1 files changed, 159 insertions, 0 deletions

diff --git a/src/memory.c b/src/memory.c
index 0e2edba..a09eadb 100644
--- a/src/memory.c
+++ b/src/memory.c
@@ -21,16 +21,175 @@
 
 #include "memory.h"
 
+/* fraction of max movement threshold */
+#define DELTA_CUT(x) (0.2 * (x))
+
+/* timer for cursor stability on finger touch/release */
+static const int FINGER_ATTACK_MS = 70;
+static const int FINGER_DECAY_MS = 120;
+
+static inline int dxval(const struct MTFinger *a, const struct MTFinger *b)
+{
+	return a->hw.position_x - b->hw.position_x;
+}
+static inline int dyval(const struct MTFinger *a, const struct MTFinger *b)
+{
+	return a->hw.position_y - b->hw.position_y;
+}
+
 void init_memory(struct Memory *mem)
 {
 	memset(mem, 0, sizeof(struct Memory));
 }
 
+/**
+ * update_configuration
+ *
+ * Update the same, fingers, added memory variables.
+ *
+ * Precondition: none
+ *
+ * Postcondition: same, fingers, added are set
+ *
+ */
+static void update_configuration(struct Memory *m,
+				 const struct MTState *prev_state,
+				 const struct MTState *state)
+{
+	const struct MTFinger *f = state->finger;
+	int i;
+	m->same = state->nfinger == prev_state->nfinger;
+	for (i = 0; i < state->nfinger; i++)
+		m->same = m->same && find_finger(prev_state, f[i].id);
+}
+
+/**
+ * update_pointers
+ *
+ * Update the pointing and ybar memory variables.
+ *
+ * Precondition: fingers, added are set
+ *
+ * Postcondition: pointing, ybar are set
+ *
+ */
+static void update_pointers(struct Memory *m,
+			    const struct MTState *state,
+			    const struct Capabilities *caps)
+{
+	const struct MTFinger *f = state->finger;
+	int i;
+
+	if (state->nfinger < 2) {
+		m->pointing = state->nfinger;
+		m->ybar = caps->abs_position_y.maximum;
+		return;
+	}
+
+	if (m->same) {
+		for (i = 0; i < state->nfinger; i++) {
+			if (GETBIT(m->pointing, i))
+				continue;
+			if (f[i].hw.position_y <= m->ybar) {
+				m->pointing = BITONES(state->nfinger);
+				return;
+			}
+		}
+		return;
+	}
+
+	m->pointing = 0;
+	m->ybar = caps->yclick;
+	for (i = 0; i < state->nfinger; i++) {
+		if (f[i].hw.position_y > caps->yclick)
+			continue;
+		if (!m->pointing || f[i].hw.position_y > m->ybar)
+			m->ybar = f[i].hw.position_y;
+		SETBIT(m->pointing, i);
+	}
+
+}
+
+/**
+ * update_movement
+ *
+ * Update the pending, moving, mvhold, mvforget, dx and dy memory variables.
+ *
+ * When moving is nonzero, gestures can be extracted from the dx and dy
+ * variables. These variables should be cleared after use.
+ *
+ * Precondition: fingers, added, pointing are set
+ *
+ * Postcondition: pending, moving, mvhold, mvforget, dx, dy are set
+ *
+ */
+static void update_movement(struct Memory *m,
+			    const struct MTState *prev_state,
+			    const struct MTState *state,
+			    const struct Capabilities *caps)
+{
+	const struct MTFinger *prev, *f = state->finger;
+	int i, x = 0, y = 0;
+	int dx, dy, xcut, ycut, xmax = 0, ymax = 0;
+
+	m->pending = 0;
+	m->moving = 0;
+
+	if (state->nfinger == 0)
+		return;
+
+	if (!m->same) {
+		m->move_time = state->evtime;
+		if (state->nfinger > prev_state->nfinger)
+			m->move_time += FINGER_ATTACK_MS;
+		else
+			m->move_time += FINGER_DECAY_MS;
+		memset(m->dx, 0, sizeof(m->dx));
+		memset(m->dy, 0, sizeof(m->dy));
+	} else {
+		for (i = 0; i < state->nfinger; i++) {
+			if (!GETBIT(m->pointing, i))
+				continue;
+			prev = find_finger(prev_state, f[i].id);
+			dx = dxval(&f[i], prev);
+			dy = dyval(&f[i], prev);
+			m->dx[i] += dx;
+			m->dy[i] += dy;
+			xmax = maxval(xmax, abs(m->dx[i]));
+			ymax = maxval(ymax, abs(m->dy[i]));
+		}
+		xcut = DELTA_CUT(xmax);
+		ycut = DELTA_CUT(ymax);
+		for (i = 0; i < state->nfinger; i++) {
+			if (!GETBIT(m->pointing, i))
+				continue;
+			if (abs(m->dx[i]) > xcut ||
+			    abs(m->dy[i]) > ycut)
+				SETBIT(m->pending, i);
+		}
+
+		/* accumulate all movement during delay */
+		if (m->pending && state->evtime >= m->move_time)
+			m->moving = m->pending;
+	}
+}
+
+void refresh_memory(struct Memory *m,
+		    const struct MTState *prev_state,
+		    const struct MTState *state,
+		    const struct Capabilities *caps)
+{
+	update_configuration(m, prev_state, state);
+	update_pointers(m, state, caps);
+	update_movement(m, prev_state, state, caps);
+}
+
 void output_memory(const struct Memory *m)
 {
 	int i;
 	xf86Msg(X_INFO, "btdata: %04x\n", m->btdata);
 	xf86Msg(X_INFO, "pointing: %04x\n", m->pointing);
+	xf86Msg(X_INFO, "pending: %04x\n", m->pending);
 	xf86Msg(X_INFO, "moving: %04x\n", m->moving);
 	xf86Msg(X_INFO, "ybar: %d\n", m->ybar);
 	xf86Msg(X_INFO, "move_time: %lld\n", m->move_time);