[PATCH 09/13] xserver: randr: Panning support

[Keith Packard]

On Fri, 2008-11-28 at 17:49 +0100, Matthias Hopf wrote:

> +    if (crtc->funcs->pan &&
> +	memcmp (mode, &saved_mode, sizeof(saved_mode)) == 0 &&
> +	saved_rotation == rotation) {
> +	crtc->funcs->pan (crtc, crtc->x, crtc->y);
> +	ret = TRUE;
> +	goto done;
> +    }

I think this also need to check for transformation changes? And output
property changes?

> +/**
> + * Pans the screen, does not change the mode
> + */

Should we call the low-level operation 'set_origin' instead of 'pan'?

> +    int				    pointerX;
> +    int				    pointerY;

I'd prefer to not shadow the pointer position inside RandR; is there
some way we can use the DIX pointer position here?

We should also start to consider how MPX plays with panning.

> +static Bool
> +xf86RandR13SetPanning (ScreenPtr           pScreen,
> +		       RRCrtcPtr           randr_crtc,
> +		       BoxPtr              totalArea,
> +		       BoxPtr              trackingArea,
> +		       INT16               *border)
> +{
> +    XF86RandRInfoPtr	randrp  = XF86RANDRINFO(pScreen);
> +    xf86CrtcPtr		crtc = randr_crtc->devPrivate;
> +    int			ret;
> +
> +    if (crtc->version < 2)
> +	return FALSE;
> +    if (totalArea)
> +	memcpy (&crtc->panningTotalArea, totalArea, sizeof(BoxRec));
> +    if (trackingArea)
> +	memcpy (&crtc->panningTrackingArea, trackingArea, sizeof(BoxRec));
> +    if (border)
> +	memcpy (crtc->panningBorder, border, 4*sizeof(INT16));
> +    ret = xf86RandR13VerifyPanningArea (crtc, pScreen->width, pScreen->height);
> +    xf86RandR13Pan (crtc, randrp->pointerX, randrp->pointerY);

Probably need to verify before setting -- protocol requests should
either succeed or fail without side effects. It looks to me like we
smash the old settings before checking the requested data. That would
mean that VerifyPanningArea would take the three rectangles as separate
arguments instead of pulling them from the crtc.

-- 
keith.packard at intel.com
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