});
return(colors);
}
}