- 1 year ago
Microsoft GDI. BitBlt vs StretchDIBits
Both BitBlt
and StretchDIBits
are functions in the Microsoft Windows Graphics Device Interface (GDI) used for graphics operations, but they serve different purposes:
BitBlt:
BitBlt
(Bit Block Transfer) is a GDI function used for simple and efficient block transfers of pixels between device contexts (DCs) or bitmaps. It can be used to copy rectangular regions of pixels from one DC or bitmap to another DC or bitmap.The basic syntax of
BitBlt
is as follows:cppBOOL BitBlt(
HDC hdcDest,
int nXDest,
int nYDest,
int nWidth,
int nHeight,
HDC hdcSrc,
int nXSrc,
int nYSrc,
DWORD dwRop
);
BitBlt
is typically used for fast, simple 2D graphics operations like copying an image, scrolling, or creating sprite animations. It is not suitable for resizing or stretching images.StretchDIBits:
StretchDIBits
is also a GDI function used for transferring pixels between DCs or bitmaps, but it is specifically designed for resizing or stretching images. It allows you to scale an image when copying it from the source to the destination DC or bitmap.The basic syntax of
StretchDIBits
is as follows:cppint StretchDIBits(
HDC hdc,
int xDest,
int yDest,
int DestWidth,
int DestHeight,
int xSrc,
int ySrc,
int SrcWidth,
int SrcHeight,
const void *lpBits,
const BITMAPINFO *lpbmi,
UINT iUsage,
DWORD rop
);
StretchDIBits
is more versatile thanBitBlt
because it allows you to scale images to different sizes while maintaining the aspect ratio. However, resizing images usingStretchDIBits
can be computationally more expensive than a simpleBitBlt
operation.
In summary, if you need to perform a simple block transfer of pixels between DCs or bitmaps, use BitBlt
. If you need to resize or stretch images while transferring them, use StretchDIBits
. The choice between the two functions depends on the specific graphics operation you want to perform.