GDI Double Buffering Not Working

Vote count:

0

I am using the Bitmap_Operations() class provided here:

http://ift.tt/1BL7Djr

I am initializing it using the following:

biop = new Bitmap_Operations();
biop->Initialize_Buffers(m_hWND, 1);
biop->Create_Buffer(0);

Then I call DrawBox() from a different thread.

void DrawBox(int x, int y, int r, int g, int b, int size, int thickness)
{
    // Brush style to hollow
    m_LogBrush.lbStyle = BS_NULL;

    // Create a logical brush and select into the context
    m_hBrush = CreateBrushIndirect(&m_LogBrush);
    HBRUSH hbrOldBrush = (HBRUSH)SelectObject(biop->Get_DC_Buffer(0), m_hBrush);

    // Create a logical pen and select into the context
    m_hPen = CreatePen(PS_SOLID, thickness, RGB(r, g, b));
    HPEN hpOldPen = (HPEN)SelectObject(biop->Get_DC_Buffer(0), m_hPen);

    // Draw the rectangle
    Rectangle(biop->Get_DC_Buffer(0), (x - size / 2), (y - size / 2), (x + size / 2), (y + size / 2));

    // Remove the object
    SelectObject(biop->Get_DC_Buffer(0), hbrOldBrush);  // first you must restore DC to original state
    SelectObject(biop->Get_DC_Buffer(0), hpOldPen);     // same here

    biop->Copy_to_Screen(0);

    DeleteObject(m_hBrush);
    DeleteObject(m_hPen);
}

The problem is, if I remove all the "biop->Get_DC_Buffer(0)" and replace with m_hDC it draws fine but with a flicker. If I leave in the buffer calls, nothing gets drawn to the screen at all.

Am I doing something wrong?

Thanks

asked 2 mins ago

Steven

1

GDI Double Buffering Not Working