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Diffstat (limited to '')
| -rw-r--r-- | info/blueshift.texinfo | 96 |
1 files changed, 90 insertions, 6 deletions
diff --git a/info/blueshift.texinfo b/info/blueshift.texinfo index f11d9f5..5595911 100644 --- a/info/blueshift.texinfo +++ b/info/blueshift.texinfo @@ -313,6 +313,7 @@ Disables or enables Blueshift. * Backlight:: Adjusting monitor backlight. * Continuous mode:: Creating continuous mode configurations. * Solar time:: Solar functions, such as elevation calcuation. +* Running without X:: Configuration options for running without X. @end menu @@ -789,12 +790,15 @@ continuous mode. To support multiple monitors in a dynamic way, the function @code{list_screens} can be used. -@code{list_screens} is parameterless and returns -the an instance of the class @code{Screens}. -Instances of @code{Screens} have one variable: -@code{screens}, a list of instances of the class -@code{Screen}. The index of each screens is their -index in @code{screens}. +@code{list_screens} has one optional parameter +and returns the an instance of the class +@code{Screens}. Instances of @code{Screens} have +one variable: @code{screens}, a list of instances +of the class @code{Screen}. The index of each +screens is their index in @code{screens}. +@code{list_screens}'s parameter, @code{method}, +selects the method and defaults to `randr', +it also supports the method `drm'. Instances of the class @code{Screen} have two variables: @code{crtc_count}, the number of CRT @@ -1213,6 +1217,86 @@ astronomical twilight, measured in degrees. @end table +@node Running without X +@section Running without X + +Blueshift has the capability of operating, +in fullness, without a display server like X. +Using Direct Rendering Manager (DRM), in Linux, +Blueshift is able to get monitor information +and get and set the colour curves for each +monitor, just as it is under X using RandR; +except this only works if the active VT does +not have a display server. + +There are however a few differences: +@itemize @bullet{} +@item +DRM returns more exact physical monitor +dimensions. For example, my CRT:s have a +visible area of slightly (off by a millimeter +or two) larger than 400 mm by 300 mm, but +RandR returns 364 mm by 291 mm which is an +aspect ratio of 5:4 rather than 4:3. +@item +DRM does not have the concept of primary +monitors, which RandR has. RandR changes +the indices of the CRTC:s so that the +primary monitors have zero as their indices. +@item +DRM does not have a concept of screens, +but it does have the concept of graphic +cards which is missing from RandR. In +practice, these are however equivalent, +and therefore the DRM methods which have +a RandR version caps the parameters for +graphic cards for @code{screen} rather +than @code{card} to maintain API +compatibility with the RandR versions. +@end itemize + +Blueshift checks for you whether you are +running in a TTY by checking the @var{DISPLAY} +environment variable, and sets the variable +@code{ttymode}. That is Blueshift will set +the variable @code{ttymode} to @code{True} +if it thinks that it is not connected to a +display server, and @code{False} otherwise. +Not that it is still possible to use the DRM +functions when connected to a display server: +nothing will happen because, all requests to +change the colour curves will be rejected. +However if you switch VT to a TTY, the requests +will be accepted and the requests to the +display server will be ignored until you +reenter the VT with that display. + +The DRM equivalent to the RandR functions +@code{randr} (applying colour curves) and +@code{randr_get} (reading current colour +curves) are @code{drm} and @code{drm_get}, +respectively. The paramers are exactly the +same for the DRM functions as they are for +the RandR functions. + +The function @code{list_screens}, which +lists all screens, CRTC:s and outputs, +runs @code{list_screens_randr} by default. +By invoking @code{list_screens} with the +argument `drm' it will instead run +@code{list_screens_drm}. It will return +equivalent data, except with it calls +screens are actually graphics cards, +and as mentioned, the CRTC:s may have +different indices and the monitors may +have different physical sizes. But the +names of the outputs (which are called +connectors in DRM contected, but for this +function it will still be called outputs +for API compatibility with the RandR +version) by be different. + + @node Related software @chapter Related software |