Minor refactoring before starting on velocity tracker changes.

Bug: 6413587
Change-Id: I5eba2bb57193bff78cb3740de5f87aca0b31d154

Author: Jeff Brown

core/java/android/view/VelocityTracker.java

@@ -298,6 +298,24 @@ public float estimateY(float time) {
             return estimate(time, yCoeff);
         }
 
+        /**
+         * Gets the X coefficient with the specified index.
+         * @param index The index of the coefficient to return.
+         * @return The X coefficient, or 0 if the index is greater than the degree.
+         */
+        public float getXCoeff(int index) {
+            return index <= degree ? xCoeff[index] : 0;
+        }
+
+        /**
+         * Gets the Y coefficient with the specified index.
+         * @param index The index of the coefficient to return.
+         * @return The Y coefficient, or 0 if the index is greater than the degree.
+         */
+        public float getYCoeff(int index) {
+            return index <= degree ? yCoeff[index] : 0;
+        }
+
         private float estimate(float time, float[] c) {
             float a = 0;
             float scale = 1;

core/jni/android_view_VelocityTracker.cpp

@@ -21,6 +21,7 @@
 #include <android_runtime/AndroidRuntime.h>
 #include <utils/Log.h>
 #include <androidfw/Input.h>
+#include <androidfw/VelocityTracker.h>
 #include "android_view_MotionEvent.h"
 
 

include/androidfw/Input.h

@@ -27,7 +27,6 @@
 #include <utils/Timers.h>
 #include <utils/RefBase.h>
 #include <utils/String8.h>
-#include <utils/BitSet.h>
 
 #ifdef HAVE_ANDROID_OS
 class SkMatrix;
@@ -607,182 +606,6 @@ class PooledInputEventFactory : public InputEventFactoryInterface {
     Vector<MotionEvent*> mMotionEventPool;
 };
 
-/*
- * Calculates the velocity of pointer movements over time.
- */
-class VelocityTracker {
-public:
-    // Default polynomial degree.  (used by getVelocity)
-    static const uint32_t DEFAULT_DEGREE = 2;
-
-    // Default sample horizon.  (used by getVelocity)
-    // We don't use too much history by default since we want to react to quick
-    // changes in direction.
-    static const nsecs_t DEFAULT_HORIZON = 100 * 1000000; // 100 ms
-
-    struct Position {
-        float x, y;
-    };
-
-    struct Estimator {
-        static const size_t MAX_DEGREE = 2;
-
-        // Polynomial coefficients describing motion in X and Y.
-        float xCoeff[MAX_DEGREE + 1], yCoeff[MAX_DEGREE + 1];
-
-        // Polynomial degree (number of coefficients), or zero if no information is
-        // available.
-        uint32_t degree;
-
-        // Confidence (coefficient of determination), between 0 (no fit) and 1 (perfect fit).
-        float confidence;
-
-        inline void clear() {
-            degree = 0;
-            confidence = 0;
-            for (size_t i = 0; i <= MAX_DEGREE; i++) {
-                xCoeff[i] = 0;
-                yCoeff[i] = 0;
-            }
-        }
-    };
-
-    VelocityTracker();
-
-    // Resets the velocity tracker state.
-    void clear();
-
-    // Resets the velocity tracker state for specific pointers.
-    // Call this method when some pointers have changed and may be reusing
-    // an id that was assigned to a different pointer earlier.
-    void clearPointers(BitSet32 idBits);
-
-    // Adds movement information for a set of pointers.
-    // The idBits bitfield specifies the pointer ids of the pointers whose positions
-    // are included in the movement.
-    // The positions array contains position information for each pointer in order by
-    // increasing id.  Its size should be equal to the number of one bits in idBits.
-    void addMovement(nsecs_t eventTime, BitSet32 idBits, const Position* positions);
-
-    // Adds movement information for all pointers in a MotionEvent, including historical samples.
-    void addMovement(const MotionEvent* event);
-
-    // Gets the velocity of the specified pointer id in position units per second.
-    // Returns false and sets the velocity components to zero if there is
-    // insufficient movement information for the pointer.
-    bool getVelocity(uint32_t id, float* outVx, float* outVy) const;
-
-    // Gets a quadratic estimator for the movements of the specified pointer id.
-    // Returns false and clears the estimator if there is no information available
-    // about the pointer.
-    bool getEstimator(uint32_t id, uint32_t degree, nsecs_t horizon,
-            Estimator* outEstimator) const;
-
-    // Gets the active pointer id, or -1 if none.
-    inline int32_t getActivePointerId() const { return mActivePointerId; }
-
-    // Gets a bitset containing all pointer ids from the most recent movement.
-    inline BitSet32 getCurrentPointerIdBits() const { return mMovements[mIndex].idBits; }
-
-private:
-    // Number of samples to keep.
-    static const uint32_t HISTORY_SIZE = 20;
-
-    struct Movement {
-        nsecs_t eventTime;
-        BitSet32 idBits;
-        Position positions[MAX_POINTERS];
-
-        inline const Position& getPosition(uint32_t id) const {
-            return positions[idBits.getIndexOfBit(id)];
-        }
-    };
-
-    uint32_t mIndex;
-    Movement mMovements[HISTORY_SIZE];
-    int32_t mActivePointerId;
-};
-
-
-/*
- * Specifies parameters that govern pointer or wheel acceleration.
- */
-struct VelocityControlParameters {
-    // A scale factor that is multiplied with the raw velocity deltas
-    // prior to applying any other velocity control factors.  The scale
-    // factor should be used to adapt the input device resolution
-    // (eg. counts per inch) to the output device resolution (eg. pixels per inch).
-    //
-    // Must be a positive value.
-    // Default is 1.0 (no scaling).
-    float scale;
-
-    // The scaled speed at which acceleration begins to be applied.
-    // This value establishes the upper bound of a low speed regime for
-    // small precise motions that are performed without any acceleration.
-    //
-    // Must be a non-negative value.
-    // Default is 0.0 (no low threshold).
-    float lowThreshold;
-
-    // The scaled speed at which maximum acceleration is applied.
-    // The difference between highThreshold and lowThreshold controls
-    // the range of speeds over which the acceleration factor is interpolated.
-    // The wider the range, the smoother the acceleration.
-    //
-    // Must be a non-negative value greater than or equal to lowThreshold.
-    // Default is 0.0 (no high threshold).
-    float highThreshold;
-
-    // The acceleration factor.
-    // When the speed is above the low speed threshold, the velocity will scaled
-    // by an interpolated value between 1.0 and this amount.
-    //
-    // Must be a positive greater than or equal to 1.0.
-    // Default is 1.0 (no acceleration).
-    float acceleration;
-
-    VelocityControlParameters() :
-            scale(1.0f), lowThreshold(0.0f), highThreshold(0.0f), acceleration(1.0f) {
-    }
-
-    VelocityControlParameters(float scale, float lowThreshold,
-            float highThreshold, float acceleration) :
-            scale(scale), lowThreshold(lowThreshold),
-            highThreshold(highThreshold), acceleration(acceleration) {
-    }
-};
-
-/*
- * Implements mouse pointer and wheel speed control and acceleration.
- */
-class VelocityControl {
-public:
-    VelocityControl();
-
-    /* Sets the various parameters. */
-    void setParameters(const VelocityControlParameters& parameters);
-
-    /* Resets the current movement counters to zero.
-     * This has the effect of nullifying any acceleration. */
-    void reset();
-
-    /* Translates a raw movement delta into an appropriately
-     * scaled / accelerated delta based on the current velocity. */
-    void move(nsecs_t eventTime, float* deltaX, float* deltaY);
-
-private:
-    // If no movements are received within this amount of time,
-    // we assume the movement has stopped and reset the movement counters.
-    static const nsecs_t STOP_TIME = 500 * 1000000; // 500 ms
-
-    VelocityControlParameters mParameters;
-
-    nsecs_t mLastMovementTime;
-    VelocityTracker::Position mRawPosition;
-    VelocityTracker mVelocityTracker;
-};
-
 } // namespace android
 
 #endif // _ANDROIDFW_INPUT_H

include/androidfw/VelocityControl.h

@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _ANDROIDFW_VELOCITY_CONTROL_H
+#define _ANDROIDFW_VELOCITY_CONTROL_H
+
+#include <androidfw/Input.h>
+#include <androidfw/VelocityTracker.h>
+#include <utils/Timers.h>
+
+namespace android {
+
+/*
+ * Specifies parameters that govern pointer or wheel acceleration.
+ */
+struct VelocityControlParameters {
+    // A scale factor that is multiplied with the raw velocity deltas
+    // prior to applying any other velocity control factors.  The scale
+    // factor should be used to adapt the input device resolution
+    // (eg. counts per inch) to the output device resolution (eg. pixels per inch).
+    //
+    // Must be a positive value.
+    // Default is 1.0 (no scaling).
+    float scale;
+
+    // The scaled speed at which acceleration begins to be applied.
+    // This value establishes the upper bound of a low speed regime for
+    // small precise motions that are performed without any acceleration.
+    //
+    // Must be a non-negative value.
+    // Default is 0.0 (no low threshold).
+    float lowThreshold;
+
+    // The scaled speed at which maximum acceleration is applied.
+    // The difference between highThreshold and lowThreshold controls
+    // the range of speeds over which the acceleration factor is interpolated.
+    // The wider the range, the smoother the acceleration.
+    //
+    // Must be a non-negative value greater than or equal to lowThreshold.
+    // Default is 0.0 (no high threshold).
+    float highThreshold;
+
+    // The acceleration factor.
+    // When the speed is above the low speed threshold, the velocity will scaled
+    // by an interpolated value between 1.0 and this amount.
+    //
+    // Must be a positive greater than or equal to 1.0.
+    // Default is 1.0 (no acceleration).
+    float acceleration;
+
+    VelocityControlParameters() :
+            scale(1.0f), lowThreshold(0.0f), highThreshold(0.0f), acceleration(1.0f) {
+    }
+
+    VelocityControlParameters(float scale, float lowThreshold,
+            float highThreshold, float acceleration) :
+            scale(scale), lowThreshold(lowThreshold),
+            highThreshold(highThreshold), acceleration(acceleration) {
+    }
+};
+
+/*
+ * Implements mouse pointer and wheel speed control and acceleration.
+ */
+class VelocityControl {
+public:
+    VelocityControl();
+
+    /* Sets the various parameters. */
+    void setParameters(const VelocityControlParameters& parameters);
+
+    /* Resets the current movement counters to zero.
+     * This has the effect of nullifying any acceleration. */
+    void reset();
+
+    /* Translates a raw movement delta into an appropriately
+     * scaled / accelerated delta based on the current velocity. */
+    void move(nsecs_t eventTime, float* deltaX, float* deltaY);
+
+private:
+    // If no movements are received within this amount of time,
+    // we assume the movement has stopped and reset the movement counters.
+    static const nsecs_t STOP_TIME = 500 * 1000000; // 500 ms
+
+    VelocityControlParameters mParameters;
+
+    nsecs_t mLastMovementTime;
+    VelocityTracker::Position mRawPosition;
+    VelocityTracker mVelocityTracker;
+};
+
+} // namespace android
+
+#endif // _ANDROIDFW_VELOCITY_CONTROL_H