Add n_arc_correction and enhanced small angle sin/cos approximation.

Firmware/ConfigurationStore.cpp

@@ -171,8 +171,8 @@ void Config_PrintSettings(uint8_t level)
   }
     // Arc Interpolation Settings
     printf_P(PSTR(
-        "%SArc Settings: P=Arc segment length max (mm) S=Arc segment length Min (mm), R=Min arc segments, F=Arc segments per second.\n%S  M214 P%.2f S%.2f R%d F%d\n"),
+        "%SArc Settings: P=Arc segment length max (mm) S=Arc segment length Min (mm), N=Num Segments Per Correction, R=Min arc segments, F=Arc segments per second.\n%S  M214 P%.2f S%.2f N%d R%d F%d\n"),
-        echomagic, echomagic, cs.mm_per_arc_segment, cs.min_mm_per_arc_segment, cs.min_arc_segments, cs.arc_segments_per_sec);
+        echomagic, echomagic, cs.mm_per_arc_segment, cs.min_mm_per_arc_segment, cs.n_arc_correction, cs.min_arc_segments, cs.arc_segments_per_sec);
 }
 #endif
 
@@ -188,7 +188,7 @@ static_assert (false, "zprobe_zoffset was not initialized in printers in field t
         "0.0, if this is not acceptable, increment EEPROM_VERSION to force use default_conf");
 #endif
 
-static_assert (sizeof(M500_conf) == 208, "sizeof(M500_conf) has changed, ensure that EEPROM_VERSION has been incremented, "
+static_assert (sizeof(M500_conf) == 209, "sizeof(M500_conf) has changed, ensure that EEPROM_VERSION has been incremented, "
         "or if you added members in the end of struct, ensure that historically uninitialized values will be initialized."
         "If this is caused by change to more then 8bit processor, decide whether make this struct packed to save EEPROM,"
         "leave as it is to keep fast code, or reorder struct members to pack more tightly.");
@@ -284,6 +284,7 @@ bool Config_RetrieveSettings()
         // Initialize arc interpolation settings if they are not already (Not sure about this bit, please review)
         if (is_uninitialized(cs.mm_per_arc_segment, sizeof(float))) cs.mm_per_arc_segment = DEFAULT_MM_PER_ARC_SEGMENT;
         if (is_uninitialized(cs.min_mm_per_arc_segment, sizeof(float))) cs.min_mm_per_arc_segment = DEFAULT_MIN_MM_PER_ARC_SEGMENT;
+        if (is_uninitialized(cs.n_arc_correction), sizeof(uint8_t)) cs.n_arc_correction = DEFAULT_N_ARC_CORRECTION;
         if (is_uninitialized(cs.min_arc_segments, sizeof(uint16_t))) cs.min_arc_segments = DEFAULT_MIN_ARC_SEGMENTS;
         if (is_uninitialized(cs.arc_segments_per_sec, sizeof(uint16_t))) cs.arc_segments_per_sec = DEFAULT_ARC_SEGMENTS_PER_SEC;
 

Firmware/ConfigurationStore.h

@@ -42,8 +42,9 @@ typedef struct
     // Arc Interpolation Settings, configurable via M214
     float mm_per_arc_segment;
     float min_mm_per_arc_segment;
-    uint16_t min_arc_segments; // If less than or equal to zero, this is disabled
+    uint8_t n_arc_correction; // If equal to zero, this is disabled
-    uint16_t arc_segments_per_sec; // If less than or equal to zero, this is disabled
+    uint16_t min_arc_segments; // If equal to zero, this is disabled
+    uint16_t arc_segments_per_sec; // If equal to zero, this is disabled
 } M500_conf;
 
 extern M500_conf cs;

Firmware/Marlin_main.cpp

@@ -7509,11 +7509,12 @@ Sigma_Exit:
 
     #### Usage
 
-        M214 [P] [S] [R] [F]
+        M214 [P] [S] [N] [R] [F]
 
     #### Parameters
     - `P` - A float representing the max and default millimeters per arc segment.  Must be greater than 0.
     - `S` - A float representing the minimum allowable millimeters per arc segment.  Set to 0 to disable
+    - `N` - An int representing the number of arcs to draw before correcting the small angle approximation.  Set to 1 or 0 to disable.
     - `R` - An int representing the minimum number of segments per arcs of any radius,
             except when the results in segment lengths greater than or less than the minimum
             and maximum segment length.  Set to 0 to disable.
@@ -7525,6 +7526,7 @@ Sigma_Exit:
         // Extract N
         float p = cs.mm_per_arc_segment;
         float s = cs.min_mm_per_arc_segment;
+        uint8_t n = cs.n_arc_correction;
         uint16_t r = cs.min_arc_segments;
         uint16_t f = cs.arc_segments_per_sec;
 
@@ -7546,6 +7548,16 @@ Sigma_Exit:
                 break;
             }
         }
+        // Extract N
+        if (code_seen('N'))
+        {
+
+            n = code_value();
+            if (n < 0)
+            {
+                break;
+            }
+        }
         // Extract R
         if (code_seen('R'))
         {
@@ -7567,6 +7579,7 @@ Sigma_Exit:
         }
         cs.mm_per_arc_segment = p;
         cs.min_mm_per_arc_segment = s;
+        cs.n_arc_correction = n;
         cs.min_arc_segments = r;
         cs.arc_segments_per_sec = f;
     }break;

Firmware/motion_control.cpp

@@ -39,6 +39,9 @@ void mc_arc(float* position, float* target, float* offset, float feed_rate, floa
     float rt_y = target[Y_AXIS] - center_axis_y;
     // 20200419 - Add a variable that will be used to hold the arc segment length
     float mm_per_arc_segment = cs.mm_per_arc_segment;
+    // 20210109 - Add a variable to hold the n_arc_correction value
+    bool correction_enabled = cs.n_arc_correction > 1;
+    uint8_t n_arc_correction = cs.n_arc_correction;
 
     // CCW angle between position and target from circle center. Only one atan2() trig computation required.
     float angular_travel_total = atan2(r_axis_x * rt_y - r_axis_y * rt_x, r_axis_x * rt_x + r_axis_y * rt_y);
@@ -126,15 +129,37 @@ void mc_arc(float* position, float* target, float* offset, float feed_rate, floa
     {
         // Initialize the extruder axis
 
-        float cos_T = cos(theta_per_segment);
+        float cos_T;
-        float sin_T = sin(theta_per_segment);
+        float sin_T;
+
+        if (correction_enabled > 1){
+            float sq_theta_per_segment = theta_per_segment * theta_per_segment;
+            // Small angle approximation
+            sin_T = theta_per_segment - sq_theta_per_segment * theta_per_segment / 6,
+            cos_T = 1 - 0.5f * sq_theta_per_segment; 
+        }
+        else {
+            cos_T = cos(theta_per_segment);
+            sin_T = sin(theta_per_segment);
+        }
+
         float r_axisi;
         uint16_t i;
 
         for (i = 1; i < segments; i++) { // Increment (segments-1)
+            if (correction_enabled && --n_arc_correction == 0) {
+                // Calculate the actual position for r_axis_x and r_axis_y
+                const float cos_Ti = cos(i * theta_per_segment), sin_Ti = sin(i * theta_per_segment);
+                r_axis_x = -offset[X_AXIS] * cos_Ti + offset[Y_AXIS] * sin_Ti;
+                r_axis_y = -offset[X_AXIS] * sin_Ti - offset[Y_AXIS] * cos_Ti;
+                // reset n_arc_correction
+                n_arc_correction = cs.n_arc_correction;
+            }
+            else {
                 r_axisi = r_axis_x * sin_T + r_axis_y * cos_T;
                 r_axis_x = r_axis_x * cos_T - r_axis_y * sin_T;
                 r_axis_y = r_axisi;
+            }
             
             // Update arc_target location
             position[X_AXIS] = center_axis_x + r_axis_x;

Firmware/variants/1_75mm_MK25-RAMBo10a-E3Dv6full.h

@@ -526,11 +526,15 @@
 #define MMU_IDLER_SENSOR_ATTEMPTS_NR 21 //max. number of attempts to load filament if first load failed; value for max bowden length and case when loading fails right at the beginning
 
 // Default Arc Interpolation Settings (Now configurable via M214)
+#define DEFAULT_N_ARC_CORRECTION       25 // Number of interpolated segments between corrections.
+/* A value of 1 or less for N_ARC_CORRECTION will trigger the use of Sin and Cos for every arc, which will improve accuracy at the
+   cost of performance*/
 #define DEFAULT_MM_PER_ARC_SEGMENT     1.0f // REQUIRED - The enforced maximum length of an arc segment
-#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f /* OPTIONAL - the enforced minimum length of an interpolated segment.  Must be smaller than
+#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f //the enforced minimum length of an interpolated segment
-    MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0 or ARC_SEGMENTS_PER_SEC > 0 */
+/*  MIN_MM_PER_ARC_SEGMENT Must be smaller than MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0
-    // If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum calculated segment length is used.
+    or ARC_SEGMENTS_PER_SEC > 0 .  If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum
-#define DEFAULT_MIN_ARC_SEGMENTS 20 // OPTIONAL - The enforced minimum segments in a full circle of the same radius.
+    calculated segment length is used. */
-#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // OPTIONAL - Use feedrate to choose segment length.
+#define DEFAULT_MIN_ARC_SEGMENTS 20 // The enforced minimum segments in a full circle of the same radius.  Set to 0 to disable
+#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // Use feedrate to choose segment length. Set to 0 to disable
 
 #endif //__CONFIGURATION_PRUSA_H

Firmware/variants/1_75mm_MK25-RAMBo13a-E3Dv6full.h

@@ -530,11 +530,15 @@
 //#define MICROMETER_LOGGING //related to D-codes D80 and D81, currently works on MK2.5 only (MK3 board pin definitions missing)
 
 // Default Arc Interpolation Settings (Now configurable via M214)
+#define DEFAULT_N_ARC_CORRECTION       25 // Number of interpolated segments between corrections.
+/* A value of 1 or less for N_ARC_CORRECTION will trigger the use of Sin and Cos for every arc, which will improve accuracy at the
+   cost of performance*/
 #define DEFAULT_MM_PER_ARC_SEGMENT     1.0f // REQUIRED - The enforced maximum length of an arc segment
-#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f /* OPTIONAL - the enforced minimum length of an interpolated segment.  Must be smaller than
+#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f //the enforced minimum length of an interpolated segment
-    MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0 or ARC_SEGMENTS_PER_SEC > 0 */
+   /*  MIN_MM_PER_ARC_SEGMENT Must be smaller than MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0
-    // If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum calculated segment length is used.
+       or ARC_SEGMENTS_PER_SEC > 0 .  If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum
-#define DEFAULT_MIN_ARC_SEGMENTS 20 // OPTIONAL - The enforced minimum segments in a full circle of the same radius.
+       calculated segment length is used. */
-#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // OPTIONAL - Use feedrate to choose segment length.
+#define DEFAULT_MIN_ARC_SEGMENTS 20 // The enforced minimum segments in a full circle of the same radius.  Set to 0 to disable
+#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // Use feedrate to choose segment length. Set to 0 to disable
 
 #endif //__CONFIGURATION_PRUSA_H

Firmware/variants/1_75mm_MK25S-RAMBo10a-E3Dv6full.h

@@ -533,11 +533,15 @@
 #define MMU_IDLER_SENSOR_ATTEMPTS_NR 21 //max. number of attempts to load filament if first load failed; value for max bowden length and case when loading fails right at the beginning
 
 // Default Arc Interpolation Settings (Now configurable via M214)
+#define DEFAULT_N_ARC_CORRECTION       25 // Number of interpolated segments between corrections.
+/* A value of 1 or less for N_ARC_CORRECTION will trigger the use of Sin and Cos for every arc, which will improve accuracy at the
+   cost of performance*/
 #define DEFAULT_MM_PER_ARC_SEGMENT     1.0f // REQUIRED - The enforced maximum length of an arc segment
-#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f /* OPTIONAL - the enforced minimum length of an interpolated segment.  Must be smaller than
+#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f //the enforced minimum length of an interpolated segment
-    MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0 or ARC_SEGMENTS_PER_SEC > 0 */
+   /*  MIN_MM_PER_ARC_SEGMENT Must be smaller than MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0
-    // If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum calculated segment length is used.
+       or ARC_SEGMENTS_PER_SEC > 0 .  If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum
-#define DEFAULT_MIN_ARC_SEGMENTS 20 // OPTIONAL - The enforced minimum segments in a full circle of the same radius.
+       calculated segment length is used. */
-#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // OPTIONAL - Use feedrate to choose segment length.
+#define DEFAULT_MIN_ARC_SEGMENTS 20 // The enforced minimum segments in a full circle of the same radius.  Set to 0 to disable
+#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // Use feedrate to choose segment length. Set to 0 to disable
 
 #endif //__CONFIGURATION_PRUSA_H

Firmware/variants/1_75mm_MK25S-RAMBo13a-E3Dv6full.h

@@ -534,11 +534,15 @@
 #define MMU_IDLER_SENSOR_ATTEMPTS_NR 21 //max. number of attempts to load filament if first load failed; value for max bowden length and case when loading fails right at the beginning
 
 // Default Arc Interpolation Settings (Now configurable via M214)
+#define DEFAULT_N_ARC_CORRECTION       25 // Number of interpolated segments between corrections.
+/* A value of 1 or less for N_ARC_CORRECTION will trigger the use of Sin and Cos for every arc, which will improve accuracy at the
+   cost of performance*/
 #define DEFAULT_MM_PER_ARC_SEGMENT     1.0f // REQUIRED - The enforced maximum length of an arc segment
-#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f /* OPTIONAL - the enforced minimum length of an interpolated segment.  Must be smaller than
+#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f //the enforced minimum length of an interpolated segment
-    MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0 or ARC_SEGMENTS_PER_SEC > 0 */
+   /*  MIN_MM_PER_ARC_SEGMENT Must be smaller than MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0
-    // If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum calculated segment length is used.
+       or ARC_SEGMENTS_PER_SEC > 0 .  If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum
-#define DEFAULT_MIN_ARC_SEGMENTS 20 // OPTIONAL - The enforced minimum segments in a full circle of the same radius.
+       calculated segment length is used. */
-#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // OPTIONAL - Use feedrate to choose segment length.
+#define DEFAULT_MIN_ARC_SEGMENTS 20 // The enforced minimum segments in a full circle of the same radius.  Set to 0 to disable
+#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // Use feedrate to choose segment length. Set to 0 to disable
 
 #endif //__CONFIGURATION_PRUSA_H

Firmware/variants/1_75mm_MK3-EINSy10a-E3Dv6full.h

@@ -672,11 +672,15 @@
 #define MMU_IDLER_SENSOR_ATTEMPTS_NR 21 //max. number of attempts to load filament if first load failed; value for max bowden length and case when loading fails right at the beginning
 
 // Default Arc Interpolation Settings (Now configurable via M214)
+#define DEFAULT_N_ARC_CORRECTION       25 // Number of interpolated segments between corrections.
+/* A value of 1 or less for N_ARC_CORRECTION will trigger the use of Sin and Cos for every arc, which will improve accuracy at the
+   cost of performance*/
 #define DEFAULT_MM_PER_ARC_SEGMENT     1.0f // REQUIRED - The enforced maximum length of an arc segment
-#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f /* OPTIONAL - the enforced minimum length of an interpolated segment.  Must be smaller than
+#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f //the enforced minimum length of an interpolated segment
-    MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0 or ARC_SEGMENTS_PER_SEC > 0 */
+   /*  MIN_MM_PER_ARC_SEGMENT Must be smaller than MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0
-    // If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum calculated segment length is used.
+       or ARC_SEGMENTS_PER_SEC > 0 .  If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum
-#define DEFAULT_MIN_ARC_SEGMENTS 20 // OPTIONAL - The enforced minimum segments in a full circle of the same radius.
+       calculated segment length is used. */
-#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // OPTIONAL - Use feedrate to choose segment length.
+#define DEFAULT_MIN_ARC_SEGMENTS 20 // The enforced minimum segments in a full circle of the same radius.  Set to 0 to disable
+#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // Use feedrate to choose segment length. Set to 0 to disable
 
 #endif //__CONFIGURATION_PRUSA_H

Firmware/variants/1_75mm_MK3S-EINSy10a-E3Dv6full.h

@@ -684,11 +684,15 @@
 #define MMU_IDLER_SENSOR_ATTEMPTS_NR 21 //max. number of attempts to load filament if first load failed; value for max bowden length and case when loading fails right at the beginning
 
 // Default Arc Interpolation Settings (Now configurable via M214)
+#define DEFAULT_N_ARC_CORRECTION       25 // Number of interpolated segments between corrections.
+/* A value of 1 or less for N_ARC_CORRECTION will trigger the use of Sin and Cos for every arc, which will improve accuracy at the
+   cost of performance*/
 #define DEFAULT_MM_PER_ARC_SEGMENT     1.0f // REQUIRED - The enforced maximum length of an arc segment
-#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f /* OPTIONAL - the enforced minimum length of an interpolated segment.  Must be smaller than
+#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f //the enforced minimum length of an interpolated segment
-    MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0 or ARC_SEGMENTS_PER_SEC > 0 */
+   /*  MIN_MM_PER_ARC_SEGMENT Must be smaller than MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0
-    // If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum calculated segment length is used.
+       or ARC_SEGMENTS_PER_SEC > 0 .  If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum
-#define DEFAULT_MIN_ARC_SEGMENTS 20 // OPTIONAL - The enforced minimum segments in a full circle of the same radius.
+       calculated segment length is used. */
-#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // OPTIONAL - Use feedrate to choose segment length.
+#define DEFAULT_MIN_ARC_SEGMENTS 20 // The enforced minimum segments in a full circle of the same radius.  Set to 0 to disable
+#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // Use feedrate to choose segment length. Set to 0 to disable
 
 #endif //__CONFIGURATION_PRUSA_H

Firmware/variants/obsolete/1_75mm_MK2-RAMBo10a-E3Dv6full.h

@@ -450,11 +450,15 @@ THERMISTORS SETTINGS
 #define MMU_IDLER_SENSOR_ATTEMPTS_NR 21 //max. number of attempts to load filament if first load failed; value for max bowden length and case when loading fails right at the beginning
 
 // Default Arc Interpolation Settings (Now configurable via M214)
+#define DEFAULT_N_ARC_CORRECTION       25 // Number of interpolated segments between corrections.
+/* A value of 1 or less for N_ARC_CORRECTION will trigger the use of Sin and Cos for every arc, which will improve accuracy at the
+   cost of performance*/
 #define DEFAULT_MM_PER_ARC_SEGMENT     1.0f // REQUIRED - The enforced maximum length of an arc segment
-#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f /* OPTIONAL - the enforced minimum length of an interpolated segment.  Must be smaller than
+#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f //the enforced minimum length of an interpolated segment
-    MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0 or ARC_SEGMENTS_PER_SEC > 0 */
+   /*  MIN_MM_PER_ARC_SEGMENT Must be smaller than MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0
-    // If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum calculated segment length is used.
+       or ARC_SEGMENTS_PER_SEC > 0 .  If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum
-#define DEFAULT_MIN_ARC_SEGMENTS 20 // OPTIONAL - The enforced minimum segments in a full circle of the same radius.
+       calculated segment length is used. */
-#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // OPTIONAL - Use feedrate to choose segment length.
+#define DEFAULT_MIN_ARC_SEGMENTS 20 // The enforced minimum segments in a full circle of the same radius.  Set to 0 to disable
+#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // Use feedrate to choose segment length. Set to 0 to disable
 
 #endif //__CONFIGURATION_PRUSA_H

Firmware/variants/obsolete/1_75mm_MK2-RAMBo13a-E3Dv6full.h

@@ -439,11 +439,15 @@ THERMISTORS SETTINGS
 #define MMU_IDLER_SENSOR_ATTEMPTS_NR 21 //max. number of attempts to load filament if first load failed; value for max bowden length and case when loading fails right at the beginning
 
 // Default Arc Interpolation Settings (Now configurable via M214)
+#define DEFAULT_N_ARC_CORRECTION       25 // Number of interpolated segments between corrections.
+/* A value of 1 or less for N_ARC_CORRECTION will trigger the use of Sin and Cos for every arc, which will improve accuracy at the
+   cost of performance*/
 #define DEFAULT_MM_PER_ARC_SEGMENT     1.0f // REQUIRED - The enforced maximum length of an arc segment
-#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f /* OPTIONAL - the enforced minimum length of an interpolated segment.  Must be smaller than
+#define DEFAULT_MIN_MM_PER_ARC_SEGMENT 0.5f //the enforced minimum length of an interpolated segment
-    MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0 or ARC_SEGMENTS_PER_SEC > 0 */
+   /*  MIN_MM_PER_ARC_SEGMENT Must be smaller than MM_PER_ARC_SEGMENT.  Only has an effect if MIN_ARC_SEGMENTS > 0
-    // If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum calculated segment length is used.
+       or ARC_SEGMENTS_PER_SEC > 0 .  If both MIN_ARC_SEGMENTS and ARC_SEGMENTS_PER_SEC is defined, the minimum
-#define DEFAULT_MIN_ARC_SEGMENTS 20 // OPTIONAL - The enforced minimum segments in a full circle of the same radius.
+       calculated segment length is used. */
-#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // OPTIONAL - Use feedrate to choose segment length.
+#define DEFAULT_MIN_ARC_SEGMENTS 20 // The enforced minimum segments in a full circle of the same radius.  Set to 0 to disable
+#define DEFAULT_ARC_SEGMENTS_PER_SEC 0 // Use feedrate to choose segment length. Set to 0 to disable
 
 #endif //__CONFIGURATION_PRUSA_H