1 #ifndef DALI_INTERNAL_SCENE_GRAPH_PAN_GESTURE_H
2 #define DALI_INTERNAL_SCENE_GRAPH_PAN_GESTURE_H
5 * Copyright (c) 2021 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <dali/devel-api/threading/mutex.h>
23 #include <dali/internal/event/events/pan-gesture/pan-gesture-impl.h>
24 #include <dali/internal/update/common/property-owner.h>
25 #include <dali/internal/update/gestures/gesture-properties.h>
26 #include <dali/public-api/common/vector-wrapper.h>
34 struct PanGestureProfiling;
39 * The latest pan gesture information is stored in this scene object.
41 class PanGesture : public PropertyOwner
53 SMOOTHING_NONE, // No smoothing.
54 SMOOTHING_LAST_VALUE, // Smooth between last value and latest value.
55 SMOOTHING_MULTI_TAP, // Uses multitap smoothing, only available with Prediction mode 2.
58 static const PredictionMode DEFAULT_PREDICTION_MODE;
59 static const int NUM_PREDICTION_MODES;
61 static const SmoothingMode DEFAULT_SMOOTHING_MODE;
62 static const int NUM_SMOOTHING_MODES;
64 // Latest Pan Information
67 * Only stores the information we actually require from Dali::PanGesture
72 * Stores the velocity, displacement and position.
81 Info(const Info& rhs) = default;
86 Info& operator=(const Info& rhs)
90 velocity = rhs.velocity;
91 displacement = rhs.displacement;
92 position = rhs.position;
101 Vector2 displacement;
110 state(GestureState::CLEAR),
118 PanInfo(const PanInfo& rhs)
128 * Assignment operator
130 PanInfo& operator=(const PanInfo& rhs)
145 * Assignment operator
146 * @param[in] gesture A Dali::Gesture
148 PanInfo& operator=(const Internal::PanGesture& rhs)
150 time = rhs.GetTime();
151 state = rhs.GetState();
153 local.velocity = rhs.GetVelocity();
154 local.displacement = rhs.GetDisplacement();
155 local.position = rhs.GetPosition();
157 screen.velocity = rhs.GetScreenVelocity();
158 screen.displacement = rhs.GetScreenDisplacement();
159 screen.position = rhs.GetScreenPosition();
172 using PanInfoHistory = std::vector<PanInfo>;
173 using PanInfoHistoryIter = PanInfoHistory::iterator;
174 using PanInfoHistoryConstIter = PanInfoHistory::const_iterator;
177 static const unsigned int PAN_GESTURE_HISTORY = 30u;
181 * Create a new PanGesture
183 static PanGesture* New();
188 ~PanGesture() override;
191 * Adds a PanGesture to the internal circular-buffer waiting to be handled by UpdateProperties.
192 * @param[in] gesture The latest pan gesture.
194 void AddGesture(const Internal::PanGesture& gesture);
197 * @brief Removes pan events from the history that are older than maxAge, leaving at least minEvents
199 * @param[in] panHistory The pan event history container
200 * @param[in] currentTime The current frame time
201 * @param[in] maxAge Maximum age of an event before removing (in millis)
202 * @param[in] minEvents The minimum number of events to leave in history, oldest events are removed before newest
204 void RemoveOldHistory(PanInfoHistory& panHistory, unsigned int currentTime, unsigned int maxAge, unsigned int minEvents);
207 * Uses elapsed time and time stamps
209 void PredictionMode1(int eventsThisFrame, PanInfo& gestureOut, PanInfoHistory& panHistory, unsigned int lastVSyncTime, unsigned int nextVSyncTime);
212 * Blends two points together.
213 * The blend value ranges are:
214 * 0.0f = use 100% of current value.
215 * 1.0f = use half-way average of current and last value.
217 * @param[in,out] gesture Pass in current gesture, outputs result of blend.
218 * @param[in] lastGesture Pass in gesture to blend between.
220 void BlendPoints(PanInfo& gesture, PanInfo& lastGesture, float blendValue);
223 * Called by the update manager so that we can update the value of our properties.
224 * @param[in] nextRenderTime The estimated time of the next render (in milliseconds).
225 * @return true, if properties were updated.
227 bool UpdateProperties(unsigned int lastRenderTime, unsigned int nextRenderTime);
230 * Retrieves a reference to the panning flag property.
231 * @return The panning flag property.
233 const GesturePropertyBool& GetPanningProperty() const;
236 * Retrieves a reference to the screen position property.
237 * @return The screen position property.
239 const GesturePropertyVector2& GetScreenPositionProperty() const;
242 * Retrieves a reference to the screen velocity property.
243 * @return The screen velocity property.
245 const GesturePropertyVector2& GetScreenVelocityProperty() const;
248 * Retrieves a reference to the screen displacement property.
249 * @return The screen displacement property.
251 const GesturePropertyVector2& GetScreenDisplacementProperty() const;
254 * Retrieves a reference to the local position property.
255 * @return The local position property.
257 const GesturePropertyVector2& GetLocalPositionProperty() const;
260 * Retrieves a reference to the local displacement property.
261 * @return The local displacement property.
263 const GesturePropertyVector2& GetLocalDisplacementProperty() const;
266 * Retrieves a reference to the local velocity property.
267 * @return The local velocity property.
269 const GesturePropertyVector2& GetLocalVelocityProperty() const;
272 * @brief Sets the prediction mode of the pan gesture
274 * @param[in] mode The prediction mode
276 void SetPredictionMode(PredictionMode mode);
279 * @brief Sets the prediction amount of the pan gesture
281 * @param[in] amount The prediction amount in milliseconds
283 void SetPredictionAmount(unsigned int amount);
286 * @brief Sets the upper bound of the prediction amount for clamping
288 * @param[in] amount The prediction amount in milliseconds
290 void SetMaximumPredictionAmount(unsigned int amount);
293 * @brief Sets the lower bound of the prediction amount for clamping
295 * @param[in] amount The prediction amount in milliseconds
297 void SetMinimumPredictionAmount(unsigned int amount);
300 * @brief Sets the amount of prediction interpolation to adjust when the pan velocity is changed
302 * @param[in] amount The prediction amount in milliseconds
304 void SetPredictionAmountAdjustment(unsigned int amount);
307 * @brief Sets the prediction mode of the pan gesture
309 * @param[in] mode The prediction mode
311 void SetSmoothingMode(SmoothingMode mode);
314 * @brief Sets the amount of smoothing to apply for the current smoothing mode
316 * @param[in] amount The amount of smoothing [0.0f,1.0f]
318 void SetSmoothingAmount(float amount);
321 * @brief Sets whether to use actual times of the real gesture and frames or not.
323 * @param[in] value True = use actual times, False = use perfect values
325 void SetUseActualTimes(bool value);
328 * @brief Sets the interpolation time range (ms) of past points to use (with weights) when interpolating.
330 * @param[in] value Time range in ms
332 void SetInterpolationTimeRange(int value);
335 * @brief Sets whether to use scalar only prediction, which when enabled, ignores acceleration.
337 * @param[in] value True = use scalar prediction only
339 void SetScalarOnlyPredictionEnabled(bool value);
342 * @brief Sets whether to use two point prediction. This combines two interpolated points to get more steady acceleration and velocity values.
344 * @param[in] value True = use two point prediction
346 void SetTwoPointPredictionEnabled(bool value);
349 * @brief Sets the time in the past to interpolate the second point when using two point interpolation.
351 * @param[in] value Time in past in ms
353 void SetTwoPointInterpolatePastTime(int value);
356 * @brief Sets the two point velocity bias. This is the ratio of first and second points to use for velocity.
358 * @param[in] value 0.0f = 100% first point. 1.0f = 100% of second point.
360 void SetTwoPointVelocityBias(float value);
363 * @brief Sets the two point acceleration bias. This is the ratio of first and second points to use for acceleration.
365 * @param[in] value 0.0f = 100% first point. 1.0f = 100% of second point.
367 void SetTwoPointAccelerationBias(float value);
370 * @brief Sets the range of time (ms) of points in the history to perform multitap smoothing with (if enabled).
372 * @param[in] value Time in past in ms
374 void SetMultitapSmoothingRange(int value);
377 * Called to provide pan-gesture profiling information.
379 void EnableProfiling();
382 * Reset default properties, custom ones not supported due to this being the only object in scene side
383 * @param updateBufferIndex index to use
385 void ResetDefaultProperties(BufferIndex updateBufferIndex);
389 * Protected constructor.
394 PanGesture(const PanGesture&);
397 // Struct to keep pairs of local and screen data together.
398 // TODO: This can encapsulate some functionality also.
399 using RelativeVectors = struct
408 * Houses new code to process input events and generate an output point.
410 * @param[in] lastVSyncTime The time of the last render (in milliseconds)
411 * @param[in] nextVSyncTime The estimated time of the next render (in milliseconds)
413 bool NewAlgorithm(unsigned int lastVSyncTime, unsigned int nextVSyncTime);
416 * Gets the (absolute) time difference between two times.
417 * This is limited by minimumDelta, so it can be safe to use as a divisor.
418 * This function is wrapped so that the behviour can be overridden to return a "perfect" time difference (overrideDifference).
420 * @param[in] timeA The first time to calculate from
421 * @param[in] timeB The second time to calculate from
422 * @param[in] minimumDelta The smallest amount the difference can become
423 * @param[in] overrideDifference The time difference to return if using perfect times
425 inline float GetDivisibleTimeDifference(int timeA, int timeB, float minimumDelta, float overrideDifference);
428 * This limits the change currentAcceleration can have over lastAcceleration by the specified changeLimit value.
430 * @param[in] currentAcceleration The acceleration to modify
431 * @param[in] lastAcceleration The acceleration to limit against
432 * @param[in] changeLimit The maximum change (in either direction)
434 void LimitAccelerationChange(RelativeVectors& currentAcceleration, RelativeVectors& lastAcceleration, float changeLimit);
437 * Reads all events received this frame into a linear buffer.
438 * A lock is held while this is done.
440 unsigned int ReadFrameEvents();
443 * Converts between input rate and internal rate (typically 60Hz internally).
444 * Also writes to the pan history container.
445 * TODO: Does not need to return the gesture if it is in the history also, but currently it's used.
446 * (if rate conversion does not generate a point there are points still in history, but this can been done with a bool property).
448 * @param[out] rateConvertedGesture Result gesture for this frame is writen here.
449 * @param[in] eventsThisFrame Number of events to convert
450 * @param[in] currentFrameTime Time of the frame we will render to
451 * @param[in] lastFrameTime Time of the last rendered frame
452 * @param[out] justStarted Set to true if we are now starting a new gesture
453 * @param[out] justFinished Set to true if we are now finishing a gesture
455 bool InputRateConversion(PanInfo& rateConvertedGesture, unsigned int eventsThisFrame, unsigned int currentFrameTime, unsigned int lastFrameTime, bool& justStarted, bool& justFinished);
458 * Generates an interpolated point at the specified point in time.
460 * @param[in] history of points to use
461 * @param[in] currentTime Time of the frame we will render to
462 * @param[in] targetTime Time of the point to generate
463 * @param[in] range Range of time (each side of target time) to use points from
464 * @param[out] outPoint Generated point
465 * @param[out] acceleration Generated acceleration
466 * @param[in] outputTimeGranularity Time difference between output point (typically 60Hz)
467 * @param[in] eraseUnused Set to true to clean up any history not used by the function
469 bool InterpolatePoint(PanInfoHistory& history, unsigned int currentTime, unsigned int targetTime, unsigned int range, PanInfo& outPoint, RelativeVectors& acceleration, int outputTimeGranularity, bool eraseUnused);
472 * Predicts a point in the future, based on the supplied point and acceleration.
473 * Other user configuration settings are considered.
475 * @param[in] startPoint Starting point to use. Position and velocity are taken from here.
476 * @param[in] accelerationToUse The acceleration to use.
477 * @param[out] predictedPoint Generated predicted point
478 * @param[in] currentFrameTime Time of the frame we will render to
479 * @param[in] previousFrameTime Time of the last rendered frame
480 * @param[in] noPreviousData Set to true if we are just starting a gesture
482 void PredictionMode2(PanInfo& startPoint, RelativeVectors& accelerationToUse, PanInfo& predictedPoint, unsigned int currentFrameTime, unsigned int previousFrameTime, bool noPreviousData);
486 PanGesture& operator=(const PanGesture&);
488 // Defines information to be gathered by the gesture reading code.
489 struct FrameGestureInfo
491 PanGesture::PanInfo frameGesture;
493 unsigned int eventsThisFrame;
498 : acceleration(0.0f),
507 * Reads gestures from input, builds history.
508 * @param[out] info Written to with information about gestures read this frame.
509 * @param[in] currentTimestamp The time of this frame.
511 bool ReadGestures(FrameGestureInfo& info, unsigned int currentTimestamp);
514 * Reads gestures from input and resamples data, builds history.
515 * @param[out] info Written to with information about gestures read this frame.
516 * @param[in] currentTimestamp The time of this frame.
518 bool ReadAndResampleGestures(FrameGestureInfo& info, unsigned int currentTimestamp);
522 GesturePropertyBool mPanning; ///< panning flag
523 GesturePropertyVector2 mScreenPosition; ///< screenPosition
524 GesturePropertyVector2 mScreenDisplacement; ///< screenDisplacement
525 GesturePropertyVector2 mScreenVelocity; ///< screenVelocity
526 GesturePropertyVector2 mLocalPosition; ///< localPosition
527 GesturePropertyVector2 mLocalDisplacement; ///< localDisplacement
528 GesturePropertyVector2 mLocalVelocity; ///< localVelocity
530 PanInfoHistory mPanHistory;
531 PanInfoHistory mPredictionHistory;
532 PanInfo mGestures[PAN_GESTURE_HISTORY]; ///< Circular buffer storing the 4 most recent gestures.
533 PanInfo mReadGestures[PAN_GESTURE_HISTORY]; ///< Linear buffer storing the most recent gestures (to reduce read lock time).
534 PanInfo mLastGesture; ///< The last gesture. (last update frame).
535 PanInfo mTargetGesture; ///< The most recent input gesture, if the current used gesture does not match.
536 PanInfo mLastUnmodifiedGesture; ///< The last gesture before any processing was done on it.
537 PanInfo mLastSecondInterpolatedPoint; ///< Stores the last second interpolated point we generated.
538 PanInfo mLastFrameReadGesture; ///< Stores the last gesture read.
539 PanInfo mLastPredictedPoint; ///< Stores the last predicted point we generated.
540 RelativeVectors mLastAcceleration; ///< Stores the acceleration value from the acceleration limiting last frame.
541 RelativeVectors mLastInterpolatedAcceleration; ///< Stores the second interpolated point acceleration value from the last frame.
542 RelativeVectors mLastInitialAcceleration; ///< Stores the initial acceleration value from the last frame.
544 volatile unsigned int mWritePosition; ///< The next PanInfo buffer to write to. (starts at 0).
545 unsigned int mReadPosition; ///< The next PanInfo buffer to read. (starts at 0).
546 bool mNotAtTarget; ///< Keeps track of if the last gesture used was the most recent received.
547 bool mInGesture; ///< True if the gesture is currently being handled i.e. between STARTED <-> FINISHED/CANCELLED.
548 bool mPredictionAmountOverridden;
549 bool mSmoothingAmountOverridden;
551 PanGestureProfiling* mProfiling; ///< NULL unless pan-gesture profiling information is required.
552 Dali::Mutex mMutex; ///< Mutex to lock access.
554 // Environment variables:
556 PredictionMode mPredictionMode; ///< The pan gesture prediction mode
557 unsigned int mPredictionAmount; ///< how far into future to predict in milliseconds
558 unsigned int mCurrentPredictionAmount; ///< the current prediction amount used by the prediction algorithm
559 unsigned int mMaxPredictionAmount; ///< the maximum prediction amount used by the prediction algorithm
560 unsigned int mMinPredictionAmount; ///< the minimum prediction amount used by the prediction algorithm
561 unsigned int mPredictionAmountAdjustment; ///< the prediction amount to adjust in milliseconds when pan velocity changes
562 SmoothingMode mSmoothingMode; ///< The pan gesture prediction mode
563 float mSmoothingAmount; ///< How much smoothing to apply [0.0f,1.0f]
564 bool mUseActualTimes; ///< Disable to optionally override actual times if they make results worse.
565 int mInterpolationTimeRange; ///< Time into past history (ms) to use points to interpolate the first point.
566 bool mScalarOnlyPredictionEnabled; ///< If enabled, prediction is done using velocity alone (no integration or acceleration).
567 bool mTwoPointPredictionEnabled; ///< If enabled, a second interpolated point is predicted and combined with the first to get more stable values.
568 int mTwoPointPastInterpolateTime; ///< The target time in the past to generate the second interpolated point.
569 float mTwoPointVelocityBias; ///< The ratio of first and second interpolated points to use for velocity. 0.0f = 100% of first point. 1.0f = 100% of second point.
570 float mTwoPointAccelerationBias; ///< The ratio of first and second interpolated points to use for acceleration. 0.0f = 100% of first point. 1.0f = 100% of second point.
571 int mMultiTapSmoothingRange; ///< The range in time (ms) of points in the history to smooth the final output against.
574 } // namespace SceneGraph
576 } // namespace Internal
580 #endif // DALI_INTERNAL_SCENE_GRAPH_PAN_GESTURE_H