G20/21 and M149 support, and code_value() refactor

This is an update of MarlinDev PR #196.

G20/21: support for switching input units between millimeters and
inches.
M149: support for changing input temperature units.

In support of these changes, code_value() and code_value_short() are
replaced with an array of functions which handle converting to the
proper types and/or units.

Marlin/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/M100_Free_Mem_Chk.cpp

 // Declare all the functions we need from Marlin_Main.cpp to do the work!
 //
 
-float code_value();
-long code_value_long();
+int code_value_int();
 bool code_seen(char);
 void serial_echopair_P(const char*, float);
 void serial_echopair_P(const char*, double);
 #if ENABLED(M100_FREE_MEMORY_CORRUPTOR)
   if (code_seen('C')) {
     int x;      // x gets the # of locations to corrupt within the memory pool
-    x = code_value();
+    x = code_value_int();
     SERIAL_ECHOLNPGM("Corrupting free memory block.\n");
     ptr = (unsigned char*) __brkval;
     SERIAL_ECHOPAIR("\n__brkval : ", ptr);

Marlin/Marlin.h

 
 #define _AXIS(AXIS) AXIS ##_AXIS
 
+typedef enum { LINEARUNIT_MM = 0, LINEARUNIT_INCH = 1 } LinearUnit;
+typedef enum { TEMPUNIT_C = 0, TEMPUNIT_K = 1, TEMPUNIT_F = 2 } TempUnit;
+
 void enable_all_steppers();
 void disable_all_steppers();
 
 
 // GCode support for external objects
 bool code_seen(char);
-float code_value();
+float code_value_float();
+unsigned long code_value_ulong();
 long code_value_long();
-int16_t code_value_short();
+int code_value_int();
+uint16_t code_value_ushort();
+uint8_t code_value_byte();
+bool code_value_bool();
+float code_value_linear_units();
+float code_value_per_axis_unit(int axis);
+float code_value_axis_units(int axis);
+float code_value_temp_abs();
+float code_value_temp_diff();
+millis_t code_value_millis();
+millis_t code_value_millis_from_seconds();
 
 #if ENABLED(DELTA)
   extern float delta[3];

Marlin/example_configurations/Felix/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/Felix/DUAL/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/Hephestos/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/Hephestos_2/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/K8200/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/RigidBot/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/SCARA/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/TAZ4/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/WITBOX/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/adafruit/ST7565/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/delta/biv2.5/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/delta/generic/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/delta/kossel_mini/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/delta/kossel_pro/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/delta/kossel_xl/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/makibox/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/example_configurations/tvrrug/Round2/Configuration.h

 //
 //#define M100_FREE_MEMORY_WATCHER // uncomment to add the M100 Free Memory Watcher for debug purpose
 
+//
+// G20/G21 Inch mode support
+//
+//#define INCH_MODE_SUPPORT
+
+//
+// M149 Set temperature units support
+//
+//#define TEMPERATURE_UNITS_SUPPORT
+
 // @section temperature
 
 // Preheat Constants

Marlin/planner.cpp

 
   void Planner::autotemp_M109() {
     autotemp_enabled = code_seen('F');
-    if (autotemp_enabled) autotemp_factor = code_value();
-    if (code_seen('S')) autotemp_min = code_value();
-    if (code_seen('B')) autotemp_max = code_value();
+    if (autotemp_enabled) autotemp_factor = code_value_temp_diff();
+    if (code_seen('S')) autotemp_min = code_value_temp_abs();
+    if (code_seen('B')) autotemp_max = code_value_temp_abs();
   }
 
 #endif