1 files changed, 261 insertions, 0 deletions

diff --git a/keyboards/rubi/lib/calc.c b/keyboards/rubi/lib/calc.c
new file mode 100644
index 000000000..7796a9be4
--- /dev/null
+++ b/keyboards/rubi/lib/calc.c
@@ -0,0 +1,261 @@
+/*
+This is the modified version of [calculator by MWWorks](https://github.com/MWWorks/mw_calc_numpad/blob/master/calc.c). Below is the quote from [MWWorks](https://github.com/MWWorks).
+
+   Calculator for QMK-based keyboard by MWWorks, https://mwworks.uk
+   This is free, usual disclaimers, don't use it to calculate megaton yields, surgery plans, etc
+
+   I did not plan to reinvent the wheel for this - I figured surely somebody somewhere has working calculator code?
+   Found lots but none that actually work like you expect a calculator to, hence DIYing it
+
+   As such, this is probably a bit janky, especially as I am a bit of a hack at C
+   Seems to be working well, with occasional glitchs, solved by clearing it
+   And some occasional floating-point issues - eg get a long decimal rather than the whole number you were expecting
+   Feel free to fix it! I think it needs to detect the precision of the two operands and then figure out what the precision of the result should be
+
+*/
+#include "rubi.h"
+
+static uint8_t calc_current_operand = 0;
+static char calc_operand_0[CALC_DIGITS+1] = "";
+static char calc_operand_1[CALC_DIGITS+1] = "";
+char calc_result[CALC_DIGITS+1] = "";
+static char calc_status[CALC_DIGITS+1] = "";
+static char calc_operator = ' ';
+static bool calc_reset = false;
+
+
+void calcBegin(void){
+}
+
+//update display
+void calcUpdate(void){
+    if (calc_display_lines == 2) {
+        if((calc_current_operand == 1) || (calc_reset)){
+            strcpy(calc_status, calc_operand_0);
+            if((strlen(calc_operand_0)>0) || (strlen(calc_operand_1)>0)){
+                uint8_t len = strlen(calc_status);
+                if (!(calc_operator == 's' || calc_operator == 'r' || calc_operator == 'n')) {
+                    calc_status[len] = calc_operator;
+                }
+                calc_status[len+1] = 0;
+                if(calc_reset
+                        && !(calc_operator == 's' || calc_operator == 'r' || calc_operator == 'n')){
+                    strncat(calc_status, calc_operand_1, CALC_DIGITS-strlen(calc_status));
+                    calc_operator = ' ';
+                }
+            }
+            strcpy(calc_status_display, calc_status);
+        }
+    } else if (calc_display_lines == 1) {
+        if(calc_reset
+                && !(calc_operator == 's' || calc_operator == 'r' || calc_operator == 'n')){
+            calc_operator = ' ';
+        }
+    }
+    calc_operator_display = calc_operator;
+    strcpy(calc_result_display, calc_result);
+}
+
+//perform calculation on the 2 operands
+void calcOperands(void){
+    float result = 0;
+    switch (calc_operator){
+
+        //standard operators
+        case '+':
+            result = strtod(calc_operand_0, NULL) + strtod(calc_operand_1, NULL);
+            break;
+
+        case '-':
+            result = strtod(calc_operand_0, NULL) - strtod(calc_operand_1, NULL);
+            break;
+
+        case '/':
+            result = strtod(calc_operand_0, NULL) / strtod(calc_operand_1, NULL);
+            break;
+
+        case '*':
+            result = strtod(calc_operand_0, NULL) * strtod(calc_operand_1, NULL);
+            break;
+
+            //single operand operators - these are all in 2
+        case 's':
+            result = sqrt(strtod(calc_operand_0, NULL));
+            break;
+
+        case 'r':
+            result = 1/(strtod(calc_operand_0, NULL));
+            break;
+
+    }
+
+    //now convert the float result into a string
+    //we know the total string size but we need to find the size of the integer component to know how much we have for decimals
+    uint8_t magnitude = ceil(log10(result));
+    uint8_t max_decimals = CALC_DIGITS-magnitude-1;
+    //but max it at 7 because that seems the useful limit of our floats
+    if(max_decimals>7){
+        max_decimals = 7;
+    }
+    dtostrf(result, CALC_DIGITS, max_decimals, calc_result);
+
+    //now to clean up the result - we need it clean as it may be the input of next calculation
+    //this seems a lot of code to format this string :| note that this c doesn't support float in sprintf
+    uint8_t i;
+
+    //first find if theres a dot
+    uint8_t dotpos = CALC_DIGITS+1;
+    for(i=0; i<strlen(calc_result); i++){
+        if(calc_result[i] == '.'){
+            dotpos = i;
+            break;
+        }
+    }
+
+    //if there is, work back to it and remove trailing 0 or .
+    if(dotpos>=0){
+        for(i=strlen(calc_result)-1; i>=dotpos; i--){
+            if((calc_result[i] == '0') || (calc_result[i] == '.')){
+                calc_result[i] = 0;
+            }else{
+                break;
+            }
+        }
+    }
+
+    //now find how many leading spaces
+    uint8_t spaces = 0;
+    for(i=0; i<strlen(calc_result); i++){
+        if(calc_result[i] == ' '){
+            spaces++;
+        }else{
+            break;
+        }
+    }
+
+    //and shift the string
+    for(i=0; i<strlen(calc_result)-spaces; i++){
+        calc_result[i] = calc_result[i+spaces];
+    }
+    calc_result[strlen(calc_result)-spaces] = 0;
+
+    calcUpdate();
+    //the result is available as the first operand for another calculation
+    strcpy(calc_operand_0, calc_result);
+    calc_operand_1[0] = 0;
+
+}
+
+void calcInput(char input){
+    char *operand = calc_operand_0;
+    if(calc_current_operand == 1){
+        operand = calc_operand_1;
+    }
+    uint8_t len = strlen(operand);
+
+    if(
+            ((input >= 48) && (input <= 57)) ||
+            (input == '.')
+      ){
+        //if this is following an equals, then we start from scratch as if new calculation
+        if(calc_reset == true){
+            calc_reset = false;
+            calc_current_operand = 0;
+            calc_operand_0[0] = 0;
+            calc_operand_1[0] = 0;
+            operand = calc_operand_0;
+            len = 0;
+        }
+
+        if(len<CALC_DIGITS){
+            operand[len] = input;
+            operand[len+1] = 0;
+            strcpy(calc_result, operand);
+            calcUpdate();
+        }
+
+        //special input to backspace
+    }else if(input == 'x'){
+        operand[len-1] = 0;
+        strcpy(calc_result, operand);
+        calcUpdate();
+
+        //clear
+    }else if(input == 'c'){
+        operand[0] = 0;
+        calc_operand_0[0] = 0;
+        calc_operand_1[0] = 0;
+        calc_operator = ' ';
+        calc_reset = true;
+        strcpy(calc_result, operand);
+        calcUpdate();
+
+        //special input switch neg/pos
+    }else if((input == 'n') && (len>0)){
+        uint8_t i;
+
+        if(operand[0] == '-'){
+            for(i=1; i<=len; i++){
+                operand[i-1] = operand[i];
+            }
+        }else if(len<CALC_DIGITS){
+            for(i=0; i<=len; i++){
+                operand[len-i+1] = operand[len-i];
+            }
+            operand[0] = '-';
+        }
+        calc_operator = input;
+        strcpy(calc_result, operand);
+        calcUpdate();
+
+
+        //standard 2 operand operators
+    }else if((input == '+') || (input == '-') || (input == '*')  || (input == '/')){
+
+        //get ready for second operand
+        if(calc_current_operand == 0){
+            calc_operator = input;
+            calc_current_operand = 1;
+            calcUpdate();
+
+            //we pressed = we now expect a new second operand
+        }else if(calc_reset){
+            calc_operator = input;
+            calc_reset = false;
+            calc_operand_1[0] = 0;
+            calcUpdate();
+
+        }else {
+            //if we use this on the second operand, calculate first, then ready for a second operand again
+            if (strlen(calc_operand_1)>0){
+                calcOperands();
+            }
+            calc_operand_1[0] = 0;
+            calc_operator = input;
+            calcUpdate();
+        }
+
+
+    }else if(input == '='){
+        //only accept = if we are on the second operand
+        if(calc_current_operand == 1){
+            //keep the second operand for a subsequent press of =; but flag to reset if start entry of new operand
+            calc_reset = true;
+            calcOperands();
+        }
+
+        //single operands - square root and reciprocal - needs to operate on 0 so it works after a previous = result
+    }else if((input == 's') || (input == 'r')){
+        //but maybe we started entering 1
+        if(calc_current_operand == 1 && !calc_reset){
+            strcpy(calc_operand_0, calc_operand_1);
+        }
+        calc_current_operand = 1;
+        calc_operand_1[0] = 0;
+        calc_operator = input;
+        calc_reset = true; //simulate another =
+        calcOperands();
+
+    }
+
+}