SetDIBitsToDevice causes image to flip, why?

[uus99]

I have a grayscale image of 100x100px, where the top half is gray (pixel value=128) and the bottom half is black (value=0); however when i plot it to screen, it comes flipped. Why is that? Can anyone help? Here is the source; The result on screen is black followed by gray, which is not what i want. Why is it flipped? void CPopUpDlg::OnButton1() { BITMAPINFO *m_pBmiImage; CDC *pDC; BYTE *m_pImg; pDC =this->GetDC(); DWORD bitmapInfoSize; int i; int Width=100; int Height=100; //image of 8bit , 100x100pixels int m_iSize = Width * Height; m_pImg = new BYTE[m_iSize]; // Bitmap info structure for the image bitmapInfoSize = sizeof(BITMAPINFO) + 255*sizeof(RGBQUAD); m_pBmiImage = (BITMAPINFO*)new BYTE[bitmapInfoSize]; m_pBmiImage->bmiHeader.biSize = sizeof(BITMAPINFOHEADER); m_pBmiImage->bmiHeader.biPlanes = 1; m_pBmiImage->bmiHeader.biBitCount = 8; m_pBmiImage->bmiHeader.biCompression = BI_RGB; m_pBmiImage->bmiHeader.biSizeImage = 0; m_pBmiImage->bmiHeader.biXPelsPerMeter = 0; m_pBmiImage->bmiHeader.biYPelsPerMeter = 0; m_pBmiImage->bmiHeader.biClrUsed = 0; m_pBmiImage->bmiHeader.biClrImportant = 0; m_pBmiImage->bmiHeader.biWidth = Width; m_pBmiImage->bmiHeader.biHeight = Height; //Set the color table as just grays. for (i = 0 ; i < 256 ; i++) { m_pBmiImage->bmiColors[i].rgbBlue = (BYTE)i; m_pBmiImage->bmiColors[i].rgbGreen = (BYTE)i; m_pBmiImage->bmiColors[i].rgbRed = (BYTE)i; m_pBmiImage->bmiColors[i].rgbReserved = 0; } //first half of the image is gray for(i=0;i<100*50;i++) m_pImg[i]=128; //second half of the image is black for(i=100*50;i<100*100;i++) m_pImg[i]=0; //Plot to screen SetDIBitsToDevice(pDC->m_hDC, 100, 100, Width, Height, 0, 0, 0, Height, m_pImg, m_pBmiImage, DIB_RGB_COLORS); delete[] m_pImg; delete m_pBmiImage; }

[Monty2]

its a complete guess, might not work but worth a try m_pBmiImage->bmiHeader.biHeight = -Height; specify negative height i can't even remember what my point is now, but anyway, i'm correct Barring unforeseen acts of God and Adminstrators, my server will be up tomorrow. I'm more worried about the Adminstrators.

[uus99]

Thanks, works just fine! Now the image plots correctly! Thanks a lot for the prompt reply!! :)