public void Render(DxCamera camera)
{
//
// Set constants.
//
_viewProjVar.SetMatrix(camera.View * camera.Projection);
_gameTimeVar.Set(_gameTime);
_timeStepVar.Set(_timeStep);
_eyePosVar.Set(camera.Eye);
_emitPosVar.Set(_emitPosW);
_emitDirVar.Set(_emitDirW);
_texArrayVar.SetResource(_texArrayRV);
_randomTexVar.SetResource(_randomTexRV);
//
// Set IA stage.
//
_dxDevice.InputAssembler.SetInputLayout(_vertexLayout);
_dxDevice.InputAssembler.SetPrimitiveTopology(PrimitiveTopology.PointList);
int stride = Marshal.SizeOf(typeof(ParticleVertex));
const int offset = 0;
// On the first pass, use the initialization VB. Otherwise, use
// the VB that contains the current particle list.
_dxDevice.InputAssembler.SetVertexBuffers(0,
new VertexBufferBinding(_firstRun ? _initVB : _drawVB, stride, offset));
//
// Draw the current particle list using stream output only to update
// them. The updated vertices are streamed out to the target VB.
//
_dxDevice.StreamOutput.SetTargets(
new StreamOutputBufferBinding(_streamOutVB, offset));
for (int p = 0; p < _streamOutTech.Description.PassCount; ++p)
{
_streamOutTech.GetPassByIndex(p).Apply();
if (_firstRun)
{
_dxDevice.Draw(1, 0);
_firstRun = false;
}
else
{
_dxDevice.DrawAuto();
}
}
// done streaming out--unbind the vertex buffer
_dxDevice.StreamOutput.SetTargets(null);
// ping-pong the vertex buffers
var tmpVB = _drawVB;
_drawVB = _streamOutVB;
_streamOutVB = tmpVB;
//
// Draw the updated particle system we just streamed out.
//
_dxDevice.InputAssembler.SetVertexBuffers(0,
new VertexBufferBinding(_drawVB, stride, offset));
for (int p = 0; p < _drawTech.Description.PassCount; ++p)
{
_drawTech.GetPassByIndex(p).Apply();
_dxDevice.DrawAuto();
}
}
