classic-trackball/firmware/production/Scroller.cpp

273 lines
6.5 KiB
C++

/*
* Copyright (c) 2019, Ploopy Corporation, a Canadian federal corporation.
*
* This 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 3 of the License, 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 Licensefalse
* along with this program; if not, write to the Free Software
* Foundation, Inc.
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#endif
#include "Scroller.h"
Scroller::Scroller(void) {
state = HIHI;
lohif = false;
hilof = false;
lowA = 1023;
highA = 0;
cLowA = false;
cHighA = false;
lowIndexA = 0;
highIndexA = 0;
lowOverflowA = false;
highOverflowA = false;
lowB = 1023;
highB = 0;
cLowB = false;
cHighB = false;
lowIndexB = 0;
highIndexB = 0;
lowOverflowB = false;
highOverflowB = false;
scrollThresholdA = 0;
scrollThresholdB = 0;
}
int Scroller::scroll(int curA, int curB) {
if (lowOverflowA == false || highOverflowA == false)
calculateThresholdA(curA);
if (lowOverflowB == false || highOverflowB == false)
calculateThresholdB(curB);
bool LO = false;
bool HI = true;
bool sA, sB;
int ret = 0;
if (curA < scrollThresholdA)
sA = LO;
else
sA = HI;
if (curB < scrollThresholdB)
sB = LO;
else
sB = HI;
if (state == HIHI) {
if (sA == LO && sB == HI) {
state = LOHI;
if (hilof) {
ret = 1;
hilof = false;
}
} else if (sA == HI && sB == LO) {
state = HILO;
if (lohif) {
ret = -1;
lohif = false;
}
}
}
else if (state == HILO) {
if (sA == HI && sB == HI) {
state = HIHI;
hilof = true;
lohif = false;
} else if (sA == LO && sB == LO) {
state = LOLO;
hilof = true;
lohif = false;
}
}
else if (state == LOLO) {
if (sA == HI && sB == LO) {
state = HILO;
if (lohif) {
ret = 1;
lohif = false;
}
} else if (sA == LO && sB == HI) {
state = LOHI;
if (hilof) {
ret = -1;
hilof = false;
}
}
}
else { // state must be LOHI
if (sA == HI && sB == HI) {
state = HIHI;
lohif = true;
hilof = false;
} else if (sA == LO && sB == LO) {
state = LOLO;
lohif = true;
hilof = false;
}
}
return ret;
}
int Scroller::calculateThresholdA(int curA) {
scrollThresholdA = calculateThreshold(curA, lowA, highA,
cLowA, cHighA, arLowA, arHighA, lowIndexA, highIndexA,
lowOverflowA, highOverflowA);
}
int Scroller::calculateThresholdB(int curB) {
scrollThresholdB = calculateThreshold(curB, lowB, highB,
cLowB, cHighB, arLowB, arHighB, lowIndexB, highIndexB,
lowOverflowB, highOverflowB);
}
int Scroller::calculateThreshold(int cur, int &low, int &high,
bool &cLow, bool &cHigh, int arLow[], int arHigh[],
int &lowIndex, int &highIndex, bool &lowOverflow,
bool &highOverflow) {
if (cur < low)
low = cur;
if (cur > high)
high = cur;
int curThresh = thresholdEquation(low, high);
int range = high - low;
// The range is enforced to be over a certain limit because noise
// can cause erroneous readings, making these calculations unstable.
if (range >= THRESH_RANGE_LIM) {
if (cur < curThresh) {
if (cHigh == true) {
// We were just high, and now we crossed to low.
// high reflects a sample of a high reading.
arHigh[highIndex] = high;
incrementIndex(highIndex, highOverflow);
int midpoint = ((high - low) / 2) + low;
low = midpoint;
high = midpoint;
cLow = false;
cHigh = false;
} else {
cLow = true;
}
} if (cur > curThresh) {
if (cLow == true) {
// We were just low, and now we crossed to high.
// low reflects a sample of a low reading.
arLow[lowIndex] = low;
incrementIndex(lowIndex, lowOverflow);
int midpoint = ((high - low) / 2) + low;
low = midpoint;
high = midpoint;
cLow = false;
cHigh = false;
} else {
cHigh = true;
}
}
}
int calcHigh = 0;
if (highOverflow == true) {
for (int i = 0; i < SCROLLER_AR_SIZE; i++) {
calcHigh += arHigh[i];
}
calcHigh = calcHigh / SCROLLER_AR_SIZE;
} else if (highIndex != 0) {
for (int i = 0; i < highIndex; i++) {
calcHigh += arHigh[i];
}
calcHigh = calcHigh / highIndex;
} else {
calcHigh = high;
}
int calcLow = 0;
if (lowOverflow == true) {
for (int i = 0; i < SCROLLER_AR_SIZE; i++) {
calcLow += arLow[i];
}
calcLow = calcLow / SCROLLER_AR_SIZE;
} else if (lowIndex != 0) {
for (int i = 0; i < lowIndex; i++) {
calcLow += arLow[i];
}
calcLow = calcLow / lowIndex;
} else {
calcLow = low;
}
return thresholdEquation(calcLow, calcHigh);
}
int Scroller::thresholdEquation(int lo, int hi) {
return ((hi - lo) / 3) + lo;
}
void Scroller::incrementIndex(int &index, bool &ovflw) {
if (index < SCROLLER_AR_SIZE - 1)
index++;
else {
index = 0;
ovflw = true;
}
}
void Scroller::debug(void) {
/*
Serial.print(F("lowA: "));
Serial.print(lowA);
Serial.print(F(", highA: "));
Serial.print(highA);
Serial.print(F(", cLowA: "));
Serial.print(cLowA ? "true" : "false");
Serial.print(F(", cHighA: "));
Serial.print(cHighA ? "true" : "false");
Serial.print(F(", lowIndexA: "));
Serial.print(lowIndexA);
Serial.print(F(", highIndexA: "));
Serial.print(highIndexA);
Serial.print(F(", lowOverflowA: "));
Serial.print(lowOverflowA ? "true" : "false");
Serial.print(F(", highOverflowA: "));
Serial.println(highOverflowA ? "true" : "false");
Serial.print(F("arLowA: "));
for (int i = 0; i < SCROLLER_AR_SIZE; i++) {
Serial.print(arLowA[i]);
Serial.print(F(","));
}
Serial.println(".");
Serial.print(F("arHighA: "));
for (int i = 0; i < SCROLLER_AR_SIZE; i++) {
Serial.print(arHighA[i]);
Serial.print(F(","));
}
Serial.println(".");
*/
Serial.print(F(", thB: "));
Serial.print(scrollThresholdB);
Serial.print(F(", thA: "));
Serial.print(scrollThresholdA);
}