Files
multirom_m86/lib/velocity_tracker.c
2015-02-16 21:01:06 +01:00

73 lines
2.0 KiB
C

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdlib.h>
#include "touch_tracker.h"
#include "util.h"
touch_tracker *touch_tracker_create(void)
{
touch_tracker *t = mzalloc(sizeof(touch_tracker));
return t;
}
void touch_tracker_destroy(touch_tracker *t)
{
free(t);
}
void touch_tracker_start(touch_tracker *t, touch_event *ev)
{
t->distance_abs_x = t->distance_abs_y = 0;
t->start_x = ev->x;
t->start_y = ev->y;
t->last_x = ev->x;
t->last_y = ev->y;
memcpy(&v->time_start, &ev->time, sizeof(struct timeval));
}
void touch_tracker_finish(touch_tracker *t, touch_event *ev)
{
t->distance_x = ev->x - t->start_x;
t->distance_y = ev->y - t->start_y;
t->period = timeval_us_diff(ev->time, t->time_start);
}
void touch_tracker_add(touch_tracker *t, touch_event *ev)
{
t->distance_abs_x += iabs(ev->x - t->last_x);
t->distance_abs_y += iabs(ev->y - t->last_y);
t->last_x = ev->x;
t->last_y = ev->y;
}
float touch_tracker_get_velocity(touch_tracker *t, int axis)
{
if(axis == TRACKER_X)
return ((((float)t->distance_x) / t->period) * 1000000) / DPI_MUL;
else
return ((((float)t->distance_y) / t->period) * 1000000) / DPI_MUL;
}
float touch_tracker_get_velocity_abs(touch_tracker *t, int axis)
{
if(axis == TRACKER_X)
return ((((float)t->distance_abs_x) / t->period) * 1000000) / DPI_MUL;
else
return ((((float)t->distance_abs_y) / t->period) * 1000000) / DPI_MUL;
}