CWE-ou-minkata/Sources/Plasma/PubUtilLib/plDrawable/plAccessGeometry.h

/*==LICENSE==*

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*==LICENSE==*/

#ifndef plAccessGeometry_inc
#define plAccessGeometry_inc

#include "hsTemplates.h"

class plDrawable;
class plDrawableSpans;
class plGeometrySpan;
class plDrawInterface;
class plAccessSpan;
class plSpan;
class plParticleSpan;
class plIcicle;
class plVertexSpan;

class plPipeline;

class plAccessGeometry : public hsRefCnt
{
protected:
	void					Nilify() { fPipe = nil; }

	friend class plAccessGeometry;

	plPipeline*						fPipe;

	static plAccessGeometry*		fInstance;
public:
	// You're welcome to make your own,
	// but this is normally just called by the global plAccessGeometry's Init() function.
	// You should normally just use the instance supplied by Instance();
	plAccessGeometry(plPipeline* pipe=nil);

	static plAccessGeometry*		Instance() { return fInstance; }

	// App will initialize, which will create the global instance.
	// DeInit will nil the global instance.
	static void Init(plPipeline* pipe);
	static void DeInit();

	// External DLL's will share the same plAccessGeometry. After the main App has
	// DeInited the AccessGeometry,
	// all calls to Instance()->Function() will return nil in one form or another (e.g.
	// empty triangle lists). The external DLL needs to either not try to use these
	// accessor functions after PythonInterface::WeAreInShutdown() (it won't do any good
	// anyway as any work done will be thrown away), or else be prepared for receiving
	// empty data where there was data before.
	static void SetTheIntance(plAccessGeometry* i);

	// You have 2 options in opening the data.
	// RO - Read Only. 
	//		If you specify useSnapShot=true, then for channels which have had a snapshot
	//		taken, you will get pointers to this constant original snapshot form. For
	//		channels which have no snapshot data, or if useSnapShot=false, you will get
	//		pointers to the current (possibly modified since load) data. See SnapShot functions
	//		below.
	// RW - Read/Write access to the source data. After closing, this modified source data
	//		will be used to update the buffer data used for rendering.
	// In the normal case of reading the original (disk image) data, performing some operation
	//		on it and updating the renderable data, you need to open the same data twice, once
	//		RO(useSnapShot=true) (to get the constant source data) and once RW (for destination data). Note that
	//		the memory returned by RO will may be the same as returned by RW if there has been no snapshot
	//		taken.
	// The RW permutation by itself is useful when performing a one-time operation on the data (e.g.
	//		loadtime), so the modified source data is, to everyone else, what was read from disk.
	//		The only way to retrieve the original source data is to read it from disk again,
	//		unless you've made a snapshot. Normally you would do a RW modify the original data,
	//		then take the snapshot if you are going to be performing more modifications.
	// In ALL MODIFICATION CASES, if the modified data is paged out, and the original paged back in, you will
	//		need to perform your operation again - your modifications aren't saved anywhere.
	void	OpenRO(plDrawable* drawable, UInt32 spanIdx, plAccessSpan& acc, hsBool useSnapShot=true) const;
	void	OpenRW(plDrawable* drawable, UInt32 spanIdx, plAccessSpan& acc, hsBool idxToo=false) const;

	// What do we need to close up here?
	void	Close(plAccessSpan& acc) const;

	// Second set. You have a SceneObject's DrawInterface. This can reference into
	// multiple drawables, and multiple spans within each drawable. You would rather
	// not deal with it. So you can open by passing in a DrawInterface, and get back
	// a list of geometry corresponding to that SceneObject/DrawInterface.
	// NOTE: the list is in no way suggested to be homogenous. In fact, it's guaranteed
	// not to be, because the reason the single object resolved into multiple geometry spans
	// (possibly across multiple drawables) is that the conceptual single object is composed 
	// of multiple types of data that can't be batched into a single drawprimitive call.
	// At the least, the different AccessSpans will have different materials. But it's just
	// as likely that they will have different underlying formats (number of UVs, etc.).
	// Again, if you are using the iterators supplied, you probably don't care, but sometimes
	// you will (like if you are messing with the UVs).
	void	OpenRO(const plDrawInterface* di, hsTArray<plAccessSpan>& accs, hsBool useSnapShot=true) const;
	void	OpenRW(const plDrawInterface* di, hsTArray<plAccessSpan>& accs, hsBool idxToo=false) const;

	void	Close(hsTArray<plAccessSpan>& accs) const;

	// SnapShot functions.
	// If you need to generate channel values based on the original values (e.g. normal perterbation)
	// you need to reserve a copy of the original data. Only the channels specified will be copied.
	// Only one snapshot is ever taken, and it is the union of all channels requested. For example,
	//		taking a snapshot of positions AFTER taking a snapshot of positions/normals is a no-op,
	//		but taking a snapshot of positions/normals AFTER a snapshot of just positions will result in
	//		a copy of positions from the old snapshot, then a copy of normals from the buffergroup
	//		into the new snapshot, then freeing of the old snapshot.
	// Still, you should only snapshot the minimum set of channels you will need to be reading in their
	//		original form later.
	// The snapshot data is refcounted. You need to match your TakeSnapShots with FreeSnapShots.
	// SnapShot data is stored interleaved for efficiency, but don't count on it. Use an iterator.
	// RestoreSnapShot will copy the stored channels back into the buffer group, resetting those channels to
	//		the state when the snapshot was taken. Note that channels not SnapShotted might have been modified
	//		via OpenRW.
	// 
	void	TakeSnapShot(plDrawable* drawable, UInt32 spanIdx, UInt32 channels) const;
	void	RestoreSnapShot(plDrawable* drawable, UInt32 spanIdx, UInt32 channels) const;
	void	ReleaseSnapShot(plDrawable* drawable, UInt32 spanIdx) const;

	void	TakeSnapShot(const plDrawInterface* di, UInt32 channels) const;
	void	RestoreSnapShot(const plDrawInterface* di, UInt32 channels) const;
	void	ReleaseSnapShot(const plDrawInterface* di) const;

	// We often have geometry spans just sitting around devoid of any DI's, drawables or sceneobjects.
	// They aren't too bad to access directly (not like diving through the drawable into buffergroups),
	// but this let's them be accessed in a manner consistent with other geometry manipulations.
	void	AccessSpanFromGeometrySpan(plAccessSpan& dst, const plGeometrySpan* src) const { IAccessSpanFromSourceSpan(dst, src); }

protected:
	void	IAccessSpanFromSourceSpan(plAccessSpan& dst, const plGeometrySpan* src) const;
	void	IAccessSpanFromSpan(plAccessSpan& dst, plDrawableSpans* drawable, const plSpan* span, hsBool useSnap, hsBool readOnly) const;
	void	IAccessSpanFromVertexSpan(plAccessSpan& dst, plDrawableSpans* drawable, const plVertexSpan* span, hsBool readOnly) const;
	void	IAccessConnectivity(plAccessSpan& dst, plDrawableSpans* drawable, const plSpan* src) const;
	void	IAccessSpanFromIcicle(plAccessSpan& dst, plDrawableSpans* drawable, const plIcicle* span, hsBool readOnly) const;
	void	IAccessSpanFromParticle(plAccessSpan& dst, plDrawableSpans* drawable, const plParticleSpan* span, hsBool readOnly) const;
	void	IAccessSpanFromSnap(plAccessSpan& dst, plDrawableSpans* drawable, const plSpan* src) const;

	void	IOpen(plDrawable* d, UInt32 spanIdx, plAccessSpan& acc, hsBool useSnap, hsBool readOnly, hsBool idxToo=true) const;
};

#endif // plAccessGeometry_inc