[PATCH] mouse wheel acceleration
Simon Thum
simon.thum at gmx.de
Sun Sep 5 10:28:09 PDT 2010
Hi Albert,
the code looks good to me in general. Besides some technicalities,
there may be a larger problem: There is an effort to support wheels with
higher precision (github.com/x-quadraht/pscroll). Whether that
particular solution will make it or not, it would be cool to handle
wheel acceleration in one place. I don't think the scheme mechanism is
especially suitable here, IMO one can achieve a much higher degree of
code sharing.
> {0, ACCEL_PROP_CONSTANT_DECELERATION},
> {0, ACCEL_PROP_ADAPTIVE_DECELERATION},
> {0, ACCEL_PROP_VELOCITY_SCALING},
> + {0, WHEELACCEL_PROP_SPEEDMULT},
> + {0, WHEELACCEL_PROP_MAXSPEED},
I would argue the terms are too inconsistent with pointer acceleration.
IMO your speed multipier is actually an acceleration factor. Maxspeed
seems to actually be a maximum speed gain, but that's negligible.
> + dev->button = NULL; /* reset it initially. some functions in InitWheelVelocityData rely on that */
This is probably superfluous, as dev is cleared on allocation.
> +/* Wheel acceleration: maximum button press multiplier */
> +#define MAX_WHEELBTN_MULTIPLIER 100
> +
...
> + * Evtl. additional events for wheel acceleration, MAX_WHEELBTN_MULTIPLIER * 2 (up + down)
> * One possible device changed event
> */
> - return 3;
> + return 1 + 1 + MAX_WHEELBTN_MULTIPLIER * 2 + 1;
Returning a high number here will increase memory consumption. This is a
bit unfortunate, but I'm unsure what you could do about it.
> +/********************************
> + * acceleration proc
> + *******************************/
> +
> +
> +void
> +ProcessWheelAccel(
> + DeviceIntPtr dev,
> + int button,
> + int* add_num_button_presses,
> + int evtime)
> +{
> + DeviceWheelVelocityPtr velocitydata =
> + (DeviceWheelVelocityPtr) dev->button->wheelAccelScheme.accelData;
> + int axeIndex = 0;
> + int delta = 0;
> + float dt;
> + *add_num_button_presses = 0;
> +
> + if (!add_num_button_presses || !velocitydata)
> + return;
> +
> + switch(button) {
> + case 4: axeIndex = 0; delta = -1; break;
> + case 5: axeIndex = 0; delta = 1; break;
> + case 6: axeIndex = 1; delta = -1; break;
> + case 7: axeIndex = 1; delta = 1; break;
> + default: /* unknown wheel button number */ return;
> + }
> +
> + if(velocitydata->lastWheelEvent[axeIndex].delta != delta)
> + /* we scrolled in a different direction than before -> dont accel */
> + goto finish;
> +
> + if(evtime < velocitydata->lastWheelEvent[axeIndex].time)
> + /* this should not happen */
> + goto finish;
> +
> + dt = evtime - velocitydata->lastWheelEvent[axeIndex].time;
> + *add_num_button_presses = (int) (velocitydata->speed_mult / dt);
> + if(*add_num_button_presses > velocitydata->max_speed)
> + *add_num_button_presses = velocitydata->max_speed;
> +
> +finish:
> + velocitydata->lastWheelEvent[axeIndex].delta = delta;
> + velocitydata->lastWheelEvent[axeIndex].time = evtime;
> +}
Most of that is done in the ptrveloc equivalent as well. You could
instantiate a PointerVelocityRec using InitVelocityData (the structure
is a bit tied to pointer accel but I'm cleaning that up.) and go like:
switch(button) {
case 4: x = 0; y = -1; break;
case 5: x = 0; y = 1; break;
case 6: x = -1; y = 0; break;
case 7: x = 1; y = 0; break;
default: /* unknown wheel button number */ return;
}
ProcessVelocityData2D(ptr, x, y, timestamp);
Besides having a time-tested algorithm, you could adapt to a smooth
wheel vs. button-based wheel by simply adjusting the PtrVelocityRec
and some boilerplate code. I'm probably fine with any patches which make
the accel stuff less pointer-specific. Plus, you get profiles more or
less for free.
Cheers,
Simon
> +
> diff --git a/hw/xfree86/loader/sdksyms.sh b/hw/xfree86/loader/sdksyms.sh
> index eea0240..fbe4663 100755
> --- a/hw/xfree86/loader/sdksyms.sh
> +++ b/hw/xfree86/loader/sdksyms.sh
> @@ -296,6 +296,7 @@ cat > sdksyms.c << EOF
> #include "property.h"
> #include "propertyst.h"
> #include "ptrveloc.h"
> +#include "wheelveloc.h"
> #include "region.h"
> #include "regionstr.h"
> #include "registry.h"
> diff --git a/include/input.h b/include/input.h
> index 4a845be..e3bc7f8 100644
> --- a/include/input.h
> +++ b/include/input.h
> @@ -146,6 +146,13 @@ typedef void (*PointerAccelSchemeProc)(
> int* /*valuators*/,
> int /*evtime*/);
>
> +/* wheel acceleration handling */
> +typedef void (*WheelAccelSchemeProc)(
> + DeviceIntPtr /*pDev*/,
> + int /*button*/,
> + int* /*add_num_button_presses*/,
> + int /*evtime*/);
> +
> typedef void (*DeviceCallbackProc)(
> DeviceIntPtr /*pDev*/);
>
> diff --git a/include/inputstr.h b/include/inputstr.h
> index 15184d0..3de7519 100644
> --- a/include/inputstr.h
> +++ b/include/inputstr.h
> @@ -241,6 +241,12 @@ typedef struct _ValuatorClassRec {
> ValuatorAccelerationRec accelScheme;
> } ValuatorClassRec, *ValuatorClassPtr;
>
> +typedef struct _WheelAccelerationRec {
> + WheelAccelSchemeProc AccelSchemeProc;
> + void *accelData; /* at disposal of AccelScheme */
> + DeviceCallbackProc AccelCleanupProc;
> +} WheelAccelerationRec, *WheelAccelerationPtr;
> +
> typedef struct _ButtonClassRec {
> int sourceid;
> CARD8 numButtons;
> @@ -256,6 +262,7 @@ typedef struct _ButtonClassRec {
> CARD8 map[MAP_LENGTH];
> union _XkbAction *xkb_acts;
> Atom labels[MAX_BUTTONS];
> + WheelAccelerationRec wheelAccelScheme;
> } ButtonClassRec, *ButtonClassPtr;
>
> typedef struct _FocusClassRec {
> diff --git a/include/wheelveloc.h b/include/wheelveloc.h
> new file mode 100644
> index 0000000..13c6146
> --- /dev/null
> +++ b/include/wheelveloc.h
> @@ -0,0 +1,61 @@
> +/*
> + *
> + * Copyright © 2010 Albert Zeyer albert . zeyer @ rwth - aachen . de
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + */
> +
> +#ifndef WHEELVELOCITY_H
> +#define WHEELVELOCITY_H
> +
> +#include <input.h> /* DeviceIntPtr */
> +
> +/**
> + * a motion history, with just enough information to
> + * calc mean velocity
> + */
> +typedef struct _WheelTracker {
> + int delta; /* accumulated delta */
> + int time; /* time of creation */
> +} WheelTrackerRec, *WheelTrackerPtr;
> +
> +/**
> + * Contains all data needed to implement wheel ballistics
> + */
> +typedef struct _DeviceWheelVelocityRec {
> + WheelTrackerRec lastWheelEvent[2]; /* 2 for both Z and W axes */
> + int add_num_button_presses;
> + float speed_mult; /* config: speed multiplier */
> + int max_speed; /* config: max speed */
> +} DeviceWheelVelocityRec, *DeviceWheelVelocityPtr;
> +
> +
> +extern _X_EXPORT void
> +InitWheelVelocityData(DeviceIntPtr dev, DeviceWheelVelocityPtr vel);
> +
> +extern _X_INTERNAL void
> +CleanupWheelAccel(DeviceIntPtr dev);
> +
> +extern _X_INTERNAL void
> +ProcessWheelAccel(DeviceIntPtr dev, int button,
> + int* add_num_button_presses, int evtime);
> +
> +
> +#endif /* POINTERVELOCITY_H */
> diff --git a/include/xserver-properties.h b/include/xserver-properties.h
> index 626d0ad..fc0fe56 100644
> --- a/include/xserver-properties.h
> +++ b/include/xserver-properties.h
> @@ -45,6 +45,11 @@
> /* FLOAT, format 32 */
> #define ACCEL_PROP_VELOCITY_SCALING "Device Accel Velocity Scaling"
>
> +/* Wheel acceleration properties */
> +/* FLOAT, format 32*/
> +#define WHEELACCEL_PROP_SPEEDMULT "Device Wheel Accel Speed Multiplier"
> +/* INTEGER of any format. 0 - no acceleration */
> +#define WHEELACCEL_PROP_MAXSPEED "Device Wheel Accel Max Speed"
>
> /* Axis labels */
> #define AXIS_LABEL_PROP "Axis Labels"
>
>
>
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