#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>

#define IS_LOOKING_N(HEADING) HEADING > 40960 && HEADING < 57344
#define IS_LOOKING_NE(HEADING) HEADING == 57344
#define IS_LOOKING_E(HEADING) HEADING > 57344 && HEADING < 8192
#define IS_LOOKING_SE(HEADING) HEADING == 8192
#define IS_LOOKING_S(HEADING) HEADING > 8192 && HEADING < 24576
#define IS_LOOKING_SW(HEADING) HEADING == 24576
#define IS_LOOKING_W(HEADING) HEADING > 24576 && HEADING < 40960
#define IS_LOOKING_NW(HEADING) HEADING == 40960

#define MAX_FACE_DIRECTION 7
#define CALC_AND_RET_FACE_DIRECTION(N_FACE_DIRECTION, N_E_S_W) N_FACE_DIRECTION = (FaceDirection)(N_FACE_DIRECTION + N_E_S_W);printf("%d\n", N_FACE_DIRECTION);N_FACE_DIRECTION = (N_FACE_DIRECTION > MAX_FACE_DIRECTION ? (FaceDirection)(N_FACE_DIRECTION - INVALID) : N_FACE_DIRECTION);printf("%d\n", N_FACE_DIRECTION);return N_FACE_DIRECTION

enum NESW
{
    N = 0,
    NW = 1,
    W = 2,
    SW = 3,
    S = 4,
    SE = 5,
    E = 6,
    NE = 7
};

enum FaceDirection
{
    FRONT = 0,
    FRONT_RIGHT = 1,
    RIGHT = 2,
    BEHIND_RIGHT = 3,
    BEHIND = 4,
    BEHIND_LEFT = 5,
    LEFT = 6,
    FRONT_LEFT = 7,
    INVALID = 8
};

FaceDirection getFaceDirection(int srcX, int srcY, int targetX, int targetY, NESW targetHeading)
{
    FaceDirection faceDirection = INVALID;
    int differenceX = abs(abs(targetX - srcX));
    int differenceY = abs(abs(targetY - srcY));

    int rectInfoY = differenceX * 2;

    if (srcY < (targetY - rectInfoY))
    {
        faceDirection = FRONT;
        CALC_AND_RET_FACE_DIRECTION(faceDirection, targetHeading);
    }
    else if (srcY > (targetY + rectInfoY))
    {
        faceDirection = BEHIND;
        CALC_AND_RET_FACE_DIRECTION(faceDirection, targetHeading);
    }

    int rectInfoX = differenceY * 2;

    if (srcX < (targetX - rectInfoX))
    {
        faceDirection = LEFT;
        CALC_AND_RET_FACE_DIRECTION(faceDirection, targetHeading);
    }
    else if (srcX > (targetX + rectInfoX))
    {
        faceDirection = RIGHT;
        CALC_AND_RET_FACE_DIRECTION(faceDirection, targetHeading);
    }

    if (srcX < targetX && srcY < targetY)
    {
        faceDirection = FRONT_LEFT;
        CALC_AND_RET_FACE_DIRECTION(faceDirection, targetHeading);
    }
    else if (srcX < targetX && srcY > targetY)
    {
        faceDirection = BEHIND_LEFT;
        CALC_AND_RET_FACE_DIRECTION(faceDirection, targetHeading);
    }
    else if (srcX > targetX && srcY > targetY)
    {
        faceDirection = BEHIND_RIGHT;
        CALC_AND_RET_FACE_DIRECTION(faceDirection, targetHeading);
    }
    else if (srcX > targetX && srcY < targetY)
    {
        faceDirection = FRONT_RIGHT;
        CALC_AND_RET_FACE_DIRECTION(faceDirection, targetHeading);
    }

    return INVALID;
}

NESW getNESW(unsigned int heading)
{
    if (IS_LOOKING_N(heading))
        return N;
    else if (IS_LOOKING_NW(heading))
        return NW;
    else if (IS_LOOKING_W(heading))
        return W;
    else if (IS_LOOKING_SW(heading))
        return SW;
    else if (IS_LOOKING_S(heading))
        return S;
    else if (IS_LOOKING_SE(heading))
        return SE;
    else if (IS_LOOKING_E(heading))
        return E;
    else if (IS_LOOKING_NE(heading))
        return NE;
}

int main(int argc, char **argv)
{
    FaceDirection fd = INVALID;
    printf("%d\n", fd);

    for (;;)
    {
        int sX = rand() % 50 - 25;
        int sY = rand() % 50 - 25;

        fd = getFaceDirection(sX, sY, 0, 0, NE);
        printf("sX: %d\tsY: %d\ttX: %d\ttY: %d\ttHeading: %d\t->\t%d\n", sX, sY, 0, 0, 50000, fd);
        Sleep(1000);
    }

    return 0;
}