The StretchDIBits function copies the color data for a rectangle of pixels in a device-independent bitmap (DIB) to the specified destination rectangle. If the destination rectangle is larger than the source rectangle, this function stretches the rows and columns of color data to fit the destination rectangle. If the destination rectangle is smaller than the source rectangle, this function compresses the rows and columns by using the specified raster operation.
int StretchDIBits(
| HDC hdc, | // handle of device context |
| int XDest, | // x-coordinate of upper-left corner of dest. rect. |
| int YDest, | // y-coordinate of upper-left corner of dest. rect. |
| int nDestWidth, | // width of destination rectangle |
| int nDestHeight, | // height of destination rectangle |
| int XSrc, | // x-coordinate of upper-left corner of source rect. |
| int YSrc, | // y-coordinate of upper-left corner of source rect. |
| int nSrcWidth, | // width of source rectangle |
| int nSrcHeight, | // height of source rectangle |
| CONST VOID *lpBits, | // address of bitmap bits |
| CONST BITMAPINFO *lpBitsInfo, | // address of bitmap data |
| UINT iUsage, | // usage |
| DWORD dwRop | // raster operation code |
| ); |
Parameters
hdc
Identifies the destination device context.
XDest
Specifies the x-coordinate, in logical units, of the upper-left corner of the destination rectangle.
YDest
Specifies the y-coordinate, in logical units, of the upper-left corner of the destination rectangle.
nDestWidth
Specifies the width, in logical units, of the destination rectangle.
nDestHeight
Specifies the height, in logical units, of the destination rectangle.
XSrc
Specifies the x-coordinate, in pixels, of the source rectangle in the DIB.
YSrc
Specifies the y-coordinate, in pixels, of the source rectangle in the DIB.
nSrcWidth
Specifies the width, in pixels, of the source rectangle in the DIB.
nSrcHeight
Specifies the height, in pixels, of the source rectangle in the DIB.
lpBits
Points to the DIB bits, which are stored as an array of bytes.
lpBitsInfo
Points to a BITMAPINFO structure that contains information about the DIB.
iUsage
Specifies whether the bmiColors member of the BITMAPINFO structure was provided and, if so, whether bmiColors contains explicit red, green, blue (RGB) values or indices. The iUsage parameter must be one of the following values:
| Value | Description |
| DIB_PAL_COLORS | The array contains 16-bit indices into the logical palette of the source device context. |
| DIB_RGB_COLORS | The color table contains literal RGB values. |
dwRop
Specifies how the source pixels, the destination device context's current brush, and the destination pixels are to be combined to form the new image.
Return Values
If the function succeeds, the return value is the number of scan lines copied.
If the function fails, the return value is GDI_ERROR. To get extended error information, call GetLastError.
Remarks
The origin of a bottom-up DIB is the bottom-left corner; the origin of a top-down DIB is the upper-left corner.
StretchDIBits creates a mirror image of a bitmap if the signs of the nSrcWidth and nDestWidth parameters, or of the nSrcHeight and nDestHeight parameters differ. If nSrcWidth and nDestWidth have different signs, the function creates a mirror image of the bitmap along the x-axis. If nSrcHeight and nDestHeight have different signs, the function creates a mirror image of the bitmap along the y-axis.
See Also