GRBL-Advanced/grbl/util.c

/*
  util.c - Shared functions
  Part of Grbl-Advanced

  Copyright (c) 2014-2016 Sungeun K. Jeon for Gnea Research LLC
  Copyright (c) 2017-2020 Patrick F.

  Grbl-Advanced 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.

  Grbl-Advanced 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 Grbl-Advanced.  If not, see <http://www.gnu.org/licenses/>.
*/
#include <ctype.h>
#include <string.h>
#include "Config.h"
#include "Protocol.h"
#include "Print.h"
#include "System.h"
#include "Settings.h"
#include "util.h"

#include "System32.h"


#define MAX_INT_DIGITS 8 // Maximum number of digits in int32 (and float)


// Extracts a floating point value from a string. The following code is based loosely on
// the avr-libc strtod() function by Michael Stumpf and Dmitry Xmelkov and many freely
// available conversion method examples, but has been highly optimized for Grbl. For known
// CNC applications, the typical decimal value is expected to be in the range of E0 to E-4.
// Scientific notation is officially not supported by g-code, and the 'E' character may
// be a g-code word on some CNC systems. So, 'E' notation will not be recognized.
// NOTE: Thanks to Radu-Eosif Mihailescu for identifying the issues with using strtod().
uint8_t Read_Float(const char *line, uint8_t *char_counter, float *float_ptr)
{
    char *ptr = (char *)line + *char_counter;
    unsigned char c;

    // Grab first character and increment pointer. No spaces assumed in line.
    c = *ptr++;

    // Capture initial positive/minus character
    bool isnegative = false;
    if(c == '-')
    {
        isnegative = true;
        c = *ptr++;
    }
    else if(c == '+')
    {
        c = *ptr++;
    }

    // Extract number into fast integer. Track decimal in terms of exponent value.
    uint32_t intval = 0;
    int8_t exp = 0;
    uint8_t ndigit = 0;
    bool isdecimal = false;

    while(1)
    {
        c -= '0';

        if(c <= 9)
        {
            ndigit++;
            if(ndigit <= MAX_INT_DIGITS)
            {
                if(isdecimal)
                {
                    exp--;
                }
                intval = (((intval << 2) + intval) << 1) + c; // intval*10 + c
            }
            else
            {
                if (!(isdecimal))
                {
                    exp++;    // Drop overflow digits
                }
            }
        }
        else if(c == (('.'-'0') & 0xff)  &&  !(isdecimal))
        {
            isdecimal = true;
        }
        else
        {
            break;
        }
        c = *ptr++;
    }

    // Return if no digits have been read.
    if(!ndigit)
    {
        return(false);
    };

    // Convert integer into floating point.
    float fval;
    fval = (float)intval;

    // Apply decimal. Should perform no more than two floating point multiplications for the
    // expected range of E0 to E-4.
    if(fval != 0)
    {
        while(exp <= -2)
        {
            fval *= 0.01;
            exp += 2;
        }
        if(exp < 0)
        {
            fval *= 0.1;
        }
        else if(exp > 0)
        {
            do
            {
                fval *= 10.0;
            }
            while(--exp > 0);
        }
    }

    // Assign floating point value with correct sign.
    if(isnegative)
    {
        *float_ptr = -fval;
    }
    else
    {
        *float_ptr = fval;
    }

    *char_counter = ptr - line - 1; // Set char_counter to next statement

    return(true);
}


// Search a float in a string and return it as string
uint8_t ExtractFloat(const char *line, int start_idx, char *float_char)
{
    unsigned int i = 0;

    float_char[0] = '\0';

    for(i = start_idx; i < strlen(line); i++)
    {
        // Search for start of float (digit or '-')
        if(!isdigit((unsigned char)line[i]) && (line[i] != '-'))
        {
            continue;
        }
        else
        {
            // Start of float found
            int j = 0;

            do
            {
                float_char[j++] = line[i++];
            }
            while(isdigit((unsigned char)line[i]) || line[i] == '.');      // Read float

            float_char[j] = '\0';

            break;
        }
    }

    // Return position after float in string
    return i;
}


// Floating value printing handlers for special variables types used in Grbl and are defined
// in the config.h.
//  - CoordValue: Handles all position or coordinate values in inches or mm reporting.
//  - RateValue: Handles feed rate and current velocity in inches or mm reporting.
void PrintFloat_CoordValue(float n)
{
    if(BIT_IS_TRUE(settings.flags, BITFLAG_REPORT_INCHES))
    {
        Printf_Float(n*INCH_PER_MM,N_DECIMAL_COORDVALUE_INCH);
    }
    else
    {
        Printf_Float(n, N_DECIMAL_COORDVALUE_MM);
    }
}


void PrintFloat_RateValue(float n)
{
    if(BIT_IS_TRUE(settings.flags, BITFLAG_REPORT_INCHES))
    {
        Printf_Float(n*INCH_PER_MM,N_DECIMAL_RATEVALUE_INCH);
    }
    else
    {
        Printf_Float(n, N_DECIMAL_RATEVALUE_MM);
    }
}


// Non-blocking delay function used for general operation and suspend features.
void Delay_sec(float seconds, uint8_t mode)
{
    uint16_t i = ceilf(1000/DWELL_TIME_STEP*seconds);

    while(i-- > 0)
    {
        if(sys.abort)
        {
            return;
        }

        if(mode == DELAY_MODE_DWELL)
        {
            Protocol_ExecuteRealtime();
        }
        else   // DELAY_MODE_SYS_SUSPEND
        {
            // Execute rt_system() only to avoid nesting suspend loops.
            Protocol_ExecRtSystem();

            if(sys.suspend & SUSPEND_RESTART_RETRACT)
            {
                // Bail, if safety door reopens.
                return;
            }
        }

        Delay_ms(DWELL_TIME_STEP); // Delay DWELL_TIME_STEP increment
    }
}


bool isEqual_f(float a, float b)
{
    if(fabsf(a-b) < 0.00001)
    {
        return true;
    }

    return false;
}

float convert_delta_vector_to_unit_vector(float *vector)
{
    uint8_t idx;
    float magnitude = 0.0;

    for(idx = 0; idx < N_AXIS; idx++)
    {
        if(vector[idx] != 0.0)
        {
            magnitude += vector[idx]*vector[idx];
        }
    }

    magnitude = sqrtf(magnitude);
    float inv_magnitude = 1.0/magnitude;

    for(idx = 0; idx < N_AXIS; idx++)
    {
        vector[idx] *= inv_magnitude;
    }

    return magnitude;
}

float limit_value_by_axis_maximum(float *max_value, float *unit_vec)
{
    uint8_t idx;
    float limit_value = SOME_LARGE_VALUE;

    for(idx = 0; idx < N_AXIS; idx++)
    {
        if(unit_vec[idx] != 0)    // Avoid divide by zero.
        {
            limit_value = min(limit_value,fabsf(max_value[idx]/unit_vec[idx]));
        }
    }

    return limit_value;
}