C C - Read pairs of integers from file

Code
#include <Windows.h>



typedef struct {

    // ONLY 4 BITS USED FOR EACH COORDINATE. MAXIMUM NUMBER IT CAN HANDLE IS 15

    // THIS LOWERS THE STRUCT SIZE BY HALF

    unsigned int X : 0b1111;

    unsigned int Y : 0b1111;

} COORDINATE;



#define IS_ANSI_INTEGER(X) (((X)>=(0x30))&&((X)<=(0x39)))

#define TO_INTEGER(X) ((X)-(0x30))

#define OTHER_ERROR 0

#define ALL_OK 1

#define CORRUPT_COORDINATE_FILE 2



unsigned char GET_COORDINATES(const unsigned short* FILE_PATH, COORDINATE** FOUND_COORDINATES, unsigned int* NUMBER_OF_COORDINATES_FOUND) {

    if (!FILE_PATH || !*FILE_PATH || !FOUND_COORDINATES || !NUMBER_OF_COORDINATES_FOUND) {

        return OTHER_ERROR;

    }

    // DOES FILE EXIST?

    if (INVALID_FILE_ATTRIBUTES == GetFileAttributesW(FILE_PATH)) {

        return OTHER_ERROR;

    }

    // OPEN FILE

    void* FILE = CreateFileW(FILE_PATH, FILE_READ_ACCESS, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);

    if (!FILE) {

        return OTHER_ERROR;

    }

    // GET THE SIZE OF FILE IN BYTES

    unsigned char STATUS = OTHER_ERROR;

    unsigned int SIZE = GetFileSize(FILE, 0);

    if (!SIZE) {

        goto ABORT_WITH_FH;

    }

    // ALLOCATE MEMORY TO STORE ENTIRE FILE

    void* MEM = VirtualAlloc(0, SIZE, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);

    if (!MEM) {

        goto ABORT_WITH_FH;

    }

    // READ ENTIRE FILE INTO MEMORY

    DWORD READ = 0;

    if (!ReadFile(FILE, MEM, SIZE, &READ, 0)) {

        goto ABORT_WITH_FH_MEM;

    }

    unsigned int INITIAL_COORDINATE_CAPACITY = 10;

    // IF SOME OTHER COORDINATES WERE PREVIOUSLY ALLOCATED, FREE THEM

    if (*FOUND_COORDINATES) {

        HeapFree(GetProcessHeap(), 0, *FOUND_COORDINATES);

        *FOUND_COORDINATES = 0;

    }

    // ALLOCATE HEAP MEMORY FOR 10 COORDINATES TO BEGIN WITH

    *FOUND_COORDINATES = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(COORDINATE) * INITIAL_COORDINATE_CAPACITY);

    if (!*FOUND_COORDINATES) {

        goto ABORT_WITH_FH_MEM;

    }

    COORDINATE CURRENT = { 0 };

    unsigned int NUMBER_COUNT = 0;

    // GO TROUGH EACH BYTE OF THE FILE

    for (unsigned char I = 0; I < SIZE; ++I) {

        // GET THE BYTE AT THE CURRENT INDEX OF THE FILE

        unsigned char C = ((unsigned char *)MEM)[I];

        // IS THE CURRENT BYTE AN ASCII NUMBER?

        if (IS_ANSI_INTEGER(C)) {

            // INCREASE THE TOTAL NUMBER OF NUMBERS FOUND

            NUMBER_COUNT += 1;

            // IF THE NUMBER COUNT IS EVEN (MEANING WE FINISHED ANOTHER PAIR OF XY COORDINATES)

            if (!(NUMBER_COUNT % 2)) {

                // CONVERT THE CURRENT ASCII BYTE TO AN ACTUAL NUMBER

                CURRENT.Y = TO_INTEGER(C);

                // IF WE ARE ABOUT TO GO OVER THE CAPACITY OF OUR COORDINATE LIST, ALLOCATE MEMORY FOR 10 MORE COORDINATES

                if (INITIAL_COORDINATE_CAPACITY == (NUMBER_COUNT / 2)) {

                    INITIAL_COORDINATE_CAPACITY += 10;

                    void* TEMP = HeapReAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, *FOUND_COORDINATES, sizeof(COORDINATE) * INITIAL_COORDINATE_CAPACITY);

                    if (!TEMP) {

                        goto ABORT_WITH_FH_MEM_HEAP;

                    }

                    *FOUND_COORDINATES = (COORDINATE*)TEMP;

                }

                // SAVE THE CURRENT COORDINATE

                *(COORDINATE*)((unsigned int)*FOUND_COORDINATES + (*NUMBER_OF_COORDINATES_FOUND * sizeof(COORDINATE))) = CURRENT;

                // INCREASE THE NUMBER OF FOUND COORDINATES

                *NUMBER_OF_COORDINATES_FOUND += 1;

            }

            // THE NUMBER COUNT IS UNEVEN/ODD, MEANS WE REACHED A NEW PAIR OF XY COORDINATES

            else {

                CURRENT.X = TO_INTEGER(C);

            }

        }

    }

    // IF THE TOTAL NUMBER COUNT IS UNEVEN/ODD, IT MEANS THERE WERE EXTRA NUMBERS IN THE FILE

    if (NUMBER_COUNT % 2) {

        STATUS = CORRUPT_COORDINATE_FILE;

        // CLOSE FILE, FREE MEMORY ALLOCATED FOR FILE DATA

        goto ABORT_WITH_FH_MEM;

    }

    STATUS = ALL_OK;

    // CLOSE FILE, FREE MEMORY ALLOCATED FOR FILE DATA

    goto ABORT_WITH_FH_MEM;

    // FREE ALLOCATED HEAP MEMORY FOR COORDINATES

ABORT_WITH_FH_MEM_HEAP:

    HeapFree(GetProcessHeap(), 0, *FOUND_COORDINATES);

    // FREE MEMORY ALLOCATED FOR FILE DATA

ABORT_WITH_FH_MEM:

    VirtualFree(MEM, 0, MEM_RELEASE);

    // CLOSE FILE

ABORT_WITH_FH:

    CloseHandle(FILE);

    return STATUS;

}



int main()

{

    COORDINATE* C = 0;

    unsigned int N = 0;

    unsigned char STATUS = GET_COORDINATES(L"C:\\Users\\User\\Desktop\\a.txt", &C, &N);

    printf("STATUS: %X\nFOUND: %d\n\n", STATUS, N);

    for (unsigned int I = 0; I < N; ++I) {

        printf("%d %d\n", C[I].X, C[I].Y);

    }

    getchar();

    return 0;

}