Re: Faulty bitmap writing function?

typedef struct pixelstruct
{
   byte r;
   byte g;
   byte b;
};

pixelstruct myPixel[500][500]

void SaveData(const char *filename)
{
FILE * f_out;

// save bitmap file headers
BITMAPFILEHEADER fileHeader;
BITMAPINFOHEADER infoHeader;

fileHeader.bfType = 0x4d42;
fileHeader.bfSize = 0;
fileHeader.bfReserved1 = 0;
fileHeader.bfReserved2 = 0;
fileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) +
sizeof(BITMAPINFOHEADER);

infoHeader.biSize = sizeof(infoHeader);
infoHeader.biWidth = bitmap_dx;
infoHeader.biHeight = bitmap_dy;
infoHeader.biPlanes = 1;
infoHeader.biBitCount = 24;
infoHeader.biCompression = BI_RGB;
infoHeader.biSizeImage = 0;
infoHeader.biXPelsPerMeter = 0;
infoHeader.biYPelsPerMeter = 0;
infoHeader.biClrUsed = 0;
infoHeader.biClrImportant = 0;

// dibsection information
BITMAPINFO info;
info.bmiHeader = infoHeader;

// ------------------
// THE IMPORTANT CODE
// ------------------
// create a dibsection and blit the window contents to the bitmap
/* HDC winDC = GetWindowDC(window);
HDC memDC = CreateCompatibleDC(hDC);
BYTE* memory = 0;
// turn winDC into bitmap
HBITMAP bitmap = CreateDIBSection(winDC, &info, DIB_RGB_COLORS,
(void**)&memory, 0, 0);
//SetBitmapBits(bitmap, sizeof(byBits), byBits);
// turn bitmap into memDC
SelectObject(memDC, bitmap);
BitBlt(memDC, 0, 0, bitmap_dx, bitmap_dy, winDC, 0, 0, SRCCOPY);
DeleteDC(memDC);
ReleaseDC(window, winDC);

// save dibsection data
int bytes = (((24*bitmap_dx + 31) & (~31))/8)*bitmap_dy;
file.write((const char *)memory,bytes);

// HA HA, forgot paste in the DeleteObject lol, happy now ;)?
//DeleteObject(bitmap);*/

//Write BMP file

RGBQUAD pRGB[256];

for (int q = 0; q < 256; q++) {
pRGB[q].rgbBlue = 0;//0xff;
pRGB[q].rgbGreen = 0;//xff;
pRGB[q].rgbRed = 0;//xff;
pRGB[q].rgbReserved = 0x0;
}

// Open file
if ((f_out = fopen(filename, "wb")) == NULL)
       OutputDebugString("Error opening file ");

// Write bmp file header
if (fwrite(&fileHeader, 1, sizeof(BITMAPFILEHEADER), f_out) <
sizeof(BITMAPFILEHEADER)) {
       OutputDebugString("Error writing bitmap file header\n");
       fclose(f_out); }

// Write bmp info header
if (fwrite(&infoHeader, 1, sizeof(BITMAPINFOHEADER), f_out) <
sizeof(BITMAPINFOHEADER)) {
       OutputDebugString("Error writing bitmap info header\n");
       fclose(f_out); }

if (fwrite(pRGB,1, sizeof(RGBQUAD)*256, f_out) < (sizeof(RGBQUAD)*256)) {
//if (fwrite(&pRGB,1, sizeof(RGBQUAD), f_out) < (sizeof(RGBQUAD))) {
OutputDebugString("Error writing RGBQUAD\n");
fclose(f_out);
}

//Write BMP data
//memset(myPixel, 0, sizeof(COLORREF)*1000*1000);
for(int i=0; i < bitmap_dy; i++) {
int j = 0;
 for(j=0; j < bitmap_dx; j++) { // i and j swapped

       fwrite(&myPixel[j][i].r,1,1,f_out);
       fwrite(&myPixel[j][i].g,1,1,f_out);
       fwrite(&myPixel[j][i].b,1,1,f_out);
           }
for(j*=3; j%4!=0; j++) fwrite(&zero,1,1,f_out); // Padding row to 4-byte
multiple!

    }
fclose(f_out);
cprintf ("\nFinished Drawing\n");
}

I've cross-checked that myPixel[4][6] for example
is black,RGB(0,0,0), but when that pixel is written to
the file. The position of the black spot has gone to
the lower right of the screen.... can anyone spot
the error of this code snippet? This is a modified version of a cloned
source
Anyway! Thanks for double-checking if you can.
Jack