/// <summary>
/// Converts a layer of voxels to a layer of arcs.
/// </summary>
/// <param name='aBlob'>
/// A 3D voxel blob.
/// </param>
/// <param name='atLayer'>
/// The layer to sample at.
/// </param>
public IEnumerator ConvertVoxelLayer(VoxelRegion region)
{
m_innerRing = int.MaxValue;
m_outerRing = int.MinValue;
Clear();
// NOTE:
// This assumes ring 0 is at the origin of the plate;
// a slightly better version could have ring 0 start
// nozzleSize * 0.5f mm away from the origin. This
// would help account for the slight spill over from
// the nozzle into adjacent rings…
for (int forRing = 0; forRing < m_maxRings; forRing += infillStep)
{
SampleArcsFrom(region, forRing);
if (Scheduler.ShouldYield())
{
yield return(null);
}
}
// NOTE for TESTING
// If we didn't added anything for ring 0, add a complete ring.
if (m_arcs[0].Count == 0)
{
int origin = Mathf.RoundToInt(region.GetSampleFromMm(m_printer.platformRadiusInMm));
byte material = region.IsValidPoint(origin, origin)
? region[origin, origin] : (byte)0;
Arc currentArc = null;
Extend(currentArc, material, 0, 0);
Extend(currentArc, 0, m_printer.platform.stepsPerRotation, 0);
UpdateRingBounds(0);
}
else
{
Text.Log(@"No worries!");
}
//*/
Contract.Assert(m_ringCount <= m_maxRings,
@"Ring count ({0}) is larger than max rings ({1}).",
m_ringCount, m_maxRings);
Contract.Assert(m_ringCount <= layerWidthInRings,
@"Ring count of {0} larger than width of {1}.",
m_ringCount, layerWidthInRings);
}
/// <summary>
/// Samples the blob for the given [ring, layer] by sampling
/// kSamplingScale * the circumference points moving in a
/// positive (ccw) angle.
/// </summary>
/// <param name='aBlob'>
/// A BLOB.
/// </param>
/// <param name='atLayer'>
/// At layer.
/// </param>
/// <param name='forRing'>
/// For ring.
/// </param>
void SampleArcsFrom(VoxelRegion region, int forRing)
{
Contract.Assert(forRing >= 0, @"Negative ring: {0}", forRing);
Contract.Assert(forRing < m_maxRings, @"Ring {0} out of bounds.", forRing);
float platformStepInDeg = m_printer.platform.degreesPerStep;
int stepsPerRotation = m_printer.platform.stepsPerRotation;
int samplesToTake = Mathf.CeilToInt(forRing * MathUtil.kTau * kSamplingScale);
float sampleSizeInRadians = MathUtil.kTau / samplesToTake;
Arc currentArc = null;
// Origin of the platform, in voxels.
int origin = Mathf.RoundToInt(region.GetSampleFromMm(m_printer.platformRadiusInMm));
// Rings -> Mm -> Voxels
float voxelRadius = region.GetSampleFromMm(forRing * m_printer.nozzleWidthInMm);
for (int sampleIndex = 0; sampleIndex < samplesToTake; ++sampleIndex)
{
float radians = sampleIndex * sampleSizeInRadians;
// Since the number of samples we're taking depends on the radius,
// we can't pre-compute the angles and use them for everything…
float sampleX = voxelRadius * Mathf.Cos(radians);
float sampleY = voxelRadius * Mathf.Sin(radians);
// NOTE: This should probably be rounded, not floored.
int sampleXInt = Mathf.RoundToInt(sampleX);
int sampleYInt = Mathf.RoundToInt(sampleY);
float sampleXFractional = sampleX - sampleXInt;
float sampleYFractional = sampleY - sampleYInt;
float xFractionalSqr = sampleXFractional * sampleXFractional;
float yFractionalSqr = sampleYFractional * sampleYFractional;
// If the sample is sufficiently good, then take the sample
// and update the arc.
if (xFractionalSqr + yFractionalSqr <= kSampleThresholdSqr)
{
int sampleAtWidth = sampleXInt + origin;
int sampleAtDepth = sampleYInt + origin;
byte material = region.IsValidPoint(sampleAtWidth, sampleAtDepth)
? region[sampleAtWidth, sampleAtDepth]
: (byte)0;
// NOTE: If we round to int, then we can get the same step
// number even if we sample different points! Doing so
// could lead to 0-length arcs.
int platformStep = Mathf.FloorToInt(radians * Mathf.Rad2Deg / platformStepInDeg);
platformStep = Mathf.Min(platformStep, stepsPerRotation);
currentArc = Extend(currentArc, material, platformStep, forRing);
}
}
// Close off the arc if open.
Extend(currentArc, 0, stepsPerRotation, forRing);
UpdateRingBounds(forRing);
}