StretchDIBits
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