/**
 * @file llviewerjointattachment.h
 * @brief Implementation of LLViewerJointAttachment class
 *
 * $LicenseInfo:firstyear=2002&license=viewergpl$
 *
 * Copyright (c) 2002-2009, Linden Research, Inc.
 *
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 *
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 *
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 *
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

#ifndef LL_LLVIEWERJOINTATTACHMENT_H
#define LL_LLVIEWERJOINTATTACHMENT_H

#include "llstring.h"
#include "lluuid.h"

#include "llviewerjoint.h"
#include "llviewerobject.h"

class LLDrawable;

class LLViewerJointAttachment final : public LLViewerJoint
{
	friend class LLVOAvatar;

protected:
	LOG_CLASS(LLViewerJointAttachment);

public:
	LLViewerJointAttachment();

	// Returns true if this object is transparent.
	// This is used to determine in which order to draw objects.
	LL_INLINE bool isTransparent() override			{ return false; }

	// Draws the shape attached to a joint.
	// Called by render().
	U32 drawShape(bool first_pass = true, bool is_dummy = false) override;

	bool updateLOD(F32 pixel_area, bool activate) override;

	LL_INLINE void setPieSlice(S32 pie_slice)		{ mPieSlice = pie_slice; }
	LL_INLINE void setVisibleInFirstPerson(bool b)	{ mVisibleInFirst = b; }
	LL_INLINE bool getVisibleInFirstPerson() const	{ return mVisibleInFirst; }
	LL_INLINE void setGroup(S32 group)				{ mGroup = group; }
	void setOriginalPosition(LLVector3 &position);
	void setAttachmentVisibility(bool visible);
	LL_INLINE void setIsHUDAttachment(bool is_hud)	{ mIsHUDAttachment = is_hud; }
	LL_INLINE bool getIsHUDAttachment() const		{ return mIsHUDAttachment; }

	LL_INLINE bool isAnimatable() const override	{ return false; }

	LL_INLINE S32 getGroup() const					{ return mGroup; }
	LL_INLINE S32 getPieSlice() const				{ return mPieSlice; }

	LL_INLINE S32 getNumObjects() const				{ return mAttachedObjects.size(); }
	S32	getNumAnimatedObjects() const;

	void clampObjectPosition();

	// Attachments operations
	bool isObjectAttached(const LLViewerObject* viewer_object) const;
	const LLViewerObject* getAttachedObject(const LLUUID& object_id) const;
	LLViewerObject* getAttachedObject(const LLUUID& object_id);

	LL_INLINE bool hasChanged(const LLVector3& pos,
							  const LLQuaternion& rot) const
	{
		constexpr F32 SMALL_CHANGE_DIST2 = 0.05f * 0.05f;
		constexpr F32 SMALL_CHANGE_ANGL = 0.225f;	// Just shy of 13 degrees
		// Angle choice and LLQuaternion::almost_equal: almost_equal uses the
		// Small Angle Approximation for cos. The approximation diverges more
		// than 1% at around 0.6620 radians. We are under this limit and to be
		// honest, an error of 1% in this case is acceptable.
		return (pos - mLastTrackedPos).lengthSquared() > SMALL_CHANGE_DIST2 ||
			   !LLQuaternion::almost_equal(rot, mLastTrackedRot,
										   SMALL_CHANGE_ANGL);
	}

	LL_INLINE void setLastTracked(const LLVector3& pos,
								  const LLQuaternion& rot)
	{
		mLastTrackedPos = pos;
		mLastTrackedRot = rot;
	}

protected:
	// Unique methods, used exclusively by LLVOAvatar
	bool addObject(LLViewerObject* object, bool is_self);
	void removeObject(LLViewerObject* object, bool is_self);

	void calcLOD();
	void setupDrawable(LLViewerObject* object);

public:
	// List of attachments for this joint
	typedef std::vector<LLPointer<LLViewerObject> > attachedobjs_vec_t;
	attachedobjs_vec_t mAttachedObjects;

protected:
	LLVector3		mOriginalPos;
	LLVector3		mLastTrackedPos;
	LLQuaternion	mLastTrackedRot;
	S32				mGroup;
	S32				mPieSlice;
	bool			mIsHUDAttachment;
	bool			mVisibleInFirst;
};

#endif // LL_LLVIEWERJOINTATTACHMENT_H