Correctly reset cached z value lookups. MarlinFirmware#23843

Marlin/src/feature/bedlevel/abl/bbl.cpp

@@ -41,6 +41,8 @@ xy_pos_t bilinear_bed_leveling::grid_spacing,
          bilinear_bed_leveling::grid_start;
 xy_float_t bilinear_bed_leveling::grid_factor;
 bed_mesh_t bilinear_bed_leveling::z_values;
+xy_pos_t bilinear_bed_leveling::cached_rel;
+xy_int8_t bilinear_bed_leveling::cached_g;
 
 /**
  * Extrapolate a single point from its neighbors
@@ -265,6 +267,8 @@ void bilinear_bed_leveling::print_leveling_grid() {
 // Refresh after other values have been updated
 void bilinear_bed_leveling::refresh_bed_level() {
   TERN_(ABL_BILINEAR_SUBDIVISION, bed_level_virt_interpolate());
+  cached_rel.x = cached_rel.y = -999.999;
+  cached_g.x = cached_g.y = -99;
 }
 
 #if ENABLED(ABL_BILINEAR_SUBDIVISION)
@@ -286,10 +290,10 @@ float bilinear_bed_leveling::get_z_correction(const xy_pos_t &raw) {
 
   static float z1, d2, z3, d4, L, D;
 
-  static xy_pos_t prev { -999.999, -999.999 }, ratio;
+  static xy_pos_t ratio;
 
   // Whole units for the grid line indices. Constrained within bounds.
-  static xy_int8_t thisg, nextg, lastg { -99, -99 };
+  static xy_int8_t thisg, nextg;
 
   // XY relative to the probed area
   xy_pos_t rel = raw - grid_start.asFloat();
@@ -300,8 +304,8 @@ float bilinear_bed_leveling::get_z_correction(const xy_pos_t &raw) {
     #define FAR_EDGE_OR_BOX 1   // Just use the grid far edge
   #endif
 
-  if (prev.x != rel.x) {
-    prev.x = rel.x;
+  if (cached_rel.x != rel.x) {
+    cached_rel.x = rel.x;
     ratio.x = rel.x * ABL_BG_FACTOR(x);
     const float gx = constrain(FLOOR(ratio.x), 0, ABL_BG_POINTS_X - (FAR_EDGE_OR_BOX));
     ratio.x -= gx;      // Subtract whole to get the ratio within the grid box
@@ -315,10 +319,10 @@ float bilinear_bed_leveling::get_z_correction(const xy_pos_t &raw) {
     nextg.x = _MIN(thisg.x + 1, ABL_BG_POINTS_X - 1);
   }
 
-  if (prev.y != rel.y || lastg.x != thisg.x) {
+  if (cached_rel.y != rel.y || cached_g.x != thisg.x) {
 
-    if (prev.y != rel.y) {
-      prev.y = rel.y;
+    if (cached_rel.y != rel.y) {
+      cached_rel.y = rel.y;
       ratio.y = rel.y * ABL_BG_FACTOR(y);
       const float gy = constrain(FLOOR(ratio.y), 0, ABL_BG_POINTS_Y - (FAR_EDGE_OR_BOX));
       ratio.y -= gy;
@@ -332,8 +336,8 @@ float bilinear_bed_leveling::get_z_correction(const xy_pos_t &raw) {
       nextg.y = _MIN(thisg.y + 1, ABL_BG_POINTS_Y - 1);
     }
 
-    if (lastg != thisg) {
-      lastg = thisg;
+    if (cached_g != thisg) {
+      cached_g = thisg;
       // Z at the box corners
       z1 = ABL_BG_GRID(thisg.x, thisg.y);       // left-front
       d2 = ABL_BG_GRID(thisg.x, nextg.y) - z1;  // left-back (delta)

Marlin/src/feature/bedlevel/abl/bbl.h

@@ -27,6 +27,8 @@ class bilinear_bed_leveling {
   static xy_pos_t grid_spacing, grid_start;
   static xy_float_t grid_factor;
   static bed_mesh_t z_values;
+  static xy_pos_t cached_rel;
+  static xy_int8_t cached_g;
 
   static void extrapolate_one_point(const uint8_t x, const uint8_t y, const int8_t xdir, const int8_t ydir);
 

Marlin/src/feature/bedlevel/bedlevel.cpp

@@ -67,12 +67,6 @@ void set_bed_leveling_enabled(const bool enable/*=true*/) {
 
     planner.synchronize();
 
-    #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
-      // Force bbl.get_z_correction to re-calculate next time
-      const xyz_pos_t reset { -9999.999, -9999.999, 0 };
-      (void)bbl.get_z_correction(reset);
-    #endif
-
     if (planner.leveling_active) {      // leveling from on to off
       if (DEBUGGING(LEVELING)) DEBUG_POS("Leveling ON", current_position);
       // change unleveled current_position to physical current_position without moving steppers.

Marlin/src/gcode/bedlevel/M420.cpp

@@ -77,6 +77,7 @@ void GcodeSuite::M420() {
         Z_VALUES(x, y) = 0.001 * random(-200, 200);
         TERN_(EXTENSIBLE_UI, ExtUI::onMeshUpdate(x, y, Z_VALUES(x, y)));
       }
+      TERN_(AUTO_BED_LEVELING_BILINEAR, bbl.refresh_bed_level());
       SERIAL_ECHOPGM("Simulated " STRINGIFY(GRID_MAX_POINTS_X) "x" STRINGIFY(GRID_MAX_POINTS_Y) " mesh ");
       SERIAL_ECHOPGM(" (", x_min);
       SERIAL_CHAR(','); SERIAL_ECHO(y_min);
@@ -180,7 +181,7 @@ void GcodeSuite::M420() {
               Z_VALUES(x, y) -= zmean;
               TERN_(EXTENSIBLE_UI, ExtUI::onMeshUpdate(x, y, Z_VALUES(x, y)));
             }
-            TERN_(ABL_BILINEAR_SUBDIVISION, bbl.refresh_bed_level());
+            TERN_(AUTO_BED_LEVELING_BILINEAR, bbl.refresh_bed_level());
           }
 
         #endif