I am using CreateDIBitmap() and always realeasing it by DeleteObject(). I am using it when my slider is moving and I noticed that memory used is increasing every time.
This is my function that creating HBITMAP from indexed bitmap data:
HBITMAP APP_Make_HBITMAP_From_Bitmap_Indexed(int _width, int _height, u_int32* _table_ptr, u_int8* _index_ptr)
{
// window bitamp structure - to use with window API
struct sAPP_Windows_Bitmap
{
BITMAPINFOHEADER bmiHeader;
RGBQUAD bmiColors[256];
};
sAPP_Windows_Bitmap tmp_w_bitmap;
tmp_w_bitmap.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
tmp_w_bitmap.bmiHeader.biWidth = _width;
tmp_w_bitmap.bmiHeader.biHeight = -1 * _height;
tmp_w_bitmap.bmiHeader.biPlanes = 1;
tmp_w_bitmap.bmiHeader.biBitCount = 8;
tmp_w_bitmap.bmiHeader.biCompression = BI_RGB;
tmp_w_bitmap.bmiHeader.biSizeImage = 0;
tmp_w_bitmap.bmiHeader.biXPelsPerMeter = 0;
tmp_w_bitmap.bmiHeader.biYPelsPerMeter = 0;
tmp_w_bitmap.bmiHeader.biClrUsed = 256;
tmp_w_bitmap.bmiHeader.biClrImportant = 0;
for (unsigned int i = 0; i < 256; i )
{
tmp_w_bitmap.bmiColors[i].rgbRed = (_table_ptr[i] >> 8) & 0x0ff;
tmp_w_bitmap.bmiColors[i].rgbGreen = (_table_ptr[i] >> 16) & 0x0ff;
tmp_w_bitmap.bmiColors[i].rgbBlue = (_table_ptr[i] >> 24) & 0x0ff;
}
return CreateDIBitmap(GetDC(APP_hWnd), &tmp_w_bitmap.bmiHeader, CBM_INIT, _index_ptr, (BITMAPINFO*)&tmp_w_bitmap, DIB_RGB_COLORS);
}
Above function is used in the WM_HSCROLL message:
case WM_HSCROLL:
{
LRESULT slider_pos = SendMessage(GetDlgItem(_hwnd, IDS_DC_SLIDER), TBM_GETPOS, 0, 0);
wchar_t output[4];
wsprintf(output, L"%ld", slider_pos);
SetWindowText(GetDlgItem(_hwnd, IDS_DC_INTENSITY), output);
int intensity = _wtoi(output);
int intensity_offset = intensity * 256;
convert_hbm_texture_256 = APP_Make_HBITMAP_From_Bitmap_Indexed(256, 256, convert_table intensity_offset, convert_index);
RedrawWindow(_hwnd, NULL, NULL, RDW_INVALIDATE);
}
break;
in WM_PAINT: message I am displayng the bitmap and Realeasing it
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(_hwnd, &ps);
EndPaint(_hwnd, &ps);
// display 256 preview
PAINTSTRUCT ps_texture_256;
HDC hdc_texture_256 = BeginPaint(GetDlgItem(_hwnd, IDS_DC_TEXTURE_256), &ps_texture_256);
HDC hdc_tmp_256 = CreateCompatibleDC(hdc_texture_256);
SelectObject(hdc_tmp_256, convert_hbm_texture_256);
BitBlt(hdc_texture_256, 0, 0, 256, 256, hdc_tmp_256, 0, 0, SRCCOPY);
DeleteDC(hdc_tmp_256);
DeleteObject(convert_hbm_texture_256);
EndPaint(GetDlgItem(_hwnd, IDS_DC_TEXTURE_256), &ps_texture_256);
return (INT_PTR)TRUE;
}
explanation:
I am using slider to move thru my color tables that has different intensity. Every time I am moving the slider the memory ussage of my application is increasing - I don't know why because I am realeasing DeleteObject(convert_hbm_texture_256); every time after display.
Please note that I am also using that same function APP_Make_HBITMAP_From_Bitmap_Indexed in different part of my application that works fine and dopesn't have that memory issues. But in this case I am only using it once (after drag and drop).
Thanks in advance..
CodePudding user response:
You definitely have a GDI leak of device contexts in APP_Make_HBITMAP_From_Bitmap_Indexed
here:
return CreateDIBitmap(GetDC(APP_hWnd), &tmp_w_bitmap.bmiHeader, CBM_INIT, _index_ptr, (BITMAPINFO*)&tmp_w_bitmap, DIB_RGB_COLORS);
You call GetDC
, but never call ReleaseDC
. It is a good idea to check entire application with some GDI leaks detection tool like GDIView or Deleaker.
A WM_PAINT handler should deal with the window whose window procedure is called. Such a handler must start with single BeginPaint and end with single EndPaint.
Your handler deals with two windows.
SelectObject returns old object's handle. You must select it back later.