CreateDIBSection

CreateDIBSection is a Windows GDI function that creates a device-independent bitmap (DIB) section, yielding an HBITMAP that can be used for rendering and, optionally, for direct memory access to the pixel data. It is commonly used when an application needs fast pixel manipulation alongside standard GDI drawing.

Prototype and parameters:

HBITMAP CreateDIBSection(

HDC hdc,

const BITMAPINFO* pbmi,

UINT iUsage,

void** ppvBits,

HANDLE hSection,

DWORD dwOffset

);

The iUsage parameter selects how to interpret the color table, typically DIB_RGB_COLORS (or DIB_PAL_COLORS in some cases). pbmi points to a BITMAPINFO describing the bitmap’s width, height, and color format. ppvBits receives a pointer to the memory buffer containing the actual pixel data. hSection may be a file mapping handle to enable shared memory; if NULL, the memory is allocated privately. dwOffset specifies where the bitmap data begins within the mapping object.

Return value and usage:

The function returns an HBITMAP handle on success, or NULL on failure (GetLastError provides details). If ppvBits is non-NULL, the returned pointer gives direct access to the bitmap pixels, which can be modified in memory and then rendered by GDI operations such as BitBlt or StretchBlt after selecting the HBITMAP into a device context.

Notes:

CreateDIBSection is useful for high-performance image processing and for scenarios requiring direct pixel access or cross-process sharing via a file mapping. It complements other GDI bitmap functions such as CreateBitmap and GetDIBits.

See also:

BITMAPINFO, HBITMAP, CreateBitmap, BitBlt, GetDIBits.