Move extrusion path gcode generation to C++ for speed.

lib/Slic3r/GCode.pm

@@ -340,35 +340,14 @@ sub extrude_path {
     
     # extrude arc or line
     $gcode .= ";_BRIDGE_FAN_START\n" if $path->is_bridge;
-    my $gcode_comments = $self->print_config->gcode_comments;
-    my $path_length = 0;
+    my $path_length = unscale $path->length;
     {
-        my $local_F = $F;
-        my $xofs = $self->shift_x - $self->extruder->extruder_offset->[X];
-        my $yofs = $self->shift_y - $self->extruder->extruder_offset->[Y];
-        foreach my $line (@{$path->lines}) {
-            $path_length += my $line_length = unscale $line->length;
-            
-            # calculate extrusion length for this line
-            my $E = 0;
-            $E = $self->extruder->extrude($e * $line_length) if $e;
-            
-            # compose G-code line
-            my $point = $line->b;
-            $gcode .= sprintf "G1 X%.3f Y%.3f",
-                ($point->x * &Slic3r::SCALING_FACTOR) + $xofs,
-                ($point->y * &Slic3r::SCALING_FACTOR) + $yofs;  #**
-            $gcode .= sprintf(" %s%.5f", $self->_extrusion_axis, $E)
-                if $E;
-            $gcode .= " F$local_F"
-                if $local_F;
-            $gcode .= " ; $description"
-                if $gcode_comments;
-            $gcode .= "\n";
-            
-            # only include F in the first line
-            $local_F = 0;
-        }
+        $gcode .= $path->gcode($self->extruder, $e, $F,
+            $self->shift_x - $self->extruder->extruder_offset->[X],
+            $self->shift_y - $self->extruder->extruder_offset->[Y],
+            $self->_extrusion_axis,
+            $self->print_config->gcode_comments ? " ; $description" : "");
+
         if ($self->enable_wipe) {
             $self->wipe_path($path->polyline->clone);
             $self->wipe_path->reverse;

xs/src/ExtrusionEntity.cpp

@@ -1,3 +1,4 @@
+#include <sstream>
 #include "ExtrusionEntity.hpp"
 #include "ExtrusionEntityCollection.hpp"
 #include "ExPolygonCollection.hpp"
@@ -100,6 +101,67 @@ ExtrusionPath::_inflate_collection(const Polylines &polylines, ExtrusionEntityCo
     }
 }
 
+#ifdef SLIC3RXS
+std::string
+ExtrusionPath::gcode(SV* extruder, double e, double F,
+    double xofs, double yofs, std::string extrusion_axis,
+    std::string gcode_line_suffix) const
+{
+    dSP;
+
+    std::stringstream stream;
+    stream.setf(std::ios::fixed);
+
+    double local_F = F;
+
+    Lines lines = this->polyline.lines();
+    for (Lines::const_iterator line_it = lines.begin();
+        line_it != lines.end(); ++line_it)
+    {
+        const double line_length = line_it->length() * SCALING_FACTOR;
+
+        // calculate extrusion length for this line
+        double E = 0;
+        if (e != 0) {
+            PUSHMARK(SP);
+            XPUSHs(extruder);
+            XPUSHs(sv_2mortal(newSVnv(e * line_length)));
+            PUTBACK;
+
+            const int count = call_method("extrude", G_SCALAR);
+            SPAGAIN;
+
+            // TODO: check that count is 1
+            E = POPn;
+        }
+
+        // compose G-code line
+
+        Point point = line_it->b;
+        const double x = point.x * SCALING_FACTOR + xofs;
+        const double y = point.y * SCALING_FACTOR + yofs;
+        stream.precision(3);
+        stream << "G1 X" << x << " Y" << y;
+
+        if (E != 0) {
+            stream.precision(5);
+            stream << " " << extrusion_axis << E;
+        }
+
+        if (local_F != 0) {
+            stream.precision(3);
+            stream << " F" << local_F;
+            local_F = 0;
+        }
+
+        stream << gcode_line_suffix;
+        stream << "\n";
+    }
+
+    return stream.str();
+}
+#endif
+
 ExtrusionLoop*
 ExtrusionLoop::clone() const
 {

xs/src/ExtrusionEntity.hpp

@@ -55,6 +55,13 @@ class ExtrusionPath : public ExtrusionEntity
     void clip_end(double distance);
     void simplify(double tolerance);
     double length() const;
+
+    #ifdef SLIC3RXS
+    std::string gcode(SV* extruder, double e, double F,
+        double xofs, double yofs, std::string extrusion_axis,
+        std::string gcode_line_suffix) const;
+    #endif
+
     private:
     void _inflate_collection(const Polylines &polylines, ExtrusionEntityCollection* collection) const;
 };

xs/xsp/ExtrusionPath.xsp

@@ -27,6 +27,9 @@
     bool is_perimeter();
     bool is_fill();
     bool is_bridge();
+    std::string gcode(SV* extruder, double e, double F,
+        double xofs, double yofs, std::string extrusion_axis,
+        std::string gcode_line_suffix);
 %{
 
 ExtrusionPath*