Verify WipeTower Footprint at Point of Generation

The clamps and validation work from estimates. Once the tower is
generated, _make_wipe_tower re-tests the exact first-layer footprint,
brim and cone base included, against the printable area and the
exclusion zone, so an off-plate tower fails with a clear error instead
of exporting unprintable G-code. The rectangle-wall mesh footprint
learns the Type2 cone base so that check and the post-generation
validation see the real outline.

Pre-generation, validation hard-checks the body plus an explicit brim
and warns on the estimated auto brim and cone base with the existing
"may collide" strings, so the user hears about a marginal position on
the first slice rather than only at generation time.

Two fff_print fixtures that print a tower at the default position move
it onto the 200 mm test bed, as the multifilament fixtures already do:
the shipped default y of 220 is off that bed, and the backstop now says
so instead of exporting the tower.

src/libslic3r/Print.cpp

@@ -1068,33 +1068,57 @@ static StringObjectException layered_print_cleareance_valid(const Print &print,
             convex_hulls_temp.push_back(wipe_tower_polygon);
         }
     }
+    // Post-generation the mesh bottom already carries the brim. Pre-generation the body grows
+    // by the brim only when its width is explicit; the auto brim and a Type2 cone base depend on
+    // the tower height, exact only once generated, so they only warn here - the exact footprint
+    // is re-checked in _make_wipe_tower.
+    const bool exact_footprint     = print.is_step_done(psWipeTower);
+    Polygons   tower_polys_checked = (!exact_footprint && config.prime_tower_brim_width.value >= 0) ?
+                                         offset(convex_hulls_temp, float(scale_(brim_width))) :
+                                         convex_hulls_temp;
+    Polygons tower_polys_estimated;
+    if (!exact_footprint && !convex_hulls_temp.empty()) {
+        Polygon base = convex_hulls_temp.front();
+        if (config.wipe_tower_wall_type.value == WipeTowerWallType::wtwCone && print.wipe_tower_type() == WipeTowerType::Type2) {
+            double max_height = 0.;
+            for (const PrintObject *object : print.objects())
+                max_height = std::max(max_height, unscale_(object->size().z()));
+            base = WipeTower2::cone_base_polygon(width, depth, max_height, config.wipe_tower_cone_angle.value);
+            base.rotate(Geometry::deg2rad(a));
+            base.translate(Point(scale_(x), scale_(y)));
+        }
+        tower_polys_estimated = offset(base, float(scale_(brim_width)));
+    }
+    // Object proximity stays a body-only warning: brim near-misses would newly warn on
+    // many setups that print fine.
     if (!intersection(convex_hulls_other, convex_hulls_temp).empty()) {
         if (warning) {
             warning->string += L("Prime Tower") + L(" is too close to others, and collisions may be caused.\n");
         }
     }
-    if (!intersection(exclude_polys, convex_hulls_temp).empty()) {
+    if (!intersection(exclude_polys, tower_polys_checked).empty()) {
-        /*if (warning) {
-            warning->string += L("Prime Tower is too close to exclusion area, there may be collisions when printing.\n");
-        }*/
         return {L("Prime Tower") + L(" is too close to an exclusion area, and collisions will be caused.\n")};
     }
-    if (print_config.enable_wrapping_detection.value && !intersection({wrapping_poly}, convex_hulls_temp).empty()) {
+    if (print_config.enable_wrapping_detection.value && !intersection({wrapping_poly}, tower_polys_checked).empty()) {
         return {L("Prime Tower") + L(" is too close to clumping detection area, and collisions will be caused.\n")};
     }
-    // No gate on "is there a tower": one that is not printed estimates to zero, so the hull
+    if (warning && !intersection(exclude_polys, tower_polys_estimated).empty()) {
-    // is degenerate and every check passes. Re-deriving it here missed the wrapping-detection
+        warning->string += L("Prime Tower") + L(" is too close to exclusion area, there may be collisions when printing.") + "\n";
+    }
+    if (warning && print_config.enable_wrapping_detection.value && !intersection({wrapping_poly}, tower_polys_estimated).empty()) {
+        warning->string += L("Prime Tower") + L(" is too close to clumping detection area, there may be collisions when printing.") + "\n";
+    }
+    // No gate on "is there a tower": one that is not printed estimates to zero, so the hulls
+    // are degenerate and every check passes. Re-deriving it here missed the wrapping-detection
     // tower on a single-filament plate.
-    // Pre-generation, grow the body by the brim to match what the generator draws;
-    // post-generation the mesh already includes it.
     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);
-    Polygons tower_polys_with_brim = print.is_step_done(psWipeTower) ?
+    if (!diff(tower_polys_checked, printable_polys).empty())
-        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")};
+    if (warning && !diff(tower_polys_estimated, printable_polys).empty())
+        warning->string += L("Prime Tower") + L(" is partially outside the printable area, and it cannot be printed.\n");
     return {};
 }
 
@@ -4390,7 +4414,9 @@ void Print::_make_wipe_tower()
                                          wipe_tower.get_wipe_tower_height(), wipe_tower.get_brim_width(),
                                          config().wipe_tower_wall_type.value == WipeTowerWallType::wtwRib,
                                          wipe_tower.get_rib_width(), wipe_tower.get_rib_length(),
-                                         config().wipe_tower_fillet_wall.value);
+                                         config().wipe_tower_fillet_wall.value,
+                                         config().wipe_tower_wall_type.value == WipeTowerWallType::wtwCone ?
+                                             (float) config().wipe_tower_cone_angle.value : 0.f);
         const Vec3d origin                      = Vec3d::Zero();
         // FakeWipeTower::pos is a bed-frame translation applied after rotation
         // (getFakeExtrusionPathsFromWipeTower2 rotates about the local origin), so the
@@ -4403,6 +4429,28 @@ void Print::_make_wipe_tower()
                                                   config().wipe_tower_rotation_angle, config().wipe_tower_cone_angle,
                                                   {scale_(origin.x()), scale_(origin.y())});
     }
+
+    // The clamps and checks above work from estimates; re-test the exact generated footprint
+    // so an off-plate tower fails with a clear error instead of exporting unprintable G-code
+    // (validate() only sees the mesh on its next run).
+    if (m_wipe_tower_data.wipe_tower_mesh_data) {
+        Polygon footprint = m_wipe_tower_data.wipe_tower_mesh_data->bottom; // includes brim and rib offset
+        footprint.rotate(Geometry::deg2rad(m_config.wipe_tower_rotation_angle.value));
+        footprint.translate(Point(scale_(m_config.wipe_tower_x.get_at(m_plate_index)),
+                                  scale_(m_config.wipe_tower_y.get_at(m_plate_index))));
+        const Polygons printable_polys = this->get_extruder_shared_printable_polygon();
+        if (!printable_polys.empty() && !diff(Polygons{footprint}, printable_polys).empty()) {
+            const BoundingBox fp = get_extents(footprint);
+            const BoundingBox pr = get_extents(printable_polys);
+            BOOST_LOG_TRIVIAL(error) << boost::format("wipe tower footprint [%1%,%2%]-[%3%,%4%] leaves printable [%5%,%6%]-[%7%,%8%]") %
+                unscaled(fp.min.x()) % unscaled(fp.min.y()) % unscaled(fp.max.x()) % unscaled(fp.max.y()) %
+                unscaled(pr.min.x()) % unscaled(pr.min.y()) % unscaled(pr.max.x()) % unscaled(pr.max.y());
+            throw Slic3r::SlicingError(L("Prime Tower") + L(" is partially outside the printable area, and it cannot be printed.\n"));
+        }
+        // The cutter/purge corner is a physical obstacle — the brim must stay out like the body.
+        if (!intersection(get_bed_excluded_area(m_config), Polygons{footprint}).empty())
+            throw Slic3r::SlicingError(L("Prime Tower") + L(" is too close to an exclusion area, and collisions will be caused.\n"));
+    }
 }
 
 // Generate a recommended G-code output file name based on the format template, default extension, and template parameters
@@ -5951,12 +5999,21 @@ ExtrusionLayers FakeWipeTower::getTrueExtrusionLayersFromWipeTower() const
     }
     return wtels;
 }
-void WipeTowerData::construct_mesh(float width, float depth, float height, float brim_width, bool is_rib_wipe_tower, float rib_width, float rib_length,bool fillet_wall)
+void WipeTowerData::construct_mesh(float width, float depth, float height, float brim_width, bool is_rib_wipe_tower, float rib_width, float rib_length,bool fillet_wall, float cone_angle)
 {
     wipe_tower_mesh_data = WipeTowerMeshData{};
     float first_layer_height=0.08; //brim height
     if (width < EPSILON || depth < EPSILON || height < EPSILON) return;
-    if (!is_rib_wipe_tower || rib_length < EPSILON) {
+    if (cone_angle > EPSILON && (!is_rib_wipe_tower || rib_length < EPSILON)) {
+        // Cone tower: the base bulges past the body box; this bottom polygon feeds the
+        // containment checks, so it must carry the bulge and the brim (cone not lofted).
+        wipe_tower_mesh_data->real_wipe_tower_mesh = make_cube(width, depth, height);
+        wipe_tower_mesh_data->bottom               = WipeTower2::cone_base_polygon(width, depth, height, cone_angle);
+        auto brim_bottom                           = offset(wipe_tower_mesh_data->bottom, scaled(brim_width));
+        if (!brim_bottom.empty())
+            wipe_tower_mesh_data->bottom = brim_bottom.front();
+        wipe_tower_mesh_data->real_brim_mesh = WipeTower::its_make_rib_brim(wipe_tower_mesh_data->bottom, first_layer_height);
+    } else if (!is_rib_wipe_tower || rib_length < EPSILON) {
         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});

src/libslic3r/Print.hpp

@@ -804,7 +804,7 @@ struct WipeTowerData
         rib_offset = Vec2f::Zero();
         wipe_tower_mesh_data  = std::nullopt;
     }
-    void construct_mesh(float width, float depth, float height, float brim_width, bool is_rib_wipe_tower, float rib_width, float rib_length, bool fillet_wall);
+    void construct_mesh(float width, float depth, float height, float brim_width, bool is_rib_wipe_tower, float rib_width, float rib_length, bool fillet_wall, float cone_angle = 0.f);
 
 private:
 	// Only allow the WipeTowerData to be instantiated internally by Print, 

tests/fff_print/test_gcodewriter.cpp

@@ -574,6 +574,9 @@ static DynamicPrintConfig dual_extruder_toolchange_config()
     config.set_key_value("nozzle_temperature_range_high", new ConfigOptionInts({240, 240}));
     config.set_key_value("flush_multiplier",     new ConfigOptionFloats({1}));
     config.set_key_value("flush_volumes_matrix", new ConfigOptionFloats({0, 140, 140, 0}));
+    // Inside the 200x200 test bed; the default y, 220, is not, and generation rejects that.
+    config.set_key_value("wipe_tower_x",         new ConfigOptionFloats({50.}));
+    config.set_key_value("wipe_tower_y",         new ConfigOptionFloats({50.}));
     return config;
 }
 

tests/fff_print/test_wipe_tower.cpp

@@ -152,6 +152,8 @@ static DynamicPrintConfig wipe_tower_toolchange_config(const std::string &gcode_
         { "outer_wall_filament_id",     2 },
         { "inner_wall_filament_id",     2 },
         { "enable_prime_tower",         true },
+        { "wipe_tower_x",               50 }, // inside the 200x200 test bed
+        { "wipe_tower_y",               50 }, // (the default y, 220, is not)
         { "layer_height",               0.3 },
         { "gcode_flavor",               gcode_flavor },
     });