LUMIERA.clone/src/proc/engine/buffhandle.hpp

139 lines
4.4 KiB
C++

/*
BUFFHANDLE.hpp - Buffer handling support for the render engine
Copyright (C) Lumiera.org
2008, Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file buffhandle.hpp
** Various bits needed to support the buffer management within the render nodes.
** When pulling data from predecessor nodes and calculating new data, each render node
** needs several input and output buffers. These may be allocated and provided by several
** different "buffer providers" (for example the frame cache). Typically, the real buffers
** will be passed as parameters to the actual job instance when scheduled, drawing on the
** results of prerequisite jobs. Yet the actual job implementation remains agnostic with
** respect to the way actual buffers are provided; the invocation just pushes BuffHandle
** objects around. The actual render function gets an array of C-pointers to the actual
** buffers, and for accessing those buffers, the node needs to keep a table of buffer
** pointers, and for releasing the buffers later on, we utilise the buffer handles.
** The usage pattern of those buffer pointer tables is stack-like, thus the actual
** implementation utilises a single large buffer pointer array per pull() call
** sequence and dynamically claims small chunks for each node.
**
** @see nodewiring-def.hpp
** @see nodeoperation.hpp
** @see bufftable.hpp storage for the buffer table
** @see engine::RenderInvocation
*/
#ifndef ENGINE_BUFFHANDLE_H
#define ENGINE_BUFFHANDLE_H
#include "lib/error.hpp"
#include "lib/streamtype.hpp"
#include "lib/bool-checkable.hpp"
namespace engine {
/**
* Handle for a buffer for processing data, abstracting away the actual implementation.
* The real buffer pointer can be retrieved by dereferencing this smart-handle class.
*
* @todo as of 6/2011 it isn't clear how buffer handles are actually created
* and how the lifecycle (and memory) management works
*/
struct BuffHandle
: lib::BoolCheckable<BuffHandle>
{
typedef lumiera::StreamType::ImplFacade::DataBuffer Buff;
typedef Buff* PBuff;
PBuff
operator->() const
{
return pBuffer_;
}
Buff&
operator* () const
{
ENSURE (pBuffer_);
return *pBuffer_;
}
bool
isValid() const
{
return pBuffer_;
}
//////////////////////TODO: the whole logic how to create a BuffHandle needs to be solved in a more clever way. --> TICKET #249
BuffHandle()
: pBuffer_(0),
sourceID_(0)
{ }
/**
* @deprecated placeholder implementation
* @todo rework the Lifecycle handling of buffers //////////TICKET #249
*/
BuffHandle(PBuff existingBuffer)
: pBuffer_(existingBuffer)
, sourceID_(0)
{ }
private:
PBuff pBuffer_;
long sourceID_; ////TICKET #249 this is a placeholder for a "type-like information", to be used for lifecycle management and sanity checks....
};
/**
* Buffer Type information.
* Given a BufferDescriptor, it is possible to allocate a buffer
* of suitable size and type by using BufferProvider::lockBuffer().
*/
struct BufferDescriptor
{
long typeToken_;
};
class ProcNode;
typedef ProcNode* PNode;
struct ChannelDescriptor ///////TODO collapse this with BufferDescriptor?
{
BufferDescriptor bufferType;
};
struct InChanDescriptor : ChannelDescriptor
{
PNode dataSrc; ///< the ProcNode to pull this input from
uint srcChannel; ///< output channel to use on the predecessor node
};
} // namespace engine
#endif