RGSS Bitmap Manipulation In C++

#include <windows.h>
#define DLLIMPORT extern "C" __declspec( dllexport )

typedef struct PixelStruct {
    unsigned char blue;
    unsigned char green;
    unsigned char red;
    unsigned char alpha;
} *PIXEL;

typedef struct {
    //-------------------------------------
    // STRUCT 1 - RGSSBITMAP
    //-------------------------------------
    char DearCompilerIReallyDontWantThis[16];
    //DWORD flags;          // char flags[4];
    //DWORD klass;          // char klass[4];
    //void (*dmark)(void*); // char dmark[4];
    //void (*dfree)(void*); // char dfree[4];

    //-------------------------------------
    // STRUCT 2 - BITMAPSTRUCT
    //-------------------------------------
    struct {
        char FuckThisShit[8];
        // DWORD unk1; // char unk1[4];
        // DWORD unk2; // char unk2[4];

    //-------------------------------------
    // STRUCT 3 - RGSSBMINFO
    //-------------------------------------
        struct {
            char ReallyDontNeedThis[8];
            //DWORD unk1; // char unk1[4];
            //DWORD unk2; // char unk2[4];

    //-------------------------------------
    // STRUCT 4 - BITMAPINFOHEADER
    //-------------------------------------
            struct {
                char PLEASEJustLetMeWork[4];
                // DWORD biSize; // char biSize[4];
                long width;
                long height;
                char COMPILER_I_WILL_NOT_SAY_ANYTHING_MORE___YOU_IDIOT[28];
                // WORD       biPlanes;        // char biPlanes[2];
                // WORD       biBitCount;      // char biBitCount[2];
                // DWORD      biCompression;   // char biCompression[4];
                // DWORD      biSizeImage;     // char biSizeImage[4];
                // LONG       biXPelsPerMeter; // char biXPelsPerMeter[4];
                // LONG       biYPelsPerMeter; // char biYPelsPerMeter[4];
                // DWORD      biClrUsed;       // char biClrUsed[4];
                // DWORD      biClrImportant;  // char biClrImportant[4];
            } *C;
    //-------------------------------------
    // STRUCT 5 - RGBQUAD
    //-------------------------------------
            PIXEL FirstRow;

    //-------------------------------------
    // STRUCT 5 - RGBQUAD
    //-------------------------------------
            PIXEL LastRow;
        } *B;
    } *A;
} RGSSBITMAP;

#define BitmapData(b) ((b)->A->B->FirstRow)
#define BitmapInfo(b) ((b)->A->B->C)

// Pega o ponteiro para o pixel em x,y no bitmap
// Entrada : Bitmap, posição x, posição y
// Saída   : Se for uma posição válida, ponteiro para o pixel, caso contrário, NULL.
PIXEL GetPixelPointer(RGSSBITMAP *bitmap, unsigned int x, unsigned int y){
    // Checa X e Y
    if (
        (x < 0) or
        (x >= BitmapInfo(bitmap)->width) or
        (y < 0) or
        (y >= BitmapInfo(bitmap)->height)
    ) return NULL;

    // Posiciona "cursor" no primeiro pixel (0,0)
    PIXEL data = (PIXEL)BitmapData(bitmap);

    // Move até a linha y
    data += y * BitmapInfo(bitmap)->width;

    // Move até a coluna x
    data += x;

    // Retorna
    return data;
}

// Equivalente a Bitmap#get_pixel, do RGSS
// Entrada : Bitmap, posição x, posição y, estrutura de saída do pixel
// Saída   : 0 = Falha | 1 = Sucesso
DLLIMPORT int BitmapGetPixel(RGSSBITMAP *bitmap, unsigned int x, unsigned int y, PIXEL out){
    PIXEL data = GetPixelPointer(bitmap, x, y);
    if (data) {
        memcpy(out, data, sizeof(PIXEL));
        return TRUE;
    } else {
        return FALSE;
    }
}

// Equivalente a Bitmap#set_pixel, do RGSS
// Entrada : Bitmap, posição x, posição y, estrutura com pixel de entrada
// Saída   : 0 = Falha | 1 = Sucesso
DLLIMPORT int BitmapSetPixel(RGSSBITMAP *bitmap, unsigned int x, unsigned int y, PIXEL in) {
    PIXEL data = GetPixelPointer(bitmap, x, y);
    if (data) {
        memcpy(data, in, sizeof(PIXEL));
        return TRUE;
    } else {
        return FALSE;
    }
}