/* ----------------------------------------------------------------------------- This source file is part of OGRE (Object-oriented Graphics Rendering Engine) For the latest info, see http://www.ogre3d.org/ Copyright (c) 2000-2005 The OGRE Team Also see acknowledgements in Readme.html This program is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA, or go to http://www.gnu.org/copyleft/lesser.txt. ----------------------------------------------------------------------------- */ #ifndef __AnimationTrack_H__ #define __AnimationTrack_H__ #include "OgrePrerequisites.h" #include "OgreSimpleSpline.h" #include "OgreRotationalSpline.h" namespace Ogre { /** A 'track' in an animation sequence, ie a sequence of keyframes which affect a certain type of animable object. @remarks This class is intended as a base for more complete classes which will actually animate specific types of object, e.g. a bone in a skeleton to affect skeletal animation. An animation will likely include multiple tracks each of which can be made up of many KeyFrame instances. Note that the use of tracks allows each animable object to have it's own number of keyframes, i.e. you do not have to have the maximum number of keyframes for all animable objects just to cope with the most animated one. @remarks Since the most common animable object is a Node, there are options in this class for associating the track with a Node which will receive keyframe updates automatically when the 'apply' method is called. @remarks By default rotation is done using shortest-path algorithm. It is possible to change this behaviour using setUseShortestRotationPath() method. */ class _OgreExport AnimationTrack { public: /// Constructor AnimationTrack(Animation* parent); /// Constructor, associates with a Node AnimationTrack(Animation* parent, Node* targetNode); virtual ~AnimationTrack(); /** Returns the number of keyframes in this animation. */ unsigned short getNumKeyFrames(void) const; /** Returns the KeyFrame at the specified index. */ KeyFrame* getKeyFrame(unsigned short index) const; /** Gets the 2 KeyFrame objects which are active at the time given, and the blend value between them. @remarks At any point in time in an animation, there are either 1 or 2 keyframes which are 'active', 1 if the time index is exactly on a keyframe, 2 at all other times i.e. the keyframe before and the keyframe after. @par This method returns those keyframes given a time index, and also returns a parametric value indicating the value of 't' representing where the time index falls between them. E.g. if it returns 0, the time index is exactly on keyFrame1, if it returns 0.5 it is half way between keyFrame1 and keyFrame2 etc. @param timePos The time index in seconds. @param keyFrame1 Pointer to a KeyFrame pointer which will receive the pointer to the keyframe just before or at this time index. @param keyFrame2 Pointer to a KeyFrame pointer which will receive the pointer to the keyframe just after this time index. @param firstKeyIndex Pointer to an unsigned short which, if supplied, will receive the index of the 'from' keyframe incase the caller needs it. @returns Parametric value indicating how far along the gap between the 2 keyframes the timePos value is, e.g. 0.0 for exactly at 1, 0.25 for a quarter etc. By definition the range of this value is: 0.0 <= returnValue < 1.0 . */ Real getKeyFramesAtTime(Real timePos, KeyFrame** keyFrame1, KeyFrame** keyFrame2, unsigned short* firstKeyIndex = 0) const; /** Creates a new KeyFrame and adds it to this animation at the given time index. @remarks It is better to create KeyFrames in time order. Creating them out of order can result in expensive reordering processing. Note that a KeyFrame at time index 0.0 is always created for you, so you don't need to create this one, just access it using getKeyFrame(0); @param timePos The time from which this KeyFrame will apply. */ KeyFrame* createKeyFrame(Real timePos); /** Removes a KeyFrame by it's index. */ void removeKeyFrame(unsigned short index); /** Removes all the KeyFrames from this track. */ void removeAllKeyFrames(void); /** Gets a KeyFrame object which contains the interpolated transforms at the time index specified. @remarks The KeyFrame objects held by this class are transformation snapshots at discrete points in time. Normally however, you want to interpolate between these keyframes to produce smooth movement, and this method allows you to do this easily. In animation terminology this is called 'tweening'. @param timeIndex The time (in relation to the whole animation sequence) @returns A new keyframe object containing the interpolated transforms. Note that the position and scaling transforms are linearly interpolated (lerp), whilst the rotation is spherically linearly interpolated (slerp) for the most natural result. */ KeyFrame getInterpolatedKeyFrame(Real timeIndex) const; /** Applies an animation track at a certain position to the target node. @remarks When a track has bee associated with a target node, you can eaisly apply the animation to the target by calling this method. @param timePos The time position in the animation to apply. @param weight The influence to give to this track, 1.0 for full influence, less to blend with other animations. @param scale The scale to apply to translations and scalings, useful for adapting an animation to a different size target. */ void apply(Real timePos, Real weight = 1.0, bool accumulate = false, Real scale = 1.0f); /** Returns a pointer to the associated Node object (if any). */ Node* getAssociatedNode(void) const; /** Sets the associated Node object which will be automatically affected by calls to 'apply'. */ void setAssociatedNode(Node* node); /** As the 'apply' method but applies to a specified Node instead of associated node. */ void applyToNode(Node* node, Real timePos, Real weight = 1.0, bool accumulate = false, Real scale = 1.0f); /** Sets the method of rotation calculation */ void setUseShortestRotationPath(bool useShortestPath); /** Gets the method of rotation calculation */ bool getUseShortestRotationPath() const; /** Internal method used to tell the track that keyframe data has been changed, which may cause it to rebuild some internal data. */ void _keyFrameDataChanged(void) const; /** Method to determine if this track has any KeyFrames which are doing anything useful - can be used to determine if this track can be optimised out. */ bool hasNonZeroKeyFrames(void) const; /** Optimise the current track by removing any duplicate keyframes. */ void optimise(void); protected: typedef std::vector KeyFrameList; KeyFrameList mKeyFrames; Real mMaxKeyFrameTime; Animation* mParent; Node* mTargetNode; // Flag indicating we need to rebuild the splines next time void buildInterpolationSplines(void) const; // Prebuilt splines, must be mutable since lazy-update in const method mutable bool mSplineBuildNeeded; mutable SimpleSpline mPositionSpline; mutable SimpleSpline mScaleSpline; mutable RotationalSpline mRotationSpline; /// Defines if rotation is done using shortest path mutable bool mUseShortestRotationPath ; }; } #endif