Preallocates texture memory for the given bitmap even if it's
not yet visible on screen. Useful for accessing the bitmap texture from a DLL.
bmap - Name or pointer of a bitmap
Pointer to the Direct3DTexture9 used by the bmap. This texture can be
manipulated by DirectX functions.
Bitmap bmap will preloaded in the video card texture memory.
low, depends on bitmap size
When preloading a bitmap, it does not 'know' yet whether it's intended for an
overlay panel, and thus black won't be transparent.
bmap splashmap = "splash.pcx";
dummy = bmap_preload(splashmap); // preload the splash screen