wglRealizeLayerPalette
[New
- Windows 95, OEM Service Release 2]
The wglRealizeLayerPalette
function maps palette entries from a given color-index layer plane into the
physical palette or initializes the palette of an RGBA layer plane.
BOOL wglRealizeLayerPalette(
|
HDC hdc, |
// device
context whose layer plane palette is to be realized |
|
int iLayerPlane, |
//
specifies an overlay or underlay plane |
|
BOOL bRealize |
//
indicates whether the palette is to be realized into the physical palette |
|
); |
|
Parameters
hdc
Specifies the
device context of a window whose layer plane palette is to be realized into the
physical palette.
iLayerPlane
Specifies the
overlay or underlay plane. Positive values of iLayerPlane identify
overlay planes, where 1 is the first overlay plane over the main plane, 2 is
the second overlay plane over the first overlay plane, and so on. Negative
values identify underlay planes, where -1 is the first underlay plane under the main plane, -2 is the second underlay plane under the first
underlay plane, and so on. The number of overlay and underlay planes is given
in the bReserved member of the PIXELFORMATDESCRIPTOR structure.
bRealize
Indicates
whether the palette is to be realized into the physical palette. When bRealize
is TRUE, the palette entries are mapped into the physical palette where
available. When bRealize is FALSE, the palette entries for the layer
plane of the window are no longer needed and might be released for use by
another foreground window.
Return Values
If the
function succeeds, the return value is TRUE, even if bRealize is TRUE
and the physical palette is not available. If the function fails or when no
pixel format is selected, the return value is FALSE. To get extended error
information, call GetLastError.
Remarks
The physical
palette for a layer plane is a shared resource among windows with layer planes.
When more than one window attempts to realize a palette for a given physical
layer plane, only one palette at a time is realized. When you call the wglRealizeLayerPalette
function, the layer palette of a foreground window is always realized first.
When a
window s layer palette is realized, its palette entries are always mapped
one-to-one into the physical palette. Unlike GDI logical palettes, with wglRealizeLayerPalette
there is no mapping of other windows layer palettes to the current physical
palette.
Whenever a
window becomes the foreground window, call wglRealizeLayerPalette to
realize its layer palettes again, even if the pixel type of the layer plane is
RGBA.
Because wglRealizeLayerPalette
doesn t realize the palette of the main plane, use GDI palette functions to
realize the main plane palette.
See Also