xvfb: add randr support (v2)

[Aaron Plattner]

On 06/08/2015 03:14 PM, Siim Põder wrote:
> Hi
> 
> This was sent to xorg-devel a few years ago. It still applies and still appears
> to work. I resending this because it affects me. Comments or application to the
> tree would be greatly appreciated :)
> 
> The motivation for getting this is chrome remote desktop that runs under Xvfb
> and wants to use RANDR to adjust screen size according to the remote desktop
> client screen size. Apparently there are other use cases as well, the bug
> mentions gnome-settings-daemon testing.

Not that this patch hurts or anything, but is there any particular
reason this remote desktop thing is using Xvfb rather than Xorg +
xf86-video-dummy?  I thought there was an effort to kill off the
redundant non-Xorg DDXes at some point.

I posted a patch series a while back to upgrade the dummy driver to be
able to support arbitrary resizing, including resizing to larger than
you started with:

http://lists.x.org/archives/xorg-devel/2015-January/045395.html

> Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=26391
> Signed-off-by: Lambros Lambrou <lambroslambrou at google.com>
> Signed-off-by: Mike Frysinger <vapier at gentoo.org>
> Signed-off-by: Michal Srb <msrb at suse.com>
> Signed-off-by: Siim Põder <siim at p6drad-teel.net>
> 
> ---
> Second version, modified according to Keith suggestion.
> Tested by adding second mode and switching - worked correctly.
> 
> diff --git a/hw/vfb/InitOutput.c b/hw/vfb/InitOutput.c
> index 97eccfd..bfca068 100644
> --- a/hw/vfb/InitOutput.c
> +++ b/hw/vfb/InitOutput.c
> @@ -66,6 +66,7 @@ from The Open Group.
>  #include "dix.h"
>  #include "miline.h"
>  #include "glx_extinit.h"
> +#include "randrstr.h"
>  
>  #define VFB_DEFAULT_WIDTH      1280
>  #define VFB_DEFAULT_HEIGHT     1024
> @@ -785,6 +786,125 @@ vfbCloseScreen(ScreenPtr pScreen)
>  }
>  
>  static Bool
> +vfbRROutputValidateMode(ScreenPtr           pScreen,
> +                        RROutputPtr         output,
> +                        RRModePtr           mode)
> +{
> +    rrScrPriv(pScreen);
> +
> +    if (pScrPriv->minWidth <= mode->mode.width &&
> +        pScrPriv->maxWidth >= mode->mode.width &&
> +        pScrPriv->minHeight <= mode->mode.height &&
> +        pScrPriv->maxHeight >= mode->mode.height)
> +        return TRUE;
> +    else
> +        return FALSE;
> +}
> +
> +static Bool
> +vfbRRScreenSetSize(ScreenPtr  pScreen,
> +                   CARD16     width,
> +                   CARD16     height,
> +                   CARD32     mmWidth,
> +                   CARD32     mmHeight)
> +{
> +    // Prevent screen updates while we change things around
> +    SetRootClip(pScreen, FALSE);
> +
> +    pScreen->width = width;
> +    pScreen->height = height;
> +    pScreen->mmWidth = mmWidth;
> +    pScreen->mmHeight = mmHeight;
> +
> +    // Restore the ability to update screen, now with new dimensions
> +    SetRootClip(pScreen, TRUE);
> +
> +    RRScreenSizeNotify (pScreen);
> +    RRTellChanged(pScreen);
> +
> +    return TRUE;
> +}
> +
> +static Bool
> +vfbRRCrtcSet(ScreenPtr pScreen,
> +             RRCrtcPtr crtc,
> +             RRModePtr mode,
> +             int       x,
> +             int       y,
> +             Rotation  rotation,
> +             int       numOutput,
> +             RROutputPtr *outputs)
> +{
> +  return RRCrtcNotify(crtc, mode, x, y, rotation, NULL, numOutput, outputs);
> +}
> +
> +static Bool
> +vfbRRGetInfo(ScreenPtr pScreen, Rotation *rotations)
> +{
> +    return TRUE;
> +}
> +
> +static Bool
> +vfbRandRInit(ScreenPtr pScreen)
> +{
> +    rrScrPrivPtr pScrPriv;
> +#if RANDR_12_INTERFACE
> +    RRModePtr  mode;
> +    RRCrtcPtr  crtc;
> +    RROutputPtr        output;
> +    xRRModeInfo modeInfo;
> +    char       name[64];
> +#endif
> +
> +    if (!RRScreenInit (pScreen))
> +       return FALSE;
> +    pScrPriv = rrGetScrPriv(pScreen);
> +    pScrPriv->rrGetInfo = vfbRRGetInfo;
> +#if RANDR_12_INTERFACE
> +    pScrPriv->rrCrtcSet = vfbRRCrtcSet;
> +    pScrPriv->rrScreenSetSize = vfbRRScreenSetSize;
> +    pScrPriv->rrOutputSetProperty = NULL;
> +#if RANDR_13_INTERFACE
> +    pScrPriv->rrOutputGetProperty = NULL;
> +#endif
> +    pScrPriv->rrOutputValidateMode = vfbRROutputValidateMode;
> +    pScrPriv->rrModeDestroy = NULL;
> +
> +    RRScreenSetSizeRange (pScreen,
> +                         1, 1,
> +                         pScreen->width, pScreen->height);
> +
> +    sprintf (name, "%dx%d", pScreen->width, pScreen->height);
> +    memset (&modeInfo, '\0', sizeof (modeInfo));
> +    modeInfo.width = pScreen->width;
> +    modeInfo.height = pScreen->height;
> +    modeInfo.nameLength = strlen (name);
> +
> +    mode = RRModeGet (&modeInfo, name);
> +    if (!mode)
> +       return FALSE;
> +
> +    crtc = RRCrtcCreate (pScreen, NULL);
> +    if (!crtc)
> +       return FALSE;
> +
> +    output = RROutputCreate (pScreen, "screen", 6, NULL);
> +    if (!output)
> +       return FALSE;
> +    if (!RROutputSetClones (output, NULL, 0))
> +       return FALSE;
> +    if (!RROutputSetModes (output, &mode, 1, 0))
> +       return FALSE;
> +    if (!RROutputSetCrtcs (output, &crtc, 1))
> +       return FALSE;
> +    if (!RROutputSetConnection (output, RR_Connected))
> +       return FALSE;
> +    RRCrtcNotify (crtc, mode, 0, 0, RR_Rotate_0, NULL, 1, &output);
> +#endif
> +    return TRUE;
> +}
> +
> +static Bool
>  vfbScreenInit(ScreenPtr pScreen, int argc, char **argv)
>  {
>      vfbScreenInfoPtr pvfb = &vfbScreens[pScreen->myNum];
> @@ -860,6 +980,9 @@ vfbScreenInit(ScreenPtr pScreen, int argc, char **argv)
>      if (!ret)
>          return FALSE;
>  
> +    if (!vfbRandRInit(pScreen))
> +       return FALSE;
> +
>      pScreen->InstallColormap = vfbInstallColormap;
>      pScreen->UninstallColormap = vfbUninstallColormap;
>      pScreen->ListInstalledColormaps = vfbListInstalledColormaps;
> 


-- 
Aaron