/*
 *  Sample code for the DIS Pointer Stressmark
 *
 * This source code is the completely correct source code based on
 * the example codes provided by Atlantic Aerospace Division, Titan
 * Systems Corporation, 2000.
 *
 * If you just compile and generate the executables from this source
 * code, this code would be enough. However, if you wish to get a complete
 * understanding of this stressmark, it is strongly suggested that you
 * read the Benchmark Analysis and Specifications Document Version 1.0
 * before going on since the detailed comments are given in this documents.
 * the comments are not repeated here.
 */

#include <math.h>

#define TRUE 1
#define FALSE !TRUE
#define SUCCESS TRUE
#define ERROR FLASE

#define MIN_PIXEL 0
#define MAX_DIMENSION 32768
#define MIN_SEED -2147483647
#define MAX_SEED -1
#define MAX_NUMBER_LINES 65536
#define MIN_BIT_DEPTH 7
#define MAX_BIT_DEPTH 15

typedef struct {
  int column;
  int row;
} Coord;

/*
 * Neighborhood structure consists of the GLCM descriptors entropy and
 * energy for each of 2 distance and 4 angels
 */
typedef struct {
  float entropy;
  float energy;
} Descriptors;

typedef struct {
  Descriptors deg0;
  Descriptors deg45;
  Descriptors deg90;
  Descriptors deg135;
} Angeles;

typedef struct {
  Angeles distShort;
  Angeles distLong;
} Neighborhood;

typedef short int Pixel; /* short int;*/

typedef struct {
  int numColumns;      /* number of columns in image */
  int numRows;         /* number of rows in image */
  Pixel maxImageValue; /* max legal image value */
  Pixel *data;         /* data pointer */
} Image;

// For correct implementation of drawLineSegment
#include "initializeImage.c"

Pixel *createImage(Pixel *image, int dimension, Pixel maxPixel, int numberLines,
                   int minThickness, int maxThickness) {
  int i;

  Coord startPoint;
  Coord endPoint;
  int thickness;
  int startValue;
  int endValue;
  Image img;
  img.numColumns = dimension;
  img.numRows = dimension;
  img.maxImageValue = maxPixel;
  img.data = image;

  for (i = 0; i < dimension * dimension; i++) {
    image[i] = 0;
  }

  for (i = 0; i < numberLines; i++) {
    float temp;
    float prev;

    temp = randomUInt(0, dimension * dimension - 1);
    startPoint.row = (int)temp / dimension;
    startPoint.column = (int)temp % dimension;
    prev = temp;

    // Make sure that the end is different than the start
    while ((temp = randomUInt(0, dimension * dimension - 1)) == prev)
      ;

    endPoint.row = (int)temp / dimension;
    endPoint.column = (int)temp % dimension;

    thickness = randomUInt(minThickness, maxThickness);
    startValue = randomUInt(MIN_PIXEL, maxPixel);
    endValue = randomUInt(MIN_PIXEL, maxPixel);

    drawLineSegment(&startPoint, &endPoint, startValue, endValue, thickness,
                    &img);
  }
  return (image);
}

void calcEntropyEnergy(int *sumHist, int *diffHist, Pixel *image, int numBins,
                       int dx, int dy, float *entropy, float *energy,
                       int dimension, Pixel maxPixel) {
  int index;
  int totalNumPixels;
  int rowIndex;
  int rowLow, rowHigh;
  int columnIndex;
  int columnLow, columnHigh;
  int columnForPixelAtDistance;
  int rowForPixelAtDistance;
  int value0RowOffset;
  int value1RowOffset;

  *entropy = 0.0;
  *energy = 0.0;

  for (index = 0; index < numBins; index++) {
    sumHist[index] = 0;
    diffHist[index] = 0;
  }

  if (dy < 0) {
    rowLow = -dy;
    rowHigh = dimension;
  } else {
    rowLow = 0;
    rowHigh = dimension - dy;
  }
  if (dx < 0) {
    columnLow = -dx;
    columnHigh = dimension;
  } else {
    columnLow = 0;
    columnHigh = dimension - dx;
  }

  totalNumPixels = 0;
  value0RowOffset = rowLow * dimension;
  value1RowOffset = (rowLow + dy) * dimension;

  for (rowIndex = rowLow; rowIndex < rowHigh; rowIndex++) {
    for (columnIndex = columnLow; columnIndex < columnHigh; columnIndex++) {
      int value0;
      int value1;
      int binIndex;

      rowForPixelAtDistance = rowIndex + dy;
      columnForPixelAtDistance = columnIndex + dx;

      value0 = *(image + value0RowOffset + columnIndex);
      value1 = *(image + value1RowOffset + columnForPixelAtDistance);

      binIndex = value0 + value1 - 2 * MIN_PIXEL;
      assert((binIndex >= 0) && (binIndex < numBins));
      sumHist[binIndex] += 1;
      binIndex = value0 - value1 + maxPixel - MIN_PIXEL;

      assert((binIndex >= 0) && (binIndex < numBins));

      diffHist[binIndex] += 1;
      totalNumPixels += 1;
    }

    value0RowOffset += dimension;
    value1RowOffset += dimension;
  }

  if (totalNumPixels > 0) {
    int index;
    double energySum;
    double energyDifference;
    double entropyValue;
    double sumNormalized;
    double diffNormalized;
    double scale;

    energySum = (double)0;
    energyDifference = (double)0;
    entropyValue = (double)0;
    scale = 1.e0 / totalNumPixels;
    for (index = 0; index < numBins; index++) {
      if (sumHist[index] > 0) {
        sumNormalized = (double)sumHist[index] * scale;
        entropyValue =
            entropyValue - sumNormalized * log((double)sumNormalized);
        energySum = energySum + sumNormalized * sumNormalized;
      }
      if (diffHist[index] > 0) {
        diffNormalized = (double)diffHist[index] * scale;
        entropyValue = entropyValue - diffNormalized * log(diffNormalized);
        energyDifference = energyDifference + diffNormalized * diffNormalized;
      }
    }
    *energy = energySum * energyDifference;
    *entropy = entropyValue;
  }
  return;
}

void neighborhoodCalculation(Pixel *image, int dimension, int distanceShort,
                             int distanceLong, Neighborhood *neighborhood,
                             Pixel maxPixel) {
  int *sumHist, *diffHist;
  int numBins;

  numBins = (2 * (maxPixel - MIN_PIXEL + 1) - 1);
  sumHist = (int *)malloc(numBins * sizeof(int));
  assert(sumHist != NULL);
  diffHist = (int *)malloc(numBins * sizeof(int));
  assert(diffHist != NULL);

  calcEntropyEnergy(sumHist, diffHist, image, numBins, distanceShort, 0,
                    &(neighborhood->distShort.deg0.entropy),
                    &(neighborhood->distShort.deg0.energy), dimension,
                    maxPixel);

  calcEntropyEnergy(sumHist, diffHist, image, numBins, distanceShort,
                    distanceShort, &(neighborhood->distShort.deg45.entropy),
                    &(neighborhood->distShort.deg45.energy), dimension,
                    maxPixel);

  calcEntropyEnergy(sumHist, diffHist, image, numBins, 0, distanceShort,
                    &(neighborhood->distShort.deg90.entropy),
                    &(neighborhood->distShort.deg90.energy), dimension,
                    maxPixel);

  calcEntropyEnergy(sumHist, diffHist, image, numBins, -distanceShort,
                    distanceShort, &(neighborhood->distShort.deg135.entropy),
                    &(neighborhood->distShort.deg135.energy), dimension,
                    maxPixel);

  calcEntropyEnergy(sumHist, diffHist, image, numBins, distanceLong, 0,
                    &(neighborhood->distLong.deg0.entropy),
                    &(neighborhood->distLong.deg0.energy), dimension, maxPixel);

  calcEntropyEnergy(sumHist, diffHist, image, numBins, distanceLong,
                    distanceLong, &(neighborhood->distLong.deg45.entropy),
                    &(neighborhood->distLong.deg45.energy), dimension,
                    maxPixel);

  calcEntropyEnergy(sumHist, diffHist, image, numBins, 0, distanceLong,
                    &(neighborhood->distLong.deg90.entropy),
                    &(neighborhood->distLong.deg90.energy), dimension,
                    maxPixel);

  calcEntropyEnergy(sumHist, diffHist, image, numBins, -distanceLong,
                    distanceLong, &(neighborhood->distLong.deg135.entropy),
                    &(neighborhood->distLong.deg135.energy), dimension,
                    maxPixel);

  free(sumHist);
  free(diffHist);

  return;
}