{

/* Since the Atom exists, request the property's contents. */ bytesAfter = 0;

numLongs = ( nVisuals * sizeof(OverlayVisualPropertyRec) + 3 ) / 4; XGetWindowProperty(display, RootWindow(display, screen),

overlayVisualsAtom, 0, numLongs, False, AnyPropertyType, &actualType, &actualFormat, &numLongs, &bytesAfter, &pOverlayVisuals);

if ( bytesAfter != 0 ) {/* Serious Failure Here */} ;

/* Loop through the pOverlayVisuals array. */

...

nOVisuals = numLongs/sizeof(OverlayVisualPropertyRec); pOVis = pOverlayVisuals;

while (--nOVisuals >= 0)

{

if ( pOVis->transparentType == TransparentPixel )

{/* Found a transparent overlay visual, set ident. aside. */}; pOVis++;

}

XFree(pOverlayVisuals);

/* There might be some additional checking of the found transparent overlay visuals wanted; e.g., for depth. */

}

XFree(pVisuals);

}

This program fragment is not complete; its main purpose is to give the idea of how to find an overlay visual having transparency.

HCRX Colormaps

The following information discusses the number of supported colormaps for the HCRX configurations.

HP VISUALIZE-EG(8): 8 Image planes

The image planes contain the default colormap permanently installed in the hardware plus one other hardware colormap available to applications. No issues involving transparency exist because of the lack of Overlay planes.

HCRX-8[Z], HP [Dual] VISUALIZE-EG and HP VISUALIZE-8: Eight Overlay Planes and Two Depth-8 Banks of Image Planes

When the default visual is in the overlay planes (default location) and the screen option EnableOverlayTransparency is not set, the overlay planes contain the default colormap permanently

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Graphics Administration Guide for HP-UX 10.20