public void MoveAngle(Guid pairId, float angleDegrees)
{
AutoSplatAngleTexturePair pair = GetPair(pairId);
if (!pair.AngleDegrees.Equals(angleDegrees))
{
AutoSplatAngleTexturePair clone = null;
if (pair.IsCriticalAngle)
{
clone = new AutoSplatAngleTexturePair(pair);
// We won't need to 'infinitesimally bump' the new angle because
// we already tested to establish that the values are not equal.
}
else
{
// Guarenteed to be neither first nor last because it's not critical
int pairIndex = GetIndex(pairId);
float prevAngle = m_AngleSortedPairs[pairIndex - 1].AngleDegrees;
float nextAngle = m_AngleSortedPairs[pairIndex + 1].AngleDegrees;
if (angleDegrees < prevAngle || angleDegrees > nextAngle)
{
// Only Add and Remove should change the sorting order
throw new ConstraintException(
"MoveAngle would change ordering of pairs;" +
"only Add and Remove should change the sorting order.");
}
// If the move would make the angle coincide exactly with one of
// its neighbors, back it off a teensie-weensie bit.
const float infinitesimal = 0.0001f;
if (angleDegrees.Equals(prevAngle))
{
angleDegrees += infinitesimal;
}
else if (angleDegrees.Equals(nextAngle))
{
angleDegrees -= infinitesimal;
}
}
float oldAngle = pair.AngleDegrees;
pair.AngleDegrees = angleDegrees;
FireAngleMoved(pairId, oldAngle, angleDegrees);
if (null != clone)
{
// So we are splitting one of the critical pairs. By waiting until
// after we've moved the original pair to add the clone, we assure
// the sorting order stays the same for pre-existing pairs. The
// Outside World cares about this order.
InternalAddAngleTexturePair(clone);
}
}
}
public AutoSplatAngleTexturePair AddAngleTexturePair(float angleDegrees, int textureIndex)
{
AutoSplatAngleTexturePair pair = new AutoSplatAngleTexturePair(angleDegrees, textureIndex);
InternalAddAngleTexturePair(pair);
return(pair);
}
/// <summary>
/// This is like an 'add' operation, but you need to restore the id of the
/// pair literally because further operations in the undo stack will refer
/// to the pair by id.
/// </summary>
/// <param name="angleDegrees">angle of the slope</param>
/// <param name="textureIndex">texture associated with the slope</param>
/// <param name="id">unique id by which the slope is accessed</param>
/// <returns></returns>
public AutoSplatAngleTexturePair UndoRemoveAngleTexturePair(float angleDegrees, int textureIndex, Guid id)
{
AutoSplatAngleTexturePair pair = new AutoSplatAngleTexturePair(angleDegrees, textureIndex, id);
InternalAddAngleTexturePair(pair);
return(pair);
}
void InternalRemoveAngleTexturePair(AutoSplatAngleTexturePair pair)
{
// You are not allowed to remove critical pairs! We have a design
// constraint that there are always a horizontal and a vertical pair.
//
// This is not as constraining as it might sound. Assume the 'remove'
// request is the outcome of a GUI action--like dragging to the trash.
// Even if you attempt to remove a critical pair, the act of moving it
// to the trash hotspot will move it away from the critical position,
// which in turn causes a new pair to be inserted to replace it in the
// critical position. You could do it all day if that's how you like
// to spend your time.
if (!pair.IsCriticalAngle)
{
m_IdToPairMap.Remove(pair.Id);
m_AngleSortedPairs.Remove(pair);
FireAngleTexturePairRemoved(pair);
}
}
public float[] GetAutoSplatSampleNormalized(float angleDegrees)
{
AutoSplatAngleTexturePair lowerPair = null;
AutoSplatAngleTexturePair higherPair = null;
// We assume the pairs are sorted in increasing order by angle
foreach (AutoSplatAngleTexturePair pair in m_AngleSortedPairs)
{
if (pair.AngleDegrees == angleDegrees)
{
lowerPair = pair;
higherPair = pair;
break;
}
if (pair.AngleDegrees < angleDegrees)
{
lowerPair = pair;
continue;
}
if (pair.AngleDegrees > angleDegrees)
{
higherPair = pair;
// We should have both the lower & upper bounds now, so break;
break;
}
}
if (lowerPair == null)
{
Debug.Assert(lowerPair != null,
"Unable to find lower angle when getting autosplat sample. Angle=" + angleDegrees + " Range=" +
this);
}
if (higherPair == null)
{
Debug.Assert(higherPair != null,
"Unable to find higher angle when getting autosplat sample. Angle=" + angleDegrees +
" Range=" + this);
}
// Compute the gradiant weighting for the lower & higher angled textures
float lowerWeight;
float higherWeight;
float angleDiff = higherPair.AngleDegrees - lowerPair.AngleDegrees;
if (angleDiff == 0 || lowerPair.TextureIndex == higherPair.TextureIndex)
{
lowerWeight = 0f;
higherWeight = 1f;
}
else
{
// How close is the angle to the higher/lower angle? Normalize
// that distance from 0..1 and use that as the gradient weights
higherWeight = (angleDegrees - lowerPair.AngleDegrees) / angleDiff;
lowerWeight = 1f - higherWeight;
}
float[] normalizedSample = new float[AlphaSplatTerrainConfig.MAX_LAYER_TEXTURES];
// It's important that we set higher second because
// if lower & higher angle are equal the same, we
// set the higherWeight to 1f above and want to make
// sure it's set that way here.
normalizedSample[lowerPair.TextureIndex] = lowerWeight;
normalizedSample[higherPair.TextureIndex] = higherWeight;
return(normalizedSample);
}
