private void RenderParticles(PartSysEmitter emitter)
{
var it = emitter.NewIterator();
var totalCount = emitter.GetActiveCount();
if (totalCount == 0)
{
return;
}
// Lazily initialize render state
if (!emitter.HasRenderState())
{
emitter.SetRenderState(
new QuadEmitterRenderState(_device, emitter));
}
var renderState = (QuadEmitterRenderState)emitter.GetRenderState();
using var spriteMemory = MemoryPool.Rent(4 * totalCount);
var sUpdateBuffer = spriteMemory.Memory.Span.Slice(0, 4 * totalCount);
var i = 0;
while (it.HasNext())
{
var particleIdx = it.Next();
FillVertex(emitter, particleIdx, sUpdateBuffer, i);
i += 4;
}
renderState.vertexBuffer.Resource.Update <SpriteVertex>(sUpdateBuffer);
_device.SetMaterial(renderState.material);
renderState.bufferBinding.Resource.Bind();
// Draw the batch
_device.DrawIndexed(PrimitiveType.TriangleList, 4 * totalCount, 6 * totalCount);
}
