When this option is enabled, the X server does the following:
• Specifies that the overlay visual has 256 entries.
• Creates the default colormap with entry 255 pre-allocated to Transparent. A client calling
XAllocNamedColor for entry Transparent in the default colormap will be returned entry 255.
• For all other colormaps, returns all 256 entries as allocable, but issues a warning message:
Warning: XCreateColormap is creating 256 entry cmaps in overlay visual.
Though allocable, entry 255 is hard-coded to transparency.
This warning is issued once per server execution.
CRX-48Z Device-Dependent Information
Supported Visuals
The following visuals are supported:
• Class PseudoColor Depth 8 Layer Image -
supports DBE and MBX hardware double-buffering
• Class PseudoColor Depth 8 Layer Overlay -
supports DBE and MBX software double-buffering
• Class DirectColor Depth 24 Layer Image –
• supports DBE and MBX hardware double-buffering
• Class TrueColor Depth 24 Layer Image -
supports DBE and MBX hardware double-buffering
Supported Screen Options
The following Screen Options are supported:
• CountTransparentInOverlayVisual
• SwapBuffersOnVBlank
• ImageTextViaBitMap
• EnableIncludeInferiorsFix
CRX-48Z Transparent Overlay Visuals
The default number of colormap entries in the overlay visual for the CRX-48Z is 255. Entry 255 is
excluded because its value is hard-coded to transparent (that is, show the image planes).
This may have the following two consequences for X11 applications running in the overlay planes (the
default visual):
• Clients attempting to allocate 256 entries do not have their request granted.
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Graphics Administration Guide for HP-UX 10.20