/**
 * Common header files and definitions for bmpedit.
 */

#if defined(__GNUC__)
    #define unlikely_if(cond) if (__builtin_expect((cond), 0))
    #define likely_if(cond) if (__builtin_expect((cond), !0))
#else
    #define unlikely_if if
    #define likely_if if
#endif


/* This pragma removes the requirement for aligned structs. It allows mapping of
 * the struct directly onto the file's contents in memory.
 */
#pragma pack(push, 1)

/**
 * Structs for the 24-bit pixel type, as well as the bmp header.
 *
 * The pixel struct is in reverse order because we read them directly from
 * mmap'd memory, which reverses the endianness.
 */
typedef struct {
    uint8_t blue;
    uint8_t green;
    uint8_t red;
} pixel;

typedef struct {
    uint32_t size;
    uint32_t width;
    uint32_t height;
    uint16_t colorplanes;
    uint16_t bpp;
    uint32_t compression;
    uint32_t arraysize;
    uint32_t h_res;
    uint32_t v_res;
    uint32_t colors;
    uint32_t important_colors;
} dib_header;

typedef struct {
    uint16_t magic;
    uint32_t size;
    uint16_t reserved1;
    uint16_t reserved2;
    uint32_t data_offset;
    dib_header dib;
} bmp_header;

typedef struct {
    int x;
    int y;
} gradients;
#pragma pack(pop)

inline static int get_gradient(gradients *gs, int rowsize, int xpos, int ypos);
inline static int bounded(int bound, int pos);
inline static pixel* lookup(pixel *data, int width, int height, int padding, int x, int y);
inline static int gen_padding(bmp_header *header);
inline static void convert_grayscale(pixel *p);
inline static int get_direction(gradients *gs, int rowsize, int xpos, int ypos);

gradients* sobel_operator(pixel *data, int rowsize, int rows, int padding);

void threshold_shade(bmp_header *header, pixel *data, int, double threshold, double);
void gaussian_blur(bmp_header *header, pixel *data, int radius, double, double);
void linear_blur(bmp_header *header, pixel *data, int lblur_times, double, double);
void monochrome_shade(bmp_header *header, pixel *data, int, double, double);
void sobel_detect(bmp_header *header, pixel *data, int radius, double threshold, double);
void canny_detect(bmp_header *header, pixel *data, int radius, double upper, double lower);


void canny_follow(pixel *data, gradients *gs, int width, int height, int padding, int x, int y, double lower);

static void usage(void);
int main(int argc, char *argv[]);