/// <summary>
/// Computes Gerstner params for a set of waves, for the given lod idx. Writes shader data to the given property.
/// Returns number of wave components rendered in this batch.
/// </summary>
int UpdateBatch(int lodIdx, int firstComponent, int lastComponentNonInc, IPropertyWrapper property)
{
int numComponents = lastComponentNonInc - firstComponent;
int numInBatch = 0;
int dropped = 0;
float twopi = 2f * Mathf.PI;
float one_over_2pi = 1f / twopi;
float minWavelengthThisBatch = OceanRenderer.Instance._lods[lodIdx].MaxWavelength() / 2f;
float maxWavelengthCurrentlyRendering = OceanRenderer.Instance._lods[OceanRenderer.Instance.CurrentLodCount - 1].MaxWavelength();
float viewerAltitudeLevelAlpha = OceanRenderer.Instance.ViewerAltitudeLevelAlpha;
// register any nonzero components
for (int i = 0; i < numComponents; i++)
{
float wl = _wavelengths[firstComponent + i];
// compute amp - contains logic for shifting wave components between last two lods..
float amp = _amplitudes[firstComponent + i];
bool renderingIntoLastTwoLods = minWavelengthThisBatch * 4.01f > maxWavelengthCurrentlyRendering;
// no special weighting needed for any lods except the last 2
if (renderingIntoLastTwoLods)
{
bool renderingIntoLastLod = minWavelengthThisBatch * 2.01f > maxWavelengthCurrentlyRendering;
if (renderingIntoLastLod)
{
// example: fade out the last lod as viewer drops in altitude, so there is no pop when the lod chain shifts in scale
amp *= viewerAltitudeLevelAlpha;
}
else
{
// rendering to second-to-last lod. nothing required unless we are dealing with large wavelengths, which we want to transition into
// this second-to-last lod when the viewer drops in altitude, ready for a seamless transition when the lod chain shifts in scale
amp *= (wl < 2f * minWavelengthThisBatch) ? 1f : 1f - viewerAltitudeLevelAlpha;
}
}
if (amp >= 0.001f)
{
if (numInBatch < BATCH_SIZE)
{
int vi = numInBatch / 4;
int ei = numInBatch - vi * 4;
UpdateBatchScratchData._twoPiOverWavelengthsBatch[vi][ei] = 2f * Mathf.PI / wl;
UpdateBatchScratchData._ampsBatch[vi][ei] = amp;
float chopScale = _spectrum._chopScales[(firstComponent + i) / _componentsPerOctave];
UpdateBatchScratchData._chopAmpsBatch[vi][ei] = -chopScale * _spectrum._chop * amp;
float angle = Mathf.Deg2Rad * (OceanRenderer.Instance._windDirectionAngle + _angleDegs[firstComponent + i]);
UpdateBatchScratchData._waveDirXBatch[vi][ei] = Mathf.Cos(angle);
UpdateBatchScratchData._waveDirZBatch[vi][ei] = Mathf.Sin(angle);
// It used to be this, but I'm pushing all the stuff that doesn't depend on position into the phase.
//half4 angle = k * (C * _CrestTime + x) + _Phases[vi];
float gravityScale = _spectrum._gravityScales[(firstComponent + i) / _componentsPerOctave];
float gravity = OceanRenderer.Instance.Gravity * _spectrum._gravityScale;
float C = Mathf.Sqrt(wl * gravity * gravityScale * one_over_2pi);
float k = twopi / wl;
// Repeat every 2pi to keep angle bounded - helps precision on 16bit platforms
UpdateBatchScratchData._phasesBatch[vi][ei] = Mathf.Repeat(_phases[firstComponent + i] + k * C * OceanRenderer.Instance.CurrentTime, Mathf.PI * 2f);
numInBatch++;
}
else
{
dropped++;
}
}
}
if (dropped > 0)
{
Debug.LogWarning(string.Format("Gerstner LOD{0}: Batch limit reached, dropped {1} wavelengths. To support bigger batch sizes, see the comment around the BATCH_SIZE declaration.", lodIdx, dropped), this);
numComponents = BATCH_SIZE;
}
if (numInBatch == 0)
{
// no waves to draw - abort
return(numInBatch);
}
// if we did not fill the batch, put a terminator signal after the last position
if (numInBatch < BATCH_SIZE)
{
int vi_last = numInBatch / 4;
int ei_last = numInBatch - vi_last * 4;
for (int vi = vi_last; vi < BATCH_SIZE / 4; vi++)
{
for (int ei = ei_last; ei < 4; ei++)
{
UpdateBatchScratchData._twoPiOverWavelengthsBatch[vi][ei] = 1f; // wary of NaNs
UpdateBatchScratchData._ampsBatch[vi][ei] = 0f;
UpdateBatchScratchData._waveDirXBatch[vi][ei] = 0f;
UpdateBatchScratchData._waveDirZBatch[vi][ei] = 0f;
UpdateBatchScratchData._phasesBatch[vi][ei] = 0f;
UpdateBatchScratchData._chopAmpsBatch[vi][ei] = 0f;
}
ei_last = 0;
}
}
// apply the data to the shape property
property.SetVectorArray(sp_TwoPiOverWavelengths, UpdateBatchScratchData._twoPiOverWavelengthsBatch);
property.SetVectorArray(sp_Amplitudes, UpdateBatchScratchData._ampsBatch);
property.SetVectorArray(sp_WaveDirX, UpdateBatchScratchData._waveDirXBatch);
property.SetVectorArray(sp_WaveDirZ, UpdateBatchScratchData._waveDirZBatch);
property.SetVectorArray(sp_Phases, UpdateBatchScratchData._phasesBatch);
property.SetVectorArray(sp_ChopAmps, UpdateBatchScratchData._chopAmpsBatch);
property.SetFloat(sp_NumInBatch, numInBatch);
property.SetFloat(sp_AttenuationInShallows, OceanRenderer.Instance._simSettingsAnimatedWaves.AttenuationInShallows);
int numVecs = (numInBatch + 3) / 4;
property.SetInt(sp_NumWaveVecs, numVecs);
OceanRenderer.Instance._lodDataAnimWaves.BindResultData(lodIdx, 0, property);
if (OceanRenderer.Instance._lodDataSeaDepths)
{
OceanRenderer.Instance._lodDataSeaDepths.BindResultData(lodIdx, 0, property, false);
}
return(numInBatch);
}