HP c8000 manual Hp Fire GL-UX configuration hints, Overlay visuals and overlay transparency

configuring X Windows on HP-UX (other graphics cards)

hp Fire GL-UX configuration hints

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;

XVisualInfogetVis;

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)

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