Merge pull request #5908 from thinkyhead/rc_fix_slowdown

General minor cleanup

Marlin/Marlin_main.cpp

   #define KEEPALIVE_STATE(n) ;
 #endif // HOST_KEEPALIVE_FEATURE
 
-#define DEFINE_PGM_READ_ANY(type, reader)       \
-  static inline type pgm_read_any(const type *p)  \
-  { return pgm_read_##reader##_near(p); }
-
-DEFINE_PGM_READ_ANY(float,       float)
-DEFINE_PGM_READ_ANY(signed char, byte)
+static inline float pgm_read_any(const float *p) { return pgm_read_float_near(p); }
+static inline signed char pgm_read_any(const signed char *p) { return pgm_read_byte_near(p); }
 
 #define XYZ_CONSTS_FROM_CONFIG(type, array, CONFIG) \
-  static const PROGMEM type array##_P[XYZ] =        \
-      { X_##CONFIG, Y_##CONFIG, Z_##CONFIG };     \
-  static inline type array(int axis)          \
-  { return pgm_read_any(&array##_P[axis]); }
+  static const PROGMEM type array##_P[XYZ] = { X_##CONFIG, Y_##CONFIG, Z_##CONFIG }; \
+  static inline type array(AxisEnum axis) { return pgm_read_any(&array##_P[axis]); }
 
 XYZ_CONSTS_FROM_CONFIG(float, base_min_pos,   MIN_POS)
 XYZ_CONSTS_FROM_CONFIG(float, base_max_pos,   MAX_POS)
     cmd[sizeof(cmd) - 1] = '\0';
     while ((c = cmd[i]) && c != '\n') i++; // find the end of this gcode command
     cmd[i] = '\0';
-    if (shove_and_echo_command(cmd)) {     // success?
-      if (c)                               // newline char?
-        injected_commands_P += i + 1;      // advance to the next command
-      else
-        injected_commands_P = NULL;        // nul char? no more commands
-    }
+    if (shove_and_echo_command(cmd))       // success?
+      injected_commands_P = c ? injected_commands_P + i + 1 : NULL; // next command or done
   }
   return (injected_commands_P != NULL);    // return whether any more remain
 }

Marlin/planner.cpp

    * Having the real displacement of the head, we can calculate the total movement length and apply the desired speed.
    */
   #if IS_CORE
-    float delta_mm[7];
+    float delta_mm[Z_HEAD + 1];
     #if CORE_IS_XY
       delta_mm[X_HEAD] = da * steps_to_mm[A_AXIS];
       delta_mm[Y_HEAD] = db * steps_to_mm[B_AXIS];
       delta_mm[C_AXIS] = CORESIGN(db - dc) * steps_to_mm[C_AXIS];
     #endif
   #else
-    float delta_mm[4];
+    float delta_mm[XYZE];
     delta_mm[X_AXIS] = da * steps_to_mm[X_AXIS];
     delta_mm[Y_AXIS] = db * steps_to_mm[Y_AXIS];
     delta_mm[Z_AXIS] = dc * steps_to_mm[Z_AXIS];
 
   // Slow down when the buffer starts to empty, rather than wait at the corner for a buffer refill
   #if ENABLED(SLOWDOWN) || ENABLED(ULTRA_LCD) || defined(XY_FREQUENCY_LIMIT)
+    // Segment time im micro seconds
     unsigned long segment_time = lround(1000000.0 / inverse_mm_s);
   #endif
   #if ENABLED(SLOWDOWN)
-    // Segment time im micro seconds
     if (moves_queued > 1 && moves_queued < (BLOCK_BUFFER_SIZE) / 2) {
       if (segment_time < min_segment_time) {
         // buffer is draining, add extra time.  The amount of time added increases if the buffer is still emptied more.

Marlin/planner.h

     #endif
 
     #if ENABLED(AUTOTEMP)
-      static float autotemp_max;
-      static float autotemp_min;
-      static float autotemp_factor;
+      static float autotemp_min, autotemp_max, autotemp_factor;
       static bool autotemp_enabled;
       static void getHighESpeed();
       static void autotemp_M104_M109();

Marlin/temperature.cpp

     #if ENABLED(FAST_PWM_FAN)
       setPwmFrequency(FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
     #endif
-    #if ENABLED(FAN_SOFT_PWM)
-      soft_pwm_fan[0] = fanSpeedSoftPwm[0] >> 1;
-    #endif
   #endif
 
   #if HAS_FAN1
     #if ENABLED(FAST_PWM_FAN)
       setPwmFrequency(FAN1_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
     #endif
-    #if ENABLED(FAN_SOFT_PWM)
-      soft_pwm_fan[1] = fanSpeedSoftPwm[1] >> 1;
-    #endif
   #endif
 
   #if HAS_FAN2
     #if ENABLED(FAST_PWM_FAN)
       setPwmFrequency(FAN2_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
     #endif
-    #if ENABLED(FAN_SOFT_PWM)
-      soft_pwm_fan[2] = fanSpeedSoftPwm[2] >> 1;
-    #endif
   #endif
 
   #if ENABLED(HEATER_0_USES_MAX6675)