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Solaris Handbook for Sun Frame Buffers

Impact on Screen Visual List by Various ffbconfig Visual Flags

Effect on the Default Visual and the Visual Group Ordering

In summary, the appearance of the X server screen visual list can be changed to fit the user's needs using any of the ffbconfig visual flags (e.g., linearorder, overlayorder, expvis, sov, etc.). This section briefly shows the effect of these visual options on the visual list.

Without any alteration using ffbconfig, the X server screen visual list can roughly be categorized in the following visual groups and order:

The default screen visual will be the 8-bit PseudoColor visual. The deflinear and defoverlay options will alter this pointer to point to the first 8- or 24-bit linear visual, depending on the X server depth when it starts up, and the first 8-bit overlay visual, respectively. You can rearrange the entire "8-bit PseudoColor Overlay" group, the "8-bit Linear StaticGray" group, and the "24-bit Linear TrueColor" group to be ahead of all other visual groups of the same depth by using the linearorder and overlayorder flags. For example, if you specify the following:


ffbconfig -overlayorder first

The screen visuals list will be rearranged in the following order:

Effect on the Number of Visual Instances Within Selected Groups

The expvis flag will change the number of visual instances in the following visual groups:

The number of instances that expvis will alter depends on whether the monitor is in monoscopic or stereoscopic resolution. In monoscopic resolution, if expvis is enabled, the order of the screen visual groups will be preserved, but within each group mentioned above, a "double-buffer capable" visual instance will be added. In stereoscopic resolution, two additional visual instances: "double-buffer, stereo capable" and "single-buffer, stereo capable", will be added. The "double-buffer capable" visual instances, if present, will always come ahead of the "single-buffer capable" visual instances, and the monoscopic visual instances will always come ahead of the stereoscopic ones.

For example, if you specify the following in stereoscopic resolution:


ffbconfig -overlayorder first -expvis enable

the screen visual list will be:

Note -

There is no double-buffer capable overlay visual instance.

Addition of the SERVER_OVERLAY_VISUALS Property and the Transparent SOV Visuals in the 8-bit Overlay Group

Without the sov option being enabled, the only overlay visuals available are the ones without transparency. Enabling the sov option will add the transparent SOV visual instances into the screen visual list and also add the SERVER_OVERLAY_VISUALS property to the root window property. The transparent SOV visual instances belong to the "8-bit PseudoColor Overlay" visual group. The SERVER_OVERLAY_VISUALS property will contain the visuals' ID, transparent type, value, and layer of all available overlay visuals of the screen.

For example, if you specify the following in stereoscopic resolution:


ffbconfig -overlayorder first -expvis enable -sov enable

the screen visuals list will be:

and the SERVER_OVERLAY_VISUALS property will contain the following information:


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              SERVER OVERLAY VISUALS (SOV) Info 
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No. of SOV visuals = 4
SOV #0,ID 0x36, TRANSPARENT_TYPE 0, VALUE   0, LAYER 1 
SOV #1,ID 0x37, TRANSPARENT_TYPE 0, VALUE   0, LAYER 1 
SOV #2,ID 0x38, TRANSPARENT_TYPE 1, VALUE 255, LAYER 1 
SOV #3,ID 0x39, TRANSPARENT_TYPE 1, VALUE 255, LAYER 1 
 
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