In this article I will briefly describe the process of using Windows' functions to load a bitmap (.bmp) file of any type, and place it on a newly-created DirectDraw surface. In this particular article, we will be using the DirectX 7.0 SDK.
[size="5"]DirectDraw Surface Creation
Creating a new DirectDraw surface is very easy, and this function will create a surface of any size. This can also be used as a general-purpose surface creation function, and if you were writing an engine class you'd probably put it in there somewhere.
All this code does is create a DDSURFACEDESC2 structure that describes the dimensions of the surface, and tells DirectDraw that it's an off-screen surface. Then, the call to DirectDraw (in this case, DirectDraw is the lpdd pointer) just creates the surface.
void CreateSurface(LPDIRECTDRAWSURFACE7 *lpSource, int xs, int ys)
ddsd.dwSize = sizeof(ddsd);
ddsd.dwFlags = DDSD_CAPS | DDSD_WIDTH | DDSD_HEIGHT;
ddsd.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN;
ddsd.dwWidth = xs;
ddsd.dwHeight = ys;
lpdd->CreateSurface(&ddsd, lpSource, NULL);
To load .bmp files we will use the standard Windows graphics library (GDI). This is best because if we're in a mode with a palette then Windows will automatically re-map the bitmap colours to the nearest in the palette. Here is the code that blits a loaded bitmap to a surface....
void DrawHBitmap(IDirectDrawSurface7 *lpSurface, HBITMAP hBitmap, int x, int y, int width, int height)
if (lpSurface == NULL || hBitmap == NULL)
hdcImage = CreateCompatibleDC(NULL);
GetObject(hBitmap, sizeof(bm), &bm);
width = width == 0 ? bm.bmWidth : width;
height = height == 0 ? bm.bmHeight : height;
BitBlt(hdc, x, y, width, height, hdcImage, 0, 0, SRCCOPY);
and here is the code that loads, blits, then unloads the bitmap:
void CreateBitmapSurface(LPDIRECTDRAWSURFACE7 lpSurface, char *fname, int xs, int ys)
CreateSurface(&lpSurface, xs, ys);
hBitmap = LoadImage(NULL, fname, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
DrawHBitmap(lpSurface, hBitmap, 0, 0, xs, ys);
And to round it all up, here's some example code that loads the file "test.bmp" (width = 128, height = 128) into the lpddsTest surface, and then releases it again:
* Declare the surface object
* Load the bitmap file into it
CreateBitmapSurface(lpddsTest, "test.bmp", 128, 128);
* The lpddsTest surface now contains the "test.bmp" file
* Release the surface