How to display a big JPEG picture with DirectDraw

[Tal Rashas Guardianship]

Hi,there I'd like to load a JPEG picture onto a DirectDraw7 surface. For parsing the JPEG, I have used GDI+, the code like this: Bitmap bitmap(L"F:\\images\\CIMG1531_1.jpg"); g_width = bitmap.GetWidth(); g_height = bitmap.GetHeight(); //create surface, load image DDSURFACEDESC2 ddsd2; INIT_STRUCT(ddsd2); ddsd2.dwFlags = DDSD_CAPS|DDSD_WIDTH|DDSD_HEIGHT; ddsd2.dwWidth = g_width; ddsd2.dwHeight = g_height; ddsd2.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN|DDSCAPS_VIDEOMEMORY; if(FAILED(g_lpdd7->CreateSurface(&ddsd2, &g_lpddsSecond, NULL))) return -1; HDC hDC; if(SUCCEEDED(g_lpddsSecond->GetDC(&hDC))) { Graphics graphics(hDC); graphics.DrawImage(&bitmap, 0, 0); g_lpddsSecond->ReleaseDC(hDC); } when the picture is small, the code works fine. otherwise, there's only a part of the picture could be display! The test picture has a resolution of 2990*2000, it's big, the problem occurs. when I change the code like this: ddsd2.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN|DDSCAPS_SYSTEMMEMORY; to create the surface in system memory, the area displayed increased, but not all yet.

[Mark Salsbery]

How are you displaying it once you've drawn it on the surface? What video mode?

[Tal Rashas Guardianship]

this is the drawing code: RECT dest, src; dest.left = pt.x+100; dest.top = pt.y+50; dest.right = pt.x + 400; dest.bottom = pt.y + 350; src.left = 0; src.top = 0; src.right = g_width-1; src.bottom = g_height-1; g_lpddsPrimary->Blt(&dest, g_lpddsSecond, &src, DDBLT_WAIT, NULL); g_lpddsPrimary is the primary surface video mode?sorry I don't know what you mean

[Mark Salsbery]

giant_hao wrote:

video mode?sorry I don't know what you mean

I meant display mode. I asked just in case you were trying to draw 2990x2000 image on 1280x1024 display without stretching. I would think your code should work. Perhaps Creating Wide Surfaces[^] is an issue since you are creating an offscreen surface larger than the primary..(?) Also what happens if you try this (keep the aspect ratio of the src image)... RECT dest, src; dest.left = pt.x+100; dest.top = pt.y+50; dest.right = dest.left + (g_width / 10 - 1); dest.bottom = dest.top + (g_height / 10 - 1); src.left = 0; src.top = 0; src.right = g_width-1; src.bottom = g_height-1; g_lpddsPrimary->Blt(&dest, g_lpddsSecond, &src, DDBLT_WAIT, NULL);