Fixes for Wipe Tower Position Clamping

Validation grows the estimated body by the brim before the tower is
generated, so a tower whose brim leaves the bed is rejected up front
instead of at export. The scene reload re-clamps the stored position,
since set_default_wipe_tower_pos_for_plate does not rerun when painting
changes the filament count. The rectangle-wall footprint polygon gets its
two missing brim corners (it was a skewed quad), so the post-generation
check covers the whole brim.

src/libslic3r/Print.cpp

@@ -1046,6 +1046,7 @@ static StringObjectException layered_print_cleareance_valid(const Print &print,
     const WipeTowerData &wipe_tower_estimate = print.wipe_tower_data(filaments_count);
     float                width               = wipe_tower_estimate.width;
     float                depth               = wipe_tower_estimate.depth;
+    float                brim_width          = wipe_tower_estimate.brim_width;
 
     Polygons convex_hulls_temp;
     if (print.has_wipe_tower()) {
@@ -1084,17 +1085,15 @@ static StringObjectException layered_print_cleareance_valid(const Print &print,
     // No gate on "is there a tower": one that is not printed estimates to zero, so the hull
     // is degenerate and every check passes. Re-deriving it here missed the wrapping-detection
     // tower on a single-filament plate.
-    // Pre-generation only the body square is tested — the auto-brim estimate can overshoot
+    // Pre-generation, grow the body by the brim to match what the generator draws;
-    // the generated brim by several mm and must not hard-fail a print that physically fits.
+    // post-generation the mesh already includes it.
-    // Post-generation the mesh bottom already includes the real brim, so the exact
-    // footprint is tested.
-    // The shared printable polygon is plate-local, while the tower polygons above are
-    // already shifted by the plate origin.
     Polygons    printable_polys = print.get_extruder_shared_printable_polygon();
     const Point plate_shift(scale_(plate_origin.x()), scale_(plate_origin.y()));
     for (Polygon &p : printable_polys)
         p.translate(plate_shift);
-    if (!diff(convex_hulls_temp, printable_polys).empty())
+    Polygons tower_polys_with_brim = print.is_step_done(psWipeTower) ?
+        convex_hulls_temp : offset(convex_hulls_temp, float(scale_(brim_width)));
+    if (!diff(tower_polys_with_brim, printable_polys).empty())
         return {L("Prime Tower") + L(" is partially outside the printable area, and it cannot be printed.\n")};
     return {};
 }
@@ -5961,8 +5960,8 @@ void WipeTowerData::construct_mesh(float width, float depth, float height, float
         wipe_tower_mesh_data->real_wipe_tower_mesh = make_cube(width, depth, height);
         wipe_tower_mesh_data->real_brim_mesh       = make_cube(width + 2 * brim_width, depth + 2 * brim_width, first_layer_height);
         wipe_tower_mesh_data->real_brim_mesh.translate({-brim_width, -brim_width, 0});
-        wipe_tower_mesh_data->bottom = {scaled(Vec2f{-brim_width, -brim_width}), scaled(Vec2f{width + brim_width, 0}), scaled(Vec2f{width + brim_width, depth + brim_width}),
+        wipe_tower_mesh_data->bottom = {scaled(Vec2f{-brim_width, -brim_width}), scaled(Vec2f{width + brim_width, -brim_width}),
-                                        scaled(Vec2f{0, depth})};
+                                        scaled(Vec2f{width + brim_width, depth + brim_width}), scaled(Vec2f{-brim_width, depth + brim_width})};
     } else {
         wipe_tower_mesh_data->real_wipe_tower_mesh = WipeTower::its_make_rib_tower(width, depth, height, rib_length, rib_width, fillet_wall);
         wipe_tower_mesh_data->bottom               = WipeTower::rib_section(width, depth, rib_length, rib_width, fillet_wall);

src/slic3r/GUI/GLCanvas3D.cpp

@@ -2906,8 +2906,20 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
                 float brim_width = float(footprint.brim_width);
                 Vec3d wipe_tower_size(footprint.width, footprint.depth, footprint.height);
 
-                // The stored position is already clamped onto the bed, by
+                // set_default_wipe_tower_pos_for_plate doesn't rerun when painting changes the
-                // set_default_wipe_tower_pos_for_plate and again on every drag.
+                // filament count, so redo its clamp here on every reload.
+                {
+                    Vec3d clamped_pos, clamped_size;
+                    part_plate->estimate_wipe_tower_polygon(full_config, plate_id, clamped_pos, clamped_size);
+                    if (std::abs(x - (float) clamped_pos(0)) > EPSILON || std::abs(y - (float) clamped_pos(1)) > EPSILON) {
+                        x = (float) clamped_pos(0);
+                        y = (float) clamped_pos(1);
+                        ConfigOptionFloat wt_x_opt(x), wt_y_opt(y);
+                        dynamic_cast<ConfigOptionFloats*>(proj_cfg.option("wipe_tower_x"))->set_at(&wt_x_opt, plate_id, 0);
+                        dynamic_cast<ConfigOptionFloats*>(proj_cfg.option("wipe_tower_y"))->set_at(&wt_y_opt, plate_id, 0);
+                    }
+                }
+
                 if (!current_print->is_step_done(psWipeTower) || !current_print->wipe_tower_data().wipe_tower_mesh_data) {
                     // update for wipe tower position
                     int volume_idx_wipe_tower_new = m_volumes.load_wipe_tower_preview(1000 + plate_id, x + plate_origin(0), y + plate_origin(1),