fix some seam_gap issues:

 * fix scale
 * continue traveling up to the old gap position (or continue with wipe_extra_perimeter)
supermerill/SuperSlicer#57

3 files changed, 41 insertions, 16 deletions

diff --git a/src/libslic3r/ExtrusionEntity.cpp b/src/libslic3r/ExtrusionEntity.cpp
index 5ed878499..250359aef 100644
--- a/src/libslic3r/ExtrusionEntity.cpp
+++ b/src/libslic3r/ExtrusionEntity.cpp
@@ -213,21 +213,25 @@ void ExtrusionLoop::split_at(const Point &point, bool prefer_non_overhang)
     this->split_at_vertex(p);
 }
 
-void ExtrusionLoop::clip_end(double distance, ExtrusionPaths* paths) const
+ExtrusionPaths clip_end(ExtrusionPaths& paths, double distance)
 {
-    *paths = this->paths;
+    ExtrusionPaths removed;
     
-    while (distance > 0 && !paths->empty()) {
-        ExtrusionPath &last = paths->back();
+    while (distance > 0 && !paths.empty()) {
+        ExtrusionPath& last = paths.back();
+        removed.push_back(last);
         double len = last.length();
         if (len <= distance) {
-            paths->pop_back();
+            paths.pop_back();
             distance -= len;
         } else {
             last.polyline.clip_end(distance);
+            removed.back().polyline.clip_start(removed.back().polyline.length() - distance);
             break;
         }
     }
+    std::reverse(removed.begin(), removed.end());
+    return removed;
 }
 
 bool ExtrusionLoop::has_overhang_point(const Point &point) const
diff --git a/src/libslic3r/ExtrusionEntity.hpp b/src/libslic3r/ExtrusionEntity.hpp
index 5369998cf..36198f125 100644
--- a/src/libslic3r/ExtrusionEntity.hpp
+++ b/src/libslic3r/ExtrusionEntity.hpp
@@ -279,6 +279,7 @@ protected:
     ExtrusionRole m_role;
 };
 typedef std::vector<ExtrusionPath> ExtrusionPaths;
+ExtrusionPaths clip_end(ExtrusionPaths& paths, double distance);
 
 class ExtrusionPath3D : public ExtrusionPath {
 public:
@@ -451,7 +452,6 @@ public:
     double length() const override;
     bool split_at_vertex(const Point &point);
     void split_at(const Point &point, bool prefer_non_overhang);
-    void clip_end(double distance, ExtrusionPaths* paths) const;
     // Test, whether the point is extruded by a bridging flow.
     // This used to be used to avoid placing seams on overhangs, but now the EdgeGrid is used instead.
     bool has_overhang_point(const Point &point) const;
diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index edf1677b2..b4f546bf7 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -2949,13 +2949,23 @@ std::string GCode::extrude_loop_vase(const ExtrusionLoop &original_loop, const s
     // clip the path to avoid the extruder to get exactly on the first point of the loop;
     // if polyline was shorter than the clipping distance we'd get a null polyline, so
     // we discard it in that case
-    double clip_length = 0;
+    coordf_t clip_length = 0;
+    coordf_t min_clip_length = scale_(EXTRUDER_CONFIG_WITH_DEFAULT(nozzle_diameter, 0)) * 0.15;
     if (m_enable_loop_clipping && m_writer.tool_is_extruder())
-        clip_length = m_config.seam_gap.get_abs_value(m_writer.tool()->id(), scale_(EXTRUDER_CONFIG_WITH_DEFAULT(nozzle_diameter, 0)));
+        clip_length = scale_(m_config.seam_gap.get_abs_value(m_writer.tool()->id(), EXTRUDER_CONFIG_WITH_DEFAULT(nozzle_diameter, 0)));
 
     // get paths
-    ExtrusionPaths paths;
-    loop.clip_end(clip_length, &paths);
+    ExtrusionPaths paths = loop.paths;
+    ExtrusionPaths clipped;
+    if (clip_length > min_clip_length) {
+        clipped = clip_end(paths, clip_length);
+        clip_end(clipped, min_clip_length);
+        for (ExtrusionPath& ep : clipped)
+            ep.mm3_per_mm = 0;
+        append(paths, clipped);
+    } else {
+        clip_end(paths, clip_length);
+    }
     if (paths.empty()) return "";
 
     // apply the small/external? perimeter speed
@@ -3063,7 +3073,9 @@ std::string GCode::extrude_loop_vase(const ExtrusionLoop &original_loop, const s
             double e_per_mm_per_height = (path->mm3_per_mm / this->m_layer->height)
                 * m_writer.tool()->e_per_mm3()
                 * this->config().print_extrusion_multiplier.get_abs_value(1);
-            if (m_writer.extrusion_axis().empty()) e_per_mm_per_height = 0;
+            if (m_writer.extrusion_axis().empty())
+                e_per_mm_per_height = 0;
+            //extrude
             {
                 std::string comment = m_config.gcode_comments ? description : "";
                 for (const Line &line : path->polyline.lines()) {
@@ -3271,13 +3283,23 @@ std::string GCode::extrude_loop(const ExtrusionLoop &original_loop, const std::s
     // clip the path to avoid the extruder to get exactly on the first point of the loop;
     // if polyline was shorter than the clipping distance we'd get a null polyline, so
     // we discard it in that case
-    double clip_length = 0;
+    coordf_t clip_length = 0;
+    coordf_t min_clip_length = scale_(EXTRUDER_CONFIG_WITH_DEFAULT(nozzle_diameter, 0)) * 0.15;
     if (m_enable_loop_clipping && m_writer.tool_is_extruder())
-        clip_length = m_config.seam_gap.get_abs_value(m_writer.tool()->id(), scale_(EXTRUDER_CONFIG_WITH_DEFAULT(nozzle_diameter, 0)));
+        clip_length = scale_(m_config.seam_gap.get_abs_value(m_writer.tool()->id(), EXTRUDER_CONFIG_WITH_DEFAULT(nozzle_diameter, 0)));
 
     // get paths
-    ExtrusionPaths paths;
-    loop.clip_end(clip_length, &paths);
+    ExtrusionPaths paths = loop.paths;
+    ExtrusionPaths clipped;
+    if (clip_length > min_clip_length) {
+        clipped = clip_end(paths, clip_length);
+        clip_end(clipped, min_clip_length);
+        for (ExtrusionPath& ep : clipped)
+            ep.mm3_per_mm = 0;
+        append(paths, clipped);
+    } else {
+        clip_end(paths, clip_length);
+    }
     if (paths.empty()) return "";
 
     // apply the small perimeter speed
@@ -3298,7 +3320,6 @@ std::string GCode::extrude_loop(const ExtrusionLoop &original_loop, const std::s
     std::string gcode;
     for (ExtrusionPaths::iterator path = paths.begin(); path != paths.end(); ++path) {
         //path->simplify(SCALED_RESOLUTION); //should already be simplified
-        //gcode += this->_extrude(*path, description, speed);
         if(path->polyline.points.size()>1)
             gcode += extrude_path(*path, description, speed);
     }