Introduce zoom, rotate and combo gestures

Introduce grail_mask bit functions, and add new gestures as separate
functions, referring to the same move model.

Signed-off-by: Henrik Rydberg <rydberg@bitmath.org>

1 files changed, 150 insertions, 0 deletions

diff --git a/src/grail-gestures.c b/src/grail-gestures.c
new file mode 100644
index 0000000..d79da96
--- /dev/null
+++ b/src/grail-gestures.c
@@ -0,0 +1,150 @@
+/*****************************************************************************
+ *
+ * grail - Gesture Recognition And Instantiation Library
+ *
+ * Copyright (C) 2010 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *      Henrik Rydberg <rydberg@bitmath.org>
+ *
+ ****************************************************************************/
+
+#include "grail-recognizer.h"
+#include <math.h>
+
+static const float SN_MOVE = 50;
+static const float SN_ZOOM = 50;
+static const float SN_ROTATE = 200;
+static const float BAR_MOVE = 1;
+static const float BAR_ZOOM = 2;
+static const float BAR_ROTATE = 4;
+
+static void compute_position(float *x, float *y,
+                             const struct touch_frame *frame)
+{
+        int i, n = frame->nactive;
+        *x = 0;
+        *y = 0;
+        if (n < 1)
+                return;
+        for (i = 0; i < n; i++) {
+                const struct touch *t = frame->active[i];
+                *x += t->prop[TP_POS_X];
+                *y += t->prop[TP_POS_Y];
+        }
+        *x /= n;
+        *y /= n;
+}
+
+static float compute_radius(float x, float y,
+                            const struct touch_frame *frame)
+{
+        int i, n = frame->nactive;
+        float r = 0, r2 = 0;
+        if (n < 2)
+                return r;
+        for (i = 0; i < n; i++) {
+                const struct touch *t = frame->active[i];
+                float dx = t->prop[TP_POS_X] - x;
+                float dy = t->prop[TP_POS_Y] - y;
+                r2 += dx * dx + dy * dy;
+        }
+        r2 /= n;
+        r = sqrt(r2);
+        return r;
+}
+
+static float compute_rotation(float x, float y, float r,
+                              const struct touch_frame *prev,
+                              const struct touch_frame *frame)
+{
+        int i, n = frame->nactive;
+        float da = 0, da2 = 0;
+        if (n < 2)
+                return da;
+        for (i = 0; i < n; i++) {
+                const struct touch *t = frame->active[i];
+                const struct touch *ot = &prev->touch[t->slot];
+                float dx = t->prop[TP_POS_X] - x;
+                float dy = t->prop[TP_POS_Y] - y;
+                float mx = t->prop[TP_POS_X] - ot->prop[TP_POS_X];
+                float my = t->prop[TP_POS_Y] - ot->prop[TP_POS_Y];
+                da2 += dx * my - dy * mx;
+        }
+        da2 /= n;
+        da = da2 / r;
+        return da;
+}
+
+static float move_filter(float x, float x0, float fuzz)
+{
+        if (x > x0 - fuzz / 2 && x < x0 + fuzz / 2)
+                return x0;
+        if (x > x0 - fuzz && x < x0 + fuzz)
+                return (x0 * 3 + x) / 4;
+        if (x > x0 - fuzz * 2 && x < x0 + fuzz * 2)
+                return (x0 + x) / 2;
+        return x;
+}
+
+void gru_init_motion(struct grail *ge, const struct touch_dev_caps *caps)
+{
+        struct gesture_recognizer *gru = ge->gru;
+        struct move_model *state = &gru->move;
+        float x = caps->info[TP_POS_X].maximum - caps->info[TP_POS_X].minimum;
+        float y = caps->info[TP_POS_Y].maximum - caps->info[TP_POS_Y].minimum;
+        float r = sqrt(x * x + y * y);
+        state->xfuzz = x / SN_MOVE;
+        state->yfuzz = y / SN_MOVE;
+        state->rfuzz = r / SN_ZOOM;
+        state->afuzz = r / SN_ROTATE;
+        state->xbar = BAR_MOVE * state->xfuzz;
+        state->ybar = BAR_MOVE * state->yfuzz;
+        state->rbar = BAR_ZOOM * state->rfuzz;
+        state->abar = BAR_ROTATE * state->afuzz;
+}
+
+void gru_reset_motion(struct grail *ge,
+                      const struct touch_frame *frame)
+{
+        struct gesture_recognizer *gru = ge->gru;
+        struct move_model *state = &gru->move;
+        compute_position(&state->x, &state->y, frame);
+        state->r = compute_radius(state->x, state->y, frame);
+        state->a = 0;
+        state->ntouch = frame->nactive;
+}
+
+void gru_compute_motion(struct grail *ge,
+                        const struct touch_frame *frame)
+{
+        struct gesture_inserter *gin = ge->gin;
+        struct gesture_recognizer *gru = ge->gru;
+        struct move_model *state = &gru->move;
+        float x, y, r, a;
+        compute_position(&x, &y, frame);
+        x = move_filter(x, state->x, state->xfuzz);
+        y = move_filter(y, state->y, state->yfuzz);
+        r = compute_radius(x, y, frame);
+        r = move_filter(r, state->r, state->rfuzz);
+        a = state->a + compute_rotation(x, y, r, &gru->frame, frame);
+        a = move_filter(a, state->a, state->afuzz);
+        state->x = x;
+        state->y = y;
+        state->r = r;
+        state->a = a;
+        state->ntouch = frame->nactive;
+}