std::string
GCode::change_layer(const Layer &layer)
{
this->layer = &layer;
this->layer_index++;
this->first_layer = (layer.id() == 0);
// avoid computing islands and overhangs if they're not needed
if (this->config.avoid_crossing_perimeters) {
ExPolygons islands;
union_(layer.slices, &islands, true);
this->avoid_crossing_perimeters.init_layer_mp(islands);
}
std::string gcode;
if (this->layer_count > 0) {
gcode += this->writer.update_progress(this->layer_index, this->layer_count);
}
coordf_t z = layer.print_z + this->config.z_offset.value; // in unscaled coordinates
if (EXTRUDER_CONFIG(retract_layer_change) && this->writer.will_move_z(z)) {
gcode += this->retract();
}
{
std::ostringstream comment;
comment << "move to next layer (" << this->layer_index << ")";
gcode += this->writer.travel_to_z(z, comment.str());
}
// forget last wiping path as wiping after raising Z is pointless
this->wipe.reset_path();
return gcode;
}
std::string
GCode::retract(bool toolchange)
{
std::string gcode;
if (this->writer.extruder() == NULL)
return gcode;
// wipe (if it's enabled for this extruder and we have a stored wipe path)
if (EXTRUDER_CONFIG(wipe) && this->wipe.has_path()) {
gcode += this->wipe.wipe(*this, toolchange);
}
/* The parent class will decide whether we need to perform an actual retraction
(the extruder might be already retracted fully or partially). We call these
methods even if we performed wipe, since this will ensure the entire retraction
length is honored in case wipe path was too short. */
gcode += toolchange ? this->writer.retract_for_toolchange() : this->writer.retract();
gcode += this->writer.reset_e();
if (this->writer.extruder()->retract_length() > 0 || this->config.use_firmware_retraction)
gcode += this->writer.lift();
return gcode;
}
// convert a model-space scaled point into G-code coordinates
Pointf
GCode::point_to_gcode(const Point &point)
{
Pointf extruder_offset = EXTRUDER_CONFIG(extruder_offset);
return Pointf(
unscale(point.x) + this->origin.x - extruder_offset.x,
unscale(point.y) + this->origin.y - extruder_offset.y
);
}
bool
GCode::needs_retraction(const Polyline &travel, ExtrusionRole role)
{
if (travel.length() < scale_(EXTRUDER_CONFIG(retract_before_travel))) {
// skip retraction if the move is shorter than the configured threshold
return false;
}
if (role == erSupportMaterial) {
const SupportLayer* support_layer = dynamic_cast<const SupportLayer*>(this->layer);
if (support_layer != NULL && support_layer->support_islands.contains(travel)) {
// skip retraction if this is a travel move inside a support material island
return false;
}
}
if (this->config.only_retract_when_crossing_perimeters && this->layer != NULL) {
if (this->config.fill_density.value > 0
&& this->layer->any_internal_region_slice_contains(travel)) {
/* skip retraction if travel is contained in an internal slice *and*
internal infill is enabled (so that stringing is entirely not visible) */
return false;
} else if (this->layer->any_bottom_region_slice_contains(travel)
&& this->layer->upper_layer != NULL
&& this->layer->upper_layer->slices.contains(travel)
&& (this->config.bottom_solid_layers.value >= 2 || this->config.fill_density.value > 0)) {
/* skip retraction if travel is contained in an *infilled* bottom slice
but only if it's also covered by an *infilled* upper layer's slice
so that it's not visible from above (a bottom surface might not have an
upper slice in case of a thin membrane) */
return false;
}
}
// retract if only_retract_when_crossing_perimeters is disabled or doesn't apply
return true;
}
std::string
GCode::extrude(ExtrusionLoop loop, std::string description, double speed)
{
// get a copy; don't modify the orientation of the original loop object otherwise
// next copies (if any) would not detect the correct orientation
// extrude all loops ccw
bool was_clockwise = loop.make_counter_clockwise();
// find the point of the loop that is closest to the current extruder position
// or randomize if requested
Point last_pos = this->last_pos();
if (this->config.spiral_vase) {
loop.split_at(last_pos);
} else if (this->config.seam_position == spNearest || this->config.seam_position == spAligned) {
Polygon polygon = loop.polygon();
// simplify polygon in order to skip false positives in concave/convex detection
// (loop is always ccw as polygon.simplify() only works on ccw polygons)
Polygons simplified = polygon.simplify(scale_(EXTRUDER_CONFIG(nozzle_diameter))/2);
// restore original winding order so that concave and convex detection always happens
// on the right/outer side of the polygon
if (was_clockwise) {
for (Polygons::iterator p = simplified.begin(); p != simplified.end(); ++p)
p->reverse();
}
// concave vertices have priority
Points candidates;
for (Polygons::const_iterator p = simplified.begin(); p != simplified.end(); ++p) {
Points concave = p->concave_points(PI*4/3);
candidates.insert(candidates.end(), concave.begin(), concave.end());
}
// if no concave points were found, look for convex vertices
if (candidates.empty()) {
for (Polygons::const_iterator p = simplified.begin(); p != simplified.end(); ++p) {
Points convex = p->convex_points(PI*2/3);
candidates.insert(candidates.end(), convex.begin(), convex.end());
}
}
// retrieve the last start position for this object
if (this->layer != NULL && this->_seam_position.count(this->layer->object()) > 0) {
last_pos = this->_seam_position[this->layer->object()];
}
Point point;
if (this->config.seam_position == spNearest) {
if (candidates.empty()) candidates = polygon.points;
last_pos.nearest_point(candidates, &point);
// On 32-bit Linux, Clipper will change some point coordinates by 1 unit
// while performing simplify_polygons(), thus split_at_vertex() won't
// find them anymore.
if (!loop.split_at_vertex(point)) loop.split_at(point);
} else if (!candidates.empty()) {
Points non_overhang;
for (Points::const_iterator p = candidates.begin(); p != candidates.end(); ++p) {
if (!loop.has_overhang_point(*p))
non_overhang.push_back(*p);
}
if (!non_overhang.empty())
candidates = non_overhang;
last_pos.nearest_point(candidates, &point);
if (!loop.split_at_vertex(point)) loop.split_at(point); // see note above
} else {
if (this->config.seam_position == spAlwaysHideSeam){
if (loop.role == elrContourInternalPerimeter) {
Polygon polygon = loop.polygon();
Point centroid = polygon.centroid();
point = Point(polygon.bounding_box().max.x, centroid.y);
point.rotate(rand() % 2*PI, centroid);
}
}
}
else{
std::string
GCode::extrude(ExtrusionLoop loop, std::string description, double speed)
{
// get a copy; don't modify the orientation of the original loop object otherwise
// next copies (if any) would not detect the correct orientation
// extrude all loops ccw
bool was_clockwise = loop.make_counter_clockwise();
SeamPosition seam_position = this->config.seam_position;
if (loop.role == elrSkirt) seam_position = spNearest;
// find the point of the loop that is closest to the current extruder position
// or randomize if requested
Point last_pos = this->last_pos();
if (this->config.spiral_vase) {
loop.split_at(last_pos);
} else if (seam_position == spNearest || seam_position == spAligned) {
const Polygon polygon = loop.polygon();
// simplify polygon in order to skip false positives in concave/convex detection
// (loop is always ccw as polygon.simplify() only works on ccw polygons)
Polygons simplified = polygon.simplify(scale_(EXTRUDER_CONFIG(nozzle_diameter))/2);
// restore original winding order so that concave and convex detection always happens
// on the right/outer side of the polygon
if (was_clockwise) {
for (Polygons::iterator p = simplified.begin(); p != simplified.end(); ++p)
p->reverse();
}
// concave vertices have priority
Points candidates;
for (Polygons::const_iterator p = simplified.begin(); p != simplified.end(); ++p) {
Points concave = p->concave_points(PI*4/3);
candidates.insert(candidates.end(), concave.begin(), concave.end());
}
// if no concave points were found, look for convex vertices
if (candidates.empty()) {
for (Polygons::const_iterator p = simplified.begin(); p != simplified.end(); ++p) {
Points convex = p->convex_points(PI*2/3);
candidates.insert(candidates.end(), convex.begin(), convex.end());
}
}
// retrieve the last start position for this object
if (this->layer != NULL && this->_seam_position.count(this->layer->object()) > 0) {
last_pos = this->_seam_position[this->layer->object()];
}
Point point;
if (seam_position == spNearest) {
if (candidates.empty()) candidates = polygon.points;
last_pos.nearest_point(candidates, &point);
// On 32-bit Linux, Clipper will change some point coordinates by 1 unit
// while performing simplify_polygons(), thus split_at_vertex() won't
// find them anymore.
if (!loop.split_at_vertex(point)) loop.split_at(point);
} else if (!candidates.empty()) {
Points non_overhang;
for (Points::const_iterator p = candidates.begin(); p != candidates.end(); ++p) {
if (!loop.has_overhang_point(*p))
non_overhang.push_back(*p);
}
if (!non_overhang.empty())
candidates = non_overhang;
last_pos.nearest_point(candidates, &point);
if (!loop.split_at_vertex(point)) loop.split_at(point); // see note above
} else {
point = last_pos.projection_onto(polygon);
loop.split_at(point);
}
if (this->layer != NULL)
this->_seam_position[this->layer->object()] = point;
} else if (seam_position == spRandom) {
if (loop.role == elrContourInternalPerimeter) {
Polygon polygon = loop.polygon();
Point centroid = polygon.centroid();
last_pos = Point(polygon.bounding_box().max.x, centroid.y);
last_pos.rotate(fmod((float)rand()/16.0, 2.0*PI), centroid);
}
loop.split_at(last_pos);
}
// 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 = this->enable_loop_clipping
? scale_(EXTRUDER_CONFIG(nozzle_diameter)) * LOOP_CLIPPING_LENGTH_OVER_NOZZLE_DIAMETER
: 0;
// get paths
ExtrusionPaths paths;
loop.clip_end(clip_length, &paths);
if (paths.empty()) return "";
// apply the small perimeter speed
if (paths.front().is_perimeter() && loop.length() <= SMALL_PERIMETER_LENGTH) {
if (speed == -1) speed = this->config.get_abs_value("small_perimeter_speed");
}
// extrude along the path
std::string gcode;
for (ExtrusionPaths::const_iterator path = paths.begin(); path != paths.end(); ++path)
gcode += this->_extrude(*path, description, speed);
// reset acceleration
gcode += this->writer.set_acceleration(this->config.default_acceleration.value);
if (this->wipe.enable)
this->wipe.path = paths.front().polyline; // TODO: don't limit wipe to last path
// make a little move inwards before leaving loop
if (paths.back().role == erExternalPerimeter && this->layer != NULL && this->config.perimeters > 1) {
// detect angle between last and first segment
// the side depends on the original winding order of the polygon (left for contours, right for holes)
Point a = paths.front().polyline.points[1]; // second point
Point b = *(paths.back().polyline.points.end()-3); // second to last point
if (was_clockwise) {
// swap points
Point c = a; a = b; b = c;
}
double angle = paths.front().first_point().ccw_angle(a, b) / 3;
// turn left if contour, turn right if hole
if (was_clockwise) angle *= -1;
// create the destination point along the first segment and rotate it
// we make sure we don't exceed the segment length because we don't know
// the rotation of the second segment so we might cross the object boundary
Line first_segment(
paths.front().polyline.points[0],
paths.front().polyline.points[1]
);
double distance = std::min(
scale_(EXTRUDER_CONFIG(nozzle_diameter)),
first_segment.length()
);
Point point = first_segment.point_at(distance);
point.rotate(angle, first_segment.a);
// generate the travel move
gcode += this->writer.travel_to_xy(this->point_to_gcode(point), "move inwards before travel");
}
return gcode;
}
