/* Copyright 2020 Christopher Courtney, aka Drashna Jael're (@drashna) <drashna@live.com> * Copyright 2020 Ploopy Corporation * * 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 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 License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "opt_encoder.h" #include <stdbool.h> enum State { HIHI, HILO, LOLO, LOHI }; enum State state; /* Variables used for scroll wheel functionality. */ bool lohif; bool hilof; int lowA; int highA; bool cLowA; bool cHighA; int lowIndexA; int highIndexA; bool lowOverflowA; bool highOverflowA; int lowB; int highB; bool cLowB; bool cHighB; int lowIndexB; int highIndexB; bool lowOverflowB; bool highOverflowB; int scrollThresholdA; int scrollThresholdB; int arLowA[SCROLLER_AR_SIZE]; int arHighA[SCROLLER_AR_SIZE]; int arLowB[SCROLLER_AR_SIZE]; int arHighB[SCROLLER_AR_SIZE]; void calculateThresholdA(int curA); void calculateThresholdB(int curB); int calculateThreshold(int cur, int* low, int* high, bool* cLow, bool* cHigh, int arLow[], int arHigh[], int* lowIndex, int* highIndex, bool* lowOverflow, bool* highOverflow); int thresholdEquation(int lo, int hi); void incrementIndex(int* index, bool* ovflw); /* Setup function for the scroll wheel. Initializes the relevant variables. */ void opt_encoder_init(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; } int8_t opt_encoder_handler(uint16_t curA, uint16_t 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; } void calculateThresholdA(int curA) { scrollThresholdA = calculateThreshold(curA, &lowA, &highA, &cLowA, &cHighA, arLowA, arHighA, &lowIndexA, &highIndexA, &lowOverflowA, &highOverflowA); } void calculateThresholdB(int curB) { scrollThresholdB = calculateThreshold(curB, &lowB, &highB, &cLowB, &cHighB, arLowB, arHighB, &lowIndexB, &highIndexB, &lowOverflowB, &highOverflowB); } int 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 >= SCROLL_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 thresholdEquation(int lo, int hi) { return ((hi - lo) / 3) + lo; } void incrementIndex(int* index, bool* ovflw) { if (*index < SCROLLER_AR_SIZE - 1) (*index)++; else { *index = 0; *ovflw = true; } }