WORD StretchBlt(
LPPDEVICE lpDestDev,
WORD wDestX,
WORD wDestY,
WORD wDestXext,
WORD wDestYext,
LPPDEVICE lpSrcDev,
WORD wSrcX,
WORD wSrcY,
WORD wSrcXext,
WORD wSrcYext,
DWORD Rop3,
LPBRUSH lpPBrush,
LPDRAWMODE lpDrawMode,
LPRECT lpClip
);
Transfers bits from a source-device rectangle to a destination-device rectangle. The function stretches or compresses the source bits to fit the destination rectangle. The transfer is controlled by a ternary raster operation value that specifies how corresponding bits from the source, destination, and pattern in a brush are combined to form the final bits in the destination.
| 1 | Success. |
| 0 | Error. |
| -1 | GDI should carry out the operation. |
| SRCCOPY (0x00CC0020) | Copies source bits to the destination rectangle: Destination = Source. |
| SRCPAINT (0x00EE0086) | Combines the source and destination bits using the bitwise OR operator:
Destination = Source | Destination. |
| SRCAND (0x008800C6) | Combines the source and destination bits using the bitwise AND operator:
Destination = Source & Destination. |
| SRCINVERT (0x00660046) | Combines the source and destination bits using the bitwise exclusive OR operator:
Destination = Source ^ Destination. |
| SRCERASE (0x00440328) | Combines the source and inverse of destination bits using the bitwise AND operator:
Destination = Source & (~ Destination). |
| NOTSRCCOPY (0x00330008) | Copies the inverse of the destination bits to the destination rectangle:
Destination = ~ Destination. |
| NOTSRCERASE (0x001100A6) | Combines the inverse of the source and destination bits using the bitwise AND operator:
Destination = (~ Source) & (~ Destination). |
| MERGECOPY (0x00C000CA) | Combines the source and brush bits using the bitwise AND operator:
Destination = Source & Pattern. |
| MERGEPAINT (0x00BB0226) | Combines the destination and inverse of the source bits using the bitwise OR operator:
Destination = (~ Source) | Destination. |
| PATCOPY (0x00F00021) | Copies the brush bits to the destination rectangle:
Destination = Pattern. |
| PATPAINT (0x00FB0A09) | Combines the destination, pattern, and the inverse of source bits using the bitwise OR operator:
Destination = (~ Source) | Pattern | Destination. |
| PATINVERT (0x005A0049) | Combines the pattern and destination bits using the bitwise exclusive OR operator:
Destination = Pattern ^ Destination. |
| DSTINVERT (0x00550009) | Copies the inverse of the destination bits:
Destination = ~ Destination. |
| BLACKNESS (0x00000042) | Set all destination bits to black. |
| WHITENESS (0x00FF0062) | Set all bits to white. |
The export ordinal for this function is 27.
A graphics device driver must export the StretchBlt function if the RC_STRETCHBLT value is set in the dpRaster member of the GDIINFO structure.
Graphics device drivers that support some StretchBlt operations, but not others, can return -1 to direct GDI to carry out the unsupported operations. This also applies to operations in which the StretchBlt function can affect the final output, such as when StretchBlt compresses a bitmap to fit a rectangle in a monochrome bitmap. Although the StretchBlt function must use the current bitmap-stretching mode when compressing or stretching bitmaps, GDI does not make the current mode available to drivers. In such cases, the function should assume that the current mode is COLORONCOLOR or it should return -1 to direct GDI use the proper mode when compressing bitmaps.
The lpDestDev and lpSrcDev parameters can specify the same device that is transferring bits from one part of a device to another is a valid operation. If the source and destination rectangle overlap, StretchBlt transfers bits carefully so that the transfer does not inadvertently overwrite source bits before they have been transferred to the destination.
The Rop3 parameter specifies whether bits from the source, destination, and brush are used in the transfer. If the ternary raster operation specified by Rop3 does not include the source, StretchBlt ignores the source bits. If it does not include the destination, StretchBlt replaces the destination bits without using them to form the final bits.
If Rop3 does not include the brush, StretchBlt ignores the brush. If Rop3 includes the brush, StretchBlt must determine whether the brush is solid or patterned (that is, has an associated bitmap). If the brush has a bitmap, StretchBlt must combine the corresponding bits of the bitmap with the source and destination bits (as specified by the raster operation) to form the final destination bits.
If the source and bitmap associated with the brush do not have the same color format as the destination, StretchBlt must convert the source and brush bitmap to the destination's color format before transferring bits. StretchBlt uses the text (foreground) and background colors specified by the lpDrawMode parameter to convert colors.
To convert a monochrome bitmap to a color bitmap, StretchBlt converts white bits (1) to the background color and converts black bits (0) to the text (foreground) color.
To convert a color bitmap to a monochrome bitmap, StretchBlt converts all pixels that match the background color to white (1), and converts all other pixels to black (0).
In some device drivers, StretchBlt must check the bkMode member of the lpDrawMode parameter as well as the Rop3 parameter to determine how to carry out the transfer. If the bkMode member specifies the background mode TRANSPARENT1, StretchBlt must not transfer source and brush bits that have the same color as the destination's background color (as specified by the bkColor member of lpDrawMode). In other words, the corresponding destination bits must be left unchanged. Other background modes do not affect the transfer. Only device drivers that have set the C1_TRANSPARENT value in the dpCaps1 member of the GDIINFO structure are required to check the background mode.
PDEVICE, PBITMAP, DRAWMODE, RECT