refactor distance cache

Change-Id: I21b54b356641a63d7be17fd34b9ede7a63ec738a

native/jni/src/correction.cpp

@@ -22,6 +22,7 @@
 #include "correction.h"
 #include "defines.h"
 #include "proximity_info_state.h"
+#include "suggest_utils.h"
 
 namespace latinime {
 
@@ -673,27 +674,9 @@ inline static bool isUpperCase(unsigned short c) {
             if (i < adjustedProximityMatchedCount) {
                 multiplyIntCapped(typedLetterMultiplier, &finalFreq);
             }
-            if (squaredDistance >= 0) {
+            const float factor =
-                // Promote or demote the score according to the distance from the sweet spot
+                    SuggestUtils::getDistanceScalingFactor(static_cast<float>(squaredDistance));
-                static const float A = ZERO_DISTANCE_PROMOTION_RATE / 100.0f;
+            if (factor > 0.0f) {
-                static const float B = 1.0f;
-                static const float C = 0.5f;
-                static const float MIN = 0.3f;
-                static const float R1 = NEUTRAL_SCORE_SQUARED_RADIUS;
-                static const float R2 = HALF_SCORE_SQUARED_RADIUS;
-                const float x = static_cast<float>(squaredDistance)
-                        / ProximityInfoState::NORMALIZED_SQUARED_DISTANCE_SCALING_FACTOR;
-                const float factor = max((x < R1)
-                        ? (A * (R1 - x) + B * x) / R1
-                        : (B * (R2 - x) + C * (x - R1)) / (R2 - R1), MIN);
-                // factor is a piecewise linear function like:
-                // A -_                  .
-                //     ^-_               .
-                // B      \              .
-                //         \_            .
-                // C         ------------.
-                //                       .
-                // 0   R1 R2             .
                 multiplyRate((int)(factor * 100.0f), &finalFreq);
             } else if (squaredDistance == PROXIMITY_CHAR_WITHOUT_DISTANCE_INFO) {
                 multiplyRate(WORDS_WITH_PROXIMITY_CHARACTER_DEMOTION_RATE, &finalFreq);

native/jni/src/proximity_info_state.cpp

@@ -101,7 +101,7 @@ void ProximityInfoState::initInputParams(const int pointerId, const float maxPoi
         mTimes.clear();
         mInputIndice.clear();
         mLengthCache.clear();
-        mDistanceCache.clear();
+        mDistanceCache_G.clear();
         mNearKeysVector.clear();
         mSearchKeysVector.clear();
         mSpeedRates.clear();
@@ -210,7 +210,7 @@ void ProximityInfoState::initInputParams(const int pointerId, const float maxPoi
         const int keyCount = mProximityInfo->getKeyCount();
         mNearKeysVector.resize(mSampledInputSize);
         mSearchKeysVector.resize(mSampledInputSize);
-        mDistanceCache.resize(mSampledInputSize * keyCount);
+        mDistanceCache_G.resize(mSampledInputSize * keyCount);
         for (int i = lastSavedInputSize; i < mSampledInputSize; ++i) {
             mNearKeysVector[i].reset();
             mSearchKeysVector[i].reset();
@@ -221,7 +221,7 @@ void ProximityInfoState::initInputParams(const int pointerId, const float maxPoi
                 const int y = mSampledInputYs[i];
                 const float normalizedSquaredDistance =
                         mProximityInfo->getNormalizedSquaredDistanceFromCenterFloatG(k, x, y);
-                mDistanceCache[index] = normalizedSquaredDistance;
+                mDistanceCache_G[index] = normalizedSquaredDistance;
                 if (normalizedSquaredDistance < NEAR_KEY_NORMALIZED_SQUARED_THRESHOLD) {
                     mNearKeysVector[i][k] = true;
                 }
@@ -686,7 +686,7 @@ float ProximityInfoState::getPointToKeyLength(
     const int keyId = mProximityInfo->getKeyIndexOf(codePoint);
     if (keyId != NOT_AN_INDEX) {
         const int index = inputIndex * mProximityInfo->getKeyCount() + keyId;
-        return min(mDistanceCache[index] * scale, mMaxPointToKeyLength);
+        return min(mDistanceCache_G[index] * scale, mMaxPointToKeyLength);
     }
     if (isSkippableCodePoint(codePoint)) {
         return 0.0f;
@@ -695,7 +695,7 @@ float ProximityInfoState::getPointToKeyLength(
     return MAX_POINT_TO_KEY_LENGTH;
 }
 
-float ProximityInfoState::getPointToKeyLength(const int inputIndex, const int codePoint) const {
+float ProximityInfoState::getPointToKeyLength_G(const int inputIndex, const int codePoint) const {
     return getPointToKeyLength(inputIndex, codePoint, 1.0f);
 }
 
@@ -706,7 +706,7 @@ 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[index] * scale, mMaxPointToKeyLength);
+        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);

native/jni/src/proximity_info_state.h

@@ -58,7 +58,7 @@ class ProximityInfoState {
               mHasTouchPositionCorrectionData(false), mMostCommonKeyWidthSquare(0), mLocaleStr(),
               mKeyCount(0), mCellHeight(0), mCellWidth(0), mGridHeight(0), mGridWidth(0),
               mIsContinuationPossible(false), mSampledInputXs(), mSampledInputYs(), mTimes(),
-              mInputIndice(), mLengthCache(), mBeelineSpeedPercentiles(), mDistanceCache(),
+              mInputIndice(), mLengthCache(), mBeelineSpeedPercentiles(), mDistanceCache_G(),
               mSpeedRates(), mDirections(), mCharProbabilities(), mNearKeysVector(),
               mSearchKeysVector(), mTouchPositionCorrectionEnabled(false), mSampledInputSize(0) {
         memset(mInputCodes, 0, sizeof(mInputCodes));
@@ -157,7 +157,7 @@ class ProximityInfoState {
     float getPointToKeyByIdLength(const int inputIndex, const int keyId, const float scale) const;
     float getPointToKeyByIdLength(const int inputIndex, const int keyId) const;
     float getPointToKeyLength(const int inputIndex, const int codePoint, const float scale) const;
-    float getPointToKeyLength(const int inputIndex, const int codePoint) const;
+    float getPointToKeyLength_G(const int inputIndex, const int codePoint) const;
 
     ProximityType getMatchedProximityId(const int index, const int c,
             const bool checkProximityChars, int *proximityIndex = 0) const;
@@ -274,7 +274,7 @@ class ProximityInfoState {
     std::vector<int> mInputIndice;
     std::vector<int> mLengthCache;
     std::vector<int> mBeelineSpeedPercentiles;
-    std::vector<float> mDistanceCache;
+    std::vector<float> mDistanceCache_G;
     std::vector<float> mSpeedRates;
     std::vector<float> mDirections;
     // probabilities of skipping or mapping to a key for each point.

native/jni/src/suggest_utils.h

@@ -0,0 +1,53 @@
+/*
+ * 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.
+ */
+
+#ifndef LATINIME_SUGGEST_UTILS_H
+#define LATINIME_SUGGEST_UTILS_H
+
+#include "defines.h"
+
+namespace latinime {
+class SuggestUtils {
+ public:
+    static float getDistanceScalingFactor(float normalizedSquaredDistance) {
+        if (normalizedSquaredDistance < 0.0f) {
+            return -1.0f;
+        }
+        // Promote or demote the score according to the distance from the sweet spot
+        static const float A = ZERO_DISTANCE_PROMOTION_RATE / 100.0f;
+        static const float B = 1.0f;
+        static const float C = 0.5f;
+        static const float MIN = 0.3f;
+        static const float R1 = NEUTRAL_SCORE_SQUARED_RADIUS;
+        static const float R2 = HALF_SCORE_SQUARED_RADIUS;
+        const float x = static_cast<float>(normalizedSquaredDistance)
+                / ProximityInfoState::NORMALIZED_SQUARED_DISTANCE_SCALING_FACTOR;
+        const float factor = max((x < R1)
+                ? (A * (R1 - x) + B * x) / R1
+                : (B * (R2 - x) + C * (x - R1)) / (R2 - R1), MIN);
+        // factor is a piecewise linear function like:
+        // A -_                  .
+        //     ^-_               .
+        // B      \              .
+        //         \_            .
+        // C         ------------.
+        //                       .
+        // 0   R1 R2             .
+        return factor;
+    }
+};
+} // namespace latinime
+#endif // LATINIME_SUGGEST_UTILS_H