129 lines
2.7 KiB
C++
129 lines
2.7 KiB
C++
/*
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* Copyright (c) 2019, Ploopy Corporation, a Canadian federal corporation.
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*
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* This is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public Licensefalse
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* along with this program; if not, write to the Free Software
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* Foundation, Inc.
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "Scroller.h"
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Scroller::Scroller(void) {
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state = HIHI;
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lohif = false;
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hilof = false;
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lowA = 50;
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highA = 150;
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lowB = 50;
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highB = 150;
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calculateThreshold(lowA, lowB);
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}
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int Scroller::scroll(int curA, int curB) {
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calculateThreshold(curA, curB);
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bool LO = false;
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bool HI = true;
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bool sA, sB;
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int ret = 0;
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if (curA < scrollThreshold)
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sA = LO;
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else
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sA = HI;
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if (curB < scrollThreshold)
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sB = LO;
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else
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sB = HI;
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if (state == HIHI) {
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if (sA == LO && sB == HI) {
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state = LOHI;
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if (hilof) {
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ret = 1;
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hilof = false;
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}
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} else if (sA == HI && sB == LO) {
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state = HILO;
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if (lohif) {
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ret = -1;
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lohif = false;
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}
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}
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}
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else if (state == HILO) {
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if (sA == HI && sB == HI) {
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state = HIHI;
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hilof = true;
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lohif = false;
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} else if (sA == LO && sB == LO) {
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state = LOLO;
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hilof = true;
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lohif = false;
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}
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}
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else if (state == LOLO) {
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if (sA == HI && sB == LO) {
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state = HILO;
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if (lohif) {
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ret = 1;
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lohif = false;
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}
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} else if (sA == LO && sB == HI) {
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state = LOHI;
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if (hilof) {
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ret = -1;
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hilof = false;
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}
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}
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}
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else { // state must be LOHI
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if (sA == HI && sB == HI) {
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state = HIHI;
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lohif = true;
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hilof = false;
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} else if (sA == LO && sB == LO) {
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state = LOLO;
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lohif = true;
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hilof = false;
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}
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}
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return ret;
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}
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int Scroller::getScrollThreshold(void) {
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return scrollThreshold;
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}
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int Scroller::calculateThreshold(int curA, int curB) {
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if (curA < lowA)
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lowA = curA;
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else if (curA > highA)
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highA = curA;
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if (curB < lowB)
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lowB = curB;
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else if (curB > highB)
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highB = curB;
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int avgA = ((highA - lowA) / 3) + lowA;
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int avgB = ((highB - lowB) / 3) + lowB;
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scrollThreshold = (avgA + avgB) / 2;
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} |