This function copies a bitmap from a source rectangle into a destination rectangle, stretching or compressing the bitmap to fit the dimensions of the destination rectangle, if necessary. Windows stretches or compresses the bitmap according to the stretching mode set in the destination device context.
At a Glance
| Header file: | Wingdi.h |
| Windows CE versions: | 1.0 and later |
Syntax
BOOL StretchBlt(HDC hdcDest, int nXOriginDest, int nYOriginDest,
int nWidthDest, int nHeightDest, HDC hdcSrc, int nXOriginSrc,
int nYOriginSrc, int nWidthSrc, int nHeightSrc, DWORD dwRop);
Parameters
hdcDest
[in] Handle to the destination device context.
nXOriginDest
[in] Specifies the x-coordinate, in logical units, of the upper-left corner of the destination rectangle.
nYOriginDest
[in] Specifies the y-coordinate, in logical units, of the upper-left corner of the destination rectangle.
nWidthDest
[in] Specifies the width, in logical units, of the destination rectangle.
nHeightDest
[in] Specifies the height, in logical units, of the destination rectangle.
hdcSrc
[in] Handle to the source device context.
nXOriginSrc
[in] Specifies the x-coordinate, in logical units, of the upper-left corner of the source rectangle.
nYOriginSrc
[in] Specifies the y-coordinate, in logical units, of the upper-left corner of the source rectangle.
nWidthSrc
[in] Specifies the width, in logical units, of the source rectangle.
nHeightSrc
[in] Specifies the height, in logical units, of the source rectangle.
dwRop
[in] Specifies the raster operation to be performed. Raster operation codes define how the system combines colors in output operations that involve a brush, a source bitmap, and a destination bitmap.
See BitBlt for a list of common raster operation codes.
Windows CE versions 1.0 and 1.01 support only the SRCCOPY and SRCINVERT raster operations.
Return Values
Nonzero indicates success. Zero indicates failure. To get extended error information, call GetLastError.
Remarks
StretchBlt stretches or compresses the source bitmap in memory and then copies the result to the destination rectangle. The color data for pattern or destination pixels is merged after the stretching or compression occurs.
When an enhanced metafile is being recorded, an error occurs (and the function returns FALSE) if the source device context identifies an enhanced-metafile device context.
If the specified raster operation requires a brush, the system uses the brush currently selected into the destination device context.
The destination coordinates are transformed by using the transformation currently specified for the destination device context; the source coordinates are transformed by using the transformation currently specified for the source device context.
If the source transformation has a rotation or shear, an error occurs.
If destination, source, and pattern bitmaps do not have the same color format, StretchBlt converts the source and pattern bitmaps to match the destination bitmap.
If StretchBlt must convert a monochrome bitmap to a color bitmap, it sets white bits (1) to the background color and black bits (0) to the foreground color. To convert a color bitmap to a monochrome bitmap, it sets pixels that match the background color to white (1) and sets all other pixels to black (0). The foreground and background colors of the device context with color are used.
StretchBlt creates a mirror image of a bitmap if the signs of the nWidthSrc and nWidthDest parameters or of the nHeightSrc and nHeightDest parameters differ. If nWidthSrc and nWidthDest have different signs, the function creates a mirror image of the bitmap along the x-axis. If nHeightSrc and nHeightDest have different signs, the function creates a mirror image of the bitmap along the y-axis. Windows CE versions 1.0 and 1.01 do not support mirroring.
Not all devices support the StretchBlt function. For more information, see the GetDeviceCaps.
See Also