[PATCH dix] dix: Added a "flat" acceleration profile that provides a linear pointer response.

[Simon Thum]

Hi Orhan,

I don't have much problems with the patch as-is, except that a
corresponding xorg.conf man page entry should be added.

The bigger problem is that I don't even like to have
ConstantDeceleration within the accel code, so adding scaling as a "flat
profile" is making the mess worse.

What I'd like to see are input transformation matrices as recently
discussed (or similar). See
http://lists.freedesktop.org/archives/xorg-devel/2011-March/020680.html
for my input on peter's request.

This would solve the problem as a side-effect, and allow for much more.
I mean, why would scaling/sensitivity "be" a single profile, and not be
available as an add-on to all profiles?

It's technically correct, and I welcome people to patch it into distros,
but for master I'd prefer a conceptually clean solution. But if it turns
out there's no support for the concept as described, we should probably
add it to master (given you provide a man page entry).

Cheers,

Simon


On 03/28/2011 08:34 PM, Orhan Kavrakoglu wrote:
> From: Orhan Kavrakoğlu <aibok42 at gmail.com>
> 
> This profile disables pointer acceleration in the conventional sense
> yet still allows one to adjust sensitivity using the "acceleration"
> control.
> 
> Signed-off-by: Orhan Kavrakoğlu <aibok42 at gmail.com>
> ---
>  dix/ptrveloc.c     |   13 +++++++++++++
>  include/ptrveloc.h |    3 ++-
>  2 files changed, 15 insertions(+), 1 deletions(-)
> 
> diff --git a/dix/ptrveloc.c b/dix/ptrveloc.c
> index ccd445e..2349c11 100644
> --- a/dix/ptrveloc.c
> +++ b/dix/ptrveloc.c
> @@ -953,6 +953,17 @@ NoProfile(
>      return 1.0f;
>  }
> 
> +static float
> +FlatProfile(
> +    DeviceIntPtr dev,
> +    DeviceVelocityPtr vel,
> +    float velocity,
> +    float threshold,
> +    float acc)
> +{
> +    return acc;
> +}
> +
>  static PointerAccelerationProfileFunc
>  GetAccelerationProfile(
>      DeviceVelocityPtr vel,
> @@ -977,6 +988,8 @@ GetAccelerationProfile(
>              return SmoothLimitedProfile;
>          case AccelProfileNone:
>              return NoProfile;
> +        case AccelProfileFlat:
> +            return FlatProfile;
>          default:
>              return NULL;
>      }
> diff --git a/include/ptrveloc.h b/include/ptrveloc.h
> index c14e12d..151dcf2 100644
> --- a/include/ptrveloc.h
> +++ b/include/ptrveloc.h
> @@ -38,7 +38,8 @@
>  #define AccelProfilePower 5
>  #define AccelProfileLinear 6
>  #define AccelProfileSmoothLimited 7
> -#define AccelProfileLAST AccelProfileSmoothLimited
> +#define AccelProfileFlat 8
> +#define AccelProfileLAST AccelProfileFlat
> 
>  /* fwd */
>  struct _DeviceVelocityRec;