diff options
Diffstat (limited to 'native/jni/src/proximity_info_state.cpp')
| -rw-r--r-- | native/jni/src/proximity_info_state.cpp | 329 |
1 files changed, 7 insertions, 322 deletions
diff --git a/native/jni/src/proximity_info_state.cpp b/native/jni/src/proximity_info_state.cpp index 058a03187..45b72eb21 100644 --- a/native/jni/src/proximity_info_state.cpp +++ b/native/jni/src/proximity_info_state.cpp @@ -138,7 +138,11 @@ void ProximityInfoState::initInputParams(const int pointerId, const float maxPoi } if (isGeometric) { // updates probabilities of skipping or mapping each key for all points. - updateAlignPointProbabilities(lastSavedInputSize); + ProximityInfoStateUtils::updateAlignPointProbabilities( + mMaxPointToKeyLength, mProximityInfo->getMostCommonKeyWidth(), + keyCount, lastSavedInputSize, mSampledInputSize, &mSampledInputXs, + &mSampledInputYs, &mSpeedRates, &mLengthCache, &mDistanceCache_G, + &mNearKeysVector, &mCharProbabilities); static const float READ_FORWORD_LENGTH_SCALE = 0.95f; const int readForwordLength = static_cast<int>( @@ -307,16 +311,10 @@ float ProximityInfoState::getPointToKeyLength_G(const int inputIndex, const int } // TODO: Remove the "scale" parameter -// This function basically converts from a length to an edit distance. Accordingly, it's obviously -// wrong to compare with mMaxPointToKeyLength. float ProximityInfoState::getPointToKeyByIdLength( const int inputIndex, const int keyId, const float scale) const { - if (keyId != NOT_AN_INDEX) { - const int index = inputIndex * mProximityInfo->getKeyCount() + keyId; - return min(mDistanceCache_G[index] * scale, mMaxPointToKeyLength); - } - // If the char is not a key on the keyboard then return the max length. - return static_cast<float>(MAX_POINT_TO_KEY_LENGTH); + return ProximityInfoStateUtils::getPointToKeyByIdLength(mMaxPointToKeyLength, + &mDistanceCache_G, mProximityInfo->getKeyCount(), inputIndex, keyId, scale); } float ProximityInfoState::getPointToKeyByIdLength(const int inputIndex, const int keyId) const { @@ -442,32 +440,6 @@ float ProximityInfoState::getDirection(const int index0, const int index1) const &mSampledInputXs, &mSampledInputYs, index0, index1); } -float ProximityInfoState::getPointAngle(const int index) const { - if (index <= 0 || index >= mSampledInputSize - 1) { - return 0.0f; - } - const float previousDirection = getDirection(index - 1, index); - const float nextDirection = getDirection(index, index + 1); - const float directionDiff = getAngleDiff(previousDirection, nextDirection); - return directionDiff; -} - -float ProximityInfoState::getPointsAngle( - const int index0, const int index1, const int index2) const { - if (index0 < 0 || index0 > mSampledInputSize - 1) { - return 0.0f; - } - if (index1 < 0 || index1 > mSampledInputSize - 1) { - return 0.0f; - } - if (index2 < 0 || index2 > mSampledInputSize - 1) { - return 0.0f; - } - const float previousDirection = getDirection(index0, index1); - const float nextDirection = getDirection(index1, index2); - return getAngleDiff(previousDirection, nextDirection); -} - float ProximityInfoState::getLineToKeyDistance( const int from, const int to, const int keyId, const bool extend) const { if (from < 0 || from > mSampledInputSize - 1) { @@ -488,293 +460,6 @@ float ProximityInfoState::getLineToKeyDistance( keyX, keyY, x0, y0, x1, y1, extend); } -// Updates probabilities of aligning to some keys and skipping. -// Word suggestion should be based on this probabilities. -void ProximityInfoState::updateAlignPointProbabilities(const int start) { - static const float MIN_PROBABILITY = 0.000001f; - static const float MAX_SKIP_PROBABILITY = 0.95f; - static const float SKIP_FIRST_POINT_PROBABILITY = 0.01f; - static const float SKIP_LAST_POINT_PROBABILITY = 0.1f; - static const float MIN_SPEED_RATE_FOR_SKIP_PROBABILITY = 0.15f; - static const float SPEED_WEIGHT_FOR_SKIP_PROBABILITY = 0.9f; - static const float SLOW_STRAIGHT_WEIGHT_FOR_SKIP_PROBABILITY = 0.6f; - static const float NEAREST_DISTANCE_WEIGHT = 0.5f; - static const float NEAREST_DISTANCE_BIAS = 0.5f; - static const float NEAREST_DISTANCE_WEIGHT_FOR_LAST = 0.6f; - static const float NEAREST_DISTANCE_BIAS_FOR_LAST = 0.4f; - - static const float ANGLE_WEIGHT = 0.90f; - static const float DEEP_CORNER_ANGLE_THRESHOLD = M_PI_F * 60.0f / 180.0f; - static const float SKIP_DEEP_CORNER_PROBABILITY = 0.1f; - static const float CORNER_ANGLE_THRESHOLD = M_PI_F * 30.0f / 180.0f; - static const float STRAIGHT_ANGLE_THRESHOLD = M_PI_F * 15.0f / 180.0f; - static const float SKIP_CORNER_PROBABILITY = 0.4f; - static const float SPEED_MARGIN = 0.1f; - static const float CENTER_VALUE_OF_NORMALIZED_DISTRIBUTION = 0.0f; - - const int keyCount = mProximityInfo->getKeyCount(); - mCharProbabilities.resize(mSampledInputSize); - // Calculates probabilities of using a point as a correlated point with the character - // for each point. - for (int i = start; i < mSampledInputSize; ++i) { - mCharProbabilities[i].clear(); - // First, calculates skip probability. Starts form MIN_SKIP_PROBABILITY. - // Note that all values that are multiplied to this probability should be in [0.0, 1.0]; - float skipProbability = MAX_SKIP_PROBABILITY; - - const float currentAngle = getPointAngle(i); - const float speedRate = getSpeedRate(i); - - float nearestKeyDistance = static_cast<float>(MAX_POINT_TO_KEY_LENGTH); - for (int j = 0; j < keyCount; ++j) { - if (mNearKeysVector[i].test(j)) { - const float distance = getPointToKeyByIdLength(i, j); - if (distance < nearestKeyDistance) { - nearestKeyDistance = distance; - } - } - } - - if (i == 0) { - skipProbability *= min(1.0f, nearestKeyDistance * NEAREST_DISTANCE_WEIGHT - + NEAREST_DISTANCE_BIAS); - // Promote the first point - skipProbability *= SKIP_FIRST_POINT_PROBABILITY; - } else if (i == mSampledInputSize - 1) { - skipProbability *= min(1.0f, nearestKeyDistance * NEAREST_DISTANCE_WEIGHT_FOR_LAST - + NEAREST_DISTANCE_BIAS_FOR_LAST); - // Promote the last point - skipProbability *= SKIP_LAST_POINT_PROBABILITY; - } else { - // If the current speed is relatively slower than adjacent keys, we promote this point. - if (getSpeedRate(i - 1) - SPEED_MARGIN > speedRate - && speedRate < getSpeedRate(i + 1) - SPEED_MARGIN) { - if (currentAngle < CORNER_ANGLE_THRESHOLD) { - skipProbability *= min(1.0f, speedRate - * SLOW_STRAIGHT_WEIGHT_FOR_SKIP_PROBABILITY); - } else { - // If the angle is small enough, we promote this point more. (e.g. pit vs put) - skipProbability *= min(1.0f, speedRate * SPEED_WEIGHT_FOR_SKIP_PROBABILITY - + MIN_SPEED_RATE_FOR_SKIP_PROBABILITY); - } - } - - skipProbability *= min(1.0f, speedRate * nearestKeyDistance * - NEAREST_DISTANCE_WEIGHT + NEAREST_DISTANCE_BIAS); - - // Adjusts skip probability by a rate depending on angle. - // ANGLE_RATE of skipProbability is adjusted by current angle. - skipProbability *= (M_PI_F - currentAngle) / M_PI_F * ANGLE_WEIGHT - + (1.0f - ANGLE_WEIGHT); - if (currentAngle > DEEP_CORNER_ANGLE_THRESHOLD) { - skipProbability *= SKIP_DEEP_CORNER_PROBABILITY; - } - // We assume the angle of this point is the angle for point[i], point[i - 2] - // and point[i - 3]. The reason why we don't use the angle for point[i], point[i - 1] - // and point[i - 2] is this angle can be more affected by the noise. - const float prevAngle = getPointsAngle(i, i - 2, i - 3); - if (i >= 3 && prevAngle < STRAIGHT_ANGLE_THRESHOLD - && currentAngle > CORNER_ANGLE_THRESHOLD) { - skipProbability *= SKIP_CORNER_PROBABILITY; - } - } - - // probabilities must be in [0.0, MAX_SKIP_PROBABILITY]; - ASSERT(skipProbability >= 0.0f); - ASSERT(skipProbability <= MAX_SKIP_PROBABILITY); - mCharProbabilities[i][NOT_AN_INDEX] = skipProbability; - - // Second, calculates key probabilities by dividing the rest probability - // (1.0f - skipProbability). - const float inputCharProbability = 1.0f - skipProbability; - - // TODO: The variance is critical for accuracy; thus, adjusting these parameter by machine - // learning or something would be efficient. - static const float SPEEDxANGLE_WEIGHT_FOR_STANDARD_DIVIATION = 0.3f; - static const float MAX_SPEEDxANGLE_RATE_FOR_STANDERD_DIVIATION = 0.25f; - static const float SPEEDxNEAREST_WEIGHT_FOR_STANDARD_DIVIATION = 0.5f; - static const float MAX_SPEEDxNEAREST_RATE_FOR_STANDERD_DIVIATION = 0.15f; - static const float MIN_STANDERD_DIVIATION = 0.37f; - - const float speedxAngleRate = min(speedRate * currentAngle / M_PI_F - * SPEEDxANGLE_WEIGHT_FOR_STANDARD_DIVIATION, - MAX_SPEEDxANGLE_RATE_FOR_STANDERD_DIVIATION); - const float speedxNearestKeyDistanceRate = min(speedRate * nearestKeyDistance - * SPEEDxNEAREST_WEIGHT_FOR_STANDARD_DIVIATION, - MAX_SPEEDxNEAREST_RATE_FOR_STANDERD_DIVIATION); - const float sigma = speedxAngleRate + speedxNearestKeyDistanceRate + MIN_STANDERD_DIVIATION; - - ProximityInfoUtils::NormalDistribution - distribution(CENTER_VALUE_OF_NORMALIZED_DISTRIBUTION, sigma); - static const float PREV_DISTANCE_WEIGHT = 0.5f; - static const float NEXT_DISTANCE_WEIGHT = 0.6f; - // Summing up probability densities of all near keys. - float sumOfProbabilityDensities = 0.0f; - for (int j = 0; j < keyCount; ++j) { - if (mNearKeysVector[i].test(j)) { - float distance = sqrtf(getPointToKeyByIdLength(i, j)); - if (i == 0 && i != mSampledInputSize - 1) { - // For the first point, weighted average of distances from first point and the - // next point to the key is used as a point to key distance. - const float nextDistance = sqrtf(getPointToKeyByIdLength(i + 1, j)); - if (nextDistance < distance) { - // The distance of the first point tends to bigger than continuing - // points because the first touch by the user can be sloppy. - // So we promote the first point if the distance of that point is larger - // than the distance of the next point. - distance = (distance + nextDistance * NEXT_DISTANCE_WEIGHT) - / (1.0f + NEXT_DISTANCE_WEIGHT); - } - } else if (i != 0 && i == mSampledInputSize - 1) { - // For the first point, weighted average of distances from last point and - // the previous point to the key is used as a point to key distance. - const float previousDistance = sqrtf(getPointToKeyByIdLength(i - 1, j)); - if (previousDistance < distance) { - // The distance of the last point tends to bigger than continuing points - // because the last touch by the user can be sloppy. So we promote the - // last point if the distance of that point is larger than the distance of - // the previous point. - distance = (distance + previousDistance * PREV_DISTANCE_WEIGHT) - / (1.0f + PREV_DISTANCE_WEIGHT); - } - } - // TODO: Promote the first point when the extended line from the next input is near - // from a key. Also, promote the last point as well. - sumOfProbabilityDensities += distribution.getProbabilityDensity(distance); - } - } - - // Split the probability of an input point to keys that are close to the input point. - for (int j = 0; j < keyCount; ++j) { - if (mNearKeysVector[i].test(j)) { - float distance = sqrtf(getPointToKeyByIdLength(i, j)); - if (i == 0 && i != mSampledInputSize - 1) { - // For the first point, weighted average of distances from the first point and - // the next point to the key is used as a point to key distance. - const float prevDistance = sqrtf(getPointToKeyByIdLength(i + 1, j)); - if (prevDistance < distance) { - distance = (distance + prevDistance * NEXT_DISTANCE_WEIGHT) - / (1.0f + NEXT_DISTANCE_WEIGHT); - } - } else if (i != 0 && i == mSampledInputSize - 1) { - // For the first point, weighted average of distances from last point and - // the previous point to the key is used as a point to key distance. - const float prevDistance = sqrtf(getPointToKeyByIdLength(i - 1, j)); - if (prevDistance < distance) { - distance = (distance + prevDistance * PREV_DISTANCE_WEIGHT) - / (1.0f + PREV_DISTANCE_WEIGHT); - } - } - const float probabilityDensity = distribution.getProbabilityDensity(distance); - const float probability = inputCharProbability * probabilityDensity - / sumOfProbabilityDensities; - mCharProbabilities[i][j] = probability; - } - } - } - - - if (DEBUG_POINTS_PROBABILITY) { - for (int i = 0; i < mSampledInputSize; ++i) { - std::stringstream sstream; - sstream << i << ", "; - sstream << "(" << mSampledInputXs[i] << ", " << mSampledInputYs[i] << "), "; - sstream << "Speed: "<< getSpeedRate(i) << ", "; - sstream << "Angle: "<< getPointAngle(i) << ", \n"; - - for (hash_map_compat<int, float>::iterator it = mCharProbabilities[i].begin(); - it != mCharProbabilities[i].end(); ++it) { - if (it->first == NOT_AN_INDEX) { - sstream << it->first - << "(skip):" - << it->second - << "\n"; - } else { - sstream << it->first - << "(" - << static_cast<char>(mProximityInfo->getCodePointOf(it->first)) - << "):" - << it->second - << "\n"; - } - } - AKLOGI("%s", sstream.str().c_str()); - } - } - - // Decrease key probabilities of points which don't have the highest probability of that key - // among nearby points. Probabilities of the first point and the last point are not suppressed. - for (int i = max(start, 1); i < mSampledInputSize; ++i) { - for (int j = i + 1; j < mSampledInputSize; ++j) { - if (!suppressCharProbabilities(i, j)) { - break; - } - } - for (int j = i - 1; j >= max(start, 0); --j) { - if (!suppressCharProbabilities(i, j)) { - break; - } - } - } - - // Converting from raw probabilities to log probabilities to calculate spatial distance. - for (int i = start; i < mSampledInputSize; ++i) { - for (int j = 0; j < keyCount; ++j) { - hash_map_compat<int, float>::iterator it = mCharProbabilities[i].find(j); - if (it == mCharProbabilities[i].end()){ - mNearKeysVector[i].reset(j); - } else if(it->second < MIN_PROBABILITY) { - // Erases from near keys vector because it has very low probability. - mNearKeysVector[i].reset(j); - mCharProbabilities[i].erase(j); - } else { - it->second = -logf(it->second); - } - } - mCharProbabilities[i][NOT_AN_INDEX] = -logf(mCharProbabilities[i][NOT_AN_INDEX]); - } -} - -// Decreases char probabilities of index0 by checking probabilities of a near point (index1) and -// increases char probabilities of index1 by checking probabilities of index0. -bool ProximityInfoState::suppressCharProbabilities(const int index0, const int index1) { - ASSERT(0 <= index0 && index0 < mSampledInputSize); - ASSERT(0 <= index1 && index1 < mSampledInputSize); - - static const float SUPPRESSION_LENGTH_WEIGHT = 1.5f; - static const float MIN_SUPPRESSION_RATE = 0.1f; - static const float SUPPRESSION_WEIGHT = 0.5f; - static const float SUPPRESSION_WEIGHT_FOR_PROBABILITY_GAIN = 0.1f; - static const float SKIP_PROBABALITY_WEIGHT_FOR_PROBABILITY_GAIN = 0.3f; - - const float keyWidthFloat = static_cast<float>(mProximityInfo->getMostCommonKeyWidth()); - const float diff = fabsf(static_cast<float>(mLengthCache[index0] - mLengthCache[index1])); - if (diff > keyWidthFloat * SUPPRESSION_LENGTH_WEIGHT) { - return false; - } - const float suppressionRate = MIN_SUPPRESSION_RATE - + diff / keyWidthFloat / SUPPRESSION_LENGTH_WEIGHT * SUPPRESSION_WEIGHT; - for (hash_map_compat<int, float>::iterator it = mCharProbabilities[index0].begin(); - it != mCharProbabilities[index0].end(); ++it) { - hash_map_compat<int, float>::iterator it2 = mCharProbabilities[index1].find(it->first); - if (it2 != mCharProbabilities[index1].end() && it->second < it2->second) { - const float newProbability = it->second * suppressionRate; - const float suppression = it->second - newProbability; - it->second = newProbability; - // mCharProbabilities[index0][NOT_AN_INDEX] is the probability of skipping this point. - mCharProbabilities[index0][NOT_AN_INDEX] += suppression; - - // Add the probability of the same key nearby index1 - const float probabilityGain = min(suppression * SUPPRESSION_WEIGHT_FOR_PROBABILITY_GAIN, - mCharProbabilities[index1][NOT_AN_INDEX] - * SKIP_PROBABALITY_WEIGHT_FOR_PROBABILITY_GAIN); - it2->second += probabilityGain; - mCharProbabilities[index1][NOT_AN_INDEX] -= probabilityGain; - } - } - return true; -} - // Get a word that is detected by tracing the most probable string into codePointBuf and // returns probability of generating the word. float ProximityInfoState::getMostProbableString(int *const codePointBuf) const { |