third_party/fastfeat/fast.h

// Copyright (c) 2006, 2008 Edward Rosten
// All rights reserved.
//
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// clang-format off
#ifndef FAST_H
#define FAST_H

typedef struct { int x, y; } xy;
typedef unsigned char byte;

int aom_fast9_corner_score(const byte* p, const int pixel[], int bstart);

// Returns NULL on memory allocation failure.
xy* aom_fast9_detect(const byte* im, int xsize, int ysize, int stride, int b, int* ret_num_corners);

// If num_corners > 0, returns NULL on memory allocation failure.
int* aom_fast9_score(const byte* i, int stride, const xy* corners, int num_corners, int b);

// Sets *ret_num_corners to -1 (and returns NULL) on memory allocation failure.
// Sets *ret_num_corners to 0 if nothing went wrong but no corners were found.
xy* aom_fast9_detect_nonmax(const byte* im, int xsize, int ysize, int stride, int b,
                            int** ret_scores, int* ret_num_corners);

xy* aom_nonmax_suppression(const xy* corners, const int* scores, int num_corners,
                           int** ret_scores, int* ret_num_nonmax);


#endif
// clang-format on