fix(engine): real-change-only toolchange ordinals and a single M1020 toolchange command

A dual-nozzle H2C print with support filament hangs at its first nozzle
switch. The emitted file shows the change-filament block's M620 O ordinal
jumping from O1 straight to O230, plus a duplicate "M1020 S<n>" toolchange
command right after every change block. Two causes, fixed together because
they interlock (the ordinal check keys off the same toolchange detection
that suppresses the duplicate):

- append_tcr incremented m_toolchange_count once per prime-tower visit
  (roughly once per layer), while the change-filament template only emits
  its M620 O{toolchange_count + 1} line on real filament changes. With 229
  change-less sparse tower layers below the first support layer, the first
  real change reported ordinal 230. The counter now advances only when the
  expanded change block really contains a toolchange command, and the
  placeholder exposes the upcoming change's ordinal (count + 1). The
  set_extruder path already counted per real change and is unchanged.

- toolchange_prefix() returned "M1020 S" for BBL printers, so the
  custom_gcode_changes_tool() dedup could never match the stock profiles'
  line-leading "T[next_filament_id] ..." commands and the writer's own
  toolchange was appended after every change block on dual-extruder
  machines. The prefix is now the plain "T" (the manual-filament-change tag
  branch stays first), and the M1020 form moved into GCodeWriter::toolchange()
  as an explicit branch that also carries the nozzle:
  "M1020 S<filament> H<nozzle>". The nozzle parameter is signed on purpose:
  the null-safe nozzle lookup legitimately yields -1, matching the stock
  templates' own H-1 convention.

The prefix change also lets the CoolingBuffer recognize the change blocks'
T commands as tool boundaries on BBL printers (its per-filament attribution
previously keyed off the duplicate M1020, or nothing at all on
single-extruder models); its existing out-of-range guard ignores
T1000-class machine commands.

Verification: full suites green (libslic3r 48998 assertions / 169 cases;
fff_print 692 / 65 including three new scenarios - writer emission per
printer kind, dedup + ordinal progression on sequential prints, and a
prime-tower regression scenario verified to fail against the old per-visit
counting). Byte gate: 18 of 20 fixtures bit-identical; the sequential repro
differs by exactly its 3 removed duplicate M1020 lines, deterministic
across two runs. Reslicing the field project that exposed the hang yields
M620 O1 followed by a gapless O2..O59 and zero duplicate M1020 lines.

Co-authored-by: songwei.li <songwei.li@bambulab.com>
This commit is contained in:
SoftFever
2026-07-12 21:04:19 +08:00
parent 3ebd68d959
commit e98750e713
4 changed files with 246 additions and 27 deletions

View File

@@ -1,6 +1,10 @@
#include <catch2/catch_all.hpp>
#include <cstdlib>
#include <memory>
#include <sstream>
#include <string>
#include <vector>
#include "libslic3r/GCodeWriter.hpp"
#include "libslic3r/GCode.hpp"
@@ -417,7 +421,7 @@ SCENARIO("Extruder reads the injected config column", "[GCodeWriter][H2C]") {
// Filament-indexed arrays keep one entry per filament.
writer.config.filament_diameter.values = {1.75, 1.75};
writer.set_extruders({0, 1});
writer.toolchange(1);
writer.toolchange(1, 1);
Extruder *fil = writer.filament();
REQUIRE(fil != nullptr);
REQUIRE(fil->id() == 1);
@@ -456,3 +460,214 @@ SCENARIO("Extruder reads the injected config column", "[GCodeWriter][H2C]") {
}
}
}
// Numeric argument of every line starting with `prefix`, in file order.
static std::vector<int> collect_line_args(const std::string &gcode, const std::string &prefix)
{
std::vector<int> values;
std::istringstream stream(gcode);
std::string line;
while (std::getline(stream, line))
if (line.compare(0, prefix.size(), prefix) == 0)
values.push_back(std::atoi(line.c_str() + int(prefix.size())));
return values;
}
static int count_lines_with_prefix(const std::string &gcode, const std::string &prefix)
{
return (int) collect_line_args(gcode, prefix).size();
}
// A toolchange ordinal sequence is healthy when it advances by exactly one per
// change block; a change-less prime-tower visit must not consume an ordinal.
static bool ordinals_consecutive(const std::vector<int> &values)
{
for (size_t i = 1; i < values.size(); ++i)
if (values[i] != values[i - 1] + 1)
return false;
return true;
}
SCENARIO("Toolchange emission and prefix per printer kind", "[GCodeWriter][H2C]") {
GIVEN("A dual-extruder writer with two filaments") {
GCodeWriter writer;
writer.config.filament_diameter.values = {1.75, 1.75};
writer.set_extruders({0, 1});
WHEN("the printer is a BBL machine") {
writer.set_is_bbl_machine(true);
THEN("the toolchange prefix is the plain T command") {
REQUIRE_THAT(writer.toolchange_prefix(), Catch::Matchers::Equals("T"));
}
THEN("toolchange emits a single M1020 with the nozzle id") {
const std::string gcode = writer.toolchange(1, 0);
REQUIRE_THAT(gcode, Catch::Matchers::ContainsSubstring("M1020 S1 H0"));
REQUIRE_THAT(gcode, !Catch::Matchers::StartsWith("T1"));
}
THEN("the other filament and nozzle emit their own ids") {
REQUIRE_THAT(writer.toolchange(0, 1), Catch::Matchers::ContainsSubstring("M1020 S0 H1"));
}
THEN("an unresolved nozzle keeps the literal -1 convention") {
REQUIRE_THAT(writer.toolchange(1, -1), Catch::Matchers::ContainsSubstring("M1020 S1 H-1"));
}
}
WHEN("the printer is a BBL machine with manual filament change") {
writer.set_is_bbl_machine(true);
writer.config.manual_filament_change.value = true;
THEN("the manual tag wins over the M1020 form") {
REQUIRE_THAT(writer.toolchange_prefix(), Catch::Matchers::StartsWith(";"));
const std::string gcode = writer.toolchange(1, 0);
REQUIRE_THAT(gcode, Catch::Matchers::ContainsSubstring(writer.toolchange_prefix() + "1"));
REQUIRE_THAT(gcode, !Catch::Matchers::ContainsSubstring("M1020"));
}
}
WHEN("the printer is not a BBL machine") {
THEN("toolchange keeps the plain T command") {
REQUIRE_THAT(writer.toolchange_prefix(), Catch::Matchers::Equals("T"));
const std::string gcode = writer.toolchange(1, 0);
REQUIRE_THAT(gcode, Catch::Matchers::StartsWith("T1"));
REQUIRE_THAT(gcode, !Catch::Matchers::ContainsSubstring("M1020"));
}
}
}
}
// Shared dual-extruder printer config for the toolchange-count scenarios below.
static DynamicPrintConfig dual_extruder_toolchange_config()
{
DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
config.set_key_value("gcode_flavor", new ConfigOptionEnum<GCodeFlavor>(gcfMarlinFirmware));
config.set_key_value("emit_machine_limits_to_gcode", new ConfigOptionBool(false));
config.set_key_value("machine_start_gcode", new ConfigOptionString(""));
config.set_key_value("layer_height", new ConfigOptionFloat(0.2));
config.set_key_value("initial_layer_print_height", new ConfigOptionFloat(0.2));
config.set_key_value("initial_layer_line_width", new ConfigOptionFloatOrPercent(0, false));
config.set_key_value("z_hop", new ConfigOptionFloats({0., 0.}));
// The change block carries both a real toolchange command and the ordinal
// placeholder the stock profiles feed to the firmware.
config.set_key_value("change_filament_gcode",
new ConfigOptionString("T[next_filament_id]\nM620 O{toolchange_count + 1}\n"));
// 2 extruders, one filament each (manual map so nothing regroups them).
config.set_key_value("nozzle_diameter", new ConfigOptionFloats({0.4, 0.4}));
config.set_key_value("printer_extruder_id", new ConfigOptionInts({1, 2}));
config.set_key_value("printer_extruder_variant", new ConfigOptionStrings({"Direct Drive Standard", "Direct Drive Standard"}));
config.set_key_value("filament_diameter", new ConfigOptionFloats({1.75, 1.75}));
config.set_key_value("filament_colour", new ConfigOptionStrings({"#FF0000", "#00FF00"}));
config.set_key_value("default_filament_colour", new ConfigOptionStrings({"#FF0000", "#00FF00"}));
config.set_key_value("filament_type", new ConfigOptionStrings({"PLA", "PLA"}));
config.option<ConfigOptionEnum<FilamentMapMode>>("filament_map_mode", true)->value = fmmManual;
config.set_key_value("filament_map", new ConfigOptionInts({1, 2}));
config.set_key_value("nozzle_temperature", new ConfigOptionInts({210, 210}));
config.set_key_value("nozzle_temperature_range_low", new ConfigOptionInts({190, 190}));
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}));
return config;
}
SCENARIO("Change blocks carry consecutive toolchange ordinals without a duplicate command", "[GCodeWriter][H2C]") {
GIVEN("Two sequentially printed objects on different extruders of a BBL machine") {
DynamicPrintConfig config = dual_extruder_toolchange_config();
config.set_key_value("print_sequence", new ConfigOptionEnum<PrintSequence>(PrintSequence::ByObject));
Model model;
auto *obj1 = model.add_object();
obj1->add_volume(cube(20));
obj1->add_instance();
auto *obj2 = model.add_object();
obj2->add_volume(cube(20));
obj2->add_instance();
obj2->config.set_key_value("extruder", new ConfigOptionInt(2));
auto slice_to_gcode = [&]() {
Print print;
print.is_BBL_printer() = true;
arrange_objects(model, InfiniteBed{}, ArrangeParams{scaled(min_object_distance(config))});
for (auto *mo : model.objects) {
mo->ensure_on_bed();
print.auto_assign_extruders(mo);
}
print.apply(model, config);
print.validate();
print.set_status_silent();
print.process();
return Slic3r::Test::gcode(print);
};
WHEN("the change block already changes the tool") {
const std::string gcode = slice_to_gcode();
const std::vector<int> ordinals = collect_line_args(gcode, "M620 O");
THEN("each change block advances the ordinal by exactly one, without inflation") {
REQUIRE(!ordinals.empty());
REQUIRE(ordinals_consecutive(ordinals));
REQUIRE(ordinals.front() <= 3);
}
THEN("the writer's own command is suppressed as a duplicate") {
REQUIRE(count_lines_with_prefix(gcode, "M1020") == 0);
REQUIRE(count_lines_with_prefix(gcode, "T1") >= 1);
}
}
WHEN("the change block does not change the tool itself") {
config.set_key_value("change_filament_gcode",
new ConfigOptionString("M620 O{toolchange_count + 1}\n"));
const std::string gcode = slice_to_gcode();
const std::vector<int> ordinals = collect_line_args(gcode, "M620 O");
THEN("the writer's toolchange survives and carries a nozzle id") {
REQUIRE(count_lines_with_prefix(gcode, "M1020 S1 H") >= 1);
}
THEN("the ordinal sequence stays consecutive") {
REQUIRE(!ordinals.empty());
REQUIRE(ordinals_consecutive(ordinals));
REQUIRE(ordinals.front() <= 3);
}
}
}
}
SCENARIO("Prime-tower visits without a filament change do not advance the toolchange ordinal", "[GCodeWriter][H2C]") {
GIVEN("A print whose only filament change happens far above the bed") {
DynamicPrintConfig config = dual_extruder_toolchange_config();
config.set_key_value("enable_prime_tower", new ConfigOptionBool(true));
// Filament 2 is used only above z=6, so every tower layer below it is a
// change-less visit — the exact geometry that used to inflate the ordinal.
Model model;
auto *obj = model.add_object();
obj->add_volume(cube(10));
obj->add_instance();
DynamicPrintConfig range_config;
range_config.set_key_value("extruder", new ConfigOptionInt(2));
// Every layer range must carry a layer_height (see layer_height_profile_from_ranges).
range_config.set_key_value("layer_height", new ConfigOptionFloat(0.2));
obj->layer_config_ranges[{6.0, 10.0}].assign_config(std::move(range_config));
Print print;
print.is_BBL_printer() = true;
arrange_objects(model, InfiniteBed{}, ArrangeParams{scaled(min_object_distance(config))});
for (auto *mo : model.objects) {
mo->ensure_on_bed();
print.auto_assign_extruders(mo);
}
print.apply(model, config);
print.validate();
print.set_status_silent();
print.process();
const std::string gcode = Slic3r::Test::gcode(print);
WHEN("the print is exported") {
const std::vector<int> ordinals = collect_line_args(gcode, "M620 O");
THEN("the prime-tower toolchange path was exercised") {
REQUIRE_THAT(gcode, Catch::Matchers::ContainsSubstring("CP TOOLCHANGE START"));
}
THEN("dozens of change-less tower layers consume no ordinal") {
REQUIRE(!ordinals.empty());
REQUIRE(ordinals_consecutive(ordinals));
REQUIRE(ordinals.front() <= 3);
}
THEN("no duplicate toolchange command follows the change block") {
REQUIRE(count_lines_with_prefix(gcode, "M1020") == 0);
}
}
}
}