From 5509afa82aa8170d5eab542c35e0b1fcb8097ab0 Mon Sep 17 00:00:00 2001
From: Joseph Lenox <lenox.joseph@gmail.com>
Date: Mon, 5 Nov 2018 19:50:29 -0600
Subject: [PATCH] #4569 Added new gcode placeholder, [filament_extruder_id]
 that is only valid in filament start/end gcode and refers to which position
 this filament is loaded in.

---
 lib/Slic3r/Print/GCode.pm       | 6 ++++++
 xs/src/libslic3r/PrintGCode.cpp | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/lib/Slic3r/Print/GCode.pm b/lib/Slic3r/Print/GCode.pm
index ef6515473..d559a5ea2 100644
--- a/lib/Slic3r/Print/GCode.pm
+++ b/lib/Slic3r/Print/GCode.pm
@@ -160,7 +160,10 @@ sub export {
     $self->_print_first_layer_temperature(0)
         if $include_start_extruder_temp;
     printf $fh "%s\n", Slic3r::ConditionalGCode::apply_math($gcodegen->placeholder_parser->process($self->config->start_gcode));
+    my $filament_extruder = 0;
     foreach my $start_gcode (@{ $self->config->start_filament_gcode }) { # process filament gcode in order
+        $gcodegen->placeholder_parser->set("filament_extruder_id", $filament_extruder);
+        $filament_extruder++;
         printf $fh "%s\n", Slic3r::ConditionalGCode::apply_math($gcodegen->placeholder_parser->process($start_gcode));
     }
     $self->_print_first_layer_temperature(1)
@@ -303,7 +306,10 @@ sub export {
     # write end commands to file
     print $fh $gcodegen->retract;   # TODO: process this retract through PressureRegulator in order to discharge fully
     print $fh $gcodegen->writer->set_fan(0);
+    my $filament_extruder = 0;
     foreach my $end_gcode (@{ $self->config->end_filament_gcode }) { # Process filament-specific gcode in extruder order.
+        $gcodegen->placeholder_parser->set("filament_extruder_id", $filament_extruder);
+        $filament_extruder++;
         printf $fh "%s\n", Slic3r::ConditionalGCode::apply_math($gcodegen->placeholder_parser->process($end_gcode));
     }
     printf $fh "%s\n", Slic3r::ConditionalGCode::apply_math($gcodegen->placeholder_parser->process($self->config->end_gcode));
diff --git a/xs/src/libslic3r/PrintGCode.cpp b/xs/src/libslic3r/PrintGCode.cpp
index 0af21863c..2f9e65e46 100644
--- a/xs/src/libslic3r/PrintGCode.cpp
+++ b/xs/src/libslic3r/PrintGCode.cpp
@@ -131,7 +131,9 @@ PrintGCode::output()
     // Apply gcode math to start gcode
     fh << apply_math(gcodegen.placeholder_parser->process(config.start_gcode.value));
 
+    auto filament_extruder {0U};
     for(const auto& start_gcode : config.start_filament_gcode.values) {
+        gcodegen.placeholder_parser->set("filament_extruder", filament_extruder++);
         fh << apply_math(gcodegen.placeholder_parser->process(start_gcode));
     }
     
@@ -278,7 +280,10 @@ PrintGCode::output()
 
     // Write end commands to file.
     fh << gcodegen.retract(); // TODO: process this retract through PressureRegulator in order to discharge fully
+
+    auto filament_extruder {0U};
     for(const auto& end_gcode : config.end_filament_gcode.values) {
+        gcodegen.placeholder_parser->set("filament_extruder", filament_extruder++);
         fh << apply_math(gcodegen.placeholder_parser->process(end_gcode));
     }