content: package com.alium.orin.helper;
  
  import android.graphics.Bitmap;
  
  import java.util.ArrayList;
  import java.util.concurrent.Callable;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  
  /**
   * Blur using Java code.
   * <p/>
   * This is a compromise between Gaussian Blur and Box blur
   * It creates much better looking blurs than Box Blur, but is
   * 7x faster than my Gaussian Blur implementation.
   * <p/>
   * I called it Stack Blur because this describes best how this
   * filter works internally: it creates a kind of moving stack
   * of colors whilst scanning through the image. Thereby it
   * just has to add one new block of color to the right side
   * of the stack and remove the leftmost color. The remaining
   * colors on the topmost layer of the stack are either added on
   * or reduced by one, depending on if they are on the right or
   * on the left side of the stack.
   *
   * @author Enrique López Mañas <eenriquelopez@gmail.com>
   *         http://www.neo-tech.es
   *         <p/>
   *         Author of the original algorithm: Mario Klingemann <mario.quasimondo.com>
   *         <p/>
   *         Based heavily on http://vitiy.info/Code/stackblur.cpp
   *         See http://vitiy.info/stackblur-algorithm-multi-threaded-blur-for-cpp/
   * @copyright: Enrique López Mañas
   * @license: Apache License 2.0
   */
  public class StackBlur {
  
      static final int EXECUTOR_THREADS = Runtime.getRuntime().availableProcessors();
      static final ExecutorService EXECUTOR = Executors.newFixedThreadPool(EXECUTOR_THREADS);
  
      private static final short[] stackblur_mul = {
              512, 512, 456, 512, 328, 456, 335, 512, 405, 328, 271, 456, 388, 335, 292, 512,
              454, 405, 364, 328, 298, 271, 496, 456, 420, 388, 360, 335, 312, 292, 273, 512,
              482, 454, 428, 405, 383, 364, 345, 328, 312, 298, 284, 271, 259, 496, 475, 456,
              437, 420, 404, 388, 374, 360, 347, 335, 323, 312, 302, 292, 282, 273, 265, 512,
              497, 482, 468, 454, 441, 428, 417, 405, 394, 383, 373, 364, 354, 345, 337, 328,
              320, 312, 305, 298, 291, 284, 278, 271, 265, 259, 507, 496, 485, 475, 465, 456,
              446, 437, 428, 420, 412, 404, 396, 388, 381, 374, 367, 360, 354, 347, 341, 335,
              329, 323, 318, 312, 307, 302, 297, 292, 287, 282, 278, 273, 269, 265, 261, 512,
              505, 497, 489, 482, 475, 468, 461, 454, 447, 441, 435, 428, 422, 417, 411, 405,
              399, 394, 389, 383, 378, 373, 368, 364, 359, 354, 350, 345, 341, 337, 332, 328,
              324, 320, 316, 312, 309, 305, 301, 298, 294, 291, 287, 284, 281, 278, 274, 271,
              268, 265, 262, 259, 257, 507, 501, 496, 491, 485, 480, 475, 470, 465, 460, 456,
              451, 446, 442, 437, 433, 428, 424, 420, 416, 412, 408, 404, 400, 396, 392, 388,
              385, 381, 377, 374, 370, 367, 363, 360, 357, 354, 350, 347, 344, 341, 338, 335,
              332, 329, 326, 323, 320, 318, 315, 312, 310, 307, 304, 302, 299, 297, 294, 292,
              289, 287, 285, 282, 280, 278, 275, 273, 271, 269, 267, 265, 263, 261, 259
      };
  
      private static final byte[] stackblur_shr = {
              9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17,
              17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19,
              19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,
              20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,
              21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
              21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22,
              22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
              22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23,
              23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
              23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
              23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
              23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
              24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
              24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
              24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
              24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24
      };
  
      public static Bitmap blur(Bitmap original, float radius) {
          int w = original.getWidth();
          int h = original.getHeight();
          int[] currentPixels = new int[w * h];
          original.getPixels(currentPixels, 0, w, 0, 0, w, h);
          int cores = EXECUTOR_THREADS;
  
          ArrayList<BlurTask> horizontal = new ArrayList<BlurTask>(cores);
          ArrayList<BlurTask> vertical = new ArrayList<BlurTask>(cores);
          for (int i = 0; i < cores; i++) {
              horizontal.add(new BlurTask(currentPixels, w, h, (int) radius, cores, i, 1));
              vertical.add(new BlurTask(currentPixels, w, h, (int) radius, cores, i, 2));
          }
  
          try {
              EXECUTOR.invokeAll(horizontal);
          } catch (InterruptedException e) {
              return null;
          }
  
          try {
              EXECUTOR.invokeAll(vertical);
          } catch (InterruptedException e) {
              return null;
          }
  
          return Bitmap.createBitmap(currentPixels, w, h, Bitmap.Config.ARGB_8888);
      }
  
      private static void blurIteration(int[] src, int w, int h, int radius, int cores, int core, int step) {
          int x, y, xp, yp, i;
          int sp;
          int stack_start;
          int stack_i;
  
          int src_i;
          int dst_i;
  
          long sum_r, sum_g, sum_b,
                  sum_in_r, sum_in_g, sum_in_b,
                  sum_out_r, sum_out_g, sum_out_b;
  
          int wm = w - 1;
          int hm = h - 1;
          int div = (radius * 2) + 1;
          int mul_sum = stackblur_mul[radius];
          byte shr_sum = stackblur_shr[radius];
          int[] stack = new int[div];
  
          if (step == 1) {
              int minY = core * h / cores;
              int maxY = (core + 1) * h / cores;
  
              for (y = minY; y < maxY; y++) {
                  sum_r = sum_g = sum_b =
                          sum_in_r = sum_in_g = sum_in_b =
                                  sum_out_r = sum_out_g = sum_out_b = 0;
  
                  src_i = w * y; // start of line (0,y)
  
                  for (i = 0; i <= radius; i++) {
                      stack_i = i;
                      stack[stack_i] = src[src_i];
                      sum_r += ((src[src_i] >>> 16) & 0xff) * (i + 1);
                      sum_g += ((src[src_i] >>> 8) & 0xff) * (i + 1);
                      sum_b += (src[src_i] & 0xff) * (i + 1);
                      sum_out_r += ((src[src_i] >>> 16) & 0xff);
                      sum_out_g += ((src[src_i] >>> 8) & 0xff);
                      sum_out_b += (src[src_i] & 0xff);
                  }
  
  
                  for (i = 1; i <= radius; i++) {
                      if (i <= wm) src_i += 1;
                      stack_i = i + radius;
                      stack[stack_i] = src[src_i];
                      sum_r += ((src[src_i] >>> 16) & 0xff) * (radius + 1 - i);
                      sum_g += ((src[src_i] >>> 8) & 0xff) * (radius + 1 - i);
                      sum_b += (src[src_i] & 0xff) * (radius + 1 - i);
                      sum_in_r += ((src[src_i] >>> 16) & 0xff);
                      sum_in_g += ((src[src_i] >>> 8) & 0xff);
                      sum_in_b += (src[src_i] & 0xff);
                  }
  
  
                  sp = radius;
                  xp = radius;
                  if (xp > wm) xp = wm;
                  src_i = xp + y * w; //   img.pix_ptr(xp, y);
                  dst_i = y * w; // img.pix_ptr(0, y);
                  for (x = 0; x < w; x++) {
                      src[dst_i] = (int)
                              ((src[dst_i] & 0xff000000) |
                                      ((((sum_r * mul_sum) >>> shr_sum) & 0xff) << 16) |
                                      ((((sum_g * mul_sum) >>> shr_sum) & 0xff) << 8) |
                                      ((((sum_b * mul_sum) >>> shr_sum) & 0xff)));
                      dst_i += 1;
  
                      sum_r -= sum_out_r;
                      sum_g -= sum_out_g;
                      sum_b -= sum_out_b;
  
                      stack_start = sp + div - radius;
                      if (stack_start >= div) stack_start -= div;
                      stack_i = stack_start;
  
                      sum_out_r -= ((stack[stack_i] >>> 16) & 0xff);
                      sum_out_g -= ((stack[stack_i] >>> 8) & 0xff);
                      sum_out_b -= (stack[stack_i] & 0xff);
  
                      if (xp < wm) {
                          src_i += 1;
                          ++xp;
                      }
  
                      stack[stack_i] = src[src_i];
  
                      sum_in_r += ((src[src_i] >>> 16) & 0xff);
                      sum_in_g += ((src[src_i] >>> 8) & 0xff);
                      sum_in_b += (src[src_i] & 0xff);
                      sum_r += sum_in_r;
                      sum_g += sum_in_g;
                      sum_b += sum_in_b;
  
                      ++sp;
                      if (sp >= div) sp = 0;
                      stack_i = sp;
  
                      sum_out_r += ((stack[stack_i] >>> 16) & 0xff);
                      sum_out_g += ((stack[stack_i] >>> 8) & 0xff);
                      sum_out_b += (stack[stack_i] & 0xff);
                      sum_in_r -= ((stack[stack_i] >>> 16) & 0xff);
                      sum_in_g -= ((stack[stack_i] >>> 8) & 0xff);
                      sum_in_b -= (stack[stack_i] & 0xff);
                  }
  
              }
          }
  
          // step 2
          else if (step == 2) {
              int minX = core * w / cores;
              int maxX = (core + 1) * w / cores;
  
              for (x = minX; x < maxX; x++) {
                  sum_r = sum_g = sum_b =
                          sum_in_r = sum_in_g = sum_in_b =
                                  sum_out_r = sum_out_g = sum_out_b = 0;
  
                  src_i = x; // x,0
                  for (i = 0; i <= radius; i++) {
                      stack_i = i;
                      stack[stack_i] = src[src_i];
                      sum_r += ((src[src_i] >>> 16) & 0xff) * (i + 1);
                      sum_g += ((src[src_i] >>> 8) & 0xff) * (i + 1);
                      sum_b += (src[src_i] & 0xff) * (i + 1);
                      sum_out_r += ((src[src_i] >>> 16) & 0xff);
                      sum_out_g += ((src[src_i] >>> 8) & 0xff);
                      sum_out_b += (src[src_i] & 0xff);
                  }
                  for (i = 1; i <= radius; i++) {
                      if (i <= hm) src_i += w; // +stride
  
                      stack_i = i + radius;
                      stack[stack_i] = src[src_i];
                      sum_r += ((src[src_i] >>> 16) & 0xff) * (radius + 1 - i);
                      sum_g += ((src[src_i] >>> 8) & 0xff) * (radius + 1 - i);
                      sum_b += (src[src_i] & 0xff) * (radius + 1 - i);
                      sum_in_r += ((src[src_i] >>> 16) & 0xff);
                      sum_in_g += ((src[src_i] >>> 8) & 0xff);
                      sum_in_b += (src[src_i] & 0xff);
                  }
  
                  sp = radius;
                  yp = radius;
                  if (yp > hm) yp = hm;
                  src_i = x + yp * w; // img.pix_ptr(x, yp);
                  dst_i = x;               // img.pix_ptr(x, 0);
                  for (y = 0; y < h; y++) {
                      src[dst_i] = (int)
                              ((src[dst_i] & 0xff000000) |
                                      ((((sum_r * mul_sum) >>> shr_sum) & 0xff) << 16) |
                                      ((((sum_g * mul_sum) >>> shr_sum) & 0xff) << 8) |
                                      ((((sum_b * mul_sum) >>> shr_sum) & 0xff)));
                      dst_i += w;
  
                      sum_r -= sum_out_r;
                      sum_g -= sum_out_g;
                      sum_b -= sum_out_b;
  
                      stack_start = sp + div - radius;
                      if (stack_start >= div) stack_start -= div;
                      stack_i = stack_start;
  
                      sum_out_r -= ((stack[stack_i] >>> 16) & 0xff);
                      sum_out_g -= ((stack[stack_i] >>> 8) & 0xff);
                      sum_out_b -= (stack[stack_i] & 0xff);
  
                      if (yp < hm) {
                          src_i += w; // stride
                          ++yp;
                      }
  
                      stack[stack_i] = src[src_i];
  
                      sum_in_r += ((src[src_i] >>> 16) & 0xff);
                      sum_in_g += ((src[src_i] >>> 8) & 0xff);
                      sum_in_b += (src[src_i] & 0xff);
                      sum_r += sum_in_r;
                      sum_g += sum_in_g;
                      sum_b += sum_in_b;
  
                      ++sp;
                      if (sp >= div) sp = 0;
                      stack_i = sp;
  
                      sum_out_r += ((stack[stack_i] >>> 16) & 0xff);
                      sum_out_g += ((stack[stack_i] >>> 8) & 0xff);
                      sum_out_b += (stack[stack_i] & 0xff);
                      sum_in_r -= ((stack[stack_i] >>> 16) & 0xff);
                      sum_in_g -= ((stack[stack_i] >>> 8) & 0xff);
                      sum_in_b -= (stack[stack_i] & 0xff);
                  }
              }
          }
  
      }
  
      private static class BlurTask implements Callable<Void> {
          private final int[] _src;
          private final int _w;
          private final int _h;
          private final int _radius;
          private final int _totalCores;
          private final int _coreIndex;
          private final int _round;
  
          public BlurTask(int[] src, int w, int h, int radius, int totalCores, int coreIndex, int round) {
              _src = src;
              _w = w;
              _h = h;
              _radius = radius;
              _totalCores = totalCores;
              _coreIndex = coreIndex;
              _round = round;
          }
  
          @Override
          public Void call() throws Exception {
              blurIteration(_src, _w, _h, _radius, _totalCores, _coreIndex, _round);
              return null;
          }
  
      }
  }
  