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-rw-r--r--src/grail-gestures.c188
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diff --git a/src/grail-gestures.c b/src/grail-gestures.c
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1/*****************************************************************************
2 *
3 * grail - Gesture Recognition And Instantiation Library
4 *
5 * Copyright (C) 2010 Canonical Ltd.
6 *
7 * This program is free software: you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation, either version 3 of the License, or (at your
10 * option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program. If not, see <http://www.gnu.org/licenses/>.
19 *
20 * Authors:
21 * Henrik Rydberg <rydberg@bitmath.org>
22 *
23 ****************************************************************************/
24
25#include "grail-recognizer.h"
26#include <math.h>
27
28static const float SN_MOVE = 200;
29static const float SN_ZOOM = 200;
30static const float SN_ROTATE = 200;
31static const float BAR_MOVE = 4;
32static const float BAR_ZOOM = 12;
33static const float BAR_ROTATE = 12;
34
35static void compute_position(float *x, float *y,
36 const struct touch_frame *frame)
37{
38 int i, n = frame->nactive;
39 *x = 0;
40 *y = 0;
41 if (n < 1)
42 return;
43 for (i = 0; i < n; i++) {
44 const struct touch *t = frame->active[i];
45 *x += t->prop[TP_POS_X];
46 *y += t->prop[TP_POS_Y];
47 }
48 *x /= n;
49 *y /= n;
50}
51
52static float compute_radius(float x, float y,
53 const struct touch_frame *frame)
54{
55 int i, n = frame->nactive;
56 float r = 0, r2 = 0;
57 if (n < 2)
58 return r;
59 for (i = 0; i < n; i++) {
60 const struct touch *t = frame->active[i];
61 float dx = t->prop[TP_POS_X] - x;
62 float dy = t->prop[TP_POS_Y] - y;
63 r2 += dx * dx + dy * dy;
64 }
65 r2 /= n;
66 r = sqrt(r2);
67 return r;
68}
69
70static float compute_rotation(float x, float y, float r,
71 const struct touch_frame *prev,
72 const struct touch_frame *frame)
73{
74 int i, n = frame->nactive;
75 float da = 0, da2 = 0;
76 if (n < 2)
77 return da;
78 for (i = 0; i < n; i++) {
79 const struct touch *t = frame->active[i];
80 const struct touch *ot = &prev->touch[t->slot];
81 float dx = t->prop[TP_POS_X] - x;
82 float dy = t->prop[TP_POS_Y] - y;
83 float mx = t->prop[TP_POS_X] - ot->prop[TP_POS_X];
84 float my = t->prop[TP_POS_Y] - ot->prop[TP_POS_Y];
85 da2 += dx * my - dy * mx;
86 }
87 da2 /= n;
88 da = da2 / r;
89 return da;
90}
91
92static float move_filter(const struct filter_model *m, float val)
93{
94 if (val > m->val - m->fuzz / 2 && val < m->val + m->fuzz / 2)
95 return m->val;
96 if (val > m->val - m->fuzz && val < m->val + m->fuzz)
97 return (m->val * 3 + val) / 4;
98 if (val > m->val - m->fuzz * 2 && val < m->val + m->fuzz * 2)
99 return (m->val + val) / 2;
100 return val;
101}
102
103static int move_reset(struct filter_model *m, float val)
104{
105 m->delta = 0;
106 m->tickle = 0;
107 m->active = 0;
108 m->val = val;
109 m->orig = val;
110}
111
112static int move_update(struct filter_model *m, float val)
113{
114 m->delta = val - m->val;
115 m->tickle = fabs(m->delta) > 0;
116 m->val = val;
117 if (!m->active && fabs(val - m->orig) > m->bar)
118 m->active = 1;
119 return m->active;
120}
121
122void gru_init_motion(struct grail *ge)
123{
124 struct gesture_recognizer *gru = ge->gru;
125 struct move_model *state = &gru->move;
126 struct grail_coord min, max;
127 grail_get_units(&min, &max, ge);
128 float x = max.x - min.x;
129 float y = max.y - min.y;
130 float r = sqrt(x * x + y * y);
131 state->x.fuzz = x / SN_MOVE;
132 state->y.fuzz = y / SN_MOVE;
133 state->r.fuzz = r / SN_ZOOM;
134 state->a.fuzz = r / SN_ROTATE;
135 state->x.bar = BAR_MOVE * state->x.fuzz;
136 state->y.bar = BAR_MOVE * state->y.fuzz;
137 state->r.bar = BAR_ZOOM * state->r.fuzz;
138 state->a.bar = BAR_ROTATE * state->a.fuzz;
139 state->multi = 0;
140}
141
142void gru_motion(struct grail *ge,
143 const struct touch_frame *frame)
144{
145 struct gesture_recognizer *gru = ge->gru;
146 struct move_model *state = &gru->move;
147 float x, y, r, a;
148 compute_position(&x, &y, frame);
149 if (frame->nactive < 2 || frame->ncreate || frame->ndestroy) {
150 r = compute_radius(x, y, frame);
151 a = 0;
152 move_reset(&state->x, x);
153 move_reset(&state->y, y);
154 move_reset(&state->r, r);
155 move_reset(&state->a, a);
156 state->multi = 0;
157 } else {
158 x = move_filter(&state->x, x);
159 y = move_filter(&state->y, y);
160 r = compute_radius(x, y, frame);
161 r = move_filter(&state->r, r);
162 a = state->a.val + compute_rotation(x, y, r, &gru->frame, frame);
163 //a = move_filter(&state->a, a);
164 move_update(&state->x, x);
165 move_update(&state->y, y);
166 move_update(&state->r, r);
167 move_update(&state->a, a);
168 state->multi = 1;
169 }
170 state->ntouch = frame->nactive;
171 state->time = frame->time;
172}
173
174void gru_event(struct grail *ge, int gid,
175 const struct move_model *move,
176 const grail_prop_t *prop, int nprop)
177{
178 gin_gid_event(ge, gid,
179 move->x.val, move->y.val, move->ntouch,
180 prop, nprop,
181 GRAIL_STATUS_UPDATE);
182}
183
184void gru_end(struct grail *ge, int gid, const struct move_model *move)
185{
186 gin_gid_end(ge, gid, move->x.val, move->y.val, move->ntouch);
187}
188
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