// Per-frame emission of particles into the GPU simulation
private static void Emit(int emitterCount, MyGPUEmitterData[] emitterData, ISrvBindable depthRead)
{
// update emitter data
var mapping = MyMapping.MapDiscard(m_emitterStructuredBuffer);
int maxParticlesToEmitThisFrame = 0;
for (int i = 0; i < emitterCount; i++)
{
mapping.WriteAndPosition(ref emitterData[i]);
if (emitterData[i].NumParticlesToEmitThisFrame > maxParticlesToEmitThisFrame)
maxParticlesToEmitThisFrame = emitterData[i].NumParticlesToEmitThisFrame;
}
mapping.Unmap();
int numThreadGroupsX = align(maxParticlesToEmitThisFrame, MAX_PARTICLE_EMIT_THREADS) / MAX_PARTICLE_EMIT_THREADS;
int numThreadGroupsY = align(emitterCount, MAX_EMITTERS) / MAX_EMITTERS;
// update emitter count
mapping = MyMapping.MapDiscard(m_emitterConstantBuffer);
mapping.WriteAndPosition(ref emitterCount);
mapping.WriteAndPosition(ref numThreadGroupsX);
mapping.Unmap();
if (maxParticlesToEmitThisFrame > 0)
{
// Set resources but don't reset any atomic counters
RC.ComputeShader.SetUav(0, m_particleBuffer);
RC.ComputeShader.SetUav(1, m_deadListBuffer);
RC.ComputeShader.SetUav(2, m_skippedParticleCountBuffer, 0);
RC.ComputeShader.SetConstantBuffer(1, m_emitterConstantBuffer);
RC.ComputeShader.SetSrv(0, depthRead);
RC.ComputeShader.SetSrv(1, m_emitterStructuredBuffer);
RC.ComputeShader.Set(m_csEmit);
RC.Dispatch(numThreadGroupsX, numThreadGroupsY, 1);
RC.ComputeShader.SetConstantBuffer(1, null);
RC.ComputeShader.Set(m_csEmitSkipFix);
// Disaptch a set of 1d thread groups to fill out the dead list, one thread per particle
RC.Dispatch(1, 1, 1);
}
}
internal static int Gather(MyGPUEmitterData[] data, out ISrvBindable textureArraySrv)
{
for (int i = 0; i < MAX_LIVE_EMITTERS; i++)
{
data[i].NumParticlesToEmitThisFrame = 0;
}
// sort emitters!
List<MyLiveData> emitters = m_emitters.Values.ToList();
//if (emitters.Count > MAX_LIVE_EMITTERS)
emitters.Sort();
int maxEmitterIndex = -1;
uint textureIndex = 0;
int unassociatedCount = 0;
int skipCount = 0;
int unsortedCount = 0;
int firstUnassociatedIndex = -1;
int lastAssociatedIndex = -1;
for (int i = 0; i < emitters.Count; i++)
{
var emitter = emitters[i];
// assiociate buffer index to new emitters & track overload to free space for unassociated near emitters later
if (emitter.BufferIndex == -1)
{
if (m_freeBufferIndices.Count > 0)
{
emitter.BufferIndex = m_freeBufferIndices.Pop();
}
else
{
unassociatedCount++;
if (firstUnassociatedIndex == -1)
firstUnassociatedIndex = i;
}
}
else
{
skipCount = unassociatedCount;
lastAssociatedIndex = i;
if (unassociatedCount > 0)
unsortedCount++;
}
if (MyCommon.TimerMs > emitter.DieAt)
emitter.GPUEmitter.Data.Flags |= GPUEmitterFlags.Dead;
if (emitter.BufferIndex != -1)
{
if ((emitter.GPUEmitter.Data.Flags & GPUEmitterFlags.FreezeEmit) == 0)
{
float toEmit = MyCommon.LastFrameDelta() * emitter.GPUEmitter.ParticlesPerSecond +
emitter.ParticlesEmittedFraction;
emitter.GPUEmitter.Data.NumParticlesToEmitThisFrame = (int)toEmit;
emitter.ParticlesEmittedFraction = toEmit - emitter.GPUEmitter.Data.NumParticlesToEmitThisFrame;
}
if (string.IsNullOrEmpty(emitter.GPUEmitter.AtlasTexture))
{
MyRenderProxy.Assert(m_textureArrayIndices.ContainsKey(emitter.GPUEmitter.AtlasTexture));
textureIndex = m_textureArrayIndices[emitter.GPUEmitter.AtlasTexture].Index;
}
else textureIndex = 0;
int bufferIndex = emitter.BufferIndex;
data[bufferIndex] = emitter.GPUEmitter.Data;
Vector3 pos = emitter.GPUEmitter.WorldPosition - MyRender11.Environment.Matrices.CameraPosition;
data[bufferIndex].RotationMatrix.M14 = pos.X;
data[bufferIndex].RotationMatrix.M24 = pos.Y;
data[bufferIndex].RotationMatrix.M34 = pos.Z;
data[bufferIndex].PositionDelta = emitter.LastWorldPosition - emitter.GPUEmitter.WorldPosition;
data[bufferIndex].TextureIndex1 |= textureIndex << (ATLAS_INDEX_BITS + ATLAS_DIMENSION_BITS * 2);
if (bufferIndex > maxEmitterIndex)
maxEmitterIndex = bufferIndex;
}
emitter.LastWorldPosition = emitter.GPUEmitter.WorldPosition;
}
/*MyRenderStats.Generic.WriteFormat("GPU particles allocated: {0}", totalParticles, VRage.Stats.MyStatTypeEnum.CurrentValue, 300, 0);
MyRenderStats.Generic.WriteFormat("GPU particles overload: {0}", overloadedParticles ? 1.0f : 0, VRage.Stats.MyStatTypeEnum.CurrentValue, 300, 0);
MyRenderStats.Generic.WriteFormat("GPU emitters overload: {0}", overloadedEmitters ? 1.0f : 0, VRage.Stats.MyStatTypeEnum.CurrentValue, 300, 0);*/
UpdateTextureArray();
textureArraySrv = m_textureArray;
// stop emitters far away to make room for emitters nearby
if (skipCount > 0 && unsortedCount > 0)
{
// iterate until buffer-unassociated index is larger then unassocited one
for (int i = firstUnassociatedIndex, j = lastAssociatedIndex; i < j; )
{
var emitter = emitters[j];
// free last buffer-associated emitter
data[emitter.BufferIndex].Flags |= GPUEmitterFlags.Dead;
data[emitter.BufferIndex].NumParticlesToEmitThisFrame = 0;
m_freeBufferIndices.Push(emitter.BufferIndex);
emitter.BufferIndex = -1;
// find new last buffer-associated emitter
do
{
j--;
}
while (j > 0 && emitters[j].BufferIndex == -1);
// find next buffer-unassociated emitter
do
{
i++;
} while (i < emitters.Count && emitters[i].BufferIndex != -1);
}
}
foreach (var emitter in emitters)
if ((emitter.GPUEmitter.Data.Flags & GPUEmitterFlags.Dead) > 0)
{
Remove(emitter);
}
return maxEmitterIndex + 1;
}