interpeter: allow comments that print params, to set the float format

printting out number to users often uses excessive decimals.
now &d,%f or %.xf (x being a number) is interpeted to be a float format
for params.

-add test for printing formatted params
-add docs on formatting of parameter numbers in comments

docs/src/gcode/overview.adoc

@@ -1075,6 +1075,26 @@ are replaced by the value of the named parameter. Named parameters
 will have white space removed from them. So, '\#<named parameter>'
 will be converted to '#<namedparameter>'.
 
+Parameter numbers can be formatted. eg:
+
+----
+(DEBUG, value = %d#<some_value>)
+----
+will print the value rounded to an integer.
+
+* %lf is default if there is no formatting string
+* %d = 0 decimals
+* %f = four decimals
+* %.xf = x (0-9) number of decimals
+
+The formatting will be preformed on all parameters in the same line unless 
+changed. ie. multiple formatting is allowed in one line.
+
+The formatting string does not need to be right beside the parameter.
+
+If the formatting string is created with the wrong pattern it will be 
+printed as characters.
+
 [[gcode:file-requirements]]
 == File Requirements(((File Requirements)))
 

src/emc/rs274ngc/interp_convert.cc

@@ -1277,6 +1277,7 @@ int Interp::convert_param_comment(char *comment, char *expanded, int len)
     FORCE_LC_NUMERIC_C;
     int i;
     char param[LINELEN+1];
+    char format[5] = "%lf";
     int paramNumber;
     int stat;
     double value;
@@ -1286,7 +1287,65 @@ int Interp::convert_param_comment(char *comment, char *expanded, int len)
 
     while(*comment)
     {
-        if(*comment == '#')
+
+        if(*comment == '%')
+        {
+            // skip over the '%'
+            comment++;
+
+            // convenient integer looking
+            if(*comment == 'd')
+            {
+                comment++;
+                strcpy(format, "%.0f");
+            }
+            // convenient 4 position float
+            else if(*comment == 'f')
+            {
+                comment++;
+                strcpy(format, "%.4f");
+            }
+            // arbitrary 0-9 position float
+            else if(*comment == '.')
+            {
+                comment++;
+                if(isdigit(*comment))
+                {
+                    // forward to the (hopefully) letter f
+                    comment++;
+                    if(*comment == 'f')
+                    {
+                        // back up to get the digit into format
+                        comment--;
+                        format[0] = '%';
+                        format[1] = '.';
+                        format[2] = *comment;
+                        format[3] = 'f';
+                        format[4] = 0;
+                        comment++;
+                        comment++;
+                    }
+                    else
+                    {
+                        // not a format string so,
+                        // back up to the digit to continue processing
+                        comment--;
+                        *expanded++ = '.';
+
+                    }
+                }
+                else
+                {
+                    *expanded++ = '.';
+                }
+
+            }
+            else
+            {
+                *expanded++ = '%';
+            }
+        }
+        else if(*comment == '#')
         {
             found = 0;
             logDebug("a parameter");
@@ -1378,7 +1437,7 @@ int Interp::convert_param_comment(char *comment, char *expanded, int len)
             {
 		// avoid -0.0/0.0 issues
 		double pvalue = equal(value, 0.0) ? 0.0 : value;
-                int n = snprintf(valbuf, VAL_LEN, "%lf", pvalue);
+                int n = snprintf(valbuf, VAL_LEN, format, pvalue);
                 bool fail = (n >= VAL_LEN || n < 0);
                 if(fail)
                     rtapi_strxcpy(valbuf, "######");

tests/interp/magic_comments/param_format_printing/expected

@@ -0,0 +1,23 @@
+ N..... USE_LENGTH_UNITS(CANON_UNITS_MM)
+ N..... SET_G5X_OFFSET(1, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000)
+ N..... SET_G92_OFFSET(0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000)
+ N..... SET_XY_ROTATION(0.0000)
+ N..... SET_FEED_REFERENCE(CANON_XYZ)
+ N..... ON_RESET()
+ N..... MESSAGE(" native value = 1.123457")
+ N..... MESSAGE(" Test round to integer: 1")
+ N..... MESSAGE(" Test round to 4 decimals: 1.1235")
+ N..... MESSAGE(" Test format separate from param: The value is: 1.1235")
+ N..... MESSAGE(" Test round to 7 decimals: 1.1234568")
+ N..... MESSAGE(" native value2 = 2.345679")
+ N..... MESSAGE(" Test2 round all params in line to 4 decimals: The values are: 1.1235, 2.3457")
+ N..... MESSAGE(" Test2 only round last value to integer: The values are: 1.123457, 2")
+ N..... SET_G5X_OFFSET(1, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000)
+ N..... SET_XY_ROTATION(0.0000)
+ N..... SET_FEED_MODE(0, 0)
+ N..... SET_FEED_RATE(0.0000)
+ N..... STOP_SPINDLE_TURNING(0)
+ N..... SET_SPINDLE_MODE(0 0.0000)
+ N..... PROGRAM_END()
+ N..... ON_RESET()
+ N..... ON_RESET()

tests/interp/magic_comments/param_format_printing/test.ngc

@@ -0,0 +1,13 @@
+#<value> = 1.123456789
+
+(DEBUG, native value = #<value>)
+(DEBUG, Test round to integer: %d#<value>)
+(DEBUG, Test round to 4 decimals: %f#<value>)
+(DEBUG, Test format separate from param: %f The value is: #<value>)
+(DEBUG, Test round to 7 decimals: %.7f#<value>)
+
+#<value2> = 2.3456789
+(DEBUG, native value2 = #<value2>)
+(DEBUG, Test2 round all params in line to 4 decimals: %f The values are: #<value>,  #<value2>)
+(DEBUG, Test2 only round last value to integer: The values are: #<value>,  %d#<value2>)
+M2

tests/interp/magic_comments/param_format_printing/test.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+rs274 -g test.ngc | awk '{$1=""; print}'
+exit ${PIPESTATUS[0]}