Merge pull request #5971 from thinkyhead/rc_fix_e_factors

Patch DISTINCT_E_FACTORS bug

Marlin/Conditionals_post.h

    */
   #if ENABLED(ADVANCE)
     #define EXTRUSION_AREA (0.25 * (D_FILAMENT) * (D_FILAMENT) * M_PI)
-    #define STEPS_PER_CUBIC_MM_E (axis_steps_per_mm[E_AXIS] / (EXTRUSION_AREA))
+    #define STEPS_PER_CUBIC_MM_E (axis_steps_per_mm[E_AXIS_N] / (EXTRUSION_AREA))
   #endif
 
   #if ENABLED(ULTIPANEL) && DISABLED(ELB_FULL_GRAPHIC_CONTROLLER)

Marlin/planner.cpp

   float current_speed[NUM_AXIS], speed_factor = 1.0; // factor <1 decreases speed
   LOOP_XYZE(i) {
     const float cs = fabs(current_speed[i] = delta_mm[i] * inverse_mm_s);
+    #if ENABLED(DISTINCT_E_FACTORS)
+      if (i == E_AXIS) i += extruder;
+    #endif
     if (cs > max_feedrate_mm_s[i]) NOMORE(speed_factor, max_feedrate_mm_s[i] / cs);
   }
 
     // Start with print or travel acceleration
     accel = ceil((esteps ? acceleration : travel_acceleration) * steps_per_mm);
 
+    #if ENABLED(DISTINCT_E_FACTORS)
+      #define ACCEL_IDX extruder
+    #else
+      #define ACCEL_IDX 0
+    #endif
+
     // Limit acceleration per axis
     if (block->step_event_count <= cutoff_long) {
       LIMIT_ACCEL_LONG(X_AXIS,0);
       LIMIT_ACCEL_LONG(Y_AXIS,0);
       LIMIT_ACCEL_LONG(Z_AXIS,0);
-      LIMIT_ACCEL_LONG(E_AXIS,extruder);
+      LIMIT_ACCEL_LONG(E_AXIS,ACCEL_IDX);
     }
     else {
       LIMIT_ACCEL_FLOAT(X_AXIS,0);
       LIMIT_ACCEL_FLOAT(Y_AXIS,0);
       LIMIT_ACCEL_FLOAT(Z_AXIS,0);
-      LIMIT_ACCEL_FLOAT(E_AXIS,extruder);
+      LIMIT_ACCEL_FLOAT(E_AXIS,ACCEL_IDX);
     }
   }
   block->acceleration_steps_per_s2 = accel;

Marlin/stepper.cpp

       X2_STEP_WRITE(v); \
     } \
     else { \
-      if (current_block->active_extruder != 0) X2_STEP_WRITE(v); else X_STEP_WRITE(v); \
+      if (current_block->active_extruder) X2_STEP_WRITE(v); else X_STEP_WRITE(v); \
     }
 #else
   #define X_APPLY_DIR(v,Q) X_DIR_WRITE(v)