native/jni/src/proximity_info_utils.h - platform/packages/inputmethods/LatinIME - Git at Google

 /*
  * 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_PROXIMITY_INFO_UTILS_H
 #define LATINIME_PROXIMITY_INFO_UTILS_H

 #include <cmath>

 #include "additional_proximity_chars.h"
 #include "char_utils.h"
 #include "defines.h"
 #include "geometry_utils.h"
 #include "hash_map_compat.h"

 namespace latinime {
 class ProximityInfoUtils {
  public:
     static AK_FORCE_INLINE int getKeyIndexOf(const int keyCount, const int c,
             const hash_map_compat<int, int> *const codeToKeyMap) {
         if (keyCount == 0) {
             // We do not have the coordinate data
             return NOT_AN_INDEX;
         }
         if (c == NOT_A_CODE_POINT) {
             return NOT_AN_INDEX;
         }
         const int lowerCode = toLowerCase(c);
         hash_map_compat<int, int>::const_iterator mapPos = codeToKeyMap->find(lowerCode);
         if (mapPos != codeToKeyMap->end()) {
             return mapPos->second;
         }
         return NOT_AN_INDEX;
     }

     static AK_FORCE_INLINE void initializeProximities(const int *const inputCodes,
             const int *const inputXCoordinates, const int *const inputYCoordinates,
             const int inputSize, const int *const keyXCoordinates,
             const int *const keyYCoordinates, const int *const keyWidths, const int *keyHeights,
             const int *const proximityCharsArray, const int cellHeight, const int cellWidth,
             const int gridWidth, const int mostCommonKeyWidth, const int keyCount,
             const char *const localeStr,
             const hash_map_compat<int, int> *const codeToKeyMap, int *inputProximities) {
         // Initialize
         // - mInputCodes
         // - mNormalizedSquaredDistances
         // TODO: Merge
         for (int i = 0; i < inputSize; ++i) {
             const int primaryKey = inputCodes[i];
             const int x = inputXCoordinates[i];
             const int y = inputYCoordinates[i];
             int *proximities = &inputProximities[i * MAX_PROXIMITY_CHARS_SIZE];
             calculateProximities(keyXCoordinates, keyYCoordinates, keyWidths, keyHeights,
                     proximityCharsArray, cellHeight, cellWidth, gridWidth, mostCommonKeyWidth,
                     keyCount, x, y, primaryKey, localeStr, codeToKeyMap, proximities);
         }

         if (DEBUG_PROXIMITY_CHARS) {
             for (int i = 0; i < inputSize; ++i) {
                 AKLOGI("---");
                 for (int j = 0; j < MAX_PROXIMITY_CHARS_SIZE; ++j) {
                     int proximityChar =
                             inputProximities[i * MAX_PROXIMITY_CHARS_SIZE + j];
                     proximityChar += 0;
                     AKLOGI("--- (%d)%c", i, proximityChar);
                 }
             }
         }
     }

     static AK_FORCE_INLINE int getStartIndexFromCoordinates(const int x, const int y,
             const int cellHeight, const int cellWidth, const int gridWidth) {
         return ((y / cellHeight) * gridWidth + (x / cellWidth)) * MAX_PROXIMITY_CHARS_SIZE;
     }

     static inline float getSquaredDistanceFloat(const float x1, const float y1, const float x2,
             const float y2) {
         return SQUARE_FLOAT(x1 - x2) + SQUARE_FLOAT(y1 - y2);
     }

     static inline float pointToLineSegSquaredDistanceFloat(const float x, const float y,
         const float x1, const float y1, const float x2, const float y2, const bool extend) {
         const float ray1x = x - x1;
         const float ray1y = y - y1;
         const float ray2x = x2 - x1;
         const float ray2y = y2 - y1;

         const float dotProduct = ray1x * ray2x + ray1y * ray2y;
         const float lineLengthSqr = SQUARE_FLOAT(ray2x) + SQUARE_FLOAT(ray2y);
         const float projectionLengthSqr = dotProduct / lineLengthSqr;

         float projectionX;
         float projectionY;
         if (!extend && projectionLengthSqr < 0.0f) {
             projectionX = x1;
             projectionY = y1;
         } else if (!extend && projectionLengthSqr > 1.0f) {
             projectionX = x2;
             projectionY = y2;
         } else {
             projectionX = x1 + projectionLengthSqr * ray2x;
             projectionY = y1 + projectionLengthSqr * ray2y;
         }
         return getSquaredDistanceFloat(x, y, projectionX, projectionY);
     }

     // Normal distribution N(u, sigma^2).
     struct NormalDistribution {
      public:
         NormalDistribution(const float u, const float sigma)
                 : mU(u), mSigma(sigma),
                   mPreComputedNonExpPart(1.0f / sqrtf(2.0f * M_PI_F * SQUARE_FLOAT(sigma))),
                   mPreComputedExponentPart(-1.0f / (2.0f * SQUARE_FLOAT(sigma))) {}

         float getProbabilityDensity(const float x) const {
             const float shiftedX = x - mU;
             return mPreComputedNonExpPart * expf(mPreComputedExponentPart * SQUARE_FLOAT(shiftedX));
         }

      private:
         DISALLOW_IMPLICIT_CONSTRUCTORS(NormalDistribution);
         const float mU; // mean value
         const float mSigma; // standard deviation
         const float mPreComputedNonExpPart; // = 1 / sqrt(2 * PI * sigma^2)
         const float mPreComputedExponentPart; // = -1 / (2 * sigma^2)
     }; // struct NormalDistribution

  private:
     DISALLOW_IMPLICIT_CONSTRUCTORS(ProximityInfoUtils);

     static bool isOnKey(const int *const keyXCoordinates, const int *const keyYCoordinates,
             const int *const keyWidths, const int *keyHeights, const int keyId, const int x,
             const int y) {
         if (keyId < 0) return true; // NOT_A_ID is -1, but return whenever < 0 just in case
         const int left = keyXCoordinates[keyId];
         const int top = keyYCoordinates[keyId];
         const int right = left + keyWidths[keyId] + 1;
         const int bottom = top + keyHeights[keyId];
         return left < right && top < bottom && x >= left && x < right && y >= top && y < bottom;
     }

     static AK_FORCE_INLINE void calculateProximities(const int *const keyXCoordinates,
             const int *const keyYCoordinates, const int *const keyWidths, const int *keyHeights,
             const int *const proximityCharsArray, const int cellHeight, const int cellWidth,
             const int gridWidth, const int mostCommonKeyWidth, const int keyCount,
             const int x, const int y, const int primaryKey, const char *const localeStr,
             const hash_map_compat<int, int> *const codeToKeyMap, int *proximities) {
         const int mostCommonKeyWidthSquare = mostCommonKeyWidth * mostCommonKeyWidth;
         int insertPos = 0;
         proximities[insertPos++] = primaryKey;
         const int startIndex = getStartIndexFromCoordinates(x, y, cellHeight, cellWidth, gridWidth);
         if (startIndex >= 0) {
             for (int i = 0; i < MAX_PROXIMITY_CHARS_SIZE; ++i) {
                 const int c = proximityCharsArray[startIndex + i];
                 if (c < KEYCODE_SPACE || c == primaryKey) {
                     continue;
                 }
                 const int keyIndex = getKeyIndexOf(keyCount, c, codeToKeyMap);
                 const bool onKey = isOnKey(keyXCoordinates, keyYCoordinates, keyWidths, keyHeights,
                         keyIndex, x, y);
                 const int distance = squaredLengthToEdge(keyXCoordinates, keyYCoordinates,
                         keyWidths, keyHeights, keyIndex, x, y);
                 if (onKey || distance < mostCommonKeyWidthSquare) {
                     proximities[insertPos++] = c;
                     if (insertPos >= MAX_PROXIMITY_CHARS_SIZE) {
                         if (DEBUG_DICT) {
                             ASSERT(false);
                         }
                         return;
                     }
                 }
             }
             const int additionalProximitySize =
                     AdditionalProximityChars::getAdditionalCharsSize(localeStr, primaryKey);
             if (additionalProximitySize > 0) {
                 proximities[insertPos++] = ADDITIONAL_PROXIMITY_CHAR_DELIMITER_CODE;
                 if (insertPos >= MAX_PROXIMITY_CHARS_SIZE) {
                     if (DEBUG_DICT) {
                         ASSERT(false);
                     }
                     return;
                 }

                 const int *additionalProximityChars =
                         AdditionalProximityChars::getAdditionalChars(localeStr, primaryKey);
                 for (int j = 0; j < additionalProximitySize; ++j) {
                     const int ac = additionalProximityChars[j];
                     int k = 0;
                     for (; k < insertPos; ++k) {
                         if (ac == proximities[k]) {
                             break;
                         }
                     }
                     if (k < insertPos) {
                         continue;
                     }
                     proximities[insertPos++] = ac;
                     if (insertPos >= MAX_PROXIMITY_CHARS_SIZE) {
                         if (DEBUG_DICT) {
                             ASSERT(false);
                         }
                         return;
                     }
                 }
             }
         }
         // Add a delimiter for the proximity characters
         for (int i = insertPos; i < MAX_PROXIMITY_CHARS_SIZE; ++i) {
             proximities[i] = NOT_A_CODE_POINT;
         }
     }

     static int squaredLengthToEdge(const int *const keyXCoordinates,
             const int *const keyYCoordinates, const int *const keyWidths, const int *keyHeights,
             const int keyId, const int x, const int y) {
         // NOT_A_ID is -1, but return whenever < 0 just in case
         if (keyId < 0) return MAX_VALUE_FOR_WEIGHTING;
         const int left = keyXCoordinates[keyId];
         const int top = keyYCoordinates[keyId];
         const int right = left + keyWidths[keyId];
         const int bottom = top + keyHeights[keyId];
         const int edgeX = x < left ? left : (x > right ? right : x);
         const int edgeY = y < top ? top : (y > bottom ? bottom : y);
         const int dx = x - edgeX;
         const int dy = y - edgeY;
         return dx * dx + dy * dy;
     }
 };
 } // namespace latinime
 #endif // LATINIME_PROXIMITY_INFO_UTILS_H
	/*
	* 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_PROXIMITY_INFO_UTILS_H
	#define LATINIME_PROXIMITY_INFO_UTILS_H

	#include <cmath>

	#include "additional_proximity_chars.h"
	#include "char_utils.h"
	#include "defines.h"
	#include "geometry_utils.h"
	#include "hash_map_compat.h"

	namespace latinime {
	class ProximityInfoUtils {
	public:
	static AK_FORCE_INLINE int getKeyIndexOf(const int keyCount, const int c,
	const hash_map_compat<int, int> *const codeToKeyMap) {
	if (keyCount == 0) {
	// We do not have the coordinate data
	return NOT_AN_INDEX;
	}
	if (c == NOT_A_CODE_POINT) {
	return NOT_AN_INDEX;
	}
	const int lowerCode = toLowerCase(c);
	hash_map_compat<int, int>::const_iterator mapPos = codeToKeyMap->find(lowerCode);
	if (mapPos != codeToKeyMap->end()) {
	return mapPos->second;
	}
	return NOT_AN_INDEX;
	}

	static AK_FORCE_INLINE void initializeProximities(const int *const inputCodes,
	const int const inputXCoordinates, const int const inputYCoordinates,
	const int inputSize, const int *const keyXCoordinates,
	const int const keyYCoordinates, const int const keyWidths, const int *keyHeights,
	const int *const proximityCharsArray, const int cellHeight, const int cellWidth,
	const int gridWidth, const int mostCommonKeyWidth, const int keyCount,
	const char *const localeStr,
	const hash_map_compat<int, int> const codeToKeyMap, int inputProximities) {
	// Initialize
	// - mInputCodes
	// - mNormalizedSquaredDistances
	// TODO: Merge
	for (int i = 0; i < inputSize; ++i) {
	const int primaryKey = inputCodes[i];
	const int x = inputXCoordinates[i];
	const int y = inputYCoordinates[i];
	int proximities = &inputProximities[i MAX_PROXIMITY_CHARS_SIZE];
	calculateProximities(keyXCoordinates, keyYCoordinates, keyWidths, keyHeights,
	proximityCharsArray, cellHeight, cellWidth, gridWidth, mostCommonKeyWidth,
	keyCount, x, y, primaryKey, localeStr, codeToKeyMap, proximities);
	}

	if (DEBUG_PROXIMITY_CHARS) {
	for (int i = 0; i < inputSize; ++i) {
	AKLOGI("---");
	for (int j = 0; j < MAX_PROXIMITY_CHARS_SIZE; ++j) {
	int proximityChar =
	inputProximities[i * MAX_PROXIMITY_CHARS_SIZE + j];
	proximityChar += 0;
	AKLOGI("--- (%d)%c", i, proximityChar);
	}
	}
	}
	}

	static AK_FORCE_INLINE int getStartIndexFromCoordinates(const int x, const int y,
	const int cellHeight, const int cellWidth, const int gridWidth) {
	return ((y / cellHeight) * gridWidth + (x / cellWidth)) * MAX_PROXIMITY_CHARS_SIZE;
	}

	static inline float getSquaredDistanceFloat(const float x1, const float y1, const float x2,
	const float y2) {
	return SQUARE_FLOAT(x1 - x2) + SQUARE_FLOAT(y1 - y2);
	}

	static inline float pointToLineSegSquaredDistanceFloat(const float x, const float y,
	const float x1, const float y1, const float x2, const float y2, const bool extend) {
	const float ray1x = x - x1;
	const float ray1y = y - y1;
	const float ray2x = x2 - x1;
	const float ray2y = y2 - y1;

	const float dotProduct = ray1x * ray2x + ray1y * ray2y;
	const float lineLengthSqr = SQUARE_FLOAT(ray2x) + SQUARE_FLOAT(ray2y);
	const float projectionLengthSqr = dotProduct / lineLengthSqr;

	float projectionX;
	float projectionY;
	if (!extend && projectionLengthSqr < 0.0f) {
	projectionX = x1;
	projectionY = y1;
	} else if (!extend && projectionLengthSqr > 1.0f) {
	projectionX = x2;
	projectionY = y2;
	} else {
	projectionX = x1 + projectionLengthSqr * ray2x;
	projectionY = y1 + projectionLengthSqr * ray2y;
	}
	return getSquaredDistanceFloat(x, y, projectionX, projectionY);
	}

	// Normal distribution N(u, sigma^2).
	struct NormalDistribution {
	public:
	NormalDistribution(const float u, const float sigma)
	: mU(u), mSigma(sigma),
	mPreComputedNonExpPart(1.0f / sqrtf(2.0f * M_PI_F * SQUARE_FLOAT(sigma))),
	mPreComputedExponentPart(-1.0f / (2.0f * SQUARE_FLOAT(sigma))) {}

	float getProbabilityDensity(const float x) const {
	const float shiftedX = x - mU;
	return mPreComputedNonExpPart * expf(mPreComputedExponentPart * SQUARE_FLOAT(shiftedX));
	}

	private:
	DISALLOW_IMPLICIT_CONSTRUCTORS(NormalDistribution);
	const float mU; // mean value
	const float mSigma; // standard deviation
	const float mPreComputedNonExpPart; // = 1 / sqrt(2 * PI * sigma^2)
	const float mPreComputedExponentPart; // = -1 / (2 * sigma^2)
	}; // struct NormalDistribution

	private:
	DISALLOW_IMPLICIT_CONSTRUCTORS(ProximityInfoUtils);

	static bool isOnKey(const int const keyXCoordinates, const int const keyYCoordinates,
	const int const keyWidths, const int keyHeights, const int keyId, const int x,
	const int y) {
	if (keyId < 0) return true; // NOT_A_ID is -1, but return whenever < 0 just in case
	const int left = keyXCoordinates[keyId];
	const int top = keyYCoordinates[keyId];
	const int right = left + keyWidths[keyId] + 1;
	const int bottom = top + keyHeights[keyId];
	return left < right && top < bottom && x >= left && x < right && y >= top && y < bottom;
	}

	static AK_FORCE_INLINE void calculateProximities(const int *const keyXCoordinates,
	const int const keyYCoordinates, const int const keyWidths, const int *keyHeights,
	const int *const proximityCharsArray, const int cellHeight, const int cellWidth,
	const int gridWidth, const int mostCommonKeyWidth, const int keyCount,
	const int x, const int y, const int primaryKey, const char *const localeStr,
	const hash_map_compat<int, int> const codeToKeyMap, int proximities) {
	const int mostCommonKeyWidthSquare = mostCommonKeyWidth * mostCommonKeyWidth;
	int insertPos = 0;
	proximities[insertPos++] = primaryKey;
	const int startIndex = getStartIndexFromCoordinates(x, y, cellHeight, cellWidth, gridWidth);
	if (startIndex >= 0) {
	for (int i = 0; i < MAX_PROXIMITY_CHARS_SIZE; ++i) {
	const int c = proximityCharsArray[startIndex + i];
	if (c < KEYCODE_SPACE \|\| c == primaryKey) {
	continue;
	}
	const int keyIndex = getKeyIndexOf(keyCount, c, codeToKeyMap);
	const bool onKey = isOnKey(keyXCoordinates, keyYCoordinates, keyWidths, keyHeights,
	keyIndex, x, y);
	const int distance = squaredLengthToEdge(keyXCoordinates, keyYCoordinates,
	keyWidths, keyHeights, keyIndex, x, y);
	if (onKey \|\| distance < mostCommonKeyWidthSquare) {
	proximities[insertPos++] = c;
	if (insertPos >= MAX_PROXIMITY_CHARS_SIZE) {
	if (DEBUG_DICT) {
	ASSERT(false);
	}
	return;
	}
	}
	}
	const int additionalProximitySize =
	AdditionalProximityChars::getAdditionalCharsSize(localeStr, primaryKey);
	if (additionalProximitySize > 0) {
	proximities[insertPos++] = ADDITIONAL_PROXIMITY_CHAR_DELIMITER_CODE;
	if (insertPos >= MAX_PROXIMITY_CHARS_SIZE) {
	if (DEBUG_DICT) {
	ASSERT(false);
	}
	return;
	}

	const int *additionalProximityChars =
	AdditionalProximityChars::getAdditionalChars(localeStr, primaryKey);
	for (int j = 0; j < additionalProximitySize; ++j) {
	const int ac = additionalProximityChars[j];
	int k = 0;
	for (; k < insertPos; ++k) {
	if (ac == proximities[k]) {
	break;
	}
	}
	if (k < insertPos) {
	continue;
	}
	proximities[insertPos++] = ac;
	if (insertPos >= MAX_PROXIMITY_CHARS_SIZE) {
	if (DEBUG_DICT) {
	ASSERT(false);
	}
	return;
	}
	}
	}
	}
	// Add a delimiter for the proximity characters
	for (int i = insertPos; i < MAX_PROXIMITY_CHARS_SIZE; ++i) {
	proximities[i] = NOT_A_CODE_POINT;
	}
	}

	static int squaredLengthToEdge(const int *const keyXCoordinates,
	const int const keyYCoordinates, const int const keyWidths, const int *keyHeights,
	const int keyId, const int x, const int y) {
	// NOT_A_ID is -1, but return whenever < 0 just in case
	if (keyId < 0) return MAX_VALUE_FOR_WEIGHTING;
	const int left = keyXCoordinates[keyId];
	const int top = keyYCoordinates[keyId];
	const int right = left + keyWidths[keyId];
	const int bottom = top + keyHeights[keyId];
	const int edgeX = x < left ? left : (x > right ? right : x);
	const int edgeY = y < top ? top : (y > bottom ? bottom : y);
	const int dx = x - edgeX;
	const int dy = y - edgeY;
	return dx * dx + dy * dy;
	}
	};
	} // namespace latinime
	#endif // LATINIME_PROXIMITY_INFO_UTILS_H