Refactor proximity info

Change-Id: I668e6abfe202e1a56d59b6b6e58d1b4f003b720a

1 files changed, 484 insertions, 0 deletions

diff --git a/native/jni/src/proximity_info_state_utils.cpp b/native/jni/src/proximity_info_state_utils.cpp
new file mode 100644
index 000000000..146ce0545
--- /dev/null
+++ b/native/jni/src/proximity_info_state_utils.cpp
@@ -0,0 +1,484 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#include <vector>
+
+#include "geometry_utils.h"
+#include "proximity_info.h"
+#include "proximity_info_params.h"
+#include "proximity_info_state_utils.h"
+
+namespace latinime {
+/* static */ int ProximityInfoStateUtils::updateTouchPoints(const int mostCommonKeyWidth,
+        const ProximityInfo *const proximityInfo, const int maxPointToKeyLength,
+        const int *const inputProximities,
+        const int *const inputXCoordinates, const int *const inputYCoordinates,
+        const int *const times, const int *const pointerIds, const int inputSize,
+        const bool isGeometric, const int pointerId, const int pushTouchPointStartIndex,
+        std::vector<int> *sampledInputXs, std::vector<int> *sampledInputYs,
+        std::vector<int> *sampledInputTimes, std::vector<int> *sampledLengthCache,
+        std::vector<int> *sampledInputIndice) {
+    if (DEBUG_SAMPLING_POINTS) {
+        if (times) {
+            for (int i = 0; i < inputSize; ++i) {
+                AKLOGI("(%d) x %d, y %d, time %d",
+                        i, xCoordinates[i], yCoordinates[i], times[i]);
+            }
+        }
+    }
+#ifdef DO_ASSERT_TEST
+    if (times) {
+        for (int i = 0; i < inputSize; ++i) {
+            if (i > 0) {
+                ASSERT(times[i] >= times[i - 1]);
+            }
+        }
+    }
+#endif
+    const bool proximityOnly = !isGeometric
+            && (inputXCoordinates[0] < 0 || inputYCoordinates[0] < 0);
+    int lastInputIndex = pushTouchPointStartIndex;
+    for (int i = lastInputIndex; i < inputSize; ++i) {
+        const int pid = pointerIds ? pointerIds[i] : 0;
+        if (pointerId == pid) {
+            lastInputIndex = i;
+        }
+    }
+    if (DEBUG_GEO_FULL) {
+        AKLOGI("Init ProximityInfoState: last input index = %d", lastInputIndex);
+    }
+    // Working space to save near keys distances for current, prev and prevprev input point.
+    NearKeysDistanceMap nearKeysDistances[3];
+    // These pointers are swapped for each inputs points.
+    NearKeysDistanceMap *currentNearKeysDistances = &nearKeysDistances[0];
+    NearKeysDistanceMap *prevNearKeysDistances = &nearKeysDistances[1];
+    NearKeysDistanceMap *prevPrevNearKeysDistances = &nearKeysDistances[2];
+    // "sumAngle" is accumulated by each angle of input points. And when "sumAngle" exceeds
+    // the threshold we save that point, reset sumAngle. This aims to keep the figure of
+    // the curve.
+    float sumAngle = 0.0f;
+
+    for (int i = pushTouchPointStartIndex; i <= lastInputIndex; ++i) {
+        // Assuming pointerId == 0 if pointerIds is null.
+        const int pid = pointerIds ? pointerIds[i] : 0;
+        if (DEBUG_GEO_FULL) {
+            AKLOGI("Init ProximityInfoState: (%d)PID = %d", i, pid);
+        }
+        if (pointerId == pid) {
+            const int c = isGeometric ?
+                    NOT_A_COORDINATE : getPrimaryCodePointAt(inputProximities, i);
+            const int x = proximityOnly ? NOT_A_COORDINATE : inputXCoordinates[i];
+            const int y = proximityOnly ? NOT_A_COORDINATE : inputYCoordinates[i];
+            const int time = times ? times[i] : -1;
+
+            if (i > 1) {
+                const float prevAngle = getAngle(
+                        inputXCoordinates[i - 2], inputYCoordinates[i - 2],
+                        inputXCoordinates[i - 1], inputYCoordinates[i - 1]);
+                const float currentAngle =
+                        getAngle(inputXCoordinates[i - 1], inputYCoordinates[i - 1], x, y);
+                sumAngle += getAngleDiff(prevAngle, currentAngle);
+            }
+
+            if (pushTouchPoint(mostCommonKeyWidth, proximityInfo, maxPointToKeyLength,
+                    i, c, x, y, time, isGeometric /* do sampling */,
+                    i == lastInputIndex, sumAngle, currentNearKeysDistances,
+                    prevNearKeysDistances, prevPrevNearKeysDistances,
+                    sampledInputXs, sampledInputYs, sampledInputTimes, sampledLengthCache,
+                    sampledInputIndice)) {
+                // Previous point information was popped.
+                NearKeysDistanceMap *tmp = prevNearKeysDistances;
+                prevNearKeysDistances = currentNearKeysDistances;
+                currentNearKeysDistances = tmp;
+            } else {
+                NearKeysDistanceMap *tmp = prevPrevNearKeysDistances;
+                prevPrevNearKeysDistances = prevNearKeysDistances;
+                prevNearKeysDistances = currentNearKeysDistances;
+                currentNearKeysDistances = tmp;
+                sumAngle = 0.0f;
+            }
+        }
+    }
+    return sampledInputXs->size();
+}
+
+/* static */ const int *ProximityInfoStateUtils::getProximityCodePointsAt(
+        const int *const inputProximities, const int index) {
+    return inputProximities + (index * MAX_PROXIMITY_CHARS_SIZE_INTERNAL);
+}
+
+/* static */ int ProximityInfoStateUtils::getPrimaryCodePointAt(
+        const int *const inputProximities, const int index) {
+    return getProximityCodePointsAt(inputProximities, index)[0];
+}
+
+/* static */ void ProximityInfoStateUtils::popInputData(std::vector<int> *sampledInputXs,
+        std::vector<int> *sampledInputYs, std::vector<int> *sampledInputTimes,
+        std::vector<int> *sampledLengthCache, std::vector<int> *sampledInputIndice) {
+    sampledInputXs->pop_back();
+    sampledInputYs->pop_back();
+    sampledInputTimes->pop_back();
+    sampledLengthCache->pop_back();
+    sampledInputIndice->pop_back();
+}
+
+/* static */ float ProximityInfoStateUtils::refreshSpeedRates(const int inputSize,
+        const int *const xCoordinates, const int *const yCoordinates, const int *const times,
+        const int lastSavedInputSize, const int sampledInputSize,
+        const std::vector<int> *const sampledInputXs,
+        const std::vector<int> *const sampledInputYs,
+        const std::vector<int> *const sampledInputTimes,
+        const std::vector<int> *const sampledLengthCache,
+        const std::vector<int> *const sampledInputIndice, std::vector<float> *sampledSpeedRates,
+        std::vector<float> *sampledDirections) {
+    // Relative speed calculation.
+    const int sumDuration = sampledInputTimes->back() - sampledInputTimes->front();
+    const int sumLength = sampledLengthCache->back() - sampledLengthCache->front();
+    const float averageSpeed = static_cast<float>(sumLength) / static_cast<float>(sumDuration);
+    sampledSpeedRates->resize(sampledInputSize);
+    for (int i = lastSavedInputSize; i < sampledInputSize; ++i) {
+        const int index = (*sampledInputIndice)[i];
+        int length = 0;
+        int duration = 0;
+
+        // Calculate velocity by using distances and durations of
+        // NUM_POINTS_FOR_SPEED_CALCULATION points for both forward and backward.
+        static const int NUM_POINTS_FOR_SPEED_CALCULATION = 2;
+        for (int j = index; j < min(inputSize - 1, index + NUM_POINTS_FOR_SPEED_CALCULATION);
+                ++j) {
+            if (i < sampledInputSize - 1 && j >= (*sampledInputIndice)[i + 1]) {
+                break;
+            }
+            length += getDistanceInt(xCoordinates[j], yCoordinates[j],
+                    xCoordinates[j + 1], yCoordinates[j + 1]);
+            duration += times[j + 1] - times[j];
+        }
+        for (int j = index - 1; j >= max(0, index - NUM_POINTS_FOR_SPEED_CALCULATION); --j) {
+            if (i > 0 && j < (*sampledInputIndice)[i - 1]) {
+                break;
+            }
+            // TODO: use mLengthCache instead?
+            length += getDistanceInt(xCoordinates[j], yCoordinates[j],
+                    xCoordinates[j + 1], yCoordinates[j + 1]);
+            duration += times[j + 1] - times[j];
+        }
+        if (duration == 0 || sumDuration == 0) {
+            // Cannot calculate speed; thus, it gives an average value (1.0);
+            (*sampledSpeedRates)[i] = 1.0f;
+        } else {
+            const float speed = static_cast<float>(length) / static_cast<float>(duration);
+            (*sampledSpeedRates)[i] = speed / averageSpeed;
+        }
+    }
+
+    // Direction calculation.
+    sampledDirections->resize(sampledInputSize - 1);
+    for (int i = max(0, lastSavedInputSize - 1); i < sampledInputSize - 1; ++i) {
+        (*sampledDirections)[i] = getDirection(sampledInputXs, sampledInputYs, i, i + 1);
+    }
+    return averageSpeed;
+}
+
+/* static */ void ProximityInfoStateUtils::refreshBeelineSpeedRates(const int mostCommonKeyWidth,
+        const float averageSpeed, const int inputSize, const int *const xCoordinates,
+        const int *const yCoordinates, const int *times, const int sampledInputSize,
+        const std::vector<int> *const sampledInputXs,
+        const std::vector<int> *const sampledInputYs, const std::vector<int> *const inputIndice,
+        std::vector<int> *beelineSpeedPercentiles) {
+    if (DEBUG_SAMPLING_POINTS) {
+        AKLOGI("--- refresh beeline speed rates");
+    }
+    beelineSpeedPercentiles->resize(sampledInputSize);
+    for (int i = 0; i < sampledInputSize; ++i) {
+        (*beelineSpeedPercentiles)[i] = static_cast<int>(calculateBeelineSpeedRate(
+                mostCommonKeyWidth, averageSpeed, i, inputSize, xCoordinates, yCoordinates, times,
+                sampledInputSize, sampledInputXs, sampledInputYs, inputIndice) * MAX_PERCENTILE);
+    }
+}
+
+/* static */float ProximityInfoStateUtils::getDirection(
+        const std::vector<int> *const sampledInputXs,
+        const std::vector<int> *const sampledInputYs, const int index0, const int index1) {
+    ASSERT(sampledInputXs && sampledInputYs);
+    const int sampledInputSize =sampledInputXs->size();
+    if (index0 < 0 || index0 > sampledInputSize - 1) {
+        return 0.0f;
+    }
+    if (index1 < 0 || index1 > sampledInputSize - 1) {
+        return 0.0f;
+    }
+    const int x1 = (*sampledInputXs)[index0];
+    const int y1 = (*sampledInputYs)[index0];
+    const int x2 = (*sampledInputXs)[index1];
+    const int y2 = (*sampledInputYs)[index1];
+    return getAngle(x1, y1, x2, y2);
+}
+
+// Calculating point to key distance for all near keys and returning the distance between
+// the given point and the nearest key position.
+/* static */ float ProximityInfoStateUtils::updateNearKeysDistances(
+        const ProximityInfo *const proximityInfo, const float maxPointToKeyLength, const int x,
+        const int y, NearKeysDistanceMap *const currentNearKeysDistances) {
+    static const float NEAR_KEY_THRESHOLD = 2.0f;
+
+    currentNearKeysDistances->clear();
+    const int keyCount = proximityInfo->getKeyCount();
+    float nearestKeyDistance = maxPointToKeyLength;
+    for (int k = 0; k < keyCount; ++k) {
+        const float dist = proximityInfo->getNormalizedSquaredDistanceFromCenterFloatG(k, x, y);
+        if (dist < NEAR_KEY_THRESHOLD) {
+            currentNearKeysDistances->insert(std::pair<int, float>(k, dist));
+        }
+        if (nearestKeyDistance > dist) {
+            nearestKeyDistance = dist;
+        }
+    }
+    return nearestKeyDistance;
+}
+
+// Check if previous point is at local minimum position to near keys.
+/* static */ bool ProximityInfoStateUtils::isPrevLocalMin(
+        const NearKeysDistanceMap *const currentNearKeysDistances,
+        const NearKeysDistanceMap *const prevNearKeysDistances,
+        const NearKeysDistanceMap *const prevPrevNearKeysDistances) {
+    static const float MARGIN = 0.01f;
+
+    for (NearKeysDistanceMap::const_iterator it = prevNearKeysDistances->begin();
+            it != prevNearKeysDistances->end(); ++it) {
+        NearKeysDistanceMap::const_iterator itPP = prevPrevNearKeysDistances->find(it->first);
+        NearKeysDistanceMap::const_iterator itC = currentNearKeysDistances->find(it->first);
+        if ((itPP == prevPrevNearKeysDistances->end() || itPP->second > it->second + MARGIN)
+                && (itC == currentNearKeysDistances->end() || itC->second > it->second + MARGIN)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+// Calculating a point score that indicates usefulness of the point.
+/* static */ float ProximityInfoStateUtils::getPointScore(const int mostCommonKeyWidth,
+        const int x, const int y, const int time, const bool lastPoint, const float nearest,
+        const float sumAngle, const NearKeysDistanceMap *const currentNearKeysDistances,
+        const NearKeysDistanceMap *const prevNearKeysDistances,
+        const NearKeysDistanceMap *const prevPrevNearKeysDistances,
+        std::vector<int> *sampledInputXs, std::vector<int> *sampledInputYs) {
+    static const int DISTANCE_BASE_SCALE = 100;
+    static const float NEAR_KEY_THRESHOLD = 0.6f;
+    static const int CORNER_CHECK_DISTANCE_THRESHOLD_SCALE = 25;
+    static const float NOT_LOCALMIN_DISTANCE_SCORE = -1.0f;
+    static const float LOCALMIN_DISTANCE_AND_NEAR_TO_KEY_SCORE = 1.0f;
+    static const float CORNER_ANGLE_THRESHOLD = M_PI_F * 2.0f / 3.0f;
+    static const float CORNER_SUM_ANGLE_THRESHOLD = M_PI_F / 4.0f;
+    static const float CORNER_SCORE = 1.0f;
+
+    const size_t size = sampledInputXs->size();
+    // If there is only one point, add this point. Besides, if the previous point's distance map
+    // is empty, we re-compute nearby keys distances from the current point.
+    // Note that the current point is the first point in the incremental input that needs to
+    // be re-computed.
+    if (size <= 1 || prevNearKeysDistances->empty()) {
+        return 0.0f;
+    }
+
+    const int baseSampleRate = mostCommonKeyWidth;
+    const int distPrev = getDistanceInt(sampledInputXs->back(), sampledInputYs->back(),
+            (*sampledInputXs)[size - 2], (*sampledInputYs)[size - 2]) * DISTANCE_BASE_SCALE;
+    float score = 0.0f;
+
+    // Location
+    if (!isPrevLocalMin(currentNearKeysDistances, prevNearKeysDistances,
+        prevPrevNearKeysDistances)) {
+        score += NOT_LOCALMIN_DISTANCE_SCORE;
+    } else if (nearest < NEAR_KEY_THRESHOLD) {
+        // Promote points nearby keys
+        score += LOCALMIN_DISTANCE_AND_NEAR_TO_KEY_SCORE;
+    }
+    // Angle
+    const float angle1 = getAngle(x, y, sampledInputXs->back(), sampledInputYs->back());
+    const float angle2 = getAngle(sampledInputXs->back(), sampledInputYs->back(),
+            (*sampledInputXs)[size - 2], (*sampledInputYs)[size - 2]);
+    const float angleDiff = getAngleDiff(angle1, angle2);
+
+    // Save corner
+    if (distPrev > baseSampleRate * CORNER_CHECK_DISTANCE_THRESHOLD_SCALE
+            && (sumAngle > CORNER_SUM_ANGLE_THRESHOLD || angleDiff > CORNER_ANGLE_THRESHOLD)) {
+        score += CORNER_SCORE;
+    }
+    return score;
+}
+
+// Sampling touch point and pushing information to vectors.
+// Returning if previous point is popped or not.
+/* static */ bool ProximityInfoStateUtils::pushTouchPoint(const int mostCommonKeyWidth,
+        const ProximityInfo *const proximityInfo, const int maxPointToKeyLength,
+        const int inputIndex, const int nodeCodePoint, int x, int y,
+        const int time, const bool sample, const bool isLastPoint, const float sumAngle,
+        NearKeysDistanceMap *const currentNearKeysDistances,
+        const NearKeysDistanceMap *const prevNearKeysDistances,
+        const NearKeysDistanceMap *const prevPrevNearKeysDistances,
+        std::vector<int> *sampledInputXs, std::vector<int> *sampledInputYs,
+        std::vector<int> *sampledInputTimes, std::vector<int> *sampledLengthCache,
+        std::vector<int> *sampledInputIndice) {
+    static const int LAST_POINT_SKIP_DISTANCE_SCALE = 4;
+
+    size_t size = sampledInputXs->size();
+    bool popped = false;
+    if (nodeCodePoint < 0 && sample) {
+        const float nearest = updateNearKeysDistances(
+                proximityInfo, maxPointToKeyLength, x, y, currentNearKeysDistances);
+        const float score = getPointScore(mostCommonKeyWidth, x, y, time, isLastPoint, nearest,
+                sumAngle, currentNearKeysDistances, prevNearKeysDistances,
+                prevPrevNearKeysDistances, sampledInputXs, sampledInputYs);
+        if (score < 0) {
+            // Pop previous point because it would be useless.
+            popInputData(sampledInputXs, sampledInputYs, sampledInputTimes, sampledLengthCache,
+                    sampledInputIndice);
+            size = sampledInputXs->size();
+            popped = true;
+        } else {
+            popped = false;
+        }
+        // Check if the last point should be skipped.
+        if (isLastPoint && size > 0) {
+            if (getDistanceInt(x, y, sampledInputXs->back(),
+                    sampledInputYs->back()) * LAST_POINT_SKIP_DISTANCE_SCALE
+                            < mostCommonKeyWidth) {
+                // This point is not used because it's too close to the previous point.
+                if (DEBUG_GEO_FULL) {
+                    AKLOGI("p0: size = %zd, x = %d, y = %d, lx = %d, ly = %d, dist = %d, "
+                           "width = %d", size, x, y, mSampledInputXs.back(),
+                           mSampledInputYs.back(), ProximityInfoUtils::getDistanceInt(
+                                   x, y, mSampledInputXs.back(), mSampledInputYs.back()),
+                           mProximityInfo->getMostCommonKeyWidth()
+                                   / LAST_POINT_SKIP_DISTANCE_SCALE);
+                }
+                return popped;
+            }
+        }
+    }
+
+    if (nodeCodePoint >= 0 && (x < 0 || y < 0)) {
+        const int keyId = proximityInfo->getKeyIndexOf(nodeCodePoint);
+        if (keyId >= 0) {
+            x = proximityInfo->getKeyCenterXOfKeyIdG(keyId);
+            y = proximityInfo->getKeyCenterYOfKeyIdG(keyId);
+        }
+    }
+
+    // Pushing point information.
+    if (size > 0) {
+        sampledLengthCache->push_back(
+                sampledLengthCache->back() + getDistanceInt(
+                        x, y, sampledInputXs->back(), sampledInputYs->back()));
+    } else {
+        sampledLengthCache->push_back(0);
+    }
+    sampledInputXs->push_back(x);
+    sampledInputYs->push_back(y);
+    sampledInputTimes->push_back(time);
+    sampledInputIndice->push_back(inputIndex);
+    if (DEBUG_GEO_FULL) {
+        AKLOGI("pushTouchPoint: x = %03d, y = %03d, time = %d, index = %d, popped ? %01d",
+                x, y, time, inputIndex, popped);
+    }
+    return popped;
+}
+
+/* static */ float ProximityInfoStateUtils::calculateBeelineSpeedRate(const int mostCommonKeyWidth,
+        const float averageSpeed, const int id, const int inputSize, const int *const xCoordinates,
+        const int *const yCoordinates, const int *times, const int sampledInputSize,
+        const std::vector<int> *const sampledInputXs,
+        const std::vector<int> *const sampledInputYs, const std::vector<int> *const inputIndice) {
+    if (sampledInputSize <= 0 || averageSpeed < 0.001f) {
+        if (DEBUG_SAMPLING_POINTS) {
+            AKLOGI("--- invalid state: cancel. size = %d, ave = %f",
+                    mSampledInputSize, mAverageSpeed);
+        }
+        return 1.0f;
+    }
+    const int lookupRadius = mostCommonKeyWidth
+            * ProximityInfoParams::LOOKUP_RADIUS_PERCENTILE / MAX_PERCENTILE;
+    const int x0 = (*sampledInputXs)[id];
+    const int y0 = (*sampledInputYs)[id];
+    const int actualInputIndex = (*inputIndice)[id];
+    int tempTime = 0;
+    int tempBeelineDistance = 0;
+    int start = actualInputIndex;
+    // lookup forward
+    while (start > 0 && tempBeelineDistance < lookupRadius) {
+        tempTime += times[start] - times[start - 1];
+        --start;
+        tempBeelineDistance = getDistanceInt(x0, y0, xCoordinates[start], yCoordinates[start]);
+    }
+    // Exclusive unless this is an edge point
+    if (start > 0 && start < actualInputIndex) {
+        ++start;
+    }
+    tempTime= 0;
+    tempBeelineDistance = 0;
+    int end = actualInputIndex;
+    // lookup backward
+    while (end < (inputSize - 1) && tempBeelineDistance < lookupRadius) {
+        tempTime += times[end + 1] - times[end];
+        ++end;
+        tempBeelineDistance = getDistanceInt(x0, y0, xCoordinates[end], yCoordinates[end]);
+    }
+    // Exclusive unless this is an edge point
+    if (end > actualInputIndex && end < (inputSize - 1)) {
+        --end;
+    }
+
+    if (start >= end) {
+        if (DEBUG_DOUBLE_LETTER) {
+            AKLOGI("--- double letter: start == end %d", start);
+        }
+        return 1.0f;
+    }
+
+    const int x2 = xCoordinates[start];
+    const int y2 = yCoordinates[start];
+    const int x3 = xCoordinates[end];
+    const int y3 = yCoordinates[end];
+    const int beelineDistance = getDistanceInt(x2, y2, x3, y3);
+    int adjustedStartTime = times[start];
+    if (start == 0 && actualInputIndex == 0 && inputSize > 1) {
+        adjustedStartTime += ProximityInfoParams::FIRST_POINT_TIME_OFFSET_MILLIS;
+    }
+    int adjustedEndTime = times[end];
+    if (end == (inputSize - 1) && inputSize > 1) {
+        adjustedEndTime -= ProximityInfoParams::FIRST_POINT_TIME_OFFSET_MILLIS;
+    }
+    const int time = adjustedEndTime - adjustedStartTime;
+    if (time <= 0) {
+        return 1.0f;
+    }
+
+    if (time >= ProximityInfoParams::STRONG_DOUBLE_LETTER_TIME_MILLIS){
+        return 0.0f;
+    }
+    if (DEBUG_DOUBLE_LETTER) {
+        AKLOGI("--- (%d, %d) double letter: start = %d, end = %d, dist = %d, time = %d,"
+                " speed = %f, ave = %f, val = %f, start time = %d, end time = %d",
+                id, mInputIndice[id], start, end, beelineDistance, time,
+                (static_cast<float>(beelineDistance) / static_cast<float>(time)), mAverageSpeed,
+                ((static_cast<float>(beelineDistance) / static_cast<float>(time))
+                        / mAverageSpeed), adjustedStartTime, adjustedEndTime);
+    }
+    // Offset 1%
+    // TODO: Detect double letter more smartly
+    return 0.01f + static_cast<float>(beelineDistance) / static_cast<float>(time) / averageSpeed;
+}
+} // namespace latinime