09:04 < danzel> TomSpilman: are you around? need some advice on making Vertex/Index buffer not suck on PSS
09:05 < TomSpilman> i am now
09:05 < danzel> awesome :)
09:05 < TomSpilman> whats up?
09:06 < danzel> So for DynamicVertexBuffer I should be able to implement it as you suggested on codeplex
09:06 < danzel> which is basically what I have implemented for Vertex+IndexBuffer at the moment
09:06 < danzel> but I assume, for Vertex+IndexBuffer I don't want to keep copying the data to hardware every frame
09:06 < danzel> as they'll most likely be static
09:07 < danzel> (On PSS we have a native VertexBuffer - PssVertexBuffer - which is a vertex and index buffer)
09:07 < danzel> so getting that to work with XNA is a bit hard as we have separate vertex and index buffer objects
09:08 < danzel> so at the moment i've made XNA Vertex/Index buffer copy the data given to them to an array
09:08 < danzel> then when you go to draw using them we do what you've suggested for DynamicVertexBuffer
09:08 < TomSpilman> that seems appropriate
09:08 < danzel> and get a PssVB from the pool, set the data etc
09:08 < TomSpilman> not sure how optimal it is
09:09 < TomSpilman> but using an array in system memory to fake a dynamic VB isn't that strange
09:09 < danzel> yeah, it'll work, but probably isn't very good if you have static 3d models etc
09:09 < TomSpilman> right
09:09 < danzel> the copy to an internal array part i'm happy with
09:10 < danzel> but uploading from that array to a hardware VB each frame seems like a waste
09:11 < danzel> but i've been having trouble figuring out how to do just one upload due to being able use the same VB
                and change IB
09:11 < danzel> do you think I probably need to care? Or should we just live with uploading them every time they are
                used?
09:11 < danzel> I hope i've explained myself well enough
09:15 < TomSpilman> so i wouldn't upload it every frame
09:15 < TomSpilman> i would keep track of if its "dirty"
09:15 < TomSpilman> if someone changes a vert or index... mark things as dirty
09:15 < TomSpilman> then update... clear the dirty flag
09:16 < TomSpilman> statics then should be one update for the most part
09:16 < danzel> cool, that was my thoughts to
09:16 < TomSpilman> dynamics update at whatever rate they update
09:16 < TomSpilman> if you want to get trickier
09:16 < danzel> thoughts on how to handle that with the IB/VB->PssVB split
09:16 < TomSpilman> you can keep track of the "dirty range"
09:16 < danzel> since you could render a VB with 2 different IBs
09:16 < TomSpilman> the min/max vert/index that changed
09:16 < TomSpilman> then only update that sub-range
09:17 < TomSpilman> yea... that is trickier
09:17 < TomSpilman> i see two options
09:18 < danzel> It probably wouldn't happen often I'd assume, so we could probably keep track of the the last IB that
                was used with a VB and re-upload the IB if it changed?
09:18 < TomSpilman> one... have one "real" PSSVertexBuffer... for each XNA IndexBufffer + VertexBuffer combination
09:19 < TomSpilman> right... or that option... have on PSSVertexBuffer for each XNA VertexBuffer... update the index
                    data every draw if it changes
09:19 < TomSpilman> its pretty unfortunate how they structured the PSS api for that
09:19 < danzel> yeah :/
09:20 < TomSpilman> under the hood i assure you they are uploading index and vertex buffers seperately
09:20 < TomSpilman> this is them trying to "optimize" stuff for you when its not needed
09:20 < danzel> yeah, there are separate calls for setting each of them, so i'd expect so
09:21 < TomSpilman> technically there is no reason why they couldn't offer 3 objects...  PSSVertexBuffer,
                    PSSIndexBuffer, PSSVertexIndexBuffer
09:21 < TomSpilman> i would keep bitching at them about that one and hope they correct their mistake
09:27 < danzel> have added a request, cheers
09:27 < TomSpilman> cool
09:28 < danzel> If i'm going to implement having one PssVertexBuffer for each XNA IB+VB combo, how would you recommend
                structuring this? Have a Dictionary<IB,PssVB> in VertexBuffer or something else?
09:29 < TomSpilman> you could do it like that for sure
09:30 < TomSpilman> gets rid of the issue of needing to make a key from IB+VB
09:30 < TomSpilman> and would be pretty simple
09:30 < TomSpilman> in most cases the dictionary would have one element
09:30 < danzel> yep
09:31 < TomSpilman> you would just need to be sure to clean up the dictionary when the VB is disposed
09:31 < TomSpilman> and of course all this would be done using internal APIs and no one from the outside would see it
09:32 < TomSpilman> just like we do with the various state objects in GraphicsDevice
09:33 < TomSpilman> when you do GraphicsDevice.VertexBuffer = foo; or .IndexBuffer = bar;
09:33 < TomSpilman> you don't really do anything... you just hold on to the current vb and ib
09:33 < TomSpilman> its when you go to draw that #if PSS code kicks in and passes the IB to the VB to get a PSSVB back
09:34 < TomSpilman> then that is set
09:34 < TomSpilman> look at how i setup the Raster/DepthSencil/BlendState stuff or the UserPrim stuff
09:35 < TomSpilman> should be a good guide as to how your system could work
09:36 < danzel> alright awesome thanks