diff options
author | Simon Thum <simon.thum@gmx.de> | 2008-07-10 22:33:39 +0930 |
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committer | Peter Hutterer <peter.hutterer@who-t.net> | 2008-07-13 20:54:33 +0930 |
commit | c9eb0e870c87d291311491452adf7f91a911e24b (patch) | |
tree | 0d8f5c9ff2ba7d17bf8574ace0d440f5e82c4e3e /dix/ptrveloc.c | |
parent | e7abe1676a6a4e4249504b8c9660cbad70569199 (diff) |
Add support for multiple pointer acceleration schemes. #8583
Available acceleration schemes:
- xorg classic scheme.
- the new "Predictable" polynomial accel scheme.
X.Org Bug 8583 <http://bugs.freedesktop.org/show_bug.cgi?id=8583>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Diffstat (limited to 'dix/ptrveloc.c')
-rw-r--r-- | dix/ptrveloc.c | 759 |
1 files changed, 759 insertions, 0 deletions
diff --git a/dix/ptrveloc.c b/dix/ptrveloc.c new file mode 100644 index 000000000..9e66ab822 --- /dev/null +++ b/dix/ptrveloc.c @@ -0,0 +1,759 @@ + +#ifdef HAVE_DIX_CONFIG_H +#include <dix-config.h> +#endif + +#include <math.h> +#include <ptrveloc.h> +#include <inputstr.h> +#include <assert.h> + +/***************************************************************************** + * Predictable pointer ballistics + * + * 2006-2008 by Simon Thum (simon [dot] thum [at] gmx de) + * + * Serves 3 complementary functions: + * 1) provide a sophisticated ballistic velocity estimate to improve + * the relation between velocity (of the device) and acceleration + * 2) make arbitrary acceleration profiles possible + * 3) decelerate by two means (constant and adaptive) if enabled + * + * Important concepts are the + * + * - Scheme + * which selects the basic algorithm + * (see devices.c/InitPointerAccelerationScheme) + * - Profile + * which returns an acceleration + * for a given velocity + * + * The profile can be selected by the user (potentially at runtime). + * the classic profile is intended to cleanly perform old-style + * function selection (threshold =/!= 0) + * + ****************************************************************************/ + +/* fwds */ +static inline void +FeedFilterStage(FilterStagePtr s, float value, int tdiff); +extern void +InitFilterStage(FilterStagePtr s, float rdecay, int lutsize); +void +CleanupFilterChain(DeviceVelocityPtr s); +int +SetAccelerationProfile(DeviceVelocityPtr s, int profile_num); +void +InitFilterChain(DeviceVelocityPtr s, float rdecay, float degression, + int stages, int lutsize); +void +CleanupFilterChain(DeviceVelocityPtr s); +static float +SimpleSmoothProfile(DeviceVelocityPtr pVel, float threshold, float acc); + + +/******************************** + * Init/Uninit etc + *******************************/ + +/** + * Init struct so it should match the average case + */ +void +InitVelocityData(DeviceVelocityPtr s) +{ + s->lrm_time = 0; + s->velocity = 0; + s->corr_mul = 10.0; /* dots per 10 milisecond should be usable */ + s->const_acceleration = 1.0; /* no acceleration/deceleration */ + s->reset_time = 300; + s->last_dx = 0; + s->last_dy = 0; + s->use_softening = 1; + s->min_acceleration = 1.0; /* don't decelerate */ + s->coupling = 0.2; + s->profile_private = NULL; + memset(&s->statistics, 0, sizeof(s->statistics)); + memset(&s->filters, 0, sizeof(s->filters)); + SetAccelerationProfile(s, 0); + InitFilterChain(s, (float)1.0/20.0, 1, 1, 40); +} + + +/** + * Clean up + */ +static void +FreeVelocityData(DeviceVelocityPtr s){ + CleanupFilterChain(s); + SetAccelerationProfile(s, -1); +} + + +/* + * dix uninit helper, called through scheme + */ +void +AccelerationDefaultCleanup(DeviceIntPtr pDev){ + /*sanity check*/ + if( pDev->valuator->accelScheme.AccelSchemeProc == acceleratePointerPredictable + && pDev->valuator->accelScheme.accelData != NULL){ + pDev->valuator->accelScheme.AccelSchemeProc = NULL; + FreeVelocityData(pDev->valuator->accelScheme.accelData); + xfree(pDev->valuator->accelScheme.accelData); + pDev->valuator->accelScheme.accelData = NULL; + } +} + +/********************* + * Filtering logic + ********************/ + +/** +Initialize a filter chain. +Expected result is a series of filters, each progressively more integrating. +*/ +void +InitFilterChain(DeviceVelocityPtr s, float rdecay, float progression, int stages, int lutsize) +{ + int fn; + if((stages > 1 && progression < 1.0f) || 0 == progression){ + ErrorF("(dix ptracc) invalid filter chain progression specified\n"); + return; + } + for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++){ + if(fn < stages){ + InitFilterStage(&s->filters[fn], rdecay, lutsize); + }else{ + InitFilterStage(&s->filters[fn], 0, 0); + } + rdecay /= progression; + } +} + + +void +CleanupFilterChain(DeviceVelocityPtr s) +{ + int fn; + + for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++) + InitFilterStage(&s->filters[fn], 0, 0); +} + + +/** + * Adjust weighting decay and lut in sync + * The weight fn is designed so its integral 0->inf is unity, so we end + * up with a stable (basically IIR) filter. It always draws + * towards its more current input values, which have more weight the older + * the last input value is. + */ +void +InitFilterStage(FilterStagePtr s, float rdecay, int lutsize) +{ + int x; + float *newlut; + float *oldlut; + + s->fading_lut_size = 0; /* prevent access */ + /* mb(); concurrency issues may arise */ + + if(lutsize > 0){ + newlut = xalloc (sizeof(float)* lutsize); + if(!newlut) + return; + for(x = 0; x < lutsize; x++) + newlut[x] = pow(0.5, ((float)x) * rdecay); + }else{ + newlut = NULL; + } + oldlut = s->fading_lut; + s->fading_lut = newlut; + s->rdecay = rdecay; + s->fading_lut_size = lutsize; + s->current = 0; + if(oldlut != NULL) + xfree(oldlut); +} + + +static inline void +FeedFilterChain(DeviceVelocityPtr s, float value, int tdiff) +{ + int fn; + + for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++){ + if(s->filters[fn].rdecay != 0) + FeedFilterStage(&s->filters[fn], value, tdiff); + else break; + } +} + + +static inline void +FeedFilterStage(FilterStagePtr s, float value, int tdiff){ + float fade; + if(tdiff < s->fading_lut_size) + fade = s->fading_lut[tdiff]; + else + fade = pow(0.5, ((float)tdiff) * s->rdecay); + s->current *= fade; /* fade out old velocity */ + s->current += value * (1.0f - fade); /* and add up current */ +} + +/** + * Select the most filtered matching result. Also, the first + * mismatching filter will be set to value (coupling). + */ +static inline float +QueryFilterChain( + DeviceVelocityPtr s, + float value, + float maxdiv) +{ + int fn, rfn = 0, cfn = -1; + float cur, result = value; + + /* try to retrieve most integrated result 'within range' + * Assumption: filter are in order least to most integrating */ + for(fn = 0; fn < MAX_VELOCITY_FILTERS; fn++){ + if(0.0f == s->filters[fn].rdecay) + break; + cur = s->filters[fn].current; + + if (fabs(value - cur) <= 1.0f || + fabs(value - cur) / (value + cur) <= maxdiv){ + result = cur; + rfn = fn; /*remember result determining filter */ + } else if(cfn == -1){ + cfn = fn; /* rememeber first mismatching filter */ + } + } + + s->statistics.filter_usecount[rfn]++; + DebugF("(dix ptraccel) result from filter stage %i, input %.2f, output %.2f\n", rfn, value, result); + + /* override one current (coupling) so the filter + * catches up quickly. */ + if(cfn != -1) + s->filters[cfn].current = result; + + return result; +} + +/******************************** + * velocity computation + *******************************/ + +/** + * return the axis if mickey is insignificant and axis-aligned, + * -1 otherwise + * 1 for x-axis + * 2 for y-axis + */ +static inline short +GetAxis(int dx, int dy){ + if(dx == 0 || dy == 0){ + if(dx == 1 || dx == -1) + return 1; + if(dy == 1 || dy == -1) + return 2; + return -1; + }else{ + return -1; + } +} + + +/** + * Perform velocity approximation + * return true if non-visible state reset is suggested + */ +static short +ProcessVelocityData(DeviceVelocityPtr s, int dx, int dy, int time) +{ + float cvelocity; + + int diff = time - s->lrm_time; + int cur_ax = GetAxis(dx, dy); + int last_ax = GetAxis(s->last_dx, s->last_dy); + short reset = (diff >= s->reset_time); + + if(cur_ax != last_ax && cur_ax != -1 && last_ax != -1 && !reset){ + /* correct for the error induced when diagonal movements are + reported as alternating axis mickeys */ + dx += s->last_dx; + dy += s->last_dy; + diff += s->last_diff; + s->last_diff = time - s->lrm_time; /* prevent repeating add-up */ + DebugF("(dix ptracc) axial correction\n"); + }else{ + s->last_diff = diff; + } + + /* + * cvelocity is not a real velocity yet, more a motion delta. contant + * acceleration is multiplied here to make the velocity an on-screen + * velocity (px/t as opposed to [insert unit]/t). This is intended to + * make multiple devices with widely varying ConstantDecelerations respond + * similar to acceleration controls. + */ + cvelocity = (float)sqrt(dx*dx + dy*dy) * s->const_acceleration; + + s->lrm_time = time; + + if (s->reset_time < 0 || diff < 0) { /* disabled or timer overrun? */ + /* simply set velocity from current movement, no reset. */ + s->velocity = cvelocity; + return 0; + } + + if (diff == 0) + diff = 1; /* prevent div-by-zero, though it shouldn't happen anyway*/ + + /* translate velocity to dots/ms (somewhat untractable in integers, + so we multiply by some per-device adjustable factor) */ + cvelocity = cvelocity * s->corr_mul / (float)diff; + + /* short-circuit: when nv-reset the rest can be skipped */ + if(reset == TRUE){ + s->velocity = cvelocity; + return TRUE; + } + + /* feed into filter chain */ + FeedFilterChain(s, cvelocity, diff); + + /* perform coupling and decide final value */ + s->velocity = QueryFilterChain(s, cvelocity, s->coupling); + + DebugF("(dix ptracc) guess: vel=%.3f diff=%d |%i|%i|%i|%i|\n", + s->velocity, diff, + s->statistics.filter_usecount[0], s->statistics.filter_usecount[1], s->statistics.filter_usecount[2], s->statistics.filter_usecount[3]); + return reset; +} + + +/** + * this flattens significant ( > 1) mickeys a little bit for more steady + * constant-velocity response + */ +static inline float +ApplySimpleSoftening(int od, int d) +{ + float res = d; + if (d <= 1 && d >= -1) + return res; + if (d > od) + res -= 0.5; + else if (d < od) + res += 0.5; + return res; +} + + +static void +ApplySofteningAndConstantDeceleration( + DeviceVelocityPtr s, + int dx, + int dy, + float* fdx, + float* fdy, + short do_soften) +{ + if (do_soften && s->use_softening) { + *fdx = ApplySimpleSoftening(s->last_dx, dx); + *fdy = ApplySimpleSoftening(s->last_dy, dy); + } else { + *fdx = dx; + *fdy = dy; + } + + *fdx *= s->const_acceleration; + *fdy *= s->const_acceleration; +} + + + +/***************************************** + * Acceleration functions and profiles + ****************************************/ + +/** + * Polynomial function similar previous one, but with f(1) = 1 + */ +static float +PolynomialAccelerationProfile(DeviceVelocityPtr pVel, float ignored, float acc) +{ + return pow(pVel->velocity, (acc - 1.0) * 0.5); +} + + +/** + * returns acceleration for velocity. + * This profile selects the two functions like the old scheme did + */ +static float +ClassicProfile( + DeviceVelocityPtr pVel, + float threshold, + float acc) +{ + + if (threshold) { + return SimpleSmoothProfile (pVel, + threshold, + acc); + } else { + return PolynomialAccelerationProfile (pVel, + 0, + acc); + } +} + + +/** + * Power profile + * This has a completely smooth transition curve, i.e. no jumps in the + * derivatives. + * + * This has the expense of overall response dependency on min-acceleration. + * In effect, min_acceleration mimics const_acceleration in this profile. + */ +static float +PowerProfile( + DeviceVelocityPtr pVel, + float threshold, + float acc) +{ + float vel_dist; + + acc = (acc-1.0) * 0.1f + 1.0; /* without this, acc of 2 is unuseable */ + + if (pVel->velocity <= threshold) + return pVel->min_acceleration; + vel_dist = pVel->velocity - threshold; + return (pow(acc, vel_dist)) * pVel->min_acceleration; +} + + +/** + * just a smooth function in [0..1] -> [0..1] + * - point symmetry at 0.5 + * - f'(0) = f'(1) = 0 + * - starts faster than sinoids, C1 (Cinf if you dare to ignore endpoints) + */ +static inline float +CalcPenumbralGradient(float x){ + x *= 2.0f; + x -= 1.0f; + return 0.5f + (x * sqrt(1.0f - x*x) + asin(x))/M_PI; +} + + +/** + * acceleration function similar to classic accelerated/unaccelerated, + * but with smooth transition in between (and towards zero for adaptive dec.). + */ +static float +SimpleSmoothProfile( + DeviceVelocityPtr pVel, + float threshold, + float acc) +{ + float velocity = pVel->velocity; + if(velocity < 1.0f) + return CalcPenumbralGradient(0.5 + velocity*0.5) * 2.0f - 1.0f; + if(threshold < 1.0f) + threshold = 1.0f; + if (velocity <= threshold) + return 1; + velocity /= threshold; + if (velocity >= acc) + return acc; + else + return 1.0f + (CalcPenumbralGradient(velocity/acc) * (acc - 1.0f)); +} + + +/** + * This profile uses the first half of the penumbral gradient as a start + * and then scales linearly. + */ +static float +SmoothLinearProfile( + DeviceVelocityPtr pVel, + float threshold, + float acc) +{ + if(acc > 1.0f) + acc -= 1.0f; /*this is so acc = 1 is no acceleration */ + else + return 1.0f; + + float nv = (pVel->velocity - threshold) * acc * 0.5f; + float res; + if(nv < 0){ + res = 0; + }else if(nv < 2){ + res = CalcPenumbralGradient(nv*0.25f)*2.0f; + }else{ + nv -= 2.0f; + res = nv * 2.0f / M_PI /* steepness of gradient at 0.5 */ + + 1.0f; /* gradient crosses 2|1 */ + } + res += pVel->min_acceleration; + return res; +} + + +static float +LinearProfile( + DeviceVelocityPtr pVel, + float threshold, + float acc) +{ + return acc * pVel->velocity; +} + + +/** + * Set the profile by number. + * Intended to make profiles exchangeable at runtime. + * If you created a profile, give it a number here to make it selectable. + * In case some profile-specific init is needed, here would be a good place, + * since FreeVelocityData() also calls this with -1. + * returns FALSE (0) if profile number is unknown. + */ +int +SetAccelerationProfile( + DeviceVelocityPtr s, + int profile_num) +{ + PointerAccelerationProfileFunc profile; + switch(profile_num){ + case -1: + profile = NULL; /* Special case to uninit properly */ + break; + case 0: + profile = ClassicProfile; + break; + case 1: + if(NULL == s->deviceSpecificProfile) + return FALSE; + profile = s->deviceSpecificProfile; + break; + case 2: + profile = PolynomialAccelerationProfile; + break; + case 3: + profile = SmoothLinearProfile; + break; + case 4: + profile = SimpleSmoothProfile; + break; + case 5: + profile = PowerProfile; + break; + case 6: + profile = LinearProfile; + break; + default: + return FALSE; + } + if(s->profile_private != NULL){ + /* Here one could free old profile-private data */ + xfree(s->profile_private); + s->profile_private = NULL; + } + /* Here one could init profile-private data */ + s->Profile = profile; + s->statistics.profile_number = profile_num; + return TRUE; +} + +/** + * device-specific profile + * + * The device-specific profile is intended as a hook for a driver + * which may want to provide an own acceleration profile. + * It should not rely on profile-private data, instead + * it should do init/uninit in the driver (ie. with DEVICE_INIT and friends). + * Users may override or choose it. + */ +extern void +SetDeviceSpecificAccelerationProfile( + DeviceIntPtr pDev, + PointerAccelerationProfileFunc profile) +{ + /*sanity check*/ + if( pDev->valuator && + pDev->valuator->accelScheme.AccelSchemeProc == + acceleratePointerPredictable && + pDev->valuator->accelScheme.accelData != NULL){ + ((DeviceVelocityPtr) + (pDev->valuator->accelScheme.accelData))->deviceSpecificProfile + = profile; + } +} + + + +/******************************** + * acceleration schemes + *******************************/ + +/** + * Modifies valuators in-place. + * This version employs a velocity approximation algorithm to + * enable fine-grained predictable acceleration profiles. + */ +void +acceleratePointerPredictable(DeviceIntPtr pDev, int first_valuator, + int num_valuators, int *valuators, int evtime) +{ + float mult = 0.0; + int dx = 0, dy = 0; + int *px = NULL, *py = NULL; + DeviceVelocityPtr velocitydata = + (DeviceVelocityPtr) pDev->valuator->accelScheme.accelData; + float fdx, fdy; /* no need to init */ + + if (!num_valuators || !valuators || !velocitydata) + return; + + if (first_valuator == 0) { + dx = valuators[0]; + px = &valuators[0]; + } + if (first_valuator <= 1 && num_valuators >= (2 - first_valuator)) { + dy = valuators[1 - first_valuator]; + py = &valuators[1 - first_valuator]; + } + + if (dx || dy){ + /* reset nonvisible state? */ + if (ProcessVelocityData(velocitydata, dx , dy, evtime)) { + /* set to center of pixel */ + pDev->last.remainder[0] = pDev->last.remainder[1] = 0.5f; + /* prevent softening (somewhat quirky solution, + as it depends on the algorithm) */ + velocitydata->last_dx = dx; + velocitydata->last_dy = dy; + } + + if (pDev->ptrfeed && pDev->ptrfeed->ctrl.num) { + /* invoke acceleration profile to determine acceleration */ + mult = velocitydata->Profile(velocitydata, + pDev->ptrfeed->ctrl.threshold, + (float)(pDev->ptrfeed->ctrl.num) / + (float)(pDev->ptrfeed->ctrl.den)); + + DebugF("(dix ptracc) resulting speed multiplier : %.3f\n", mult); + /* enforce min_acceleration */ + if (mult < velocitydata->min_acceleration) { + DebugF("(dix ptracc) enforced min multiplier : %.3f\n", + velocitydata->min_acceleration); + mult = velocitydata->min_acceleration; + } + + if(mult != 1.0 || velocitydata->const_acceleration != 1.0) { + ApplySofteningAndConstantDeceleration( velocitydata, + dx, dy, + &fdx, &fdy, + mult > 1.0); + if (dx) { + pDev->last.remainder[0] = mult * fdx + pDev->last.remainder[0]; + *px = (int)pDev->last.remainder[0]; + pDev->last.remainder[0] = pDev->last.remainder[0] - (float)*px; + } + if (dy) { + pDev->last.remainder[1] = mult * fdy + pDev->last.remainder[1]; + *py = (int)pDev->last.remainder[1]; + pDev->last.remainder[1] = pDev->last.remainder[1] - (float)*py; + } + } + } + } + /* remember last motion delta (for softening/slow movement treatment) */ + velocitydata->last_dx = dx; + velocitydata->last_dy = dy; +} + + + +/** + * Originally a part of xf86PostMotionEvent; modifies valuators + * in-place. Retained mostly for embedded scenarios. + */ +void +acceleratePointerClassic(DeviceIntPtr pDev, int first_valuator, + int num_valuators, int *valuators, int ignored) +{ + float mult = 0.0; + int dx = 0, dy = 0; + int *px = NULL, *py = NULL; + + if (!num_valuators || !valuators) + return; + + if (first_valuator == 0) { + dx = valuators[0]; + px = &valuators[0]; + } + if (first_valuator <= 1 && num_valuators >= (2 - first_valuator)) { + dy = valuators[1 - first_valuator]; + py = &valuators[1 - first_valuator]; + } + + if (!dx && !dy) + return; + + if (pDev->ptrfeed && pDev->ptrfeed->ctrl.num) { + /* modeled from xf86Events.c */ + if (pDev->ptrfeed->ctrl.threshold) { + if ((abs(dx) + abs(dy)) >= pDev->ptrfeed->ctrl.threshold) { + pDev->last.remainder[0] = ((float)dx * + (float)(pDev->ptrfeed->ctrl.num)) / + (float)(pDev->ptrfeed->ctrl.den) + + pDev->last.remainder[0]; + if (px) { + *px = (int)pDev->last.remainder[0]; + pDev->last.remainder[0] = pDev->last.remainder[0] - + (float)(*px); + } + + pDev->last.remainder[1] = ((float)dy * + (float)(pDev->ptrfeed->ctrl.num)) / + (float)(pDev->ptrfeed->ctrl.den) + + pDev->last.remainder[1]; + if (py) { + *py = (int)pDev->last.remainder[1]; + pDev->last.remainder[1] = pDev->last.remainder[1] - + (float)(*py); + } + } + } + else { + mult = pow((float)dx * (float)dx + (float)dy * (float)dy, + ((float)(pDev->ptrfeed->ctrl.num) / + (float)(pDev->ptrfeed->ctrl.den) - 1.0) / + 2.0) / 2.0; + if (dx) { + pDev->last.remainder[0] = mult * (float)dx + + pDev->last.remainder[0]; + *px = (int)pDev->last.remainder[0]; + pDev->last.remainder[0] = pDev->last.remainder[0] - + (float)(*px); + } + if (dy) { + pDev->last.remainder[1] = mult * (float)dy + + pDev->last.remainder[1]; + *py = (int)pDev->last.remainder[1]; + pDev->last.remainder[1] = pDev->last.remainder[1] - + (float)(*py); + } + } + } +} |