1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
// Copyright 2012 The ChromiumOS Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "include/iir_filter_interpreter.h"
#include <utility>
#include <vector>
namespace gestures {
void IirFilterInterpreter::IoHistory::Increment() {
out_head = NextOutHead();
in_head = NextInHead();
}
// Uses exact comparisions, rather than approximate float comparisions,
// for operator==
bool IirFilterInterpreter::IoHistory::operator==(
const IirFilterInterpreter::IoHistory& that) const {
for (size_t i = 0; i < kInSize; i++)
if (in[i] != that.in[i])
return false;
for (size_t i = 0; i < kOutSize; i++)
if (out[i] != that.out[i])
return false;
return true;
}
// The default filter is a low-pass 2nd order Butterworth IIR filter with a
// normalized cutoff frequency of 0.2.
IirFilterInterpreter::IirFilterInterpreter(PropRegistry* prop_reg,
Interpreter* next,
Tracer* tracer)
: FilterInterpreter(nullptr, next, tracer, false),
using_iir_(true),
b0_(prop_reg, "IIR b0", 0.0674552738890719),
b1_(prop_reg, "IIR b1", 0.134910547778144),
b2_(prop_reg, "IIR b2", 0.0674552738890719),
b3_(prop_reg, "IIR b3", 0.0),
a1_(prop_reg, "IIR a1", -1.1429805025399),
a2_(prop_reg, "IIR a2", 0.412801598096189),
iir_dist_thresh_(prop_reg, "IIR Distance Threshold", 10),
adjust_iir_on_warp_(prop_reg, "Adjust IIR History On Warp", false) {
InitName();
b0_.SetDelegate(this);
b1_.SetDelegate(this);
b2_.SetDelegate(this);
b3_.SetDelegate(this);
a1_.SetDelegate(this);
a2_.SetDelegate(this);
iir_dist_thresh_.SetDelegate(this);
}
void IirFilterInterpreter::SyncInterpretImpl(HardwareState& hwstate,
stime_t* timeout) {
const char name[] = "IirFilterInterpreter::SyncInterpretImpl";
LogHardwareStatePre(name, hwstate);
// Delete old entries from map
std::vector<short> dead_ids;
dead_ids.reserve(histories_.size());
for (std::map<short, IoHistory>::iterator it = histories_.begin(),
e = histories_.end(); it != e; ++it)
if (!hwstate.GetFingerState((*it).first))
dead_ids.push_back((*it).first);
for (auto dead_id : dead_ids)
histories_.erase(dead_id);
// Modify current hwstate
for (size_t i = 0; i < hwstate.finger_cnt; i++) {
FingerState& fs = hwstate.fingers[i];
std::map<short, IoHistory>::iterator history =
histories_.find(fs.tracking_id);
if (history == histories_.end()) {
// new finger
IoHistory hist(fs);
histories_[fs.tracking_id] = hist;
continue;
}
// existing finger, apply filter
IoHistory* hist = &(*history).second;
// Finger WARP detected, adjust the IO history
if (adjust_iir_on_warp_.val_) {
float dx = 0.0, dy = 0.0;
if (fs.flags & GESTURES_FINGER_WARP_X_MOVE)
dx = fs.position_x - hist->PrevIn(0)->position_x;
if (fs.flags & GESTURES_FINGER_WARP_Y_MOVE)
dy = fs.position_y - hist->PrevIn(0)->position_y;
hist->WarpBy(dx, dy);
}
float dx = fs.position_x - hist->PrevOut(0)->position_x;
float dy = fs.position_y - hist->PrevOut(0)->position_y;
// IIR filter is too smooth for a quick finger movement. We do a simple
// rolling average if the position change between current and previous
// frames is larger than iir_dist_thresh_.
if (dx * dx + dy * dy > iir_dist_thresh_.val_ * iir_dist_thresh_.val_)
using_iir_ = false;
else
using_iir_ = true;
// TODO(adlr): consider applying filter to other fields
float FingerState::*fields[] = { &FingerState::position_x,
&FingerState::position_y,
&FingerState::pressure };
for (size_t f_idx = 0; f_idx < arraysize(fields); f_idx++) {
float FingerState::*field = fields[f_idx];
// Keep the current pressure reading, so we could make sure the pressure
// values will be same if there is two fingers on a SemiMT device.
if (hwprops_ && hwprops_->support_semi_mt &&
(field == &FingerState::pressure)) {
hist->NextOut()->pressure = fs.pressure;
continue;
}
if (adjust_iir_on_warp_.val_) {
if (field == &FingerState::position_x &&
(fs.flags & GESTURES_FINGER_WARP_X_MOVE)) {
hist->NextOut()->position_x = fs.position_x;
continue;
}
if (field == &FingerState::position_y &&
(fs.flags & GESTURES_FINGER_WARP_Y_MOVE)) {
hist->NextOut()->position_y = fs.position_y;
continue;
}
}
if (using_iir_) {
hist->NextOut()->*field =
b3_.val_ * hist->PrevIn(2)->*field +
b2_.val_ * hist->PrevIn(1)->*field +
b1_.val_ * hist->PrevIn(0)->*field +
b0_.val_ * fs.*field -
a2_.val_ * hist->PrevOut(1)->*field -
a1_.val_ * hist->PrevOut(0)->*field;
} else {
hist->NextOut()->*field = 0.5 * (fs.*field + hist->PrevOut(0)->*field);
}
}
float FingerState::*pass_fields[] = { &FingerState::touch_major,
&FingerState::touch_minor,
&FingerState::width_major,
&FingerState::width_minor,
&FingerState::orientation };
for (size_t f_idx = 0; f_idx < arraysize(pass_fields); f_idx++)
hist->NextOut()->*pass_fields[f_idx] = fs.*pass_fields[f_idx];
hist->NextOut()->flags = fs.flags;
*hist->NextIn() = fs;
fs = *hist->NextOut();
hist->Increment();
}
LogHardwareStatePost(name, hwstate);
next_->SyncInterpret(hwstate, timeout);
}
void IirFilterInterpreter::DoubleWasWritten(DoubleProperty* prop) {
histories_.clear();
}
void IirFilterInterpreter::IoHistory::WarpBy(float dx, float dy) {
for (size_t i = 0; i < kInSize; i++) {
PrevIn(i)->position_x += dx;
PrevIn(i)->position_y += dy;
}
for (size_t i = 0; i < kOutSize; i++) {
PrevOut(i)->position_x += dx;
PrevOut(i)->position_y += dy;
}
}
} // namespace gestures
|
