1 files changed, 393 insertions, 0 deletions

diff --git a/src/core.c b/src/core.c
new file mode 100644
index 0000000..3df8257
--- /dev/null
+++ b/src/core.c
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+/*****************************************************************************
+ *
+ * mtdev - MT device event converter (MIT license)
+ *
+ * Copyright (C) 2010 Henrik Rydberg <rydberg@euromail.se>
+ * Copyright (C) 2010 Canonical Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ ****************************************************************************/
+
+#include "state.h"
+#include "iobuf.h"
+#include "evbuf.h"
+
+static inline int istouch(const struct mtdev_slot *data,
+                          const struct mtdev_caps *caps)
+{
+        return data->abs[MTDEV_TOUCH_MAJOR] ||
+                !caps->has_abs[MTDEV_TOUCH_MAJOR];
+}
+
+/* Dmitry Torokhov's code from kernel/driver/input/input.c */
+static int defuzz(int value, int old_val, int fuzz)
+{
+        if (fuzz) {
+                if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
+                        return old_val;
+
+                if (value > old_val - fuzz && value < old_val + fuzz)
+                        return (old_val * 3 + value) / 4;
+
+                if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
+                        return (old_val + value) / 2;
+        }
+
+        return value;
+}
+
+/*
+ * solve - solve contact matching problem
+ * @state: mtdev state
+ * @caps: device capabilities
+ * @sid: array of current tracking ids
+ * @sx: array of current position x
+ * @sy: array of current position y
+ * @sn: number of current contacts
+ * @nid: array of new or matched tracking ids, to be filled
+ * @nx: array of new position x
+ * @ny: array of new position y
+ * @nn: number of new contacts
+ * @touch: which of the new contacts to fill
+ */
+static void solve(struct mtdev_state *state, const struct mtdev_caps *caps,
+                  const int *sid, const int *sx, const int *sy, int sn,
+                  int *nid, const int *nx, const int *ny, int nn,
+                  bitmask_t touch)
+{
+        int A[DIM2_FINGER], *row;
+        int n2s[DIM_FINGER];
+        int id, i, j;
+
+        /* setup distance matrix for contact matching */
+        for (j = 0; j < sn; j++) {
+                row = A + nn * j;
+                for (i = 0; i < nn; i++)
+                        row[i] = dist2(nx[i] - sx[j], ny[i] - sy[j]);
+        }
+
+        match_fingers(n2s, A, nn, sn);
+
+        /* update matched contacts and create new ones */
+        foreach_bit(i, touch) {
+                j = n2s[i];
+                id = j >= 0 ? sid[j] : caps->nullid;
+                while (id == caps->nullid)
+                        id = ++state->lastid;
+                nid[i] = id;
+        }
+}
+
+/*
+ * assign_tracking_id - assign tracking ids to all contacts
+ * @state: mtdev state
+ * @caps: device capabilities
+ * @data: array of all present contacts, to be filled
+ * @prop: array of all set contacts properties
+ * @size: number of contacts in array
+ * @touch: which of the contacts are actual touches
+ */
+static void assign_tracking_id(struct mtdev_state *state,
+                               const struct mtdev_caps *caps,
+                               struct mtdev_slot *data, bitmask_t *prop,
+                               int size, bitmask_t touch)
+{
+        int sid[DIM_FINGER], sx[DIM_FINGER], sy[DIM_FINGER], sn = 0;
+        int nid[DIM_FINGER], nx[DIM_FINGER], ny[DIM_FINGER], i;
+        foreach_bit(i, state->used) {
+                sid[sn] = state->data[i].abs[MTDEV_TRACKING_ID];
+                sx[sn] = state->data[i].abs[MTDEV_POSITION_X];
+                sy[sn] = state->data[i].abs[MTDEV_POSITION_Y];
+                sn++;
+        }
+        for (i = 0; i < size; i++) {
+                nx[i] = data[i].abs[MTDEV_POSITION_X];
+                ny[i] = data[i].abs[MTDEV_POSITION_Y];
+        }
+        solve(state, caps, sid, sx, sy, sn, nid, nx, ny, size, touch);
+        for (i = 0; i < size; i++) {
+                data[i].abs[MTDEV_TRACKING_ID] =
+                        GETBIT(touch, i) ? nid[i] : caps->nullid;
+                prop[i] |= BITMASK(MTDEV_TRACKING_ID);
+        }
+}
+
+/*
+ * process_typeA - consume MT events and update mtdev state
+ * @state: mtdev state
+ * @data: array of all present contacts, to be filled
+ * @prop: array of all set contacts properties, to be filled
+ *
+ * This function is called when a SYN_REPORT is seen, right before
+ * that event is pushed to the queue.
+ *
+ * Returns -1 if the packet is not MT related and should not affect
+ * the current mtdev state.
+ */
+static int process_typeA(struct mtdev_state *state,
+                         struct mtdev_slot *data, bitmask_t *prop)
+{
+        struct input_event ev;
+        int consumed, mtcode;
+        int mtcnt = 0, size = 0;
+        prop[size] = 0;
+        while (!evbuf_empty(&state->inbuf)) {
+                evbuf_get(&state->inbuf, &ev);
+                consumed = 0;
+                switch (ev.type) {
+                case EV_SYN:
+                        switch (ev.code) {
+                        case SYN_MT_REPORT:
+                                if (size < DIM_FINGER &&
+                                    GETBIT(prop[size], MTDEV_POSITION_X) &&
+                                    GETBIT(prop[size], MTDEV_POSITION_Y))
+                                        size++;
+                                if (size < DIM_FINGER)
+                                        prop[size] = 0;
+                                mtcnt++;
+                                consumed = 1;
+                                break;
+                        }
+                        break;
+                case EV_KEY:
+                        switch (ev.code) {
+                        case BTN_TOUCH:
+                                mtcnt++;
+                                break;
+                        }
+                        break;
+                case EV_ABS:
+                        if (size < DIM_FINGER && mtdev_is_absmt(ev.code)) {
+                                mtcode = mtdev_abs2mt(ev.code);
+                                data[size].abs[mtcode] = ev.value;
+                                prop[size] |= BITMASK(mtcode);
+                                mtcnt++;
+                                consumed = 1;
+                        }
+                        break;
+                }
+                if (!consumed)
+                        evbuf_put(&state->outbuf, &ev);
+        }
+        return mtcnt ? size : -1;
+}
+
+/*
+ * process_typeB - propagate events without parsing
+ * @state: mtdev state
+ *
+ * This function is called when a SYN_REPORT is seen, right before
+ * that event is pushed to the queue.
+ */
+static void process_typeB(struct mtdev_state *state)
+{
+        struct input_event ev;
+        while (!evbuf_empty(&state->inbuf)) {
+                evbuf_get(&state->inbuf, &ev);
+                evbuf_put(&state->outbuf, &ev);
+        }
+}
+
+/*
+ * filter_data - apply input filtering on new incoming data
+ * @state: mtdev state
+ * @caps: device capabilities
+ * @data: the incoming data to filter
+ * @prop: the properties to filter
+ * @slot: the slot the data refers to
+ */
+static void filter_data(const struct mtdev_state *state,
+                        const struct mtdev_caps *caps,
+                        struct mtdev_slot *data, bitmask_t prop,
+                        int slot)
+{
+        int i;
+        foreach_bit(i, prop) {
+                int fuzz = caps->abs[i].fuzz;
+                int oldval = state->data[slot].abs[i];
+                data->abs[i] = defuzz(data->abs[i], oldval, fuzz);
+        }
+}
+
+/*
+ * push_slot_changes - propagate state changes
+ * @state: mtdev state
+ * @data: the incoming data to propagate
+ * @prop: the properties to propagate
+ * @slot: the slot the data refers to
+ * @syn: reference to the SYN_REPORT event
+ */
+static void push_slot_changes(struct mtdev_state *state,
+                              const struct mtdev_slot *data, bitmask_t prop,
+                              int slot, const struct input_event *syn)
+{
+        struct input_event ev;
+        int i, count = 0;
+        foreach_bit(i, prop)
+                if (state->data[slot].abs[i] != data->abs[i])
+                        count++;
+        if (!count)
+                return;
+        ev.time = syn->time;
+        ev.type = EV_ABS;
+        ev.code = ABS_MT_SLOT;
+        ev.value = slot;
+        if (state->slot != ev.value) {
+                evbuf_put(&state->outbuf, &ev);
+                state->slot = ev.value;
+        }
+        foreach_bit(i, prop) {
+                ev.code = mtdev_mt2abs(i);
+                ev.value = data->abs[i];
+                if (state->data[slot].abs[i] != ev.value) {
+                        evbuf_put(&state->outbuf, &ev);
+                        state->data[slot].abs[i] = ev.value;
+                }
+        }
+}
+
+/*
+ * apply_typeA_changes - parse and propagate state changes
+ * @state: mtdev state
+ * @caps: device capabilities
+ * @data: array of data to apply
+ * @prop: array of properties to apply
+ * @size: number of contacts in array
+ * @syn: reference to the SYN_REPORT event
+ */
+static void apply_typeA_changes(struct mtdev_state *state,
+                                const struct mtdev_caps *caps,
+                                struct mtdev_slot *data, const bitmask_t *prop,
+                                int size, const struct input_event *syn)
+{
+        bitmask_t unused = ~state->used;
+        bitmask_t used = 0;
+        int i, slot, id;
+        for (i = 0; i < size; i++) {
+                id = data[i].abs[MTDEV_TRACKING_ID];
+                foreach_bit(slot, state->used) {
+                        if (state->data[slot].abs[MTDEV_TRACKING_ID] != id)
+                                continue;
+                        filter_data(state, caps, &data[i], prop[i], slot);
+                        push_slot_changes(state, &data[i], prop[i], slot, syn);
+                        SETBIT(used, slot);
+                        id = caps->nullid;
+                        break;
+                }
+                if (id != caps->nullid) {
+                        slot = firstbit(unused);
+                        push_slot_changes(state, &data[i], prop[i], slot, syn);
+                        SETBIT(used, slot);
+                        CLEARBIT(unused, slot);
+                }
+        }
+
+        /* clear unused slots and update slot usage */
+        foreach_bit(slot, state->used & ~used) {
+                struct mtdev_slot tdata = state->data[slot];
+                bitmask_t tprop = BITMASK(MTDEV_TRACKING_ID);
+                tdata.abs[MTDEV_TRACKING_ID] = caps->nullid;
+                push_slot_changes(state, &tdata, tprop, slot, syn);
+        }
+        state->used = used;
+}
+
+/*
+ * convert_A_to_B - propagate a type A packet as a type B packet
+ * @state: mtdev state
+ * @caps: device capabilities
+ * @syn: reference to the SYN_REPORT event
+ */
+static void convert_A_to_B(struct mtdev_state *state,
+                           const struct mtdev_caps *caps,
+                           const struct input_event *syn)
+{
+        struct mtdev_slot data[DIM_FINGER];
+        bitmask_t prop[DIM_FINGER];
+        int size = process_typeA(state, data, prop);
+        if (size < 0)
+                return;
+        if (!caps->has_abs[MTDEV_TRACKING_ID]) {
+                bitmask_t touch = 0;
+                int i;
+                for (i = 0; i < size; i++)
+                        MODBIT(touch, i, istouch(&data[i], caps));
+                assign_tracking_id(state, caps, data, prop, size, touch);
+        }
+        apply_typeA_changes(state, caps, data, prop, size, syn);
+}
+
+int mtdev_init(struct mtdev *dev)
+{
+        memset(dev, 0, sizeof(struct mtdev));
+        dev->state = calloc(1, sizeof(struct mtdev_state));
+        if (!dev->state)
+                return -ENOMEM;
+        return 0;
+}
+
+int mtdev_open(struct mtdev *dev, int fd)
+{
+        int ret;
+        ret = mtdev_init(dev);
+        if (ret)
+                goto error;
+        ret = mtdev_configure(dev, fd);
+        if (ret)
+                goto mtdev;
+        return 0;
+ mtdev:
+        mtdev_close(dev);
+ error:
+        return ret;
+}
+
+void mtdev_put(struct mtdev *dev, const struct input_event *ev)
+{
+        struct mtdev_state *state = dev->state;
+        if (ev->type == EV_SYN && ev->code == SYN_REPORT) {
+                bitmask_t head = state->outbuf.head;
+                if (dev->state)
+                        convert_A_to_B(state, &dev->caps, ev);
+                else
+                        process_typeB(state);
+                if (state->outbuf.head != head)
+                        evbuf_put(&state->outbuf, ev);
+        } else {
+                evbuf_put(&state->inbuf, ev);
+        }
+}
+
+int mtdev_empty(struct mtdev *dev)
+{
+        return evbuf_empty(&dev->state->outbuf);
+}
+
+void mtdev_get(struct mtdev *dev, struct input_event* ev)
+{
+        evbuf_get(&dev->state->outbuf, ev);
+}
+
+void mtdev_close(struct mtdev *dev)
+{
+        free(dev->state);
+        memset(dev, 0, sizeof(struct mtdev));
+}