hp workstations - hp-ux 11.x graphics administration guide

configuring X Windows on HP-UX (other graphics cards)
hp Fire GL-UX configuration hints
Chapter 372
hp Fire GL-UX configuration hints
overlay visuals and overlay transparency
HP Fire GL-UX devices have one visual in the overlay planes, depth-8
PseudoColor. To allow applications to determine which visuals are in the
overlay planes, overlay visuals are listed in the
"SERVER_OVERLAY_VISUALS" property attached to the root window.
The default overlay visual has a transparent type of "1" (Transparent-
Pixel).
If you need an overlay colormap that supports transparency, create the
colormap using the visual that has transparency in its
SERVER_OVERLAY_VISUALS property. To look at the contents of this
property, you would use code similar to the following:
{
typedef struct {
VisualID overlayVisualID;
Card32 transparentType;
/* None, TransparentPixel, TransparentMask */
Card32 value;
/* Either pixel value or pixel mask */
Card32 layer;
} OverlayVisualPropertyRec;
OverlayVisualPropertyRec *pOverlayVisuals, *pOVis;
XVisualInfo getVis;
XVisualInfo *pVisuals;
Atom overlayVisualsAtom, actualType;
...
/* Get the visuals for this screen and allocate. */
getVis.screen = screen;
pVisuals = XGetVisualInfo(display, VisualScreenMask,
&getVis, &nVisuals);
pOverlayVisuals = (OverlayVisualPropertyRec *)
malloc ( (size_t)nVisuals *
sizeof(OverlayVisualPropertyRec) );
/*
** Get the overlay visual information for this screen. Obtain
** this information from the SERVER_OVERLAY_VISUALS property.
*/
overlayVisualsAtom = XInternAtom(display,"SERVER_OVERLAY_VISUALS",
True);
if (overlayVisualsAtom != None)
GAG11.book Page 72 Tuesday, February 14, 2006 9:11 AM