/*******************************************************************************#
#           guvcview              http://guvcview.sourceforge.net # # # # Paulo
Assis <pj.assis@gmail.com>                                    # # # # This
program is free software; you can redistribute it and/or modify          # # it
under the terms of the GNU General Public License as published by          # #
the Free Software Foundation; either version 2 of the License, or             #
# (at your option) any later version. # # # # This program is distributed in the
hope that it will be useful,               # # but WITHOUT ANY WARRANTY; without
even the implied warranty of                # # MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.  See the                 # # GNU General Public License for
more details.                                  # # # # You should have received
a copy of the GNU General Public License             # # along with this
program; if not, write to the Free Software                   # # Foundation,
Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA     # # #
********************************************************************************/

#include <assert.h>
#include <inttypes.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

#include "gview.h"
#include "gviewrender.h"
// #include "../config.h"

static uint8_t fx_bin_treshold = 0x7F; /* 127 -> 50% */

/*
 * set fx binary filter treshold
 * args:
 *    treshold - 0x0 to 0xff
 *
 * asserts:
 *    none
 *
 * returns: void
 */
void set_fx_bin_treshold(uint8_t treshold) { fx_bin_treshold = treshold; }

/*random generator (HAS_GSL is set in ../config.h)*/
#ifdef HAS_GSL
#include <gsl/gsl_rng.h>
#endif

typedef struct _blur_t {
  int n;          // number of iterations
  int sigma;      // deviation
  int *bSizes;    // box sizes array
  int **divTable; // division lookup table for each box size
} blur_t;

static blur_t *blur[2] = {NULL, NULL};

uint8_t *tmpbuffer = NULL;
uint32_t *TB_Sqrt_ind = NULL; // look up table for sqrt lens distort indexes
uint32_t *TB_Pow_ind = NULL;  // look up table for pow lens distort indexes
uint32_t *TB_Pow2_ind = NULL; // look up table for pow2 lens distort indexes

typedef struct _particle_t {
  int PX;
  int PY;
  uint8_t Y;
  uint8_t U;
  uint8_t V;
  int size;
  float decay;
} particle_t;

static particle_t *particles = NULL;

/*
 * Flip yu12 frame - horizontal
 * args:
 *    frame - pointer to frame buffer (yu12=iyuv format)
 *    width - frame width
 *    height- frame height
 *
 * asserts:
 *    frame is not null
 *
 * returns: void
 */
static void fx_yu12_mirror(uint8_t *frame, int width, int height) {
  /*asserts*/
  assert(frame != NULL);

  int h = 0;
  int w = 0;
  int y_sizeline = width;
  int c_sizeline = width / 2;

  uint8_t *end = NULL;
  uint8_t *end2 = NULL;

  uint8_t *py = frame;
  uint8_t *pu = frame + (width * height);
  uint8_t *pv = pu + ((width * height) / 4);

  uint8_t pixel = 0;
  uint8_t pixel2 = 0;

  /*mirror y*/
  for (h = 0; h < height; h++) {
    py = frame + (h * width);
    end = py + width - 1;
    for (w = 0; w < width / 2; w++) {
      pixel = *py;
      *py++ = *end;
      *end-- = pixel;
    }
  }

  /*mirror u v*/
  for (h = 0; h < height; h += 2) {
    pu = frame + (width * height) + ((h * width) / 4);
    pv = pu + ((width * height) / 4);
    end = pu + (width / 2) - 1;
    end2 = pv + (width / 2) - 1;
    for (w = 0; w < width / 2; w += 2) {
      pixel = *pu;
      pixel2 = *pv;
      *pu++ = *end;
      *pv++ = *end2;
      *end-- = pixel;
      *end2-- = pixel2;
    }
  }
}

/*
 * Flip half yu12 frame - horizontal
 * args:
 *    frame - pointer to frame buffer (yu12=iyuv format)
 *    width - frame width
 *    height- frame height
 *
 * asserts:
 *    frame is not null
 *
 * returns: void
 */
static void fx_yu12_half_mirror(uint8_t *frame, int width, int height) {
  /*asserts*/
  assert(frame != NULL);

  int h = 0;
  int w = 0;

  uint8_t *end = NULL;
  uint8_t *end2 = NULL;

  uint8_t *py = frame;
  uint8_t *pu = frame + (width * height);
  uint8_t *pv = pu + ((width * height) / 4);

  uint8_t pixel = 0;
  uint8_t pixel2 = 0;

  /*mirror y*/
  for (h = 0; h < height; h++) {
    py = frame + (h * width);
    end = py + width - 1;
    for (w = 0; w < width / 2; w++) {
      *end-- = *py++;
    }
  }

  /*mirror u v*/
  for (h = 0; h < height; h += 2) {
    pu = frame + (width * height) + ((h * width) / 4);
    pv = pu + ((width * height) / 4);
    end = pu + (width / 2) - 1;
    end2 = pv + (width / 2) - 1;
    for (w = 0; w < width / 2; w += 2) {
      *end-- = *pu++;
      *end2-- = *pv++;
    }
  }
}

/*
 * Invert YUV frame
 * args:
 *    frame - pointer to frame buffer (any yuv format)
 *    width - frame width
 *    height- frame height
 *
 * asserts:
 *    frame is not null
 *
 * returns: void
 */
static void fx_yuv_negative(uint8_t *frame, int width, int height) {
  /*asserts*/
  assert(frame != NULL);

  int size = (width * height * 5) / 4;

  int i = 0;
  for (i = 0; i < size; i++)
    frame[i] = ~frame[i];
}

/*
 * Flip yu12 frame - vertical
 * args:
 *    frame - pointer to frame buffer (yu12 format)
 *    width - frame width
 *    height- frame height
 *
 * asserts:
 *    frame is not null
 *
 * returns: void
 */
static void fx_yu12_upturn(uint8_t *frame, int width, int height) {
  /*asserts*/
  assert(frame != NULL);

  int h = 0;

  uint8_t line[width]; /*line1 buffer*/

  uint8_t *pi = frame;                       // begin of first y line
  uint8_t *pf = pi + (width * (height - 1)); // begin of last y line

  /*upturn y*/
  for (h = 0; h < height / 2; ++h) { /*line iterator*/
    memcpy(line, pi, width);
    memcpy(pi, pf, width);
    memcpy(pf, line, width);

    pi += width;
    pf -= width;
  }

  /*upturn u*/
  pi = frame + (width * height);                  // begin of first u line
  pf = pi + ((width * height) / 4) - (width / 2); // begin of last u line
  for (h = 0; h < height / 2; h += 2) // every two lines = height / 4
  {                                   /*line iterator*/
    memcpy(line, pi, width / 2);
    memcpy(pi, pf, width / 2);
    memcpy(pf, line, width / 2);

    pi += width / 2;
    pf -= width / 2;
  }

  /*upturn v*/
  pi = frame + ((width * height * 5) / 4);        // begin of first v line
  pf = pi + ((width * height) / 4) - (width / 2); // begin of last v line
  for (h = 0; h < height / 2; h += 2) // every two lines = height / 4
  {                                   /*line iterator*/
    memcpy(line, pi, width / 2);
    memcpy(pi, pf, width / 2);
    memcpy(pf, line, width / 2);

    pi += width / 2;
    pf -= width / 2;
  }
}

/*
 * Flip half yu12 frame - vertical
 * args:
 *    frame - pointer to frame buffer (yu12 format)
 *    width - frame width
 *    height- frame height
 *
 * asserts:
 *    frame is not null
 *
 * returns: void
 */
static void fx_yu12_half_upturn(uint8_t *frame, int width, int height) {
  /*asserts*/
  assert(frame != NULL);

  int h = 0;

  uint8_t line[width]; /*line1 buffer*/

  uint8_t *pi = frame;                       // begin of first y line
  uint8_t *pf = pi + (width * (height - 1)); // begin of last y line

  /*upturn y*/
  for (h = 0; h < height / 2; ++h) { /*line iterator*/
    memcpy(line, pi, width);
    memcpy(pf, line, width);

    pi += width;
    pf -= width;
  }

  /*upturn u*/
  pi = frame + (width * height);                  // begin of first u line
  pf = pi + ((width * height) / 4) - (width / 2); // begin of last u line
  for (h = 0; h < height / 2; h += 2) // every two lines = height / 4
  {                                   /*line iterator*/
    memcpy(line, pi, width / 2);
    memcpy(pf, line, width / 2);

    pi += width / 2;
    pf -= width / 2;
  }

  /*upturn v*/
  pi = frame + ((width * height * 5) / 4);        // begin of first v line
  pf = pi + ((width * height) / 4) - (width / 2); // begin of last v line
  for (h = 0; h < height / 2; h += 2) // every two lines = height / 4
  {                                   /*line iterator*/
    memcpy(line, pi, width / 2);
    memcpy(pf, line, width / 2);

    pi += width / 2;
    pf -= width / 2;
  }
}

/*
 * Monochromatic effect for yu12 frame
 * args:
 *     frame - pointer to frame buffer (yu12 format)
 *     width - frame width
 *     height- frame height
 *
 * asserts:
 *     frame is not null
 *
 * returns: void
 */
static void fx_yu12_monochrome(uint8_t *frame, int width, int height) {

  uint8_t *puv = frame + (width * height); // skip luma

  int i = 0;

  for (i = 0; i < (width * height) / 2; ++i) { /* keep Y - luma */
    *puv++ = 0x80; /*median (half the max value)=128*/
  }
}

/*
 * Monochromatic Binary effect for yu12 frame
 * args:
 *     frame - pointer to frame buffer (yu12 format)
 *     width - frame width
 *     height- frame height
 *
 * asserts:
 *     frame is not null
 *
 * returns: void
 */
static void fx_yu12_binary(uint8_t *frame, int width, int height) {
  uint8_t *puv = frame;
  int i = 0;
  for (i = 0; i < (width * height); ++i) {
    if (*puv <= fx_bin_treshold)
      *puv++ = 0;
    else
      *puv++ = 255;
  }
}

#ifdef HAS_GSL

/*
 * Break yu12 image in little square pieces
 * args:
 *    frame  - pointer to frame buffer (yu12 format)
 *    width  - frame width
 *    height - frame height
 *    piece_size - multiple of 2 (we need at least 2 pixels to get the entire
 * pixel information)
 *
 * asserts:
 *    frame is not null
 */
static void fx_yu12_pieces(uint8_t *frame, int width, int height,
                           int piece_size) {
  int numx = width / piece_size;  // number of pieces in x axis
  int numy = height / piece_size; // number of pieces in y axis

  uint8_t piece[(piece_size * piece_size * 3) / 2];
  uint8_t *ppiece = piece;

  int i = 0, j = 0, w = 0, h = 0;

  /*random generator setup*/
  gsl_rng_env_setup();
  const gsl_rng_type *T = gsl_rng_default;
  gsl_rng *r = gsl_rng_alloc(T);

  int rot = 0;

  uint8_t *py = NULL;
  uint8_t *pu = NULL;
  uint8_t *pv = NULL;

  for (h = 0; h < height; h += piece_size) {
    for (w = 0; w < width; w += piece_size) {
      uint8_t *ppy = piece;
      uint8_t *ppu = piece + (piece_size * piece_size);
      uint8_t *ppv = ppu + ((piece_size * piece_size) / 4);

      for (i = 0; i < piece_size; ++i) {
        py = frame + ((h + i) * width) + w;
        for (j = 0; j < piece_size; ++j) {
          *ppy++ = *py++;
        }
      }

      for (i = 0; i < piece_size; i += 2) {
        uint8_t *pu =
            frame + (width * height) + (((h + i) * width) / 4) + (w / 2);
        uint8_t *pv = pu + ((width * height) / 4);

        for (j = 0; j < piece_size; j += 2) {
          *ppu++ = *pu++;
          *ppv++ = *pv++;
        }
      }

      ppy = piece;
      ppu = piece + (piece_size * piece_size);
      ppv = ppu + ((piece_size * piece_size) / 4);

      /*rotate piece and copy it to frame*/
      // rotation is random
      rot = (int)lround(8 * gsl_rng_uniform(r)); /*0 to 8*/

      switch (rot) {
      case 0: // do nothing
        break;
      case 5:
      case 1: // mirror
        fx_yu12_mirror(piece, piece_size, piece_size);
        break;
      case 6:
      case 2: // upturn
        fx_yu12_upturn(piece, piece_size, piece_size);
        break;
      case 4:
      case 3: // mirror upturn
        fx_yu12_upturn(piece, piece_size, piece_size);
        fx_yu12_mirror(piece, piece_size, piece_size);
        break;
      default: // do nothing
        break;
      }

      ppy = piece;
      ppu = piece + (piece_size * piece_size);
      ppv = ppu + ((piece_size * piece_size) / 4);

      for (i = 0; i < piece_size; ++i) {
        py = frame + ((h + i) * width) + w;
        for (j = 0; j < piece_size; ++j) {
          *py++ = *ppy++;
        }
      }

      for (i = 0; i < piece_size; i += 2) {
        uint8_t *pu =
            frame + (width * height) + (((h + i) * width) / 4) + (w / 2);
        uint8_t *pv = pu + ((width * height) / 4);

        for (j = 0; j < piece_size; j += 2) {
          *pu++ = *ppu++;
          *pv++ = *ppv++;
        }
      }
    }
  }

  /*free the random seed generator*/
  gsl_rng_free(r);
}

/*
 * Trail of particles obtained from the image frame
 * args:
 *    frame  - pointer to frame buffer (yu12 format)
 *    width  - frame width
 *    height - frame height
 *    trail_size  - trail size (in frames)
 *    particle_size - maximum size in pixels - should be even (square - size x
 * size)
 *
 * asserts:
 *    frame is not null
 *
 * returns: void
 */
static void fx_particles(uint8_t *frame, int width, int height, int trail_size,
                         int particle_size) {
  /*asserts*/
  assert(frame != NULL);

  int i, j, w, h = 0;
  int part_w = width >> 7;
  int part_h = height >> 6;

  /*random generator setup*/
  gsl_rng_env_setup();
  const gsl_rng_type *T = gsl_rng_default;
  gsl_rng *r = gsl_rng_alloc(T);

  /*allocation*/
  if (particles == NULL) {
    particles = calloc(trail_size * part_w * part_h, sizeof(particle_t));
    if (particles == NULL) {
      fprintf(stderr,
              "RENDER: FATAL memory allocation failure (fx_particles): %s\n",
              strerror(errno));
      exit(-1);
    }
  }

  particle_t *part = particles;
  particle_t *part1 = part;

  /*move particles in trail*/
  for (i = trail_size; i > 1; --i) {
    part += (i - 1) * part_w * part_h;
    part1 += (i - 2) * part_w * part_h;

    for (j = 0; j < part_w * part_h; ++j) {
      if (part1->decay > 0) {
        part->PX = part1->PX + (int)lround(3 * gsl_rng_uniform(r)); /*0  to 3*/
        part->PY =
            part1->PY - 4 + (int)lround(5 * gsl_rng_uniform(r)); /*-4 to 1*/

        if (ODD(part->PX))
          part->PX++; /*make sure PX is allways even*/

        if ((part->PX > (width - particle_size)) ||
            (part->PY > (height - particle_size)) || (part->PX < 0) ||
            (part->PY < 0)) {
          part->PX = 0;
          part->PY = 0;
          part->decay = 0;
        } else {
          part->decay = part1->decay - 1;
        }

        part->Y = part1->Y;
        part->U = part1->U;
        part->V = part1->V;
        part->size = part1->size;
      } else {
        part->decay = 0;
      }
      part++;
      part1++;
    }
    part = particles; /*reset*/
    part1 = part;
  }

  part = particles; /*reset*/

  /*get particles from frame (one pixel per particle - make PX allways even)*/
  for (i = 0; i < part_w * part_h; i++) {
    /* (2 * particle_size) to (width - 4 * particle_size)*/
    part->PX = 2 * particle_size +
               (int)lround((width - 6 * particle_size) * gsl_rng_uniform(r));
    /* (2 * particle_size) to (height - 4 * particle_size)*/
    part->PY = 2 * particle_size +
               (int)lround((height - 6 * particle_size) * gsl_rng_uniform(r));

    if (ODD(part->PX))
      part->PX++;

    int y_pos = part->PX + (part->PY * width);
    int u_pos = (part->PX + (part->PY * width / 2)) / 2;
    int v_pos = u_pos + ((width * height) / 4);

    part->Y = frame[y_pos];
    part->U = frame[u_pos];
    part->V = frame[v_pos];

    part->size = 1 + (int)lround((particle_size - 1) * gsl_rng_uniform(r));
    if (ODD(part->size))
      part->size++;

    part->decay = (float)trail_size;

    part++; /*next particle*/
  }

  part = particles; /*reset*/
  int line = 0;
  float blend = 0;
  float blend1 = 0;
  /*render particles to frame (expand pixel to particle size)*/
  for (i = 0; i < trail_size * part_w * part_h; i++) {
    if (part->decay > 0) {
      int y_pos = part->PX + (part->PY * width);
      int u_pos = (part->PX + (part->PY * width / 2)) / 2;
      int v_pos = u_pos + ((width * height) / 4);

      blend = part->decay / trail_size;
      blend1 = 1 - blend;

      // y
      for (h = 0; h < (part->size); h++) {
        line = h * width;
        for (w = 0; w < (part->size); w++) {
          frame[y_pos + line + w] =
              CLIP((part->Y * blend) + (frame[y_pos + line + w] * blend1));
        }
      }

      // u v
      for (h = 0; h < (part->size); h += 2) {
        line = (h * width) / 4;
        for (w = 0; w < (part->size); w += 2) {
          frame[u_pos + line + (w / 2)] = CLIP(
              (part->U * blend) + (frame[u_pos + line + (w / 2)] * blend1));
          frame[v_pos + line + (w / 2)] = CLIP(
              (part->V * blend) + (frame[v_pos + line + (w / 2)] * blend1));
        }
      }
    }
    part++;
  }

  /*free the random seed generator*/
  gsl_rng_free(r);
}

#endif

/*
 * Normalize X coordinate
 * args:
 *      i - pixel position from 0 to width-1
 *      width - frame width
 *
 * returns:
 *         normalized x coordinate (-1 to 1))
 */
double normX(int i, int width) {
  if (i < 0)
    return -1.0;
  if (i >= width)
    return 1.0;

  double x = (double)((2 * (double)(i)) / (double)(width)) - 1;

  if (x < -1)
    return -1;
  if (x > 1)
    return 1;

  return x;
}

/*
 * Normalize Y coordinate
 * args:
 *      j - pixel position from 0 to height-1
 *      height - frame height
 *
 * returns:
 *         normalized y coordinate (-1 to 1))
 */
double normY(int j, int height) {
  if (j < 0)
    return -1.0;
  if (j >= height)
    return 1.0;

  double y = (double)((2 * (double)(j)) / (double)(height)) - 1;

  if (y < -1)
    return -1;
  if (y > 1)
    return 1;

  return y;
}

/*
 * Denormalize X coordinate
 * args:
 *      x - normalized pixel position from -1 to 1
 *      width - frame width
 *
 * returns:
 *         x coordinate (0 to width -1)
 */
int denormX(double x, int width) {
  int i = (int)lround(0.5 * width * (x + 1) - 1);

  if (i < 0)
    return 0;
  if (i >= width)
    return (width - 1);

  return i;
}

/*
 * denormalize Y coordinate
 * args:
 *      y - normalized pixel position from -1 to 1
 *      height - frame height
 *
 * returns:
 *         y coordinate (0 to height -1)
 */
int denormY(double y, int height) {

  int j = (int)lround(0.5 * height * (y + 1) - 1);

  if (j < 0)
    return 0;
  if (j >= height)
    return (height - 1);

  return j;
}

#define PI 3.14159265
#define DPI 6.28318531
#define PI2 1.57079632

/*
 * fast sin replacement
 */
double fast_sin(double x) {
  if (x < -PI)
    x += DPI;
  else if (x > PI)
    x -= DPI;

  if (x < 0)
    return ((1.27323954 * x) + (.405284735 * x * x));
  else
    return ((1.27323954 * x) - (.405284735 * x * x));
}

/*
 * fast cos replacement
 */
double fast_cos(double x) {
  x += PI2;
  if (x > PI)
    x -= DPI;

  if (x < 0)
    return ((1.27323954 * x) + (.405284735 * x * x));
  else
    return ((1.27323954 * x) - (.405284735 * x * x));
}

/*
 * fast atan2 replacement
 */
double fast_atan2(double y, double x) {
  if (x == 0.0f) {
    if (y > 0.0f)
      return PI2;
    if (y == 0.0f)
      return 0.0f;
    return -PI2;
  }
  double atan;
  double z = y / x;
  if (fabs(z) < 1.0f) {
    atan = z / (1.0f + 0.28f * z * z);
    if (x < 0.0f) {
      if (y < 0.0f)
        return atan - PI;
      return atan + PI;
    }
  } else {
    atan = PI2 - z / (z * z + 0.28f);
    if (y < 0.0f)
      return atan - PI;
  }
  return atan;
}

/*
 * calculate coordinate in input frame from point in ouptut
 * (all coordinates are normalized)
 * args:
 *      x,y - output cordinates
 *      xnew, ynew - pointers to input coordinates
 *      type - type of distortion
 */
void eval_coordinates(double x, double y, double *xnew, double *ynew,
                      int type) {
  double phi, radius, radius2;

  switch (type) {
  case REND_FX_YUV_POW_DISTORT:
    radius2 = x * x + y * y;
    radius = radius2; // pow(radius,2)
    phi = fast_atan2(y, x);
    // phi = atan2(y,x);

    *xnew = radius * fast_cos(phi);
    *ynew = radius * fast_sin(phi);
    //*xnew = radius * cos(phi);
    //*ynew = radius * sin(phi);
    break;

  case REND_FX_YUV_POW2_DISTORT:
    *xnew = x * x * SIGN(x);
    *ynew = y * y * SIGN(y);
    break;

  case REND_FX_YUV_SQRT_DISTORT:
  default:
    /* square root radial funtion */
    radius2 = x * x + y * y;
    radius = sqrt(radius2);
    radius = sqrt(radius);
    phi = fast_atan2(y, x);
    // phi = atan2(y,x);

    *xnew = radius * fast_cos(phi);
    *ynew = radius * fast_sin(phi);
    //*xnew = radius * cos(phi);
    //*ynew = radius * sin(phi);
    break;
  }
}

/*
 * generate box sizes for box blur and precalculate all possible division values
 * args:
 *    sigma - standard deviation
 *    n - number of boxes
 *    blur - pointer to blur struct
 *
 * asserts:
 *    blur is not NULL
 *
 * returns: void
 */
static void boxes4gauss(int sigma, int n, blur_t *blur) {
  assert(blur != NULL);

  if (blur->n == n && blur->sigma == sigma)
    return; // already done

  int i = 0;
  int j = 0;

  blur->n = n;
  blur->sigma = sigma;

  // allocate box sizes array
  if (blur->bSizes != NULL)
    free(blur->bSizes);
  blur->bSizes = calloc(n, sizeof(int));

  double ideal_width = sqrt((12 * sigma * sigma / n) + 1);

  int wl = lround(floor(ideal_width));
  if (wl % 2 == 0)
    wl--;
  int wu = wl + 2;

  double ideal_m =
      (n * wl * wl + 4 * n * wl + 3 * n - 12 * sigma * sigma) / (4 * wl + 4);

  int m = lround(ideal_m);

  // allocate division lookup table
  if (blur->divTable != NULL) {
    for (i = 0; i < n; ++i)
      free(blur->divTable[i]);
    free(blur->divTable);
  }
  blur->divTable = calloc(n, sizeof(int *));

  for (i = 0; i < n; ++i) {
    blur->bSizes[i] = (i < m) ? wl : wu;
    blur->bSizes[i] -= 1;
    blur->bSizes[i] /= 2;

    // precalculate all possible division values for this box size
    int divider = blur->bSizes[i] + blur->bSizes[i] + 1; // r + r +1
    blur->divTable[i] = calloc(256 * divider, sizeof(int));

    for (j = 0; j < 256 * divider; ++j)
      blur->divTable[i][j] = j / divider;
  }
}

/*
 * box blur horizontal
 * args:
 *    scl - source channel (pix buffer)
 *    tcl - temporary channel (pix buffer)
 *    w - width
 *    h - height
 *    r_ind - size indice in box size array
 *    blur - pointer to blur struct
 *
 * asserts:
 *    none
 *
 * returns: void
 */
void boxBlurH(uint8_t *scl, uint8_t *tcl, int w, int h, int r_ind,
              blur_t *blur) {
  int r = blur->bSizes[r_ind];

  int i = 0;
  int j = 0;

  for (i = 0; i < h; ++i) {
    int ti = i * w;
    int li = ti;
    int ri = ti + r;

    int fv = scl[ti];
    int lv = scl[ti + w - 1];
    int val = (r + 1) * fv;

    for (j = 0; j < r; ++j)
      val += scl[ti + j];

    for (j = 0; j <= r; ++j) {
      val += scl[ri++] - fv;
      tcl[ti++] = (uint8_t)blur->divTable[r_ind][val] & 0xff;
    }

    for (j = r + 1; j < w - r; ++j) {
      val += scl[ri++] - scl[li++];
      tcl[ti++] = (uint8_t)blur->divTable[r_ind][val] & 0xff;
    }

    for (j = w - r; j < w; ++j) {
      val += lv - scl[li++];
      tcl[ti++] = (uint8_t)blur->divTable[r_ind][val] & 0xff;
    }
  }
}

/*
 * box blur total
 * args:
 *    scl - source channel (pix buffer)
 *    tcl - temporary channel (pix buffer)
 *    w - width
 *    h - height
 *    r_ind - iteration index
 *    blur - pointer to blur struct
 *
 * asserts:
 *    none
 *
 * returns: void
 */
void boxBlurT(uint8_t *scl, uint8_t *tcl, int w, int h, int r_ind,
              blur_t *blur) {
  int r = blur->bSizes[r_ind];

  int i = 0;
  int j = 0;

  for (i = 0; i < w; ++i) {
    int ti = i;
    int li = ti;
    int ri = ti + r * w;

    int fv = scl[ti];
    int lv = scl[ti + w * (h - 1)];
    int val = (r + 1) * fv;

    for (j = 0; j < r; ++j)
      val += scl[ti + j * w];

    for (j = 0; j <= r; ++j) {
      val += scl[ri] - fv;
      tcl[ti] = (uint8_t)blur->divTable[r_ind][val] & 0xff;
      ri += w;
      ti += w;
    }

    for (j = r + 1; j < h - r; ++j) {
      val += scl[ri] - scl[li];
      tcl[ti] = (uint8_t)blur->divTable[r_ind][val] & 0xff;
      li += w;
      ri += w;
      ti += w;
    }

    for (j = h - r; j < h; ++j) {
      val += lv - scl[li];
      tcl[ti] = (uint8_t)blur->divTable[r_ind][val] & 0xff;
      li += w;
      ti += w;
    }
  }
}

/*
 * box blur
 * args:
 *    scl - source channel (pix buffer)
 *    tcl - temporary channel (pix buffer)
 *    width - channel width
 *    height - channel height
 *    r_ind - size indice in box size array
 *    blur - pointer to blur struct
 *
 * asserts:
 *    none
 *
 * returns: void
 */
void boxBlur(uint8_t *scl, uint8_t *tcl, int width, int height, int r_ind,
             blur_t *blur) {
  memcpy(tcl, scl, width * height);

  boxBlurH(tcl, scl, width, height, r_ind, blur);
  boxBlurT(scl, tcl, width, height, r_ind, blur);
}

/*
 * gaussian blur aprox with 3 box blur iterations
 * args:
 *    frame  - pointer to frame buffer (yu12 format)
 *    width  - frame width
 *    height - frame height
 *    sigma - deviation
 *    ind - blur struct index to use
 *
 * asserts:
 *    frame is not null
 *    ind is smaller than blur struct array lenght
 *
 * returns: void
 */
void fx_yu12_gauss_blur(uint8_t *frame, int width, int height, int sigma,
                        int ind) {
  assert(frame != NULL);

  assert(ind < ARRAY_LENGTH(blur));

  if (!tmpbuffer)
    tmpbuffer = malloc(width * height * 3 / 2);

  if (!blur[ind])
    blur[ind] = calloc(1, sizeof(blur_t));

  // iterate 3 times
  boxes4gauss(sigma, 3, blur[ind]);

  boxBlur(frame, tmpbuffer, width, height, 0, blur[ind]);
  boxBlur(tmpbuffer, frame, width, height, 1, blur[ind]);
  boxBlur(frame, tmpbuffer, width, height, 2, blur[ind]);
}

/*
 * distort (lens effect)
 * args:
 *    frame  - pointer to frame buffer (yu12 format)
 *    width  - frame width
 *    height - frame height
 *    box_width - central box width where distort is to be applied (if < 10 use
 * frame width) box_height - central box height where distort is to be applied
 * (if < 10 use frame height)
 *
 * asserts:
 *    frame is not null
 *
 * returns: void
 */
void fx_yu12_distort(uint8_t *frame, int width, int height, int box_width,
                     int box_height, int type) {
  assert(frame != NULL);

  if (!tmpbuffer)
    tmpbuffer = malloc(width * height * 3 / 2);

  memcpy(tmpbuffer, frame, width * height * 3 / 2);
  uint8_t *pu = frame + (width * height);
  uint8_t *pv = pu + (width * height) / 4;
  uint8_t *tpu = tmpbuffer + (width * height);
  uint8_t *tpv = tpu + (width * height) / 4;

  // index table
  uint32_t *idx_table = NULL;
  uint32_t *tb_pu = NULL;
  uint32_t *tb_pv = NULL;

  int j = 0;
  int i = 0;
  int den_x = 0;
  int den_y = 0;
  double x = 0;
  double y = 0;
  double xnew = 0;
  double ynew = 0;
  uint32_t ind = 0;

  int start_x = 0;
  int start_y = 0;

  if (box_width > 10 && width > box_width)
    start_x = (width - box_width) / 2;
  else
    box_width = width;

  if (box_height > 10 && height > box_height)
    start_y = (height - box_height) / 2;
  else
    box_height = height;

  // choose lookup table
  switch (type) {
  case REND_FX_YUV_POW_DISTORT:
    idx_table = TB_Pow_ind;
    break;

  case REND_FX_YUV_POW2_DISTORT:
    idx_table = TB_Pow2_ind;
    break;

  case REND_FX_YUV_SQRT_DISTORT:
  default:
    idx_table = TB_Sqrt_ind;
    break;
  }

  if (idx_table == NULL) // fill lookup table
  {
    idx_table = calloc(width * height * 3 / 2, sizeof(uint32_t));

    tb_pu = idx_table + (width * height);
    tb_pv = tb_pu + (width * height) / 4;

    for (j = 0; j < height; ++j) {
      y = normY(j, height);
      for (i = 0; i < width; ++i) {
        x = normX(i, width);
        eval_coordinates(x, y, &xnew, &ynew, type);

        den_x = denormX(xnew, width);
        den_y = denormY(ynew, height);

        idx_table[i + (j * width)] = den_x + (den_y * width);
      }
    }

    for (j = 0; j < height / 2; ++j) {
      y = normY(j, height / 2);
      for (i = 0; i < width / 2; ++i) {
        x = normX(i, width / 2);
        eval_coordinates(x, y, &xnew, &ynew, type);

        den_x = denormX(xnew, width / 2);
        den_y = denormY(ynew, height / 2);

        tb_pu[i + (j * width / 2)] = den_x + (den_y * width / 2);
        tb_pv[i + (j * width / 2)] = den_x + (den_y * width / 2);
      }
    }
    // store the table pointer in the matching global
    switch (type) {
    case REND_FX_YUV_POW_DISTORT:
      TB_Pow_ind = idx_table;
      break;

    case REND_FX_YUV_POW2_DISTORT:
      TB_Pow2_ind = idx_table;
      break;

    case REND_FX_YUV_SQRT_DISTORT:
    default:
      TB_Sqrt_ind = idx_table;
      break;
    }
  }

  // apply the distortion
  //(luma)
  for (j = 0; j < box_height; j++) {
    for (i = 0; i < box_width; i++) {
      int bi = i + start_x;
      int bj = j + start_y;

      ind = bi + (bj * box_width);

      frame[ind] = tmpbuffer[idx_table[ind]];
    }
  }
  // chroma
  tb_pu = idx_table + (width * height);
  tb_pv = tb_pu + (width * height) / 4;

  for (j = 0; j < box_height / 2; j++) {
    for (i = 0; i < box_width / 2; i++) {
      int bi = i + start_x / 2;
      int bj = j + start_y / 2;

      ind = bi + (bj * box_width / 2);

      pu[ind] = tpu[tb_pu[ind]];
      pv[ind] = tpv[tb_pv[ind]];
    }
  }
}

/*
 * Apply fx filters
 * args:
 *    frame - pointer to frame buffer (yu12 format)
 *    width - frame width
 *    height - frame height
 *    mask  - or'ed filter mask
 *
 * asserts:
 *    frame is not null
 *
 * returns: void
 */
void render_fx_apply(uint8_t *frame, int width, int height, uint32_t mask) {
  if (mask != REND_FX_YUV_NOFILT) {
#ifdef HAS_GSL
    if (mask & REND_FX_YUV_PARTICLES)
      fx_particles(frame, width, height, 20, 4);
#endif

    if (mask & REND_FX_YUV_MIRROR)
      fx_yu12_mirror(frame, width, height);

    if (mask & REND_FX_YUV_HALF_MIRROR)
      fx_yu12_half_mirror(frame, width, height);

    if (mask & REND_FX_YUV_UPTURN)
      fx_yu12_upturn(frame, width, height);

    if (mask & REND_FX_YUV_HALF_UPTURN)
      fx_yu12_half_upturn(frame, width, height);

    if (mask & REND_FX_YUV_NEGATE)
      fx_yuv_negative(frame, width, height);

    if (mask & REND_FX_YUV_MONOCR)
      fx_yu12_monochrome(frame, width, height);

#ifdef HAS_GSL
    if (mask & REND_FX_YUV_PIECES)
      fx_yu12_pieces(frame, width, height, 16);
#endif
    if (mask & REND_FX_YUV_SQRT_DISTORT)
      fx_yu12_distort(frame, width, height, 0, 0, REND_FX_YUV_SQRT_DISTORT);

    if (mask & REND_FX_YUV_POW_DISTORT)
      fx_yu12_distort(frame, width, height, 0, 0, REND_FX_YUV_POW_DISTORT);

    if (mask & REND_FX_YUV_POW2_DISTORT)
      fx_yu12_distort(frame, width, height, 0, 0, REND_FX_YUV_POW2_DISTORT);

    if (mask & REND_FX_YUV_BLUR)
      fx_yu12_gauss_blur(frame, width, height, 2, 0);

    if (mask & REND_FX_YUV_BLUR2)
      fx_yu12_gauss_blur(frame, width, height, 6, 1);

    if (mask & REND_FX_YUV_BINARY)
      fx_yu12_binary(frame, width, height);

  } else
    render_clean_fx();
}

/*
 * clean fx filters
 * args:
 *    none
 *
 * asserts:
 *    none
 *
 * returns: void
 */
void render_clean_fx() {
  if (particles != NULL) {
    free(particles);
    particles = NULL;
  }

  int j = 0;
  for (j = 0; j < 2; ++j) {
    if (blur[j] != NULL) {
      if (blur[j]->bSizes != NULL)
        free(blur[j]->bSizes);

      if (blur[j]->divTable != NULL) {
        int i = 0;
        for (i = 0; i < blur[j]->n; ++i)
          free(blur[j]->divTable[i]);
        free(blur[j]->divTable);
      }
      free(blur[j]);
      blur[j] = NULL;
    }
  }

  if (tmpbuffer != NULL) {
    free(tmpbuffer);
    tmpbuffer = NULL;
  }

  if (TB_Sqrt_ind != NULL) {
    free(TB_Sqrt_ind);
    TB_Sqrt_ind = NULL;
  }

  if (TB_Pow_ind != NULL) {
    free(TB_Pow_ind);
    TB_Pow_ind = NULL;
  }

  if (TB_Pow2_ind != NULL) {
    free(TB_Pow2_ind);
    TB_Pow2_ind = NULL;
  }
}