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/*
* Copyright (C) 2013 Team XBMC
* http://xbmc.org
*
* 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 2, 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 XBMC; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*
*/
#ifndef _USE_MATH_DEFINES
#define _USE_MATH_DEFINES
#endif
#include <math.h>
#include <stdlib.h>
#include "GenericTouchSwipeDetector.h"
// maximum time between touch down and up (in nanoseconds)
#define SWIPE_MAX_TIME 500000000
// maxmium swipe distance between touch down and up (in multiples of screen DPI)
#define SWIPE_MIN_DISTANCE 0.5f
// original maximum variance of the touch movement
#define SWIPE_MAX_VARIANCE 0.2f
// tangens of the maximum angle (20 degrees) the touch movement may vary in a
// direction perpendicular to the swipe direction (in radians)
// => tan(20 deg) = tan(20 * M_PI / 180)
#define SWIPE_MAX_VARIANCE_ANGLE 0.36397023f
CGenericTouchSwipeDetector::CGenericTouchSwipeDetector(ITouchActionHandler *handler, float dpi)
: IGenericTouchGestureDetector(handler, dpi),
m_directions(TouchMoveDirectionLeft | TouchMoveDirectionRight | TouchMoveDirectionUp | TouchMoveDirectionDown),
m_swipeDetected(false), m_size(0)
{ }
bool CGenericTouchSwipeDetector::OnTouchDown(unsigned int index, const Pointer &pointer)
{
if (index < 0 || index >= TOUCH_MAX_POINTERS)
return false;
m_size += 1;
if (m_size > 1)
return true;
// reset all values
m_done = false;
m_swipeDetected = false;
m_directions = TouchMoveDirectionLeft | TouchMoveDirectionRight | TouchMoveDirectionUp | TouchMoveDirectionDown;
return true;
}
bool CGenericTouchSwipeDetector::OnTouchUp(unsigned int index, const Pointer &pointer)
{
if (index < 0 || index >= TOUCH_MAX_POINTERS)
return false;
m_size -= 1;
if (m_done)
return false;
m_done = true;
// check if a swipe has been detected and if it has a valid direction
if (!m_swipeDetected || m_directions == TouchMoveDirectionNone)
return false;
// check if the swipe has been performed in the proper time span
if ((pointer.current.time - pointer.down.time) > SWIPE_MAX_TIME)
return false;
// calculate the velocity of the swipe
float velocityX = 0.0f; // number of pixels per second
float velocityY = 0.0f; // number of pixels per second
pointer.velocity(velocityX, velocityY, false);
// call the OnSwipe() callback
OnSwipe((TouchMoveDirection)m_directions, pointer.down.x, pointer.down.y, pointer.current.x, pointer.current.y, velocityX, velocityY, m_size + 1);
return true;
}
bool CGenericTouchSwipeDetector::OnTouchMove(unsigned int index, const Pointer &pointer)
{
if (index < 0 || index >= TOUCH_MAX_POINTERS)
return false;
// only handle swipes of moved pointers
if (index >= m_size || m_done || !pointer.moving)
return false;
float deltaXmovement = pointer.current.x - pointer.last.x;
float deltaYmovement = pointer.current.y - pointer.last.y;
if (deltaXmovement > 0.0f)
m_directions &= ~TouchMoveDirectionLeft;
else if (deltaXmovement < 0.0f)
m_directions &= ~TouchMoveDirectionRight;
if (deltaYmovement > 0.0f)
m_directions &= ~TouchMoveDirectionUp;
else if (deltaYmovement < 0.0f)
m_directions &= ~TouchMoveDirectionDown;
if (m_directions == TouchMoveDirectionNone)
{
m_done = true;
return false;
}
float deltaXabs = abs(pointer.current.x - pointer.down.x);
float deltaYabs = abs(pointer.current.y - pointer.down.y);
float varXabs = deltaYabs * SWIPE_MAX_VARIANCE_ANGLE + (m_dpi * SWIPE_MAX_VARIANCE) / 2;
float varYabs = deltaXabs * SWIPE_MAX_VARIANCE_ANGLE + (m_dpi * SWIPE_MAX_VARIANCE) / 2;
if (m_directions & TouchMoveDirectionLeft)
{
// check if the movement went too much in Y direction
if (deltaYabs > varYabs)
m_directions &= ~TouchMoveDirectionLeft;
// check if the movement went far enough in the X direction
else if (deltaXabs > m_dpi * SWIPE_MIN_DISTANCE)
m_swipeDetected = true;
}
if (m_directions & TouchMoveDirectionRight)
{
// check if the movement went too much in Y direction
if (deltaYabs > varYabs)
m_directions &= ~TouchMoveDirectionRight;
// check if the movement went far enough in the X direction
else if (deltaXabs > m_dpi * SWIPE_MIN_DISTANCE)
m_swipeDetected = true;
}
if (m_directions & TouchMoveDirectionUp)
{
// check if the movement went too much in X direction
if (deltaXabs > varXabs)
m_directions &= ~TouchMoveDirectionUp;
// check if the movement went far enough in the Y direction
else if (deltaYabs > m_dpi * SWIPE_MIN_DISTANCE)
m_swipeDetected = true;
}
if (m_directions & TouchMoveDirectionDown)
{
// check if the movement went too much in X direction
if (deltaXabs > varXabs)
m_directions &= ~TouchMoveDirectionDown;
// check if the movement went far enough in the Y direction
else if (deltaYabs > m_dpi * SWIPE_MIN_DISTANCE)
m_swipeDetected = true;
}
if (m_directions == TouchMoveDirectionNone)
{
m_done = true;
return false;
}
return true;
}
bool CGenericTouchSwipeDetector::OnTouchUpdate(unsigned int index, const Pointer &pointer)
{
if (index < 0 || index >= TOUCH_MAX_POINTERS)
return false;
if (m_done)
return true;
return OnTouchMove(index, pointer);
}
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