Use arrays for delta tower parameters

Marlin/Marlin.h

                delta_radius,
                delta_diagonal_rod,
                delta_segments_per_second,
-               delta_diagonal_rod_trim_tower_1,
-               delta_diagonal_rod_trim_tower_2,
-               delta_diagonal_rod_trim_tower_3,
-               delta_tower_angle_trim_1,
-               delta_tower_angle_trim_2,
-               delta_tower_angle_trim_3,
+               delta_diagonal_rod_trim[ABC],
+               delta_tower_angle_trim[ABC],
                delta_clip_start_height;
   void recalc_delta_settings(float radius, float diagonal_rod);
 #elif IS_SCARA

Marlin/Marlin_main.cpp

   float delta[ABC],
         endstop_adj[ABC] = { 0 };
 
-  // these are the default values, can be overriden with M665
-  float delta_radius = DELTA_RADIUS,
-        delta_tower_angle_trim_1 = DELTA_TOWER_ANGLE_TRIM_1,
-        delta_tower_angle_trim_2 = DELTA_TOWER_ANGLE_TRIM_2,
-        delta_tower_angle_trim_3 = DELTA_TOWER_ANGLE_TRIM_3,
-        delta_tower1_x = -sin(RADIANS(60 - delta_tower_angle_trim_1)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_1), // front left tower
-        delta_tower1_y = -cos(RADIANS(60 - delta_tower_angle_trim_1)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_1),
-        delta_tower2_x =  sin(RADIANS(60 + delta_tower_angle_trim_2)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_2), // front right tower
-        delta_tower2_y = -cos(RADIANS(60 + delta_tower_angle_trim_2)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_2),
-        delta_tower3_x = -sin(RADIANS(     delta_tower_angle_trim_3)),                                                    // back middle tower
-        delta_tower3_y =  cos(RADIANS(     delta_tower_angle_trim_3)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_3),
-        delta_diagonal_rod = DELTA_DIAGONAL_ROD,
-        delta_diagonal_rod_trim_tower_1 = DELTA_DIAGONAL_ROD_TRIM_TOWER_1,
-        delta_diagonal_rod_trim_tower_2 = DELTA_DIAGONAL_ROD_TRIM_TOWER_2,
-        delta_diagonal_rod_trim_tower_3 = DELTA_DIAGONAL_ROD_TRIM_TOWER_3,
-        delta_diagonal_rod_2_tower_1 = sq(delta_diagonal_rod + delta_diagonal_rod_trim_tower_1),
-        delta_diagonal_rod_2_tower_2 = sq(delta_diagonal_rod + delta_diagonal_rod_trim_tower_2),
-        delta_diagonal_rod_2_tower_3 = sq(delta_diagonal_rod + delta_diagonal_rod_trim_tower_3),
-        delta_segments_per_second = DELTA_SEGMENTS_PER_SECOND,
+  // These values are loaded or reset at boot time when setup() calls
+  // Config_RetrieveSettings(), which calls recalc_delta_settings().
+  float delta_radius,
+        delta_tower_angle_trim[ABC],
+        delta_tower[ABC][2],
+        delta_diagonal_rod,
+        delta_diagonal_rod_trim[ABC],
+        delta_diagonal_rod_2_tower[ABC],
+        delta_segments_per_second,
         delta_clip_start_height = Z_MAX_POS;
 
   float delta_safe_distance_from_top();
     if (code_seen('L')) delta_diagonal_rod = code_value_linear_units();
     if (code_seen('R')) delta_radius = code_value_linear_units();
     if (code_seen('S')) delta_segments_per_second = code_value_float();
-    if (code_seen('A')) delta_diagonal_rod_trim_tower_1 = code_value_linear_units();
-    if (code_seen('B')) delta_diagonal_rod_trim_tower_2 = code_value_linear_units();
-    if (code_seen('C')) delta_diagonal_rod_trim_tower_3 = code_value_linear_units();
-    if (code_seen('I')) delta_tower_angle_trim_1 = code_value_linear_units();
-    if (code_seen('J')) delta_tower_angle_trim_2 = code_value_linear_units();
-    if (code_seen('K')) delta_tower_angle_trim_3 = code_value_linear_units();
+    if (code_seen('A')) delta_diagonal_rod_trim[A_AXIS] = code_value_linear_units();
+    if (code_seen('B')) delta_diagonal_rod_trim[B_AXIS] = code_value_linear_units();
+    if (code_seen('C')) delta_diagonal_rod_trim[C_AXIS] = code_value_linear_units();
+    if (code_seen('I')) delta_tower_angle_trim[A_AXIS] = code_value_linear_units();
+    if (code_seen('J')) delta_tower_angle_trim[B_AXIS] = code_value_linear_units();
+    if (code_seen('K')) delta_tower_angle_trim[C_AXIS] = code_value_linear_units();
     recalc_delta_settings(delta_radius, delta_diagonal_rod);
   }
   /**
    * settings have been changed (e.g., by M665).
    */
   void recalc_delta_settings(float radius, float diagonal_rod) {
-    delta_tower1_x = -sin(RADIANS(60 - delta_tower_angle_trim_1)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_1), // front left tower
-    delta_tower1_y = -cos(RADIANS(60 - delta_tower_angle_trim_1)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_1),
-    delta_tower2_x =  sin(RADIANS(60 + delta_tower_angle_trim_2)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_2), // front right tower
-    delta_tower2_y = -cos(RADIANS(60 + delta_tower_angle_trim_2)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_2),
-    delta_tower3_x = -sin(RADIANS(     delta_tower_angle_trim_3)),                                              // back middle tower
-    delta_tower3_y =  cos(RADIANS(     delta_tower_angle_trim_3)) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_3),
-    delta_diagonal_rod_2_tower_1 = sq(diagonal_rod + delta_diagonal_rod_trim_tower_1);
-    delta_diagonal_rod_2_tower_2 = sq(diagonal_rod + delta_diagonal_rod_trim_tower_2);
-    delta_diagonal_rod_2_tower_3 = sq(diagonal_rod + delta_diagonal_rod_trim_tower_3);
+    delta_tower[A_AXIS][X_AXIS] = -sin(RADIANS(60 - delta_tower_angle_trim[A_AXIS])) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_1), // front left tower
+    delta_tower[A_AXIS][Y_AXIS] = -cos(RADIANS(60 - delta_tower_angle_trim[A_AXIS])) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_1),
+    delta_tower[B_AXIS][X_AXIS] =  sin(RADIANS(60 + delta_tower_angle_trim[B_AXIS])) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_2), // front right tower
+    delta_tower[B_AXIS][Y_AXIS] = -cos(RADIANS(60 + delta_tower_angle_trim[B_AXIS])) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_2),
+    delta_tower[C_AXIS][X_AXIS] = -sin(RADIANS(     delta_tower_angle_trim[C_AXIS])) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_3), // back middle tower
+    delta_tower[C_AXIS][Y_AXIS] =  cos(RADIANS(     delta_tower_angle_trim[C_AXIS])) * (delta_radius + DELTA_RADIUS_TRIM_TOWER_3),
+    delta_diagonal_rod_2_tower[A_AXIS] = sq(diagonal_rod + delta_diagonal_rod_trim[A_AXIS]);
+    delta_diagonal_rod_2_tower[B_AXIS] = sq(diagonal_rod + delta_diagonal_rod_trim[B_AXIS]);
+    delta_diagonal_rod_2_tower[C_AXIS] = sq(diagonal_rod + delta_diagonal_rod_trim[C_AXIS]);
   }
 
   #if ENABLED(DELTA_FAST_SQRT)
    */
 
   // Macro to obtain the Z position of an individual tower
-  #define DELTA_Z(T) raw[Z_AXIS] + _SQRT(    \
-    delta_diagonal_rod_2_tower_##T - HYPOT2( \
-        delta_tower##T##_x - raw[X_AXIS],    \
-        delta_tower##T##_y - raw[Y_AXIS]     \
-      )                                      \
+  #define DELTA_Z(T) raw[Z_AXIS] + _SQRT(     \
+    delta_diagonal_rod_2_tower[T] - HYPOT2(   \
+        delta_tower[T][X_AXIS] - raw[X_AXIS], \
+        delta_tower[T][Y_AXIS] - raw[Y_AXIS]  \
+      )                                       \
     )
 
   #define DELTA_RAW_IK() do {   \
-    delta[A_AXIS] = DELTA_Z(1); \
-    delta[B_AXIS] = DELTA_Z(2); \
-    delta[C_AXIS] = DELTA_Z(3); \
+    delta[A_AXIS] = DELTA_Z(A_AXIS); \
+    delta[B_AXIS] = DELTA_Z(B_AXIS); \
+    delta[C_AXIS] = DELTA_Z(C_AXIS); \
   } while(0)
 
   #define DELTA_LOGICAL_IK() do {      \
    */
   void forward_kinematics_DELTA(float z1, float z2, float z3) {
     // Create a vector in old coordinates along x axis of new coordinate
-    float p12[3] = { delta_tower2_x - delta_tower1_x, delta_tower2_y - delta_tower1_y, z2 - z1 };
+    float p12[3] = { delta_tower[B_AXIS][X_AXIS] - delta_tower[A_AXIS][X_AXIS], delta_tower[B_AXIS][Y_AXIS] - delta_tower[A_AXIS][Y_AXIS], z2 - z1 };
 
     // Get the Magnitude of vector.
     float d = sqrt( sq(p12[0]) + sq(p12[1]) + sq(p12[2]) );
     float ex[3] = { p12[0] / d, p12[1] / d, p12[2] / d };
 
     // Get the vector from the origin of the new system to the third point.
-    float p13[3] = { delta_tower3_x - delta_tower1_x, delta_tower3_y - delta_tower1_y, z3 - z1 };
+    float p13[3] = { delta_tower[C_AXIS][X_AXIS] - delta_tower[A_AXIS][X_AXIS], delta_tower[C_AXIS][Y_AXIS] - delta_tower[A_AXIS][Y_AXIS], z3 - z1 };
 
     // Use the dot product to find the component of this vector on the X axis.
     float i = ex[0] * p13[0] + ex[1] * p13[1] + ex[2] * p13[2];
 
     // We now have the d, i and j values defined in Wikipedia.
     // Plug them into the equations defined in Wikipedia for Xnew, Ynew and Znew
-    float Xnew = (delta_diagonal_rod_2_tower_1 - delta_diagonal_rod_2_tower_2 + sq(d)) / (d * 2),
-          Ynew = ((delta_diagonal_rod_2_tower_1 - delta_diagonal_rod_2_tower_3 + HYPOT2(i, j)) / 2 - i * Xnew) / j,
-          Znew = sqrt(delta_diagonal_rod_2_tower_1 - HYPOT2(Xnew, Ynew));
+    float Xnew = (delta_diagonal_rod_2_tower[A_AXIS] - delta_diagonal_rod_2_tower[B_AXIS] + sq(d)) / (d * 2),
+          Ynew = ((delta_diagonal_rod_2_tower[A_AXIS] - delta_diagonal_rod_2_tower[C_AXIS] + HYPOT2(i, j)) / 2 - i * Xnew) / j,
+          Znew = sqrt(delta_diagonal_rod_2_tower[A_AXIS] - HYPOT2(Xnew, Ynew));
 
     // Start from the origin of the old coordinates and add vectors in the
     // old coords that represent the Xnew, Ynew and Znew to find the point
     // in the old system.
-    cartes[X_AXIS] = delta_tower1_x + ex[0] * Xnew + ey[0] * Ynew - ez[0] * Znew;
-    cartes[Y_AXIS] = delta_tower1_y + ex[1] * Xnew + ey[1] * Ynew - ez[1] * Znew;
+    cartes[X_AXIS] = delta_tower[A_AXIS][X_AXIS] + ex[0] * Xnew + ey[0] * Ynew - ez[0] * Znew;
+    cartes[Y_AXIS] = delta_tower[A_AXIS][Y_AXIS] + ex[1] * Xnew + ey[1] * Ynew - ez[1] * Znew;
     cartes[Z_AXIS] =             z1 + ex[2] * Xnew + ey[2] * Ynew - ez[2] * Znew;
   }
 

Marlin/configuration_store.cpp

  *  308  G29 L F   bilinear_start                  (int x2)
  *  312            bed_level_grid[][]              (float x9, up to float x256) +988
  *
- * DELTA (if deltabot):                            48 bytes
- *  348  M666 XYZ  endstop_adj                     (float x3)
- *  360  M665 R    delta_radius                    (float)
- *  364  M665 L    delta_diagonal_rod              (float)
- *  368  M665 S    delta_segments_per_second       (float)
- *  372  M665 A    delta_diagonal_rod_trim_tower_1 (float)
- *  376  M665 B    delta_diagonal_rod_trim_tower_2 (float)
- *  380  M665 C    delta_diagonal_rod_trim_tower_3 (float)
- *  384  M665 I    delta_tower_angle_trim_1        (float)
- *  388  M665 J    delta_tower_angle_trim_2        (float)
- *  392  M665 K    delta_tower_angle_trim_3        (float)
+ * DELTA (if deltabot):                             48 bytes
+ *  348  M666 XYZ  endstop_adj                      (float x3)
+ *  360  M665 R    delta_radius                     (float)
+ *  364  M665 L    delta_diagonal_rod               (float)
+ *  368  M665 S    delta_segments_per_second        (float)
+ *  372  M665 A    delta_diagonal_rod_trim[A]       (float)
+ *  376  M665 B    delta_diagonal_rod_trim[B]       (float)
+ *  380  M665 C    delta_diagonal_rod_trim[C]       (float)
+ *  384  M665 I    delta_tower_angle_trim[A]        (float)
+ *  388  M665 J    delta_tower_angle_trim[B]        (float)
+ *  392  M665 K    delta_tower_angle_trim[C]        (float)
  *
  * Z_DUAL_ENDSTOPS (if not deltabot):              48 bytes
  *  348  M666 Z    z_endstop_adj                   (float)
       EEPROM_WRITE(delta_radius);              // 1 float
       EEPROM_WRITE(delta_diagonal_rod);        // 1 float
       EEPROM_WRITE(delta_segments_per_second); // 1 float
-      EEPROM_WRITE(delta_diagonal_rod_trim_tower_1);  // 1 float
-      EEPROM_WRITE(delta_diagonal_rod_trim_tower_2);  // 1 float
-      EEPROM_WRITE(delta_diagonal_rod_trim_tower_3);  // 1 float
-      EEPROM_WRITE(delta_tower_angle_trim_1); // 1 float
-      EEPROM_WRITE(delta_tower_angle_trim_2); // 1 float
-      EEPROM_WRITE(delta_tower_angle_trim_3); // 1 float
+      EEPROM_WRITE(delta_diagonal_rod_trim);   // 3 floats
+      EEPROM_WRITE(delta_tower_angle_trim);    // 3 floats
     #elif ENABLED(Z_DUAL_ENDSTOPS)
-      EEPROM_WRITE(z_endstop_adj);            // 1 float
+      EEPROM_WRITE(z_endstop_adj);             // 1 float
       dummy = 0.0f;
       for (uint8_t q = 11; q--;) EEPROM_WRITE(dummy);
     #else
         }
 
       #if ENABLED(DELTA)
-        EEPROM_READ(endstop_adj);                // 3 floats
-        EEPROM_READ(delta_radius);               // 1 float
-        EEPROM_READ(delta_diagonal_rod);         // 1 float
-        EEPROM_READ(delta_segments_per_second);  // 1 float
-        EEPROM_READ(delta_diagonal_rod_trim_tower_1);  // 1 float
-        EEPROM_READ(delta_diagonal_rod_trim_tower_2);  // 1 float
-        EEPROM_READ(delta_diagonal_rod_trim_tower_3);  // 1 float
-        EEPROM_READ(delta_tower_angle_trim_1); // 1 float
-        EEPROM_READ(delta_tower_angle_trim_2); // 1 float
-        EEPROM_READ(delta_tower_angle_trim_3); // 1 float
+        EEPROM_READ(endstop_adj);               // 3 floats
+        EEPROM_READ(delta_radius);              // 1 float
+        EEPROM_READ(delta_diagonal_rod);        // 1 float
+        EEPROM_READ(delta_segments_per_second); // 1 float
+        EEPROM_READ(delta_diagonal_rod_trim);   // 3 floats
+        EEPROM_READ(delta_tower_angle_trim);    // 3 floats
       #elif ENABLED(Z_DUAL_ENDSTOPS)
         EEPROM_READ(z_endstop_adj);
         dummy = 0.0f;
   #endif
 
   #if ENABLED(DELTA)
-    const float adj[ABC] = DELTA_ENDSTOP_ADJ;
-    endstop_adj[A_AXIS] = adj[A_AXIS];
-    endstop_adj[B_AXIS] = adj[B_AXIS];
-    endstop_adj[C_AXIS] = adj[C_AXIS];
+    const float adj[ABC] = DELTA_ENDSTOP_ADJ,
+                drt[ABC] = { DELTA_DIAGONAL_ROD_TRIM_TOWER_1, DELTA_DIAGONAL_ROD_TRIM_TOWER_2, DELTA_DIAGONAL_ROD_TRIM_TOWER_3 },
+                dta[ABC] = { DELTA_TOWER_ANGLE_TRIM_1, DELTA_TOWER_ANGLE_TRIM_2, DELTA_TOWER_ANGLE_TRIM_3 };
+    COPY(endstop_adj, adj);
     delta_radius = DELTA_RADIUS;
     delta_diagonal_rod = DELTA_DIAGONAL_ROD;
     delta_segments_per_second = DELTA_SEGMENTS_PER_SECOND;
-    delta_diagonal_rod_trim_tower_1 = DELTA_DIAGONAL_ROD_TRIM_TOWER_1;
-    delta_diagonal_rod_trim_tower_2 = DELTA_DIAGONAL_ROD_TRIM_TOWER_2;
-    delta_diagonal_rod_trim_tower_3 = DELTA_DIAGONAL_ROD_TRIM_TOWER_3;
-    delta_tower_angle_trim_1 = DELTA_TOWER_ANGLE_TRIM_1;
-    delta_tower_angle_trim_2 = DELTA_TOWER_ANGLE_TRIM_2;
-    delta_tower_angle_trim_3 = DELTA_TOWER_ANGLE_TRIM_3;
+    COPY(delta_diagonal_rod_trim, drt);
+    COPY(delta_tower_angle_trim, dta);
   #elif ENABLED(Z_DUAL_ENDSTOPS)
     z_endstop_adj = 0;
   #endif
       SERIAL_ECHOPAIR("  M665 L", delta_diagonal_rod);
       SERIAL_ECHOPAIR(" R", delta_radius);
       SERIAL_ECHOPAIR(" S", delta_segments_per_second);
-      SERIAL_ECHOPAIR(" A", delta_diagonal_rod_trim_tower_1);
-      SERIAL_ECHOPAIR(" B", delta_diagonal_rod_trim_tower_2);
-      SERIAL_ECHOPAIR(" C", delta_diagonal_rod_trim_tower_3);
-      SERIAL_ECHOPAIR(" I", delta_tower_angle_trim_1);
-      SERIAL_ECHOPAIR(" J", delta_tower_angle_trim_2);
-      SERIAL_ECHOPAIR(" K", delta_tower_angle_trim_3);
+      SERIAL_ECHOPAIR(" A", delta_diagonal_rod_trim[A_AXIS]);
+      SERIAL_ECHOPAIR(" B", delta_diagonal_rod_trim[B_AXIS]);
+      SERIAL_ECHOPAIR(" C", delta_diagonal_rod_trim[C_AXIS]);
+      SERIAL_ECHOPAIR(" I", delta_tower_angle_trim[A_AXIS]);
+      SERIAL_ECHOPAIR(" J", delta_tower_angle_trim[B_AXIS]);
+      SERIAL_ECHOPAIR(" K", delta_tower_angle_trim[C_AXIS]);
       SERIAL_EOL;
     #elif ENABLED(Z_DUAL_ENDSTOPS)
       CONFIG_ECHO_START;