1 files changed, 121 insertions, 0 deletions
diff --git a/media/libaom/src/third_party/fastfeat/nonmax.c b/media/libaom/src/third_party/fastfeat/nonmax.c
new file mode 100644
index 000000000..0438c4dc1
--- /dev/null
+++ b/media/libaom/src/third_party/fastfeat/nonmax.c
@@ -0,0 +1,121 @@
+// clang-format off
+#include <stdlib.h>
+#include "fast.h"
+
+
+#define Compare(X, Y) ((X)>=(Y))
+
+xy* nonmax_suppression(const xy* corners, const int* scores, int num_corners, int* ret_num_nonmax)
+{
+  int num_nonmax=0;
+  int last_row;
+  int* row_start;
+  int i, j;
+  xy* ret_nonmax;
+  const int sz = (int)num_corners;
+
+  /*Point above points (roughly) to the pixel above the one of interest, if there
+    is a feature there.*/
+  int point_above = 0;
+  int point_below = 0;
+
+
+  if(num_corners < 1)
+  {
+    *ret_num_nonmax = 0;
+    return 0;
+  }
+
+  ret_nonmax = (xy*)malloc(num_corners * sizeof(xy));
+
+  /* Find where each row begins
+     (the corners are output in raster scan order). A beginning of -1 signifies
+     that there are no corners on that row. */
+  last_row = corners[num_corners-1].y;
+  row_start = (int*)malloc((last_row+1)*sizeof(int));
+
+  for(i=0; i < last_row+1; i++)
+    row_start[i] = -1;
+
+  {
+    int prev_row = -1;
+    for(i=0; i< num_corners; i++)
+      if(corners[i].y != prev_row)
+      {
+        row_start[corners[i].y] = i;
+        prev_row = corners[i].y;
+      }
+  }
+
+
+
+  for(i=0; i < sz; i++)
+  {
+    int score = scores[i];
+    xy pos = corners[i];
+
+    /*Check left */
+    if(i > 0)
+      if(corners[i-1].x == pos.x-1 && corners[i-1].y == pos.y && Compare(scores[i-1], score))
+        continue;
+
+    /*Check right*/
+    if(i < (sz - 1))
+      if(corners[i+1].x == pos.x+1 && corners[i+1].y == pos.y && Compare(scores[i+1], score))
+        continue;
+
+    /*Check above (if there is a valid row above)*/
+    if(pos.y > 0)
+      if (row_start[pos.y - 1] != -1)
+      {
+        /*Make sure that current point_above is one
+          row above.*/
+        if(corners[point_above].y < pos.y - 1)
+          point_above = row_start[pos.y-1];
+
+        /*Make point_above point to the first of the pixels above the current point,
+          if it exists.*/
+        for(; corners[point_above].y < pos.y && corners[point_above].x < pos.x - 1; point_above++)
+        {}
+
+
+        for(j=point_above; corners[j].y < pos.y && corners[j].x <= pos.x + 1; j++)
+        {
+          int x = corners[j].x;
+          if( (x == pos.x - 1 || x ==pos.x || x == pos.x+1) && Compare(scores[j], score))
+            goto cont;
+        }
+
+      }
+
+    /*Check below (if there is anything below)*/
+    if(pos.y >= 0)
+      if (pos.y != last_row && row_start[pos.y + 1] != -1 && point_below < sz) /*Nothing below*/
+      {
+        if(corners[point_below].y < pos.y + 1)
+          point_below = row_start[pos.y+1];
+
+        /* Make point below point to one of the pixels belowthe current point, if it
+           exists.*/
+        for(; point_below < sz && corners[point_below].y == pos.y+1 && corners[point_below].x < pos.x - 1; point_below++)
+        {}
+
+        for(j=point_below; j < sz && corners[j].y == pos.y+1 && corners[j].x <= pos.x + 1; j++)
+        {
+          int x = corners[j].x;
+          if( (x == pos.x - 1 || x ==pos.x || x == pos.x+1) && Compare(scores[j],score))
+            goto cont;
+        }
+      }
+
+    ret_nonmax[num_nonmax++] = corners[i];
+cont:
+    ;
+  }
+
+  free(row_start);
+  *ret_num_nonmax = num_nonmax;
+  return ret_nonmax;
+}
+
+// clang-format on