[DimensionSlider]

Задача решена следующим способом

Код:

HANDLE hBmp


case WM_CREATE:
			hBmp = LoadImageA( 0, "IntroPic.bmp", IMAGE_BITMAP, 0, 0, LR_DEFAULTCOLOR | LR_LOADFROMFILE);
			
			break;
		
		case WM_ERASEBKGND:
			BITMAP bm;			
			HDC hdcMem; 
			hdcMem = CreateCompatibleDC( hDC ); 
			SelectObject(hdcMem, hBmp); 
			GetObject( hBmp, sizeof(BITMAP), (LPVOID)&bm);
			RECT r; 
			GetClientRect(hWnd, &r); 
				
			w = r.right  - r.left;
			h = r.bottom - r.top;
			bw = bm.bmWidth;
			bh = bm.bmHeight; 

			for(int i = 0; i < w; i += bw)
				for(int j = 0; j < h; j += bh)
					BitBlt(hDC, i, j, bm.bmWidth, bm.bmHeight, hdcMem, 0, 0, SRCCOPY); 

			DeleteDC( hdcMem ); 


			break;