PrusaSlicer-NonPlainar/src/libslic3r/GCode/WipeTowerPrusaMM.cpp

/*

TODO LIST
---------

1. cooling moves - DONE
2. account for perimeter and finish_layer extrusions and subtract it from last wipe - DONE
3. priming extrusions (last wipe must clear the color) - DONE
4. Peter's wipe tower - layer's are not exactly square
5. Peter's wipe tower - variable width for higher levels
6. Peter's wipe tower - make sure it is not too sparse (apply max_bridge_distance and make last wipe longer)
7. Peter's wipe tower - enable enhanced first layer adhesion 

*/

#include "WipeTowerPrusaMM.hpp"

#include <assert.h>
#include <math.h>
#include <iostream>
#include <vector>
#include <numeric>

#include "Analyzer.hpp"

#if defined(__linux) || defined(__GNUC__ )
#include <strings.h>
#endif /* __linux */

#ifdef _MSC_VER 
#define strcasecmp _stricmp
#endif


namespace Slic3r
{

namespace PrusaMultiMaterial {

class Writer
{
public:
	Writer(float layer_height, float line_width, GCodeFlavor flavor, const std::vector<WipeTowerPrusaMM::FilamentParameters>& filament_parameters) :
		m_current_pos(std::numeric_limits<float>::max(), std::numeric_limits<float>::max()),
		m_current_z(0.f),
		m_current_feedrate(0.f),
		m_layer_height(layer_height),
		m_extrusion_flow(0.f),
		m_preview_suppressed(false),
		m_elapsed_time(0.f),
        m_default_analyzer_line_width(line_width),
        m_gcode_flavor(flavor),
        m_filpar(filament_parameters)
        {
            // adds tag for analyzer:
            char buf[64];
            sprintf(buf, ";%s%f\n", GCodeAnalyzer::Height_Tag.c_str(), m_layer_height); // don't rely on GCodeAnalyzer knowing the layer height - it knows nothing at priming
            m_gcode += buf;
            sprintf(buf, ";%s%d\n", GCodeAnalyzer::Extrusion_Role_Tag.c_str(), erWipeTower);
            m_gcode += buf;
            change_analyzer_line_width(line_width);
        }

    Writer&              change_analyzer_line_width(float line_width) {
            // adds tag for analyzer:
            char buf[64];
            sprintf(buf, ";%s%f\n", GCodeAnalyzer::Width_Tag.c_str(), line_width);
            m_gcode += buf;
            return *this;
    }

        Writer&          change_analyzer_mm3_per_mm(float len, float e) {
            static const float area = M_PI * 1.75f * 1.75f / 4.f;
            float mm3_per_mm = (len == 0.f ? 0.f : area * e / len);
            // adds tag for analyzer:
            char buf[64];
            sprintf(buf, ";%s%f\n", GCodeAnalyzer::Mm3_Per_Mm_Tag.c_str(), mm3_per_mm);
            m_gcode += buf;
            return *this;
    }

	Writer& 			 set_initial_position(const WipeTower::xy &pos, float width = 0.f, float depth = 0.f, float internal_angle = 0.f) {
        m_wipe_tower_width = width;
        m_wipe_tower_depth = depth;
        m_internal_angle = internal_angle;
		m_start_pos = WipeTower::xy(pos,0.f,m_y_shift).rotate(m_wipe_tower_width, m_wipe_tower_depth, m_internal_angle);
		m_current_pos = pos;
		return *this;
	}

	Writer&				 set_initial_tool(const unsigned int tool) { m_current_tool = tool; return *this; }

	Writer&				 set_z(float z) 
		{ m_current_z = z; return *this; }

	Writer& 			 set_extrusion_flow(float flow)
		{ m_extrusion_flow = flow; return *this; }

	Writer&				 set_y_shift(float shift) {
        m_current_pos.y -= shift-m_y_shift;
        m_y_shift = shift;
        return (*this);
    }

	// Suppress / resume G-code preview in Slic3r. Slic3r will have difficulty to differentiate the various
	// filament loading and cooling moves from normal extrusion moves. Therefore the writer
	// is asked to suppres output of some lines, which look like extrusions.
	Writer& 			 suppress_preview() { change_analyzer_line_width(0.f); m_preview_suppressed = true; return *this; }
	Writer& 			 resume_preview()   { change_analyzer_line_width(m_default_analyzer_line_width); m_preview_suppressed = false; return *this; }

	Writer& 			 feedrate(float f)
	{
		if (f != m_current_feedrate)
			m_gcode += "G1" + set_format_F(f) + "\n";
		return *this;
	}

	const std::string&   gcode() const { return m_gcode; }
	const std::vector<WipeTower::Extrusion>& extrusions() const { return m_extrusions; }
	float                x()     const { return m_current_pos.x; }
	float                y()     const { return m_current_pos.y; }
	const WipeTower::xy& pos()   const { return m_current_pos; }
	const WipeTower::xy	 start_pos_rotated() const { return m_start_pos; }
	const WipeTower::xy  pos_rotated() const { return WipeTower::xy(m_current_pos, 0.f, m_y_shift).rotate(m_wipe_tower_width, m_wipe_tower_depth, m_internal_angle); }
	float 				 elapsed_time() const { return m_elapsed_time; }
    float                get_and_reset_used_filament_length() { float temp = m_used_filament_length; m_used_filament_length = 0.f; return temp; }

	// Extrude with an explicitely provided amount of extrusion.
	Writer& extrude_explicit(float x, float y, float e, float f = 0.f, bool record_length = false, bool limit_volumetric_flow = true)
	{
		if (x == m_current_pos.x && y == m_current_pos.y && e == 0.f && (f == 0.f || f == m_current_feedrate))
			// Neither extrusion nor a travel move.
			return *this;

		float dx = x - m_current_pos.x;
		float dy = y - m_current_pos.y;
		double len = sqrt(dx*dx+dy*dy);
        if (record_length)
            m_used_filament_length += e;

		// Now do the "internal rotation" with respect to the wipe tower center
		WipeTower::xy rotated_current_pos(WipeTower::xy(m_current_pos,0.f,m_y_shift).rotate(m_wipe_tower_width, m_wipe_tower_depth, m_internal_angle)); // this is where we are
		WipeTower::xy rot(WipeTower::xy(x,y+m_y_shift).rotate(m_wipe_tower_width, m_wipe_tower_depth, m_internal_angle));                               // this is where we want to go

		if (! m_preview_suppressed && e > 0.f && len > 0.) {
            change_analyzer_mm3_per_mm(len, e);
			// Width of a squished extrusion, corrected for the roundings of the squished extrusions.
			// This is left zero if it is a travel move.
			float width = float(double(e) * /*Filament_Area*/2.40528 / (len * m_layer_height));
			// Correct for the roundings of a squished extrusion.
			width += m_layer_height * float(1. - M_PI / 4.);
			if (m_extrusions.empty() || m_extrusions.back().pos != rotated_current_pos)
				m_extrusions.emplace_back(WipeTower::Extrusion(rotated_current_pos, 0, m_current_tool));
			m_extrusions.emplace_back(WipeTower::Extrusion(WipeTower::xy(rot.x, rot.y), width, m_current_tool));
		}

		m_gcode += "G1";
		if (std::abs(rot.x - rotated_current_pos.x) > EPSILON)
			m_gcode += set_format_X(rot.x);

		if (std::abs(rot.y - rotated_current_pos.y) > EPSILON)
			m_gcode += set_format_Y(rot.y);


		if (e != 0.f)
			m_gcode += set_format_E(e);

		if (f != 0.f && f != m_current_feedrate) {
            if (limit_volumetric_flow) {
                float e_speed = e / (((len == 0) ? std::abs(e) : len) / f * 60.f);
                f /= std::max(1.f, e_speed / m_filpar[m_current_tool].max_e_speed);
            }
			m_gcode += set_format_F(f);
        }

        m_current_pos.x = x;
        m_current_pos.y = y;

		// Update the elapsed time with a rough estimate.
		m_elapsed_time += ((len == 0) ? std::abs(e) : len) / m_current_feedrate * 60.f;
		m_gcode += "\n";
		return *this;
	}

	Writer& extrude_explicit(const WipeTower::xy &dest, float e, float f = 0.f, bool record_length = false, bool limit_volumetric_flow = true)
		{ return extrude_explicit(dest.x, dest.y, e, f, record_length); }

	// Travel to a new XY position. f=0 means use the current value.
	Writer& travel(float x, float y, float f = 0.f)
		{ return extrude_explicit(x, y, 0.f, f); }

	Writer& travel(const WipeTower::xy &dest, float f = 0.f) 
		{ return extrude_explicit(dest.x, dest.y, 0.f, f); }

	// Extrude a line from current position to x, y with the extrusion amount given by m_extrusion_flow.
	Writer& extrude(float x, float y, float f = 0.f)
	{
		float dx = x - m_current_pos.x;
		float dy = y - m_current_pos.y;
		return extrude_explicit(x, y, sqrt(dx*dx+dy*dy) * m_extrusion_flow, f, true);
	}

	Writer& extrude(const WipeTower::xy &dest, const float f = 0.f) 
		{ return extrude(dest.x, dest.y, f); }
        
    Writer& rectangle(const WipeTower::xy& ld,float width,float height,const float f = 0.f)
    {
        WipeTower::xy corners[4];
        corners[0] = ld;
        corners[1] = WipeTower::xy(ld,width,0.f);
        corners[2] = WipeTower::xy(ld,width,height);
        corners[3] = WipeTower::xy(ld,0.f,height);
        int index_of_closest = 0;
        if (x()-ld.x > ld.x+width-x())    // closer to the right
            index_of_closest = 1;
        if (y()-ld.y > ld.y+height-y())   // closer to the top
            index_of_closest = (index_of_closest==0 ? 3 : 2);

        travel(corners[index_of_closest].x, y());      // travel to the closest corner
        travel(x(),corners[index_of_closest].y);

        int i = index_of_closest;
        do {
            ++i;
            if (i==4) i=0;
            extrude(corners[i], f);
        } while (i != index_of_closest);
        return (*this);
    }

	Writer& load(float e, float f = 0.f)
	{
		if (e == 0.f && (f == 0.f || f == m_current_feedrate))
			return *this;
		m_gcode += "G1";
		if (e != 0.f)
			m_gcode += set_format_E(e);
		if (f != 0.f && f != m_current_feedrate)
			m_gcode += set_format_F(f);
		m_gcode += "\n";
		return *this;
	}
 
	// Derectract while moving in the X direction.
	// If |x| > 0, the feed rate relates to the x distance,
	// otherwise the feed rate relates to the e distance.
	Writer& load_move_x(float x, float e, float f = 0.f)
		{ return extrude_explicit(x, m_current_pos.y, e, f); }

	Writer& retract(float e, float f = 0.f)
		{ return load(-e, f); }

// Loads filament while also moving towards given points in x-axis (x feedrate is limited by cutting the distance short if necessary)
    Writer& load_move_x_advanced(float farthest_x, float loading_dist, float loading_speed, float max_x_speed = 50.f)
    {
        float time = std::abs(loading_dist / loading_speed);
        float x_speed = std::min(max_x_speed, std::abs(farthest_x - x()) / time);
        float feedrate = 60.f * std::hypot(x_speed, loading_speed);

        float end_point = x() + (farthest_x > x() ? 1.f : -1.f) * x_speed * time;
        return extrude_explicit(end_point, y(), loading_dist, feedrate);
    }

	// Elevate the extruder head above the current print_z position.
	Writer& z_hop(float hop, float f = 0.f)
	{ 
		m_gcode += std::string("G1") + set_format_Z(m_current_z + hop);
		if (f != 0 && f != m_current_feedrate)
			m_gcode += set_format_F(f);
		m_gcode += "\n";
		return *this;
	}

	// Lower the extruder head back to the current print_z position.
	Writer& z_hop_reset(float f = 0.f) 
		{ return z_hop(0, f); }

	// Move to x1, +y_increment,
	// extrude quickly amount e to x2 with feed f.
	Writer& ram(float x1, float x2, float dy, float e0, float e, float f)
	{
		extrude_explicit(x1, m_current_pos.y + dy, e0, f, true, false);
		extrude_explicit(x2, m_current_pos.y, e, 0.f, true, false);
		return *this;
	}

	// Let the end of the pulled out filament cool down in the cooling tube
	// by moving up and down and moving the print head left / right
	// at the current Y position to spread the leaking material.
	Writer& cool(float x1, float x2, float e1, float e2, float f)
	{
		extrude_explicit(x1, m_current_pos.y, e1, f);
		extrude_explicit(x2, m_current_pos.y, e2);
		return *this;
	}

	Writer& set_tool(int tool) 
	{
		char buf[64];
		sprintf(buf, "T%d\n", tool);
		m_gcode += buf;
		m_current_tool = tool;
		return *this;
	}

	// Set extruder temperature, don't wait by default.
	Writer& set_extruder_temp(int temperature, bool wait = false)
	{
        char buf[128];
        sprintf(buf, "M%d S%d\n", wait ? 109 : 104, temperature);
        m_gcode += buf;
        return *this;
	};

    // Wait for a period of time (seconds).
	Writer& wait(float time)
	{
        if (time==0)
            return *this;
		char buf[128];
		sprintf(buf, "G4 S%.3f\n", time);
		m_gcode += buf;
		return *this;
	};

	// Set speed factor override percentage.
	Writer& speed_override(int speed) 
	{
		char buf[128];
		sprintf(buf, "M220 S%d\n", speed);
		m_gcode += buf;
		return *this;
	};

	// Let the firmware back up the active speed override value.
	Writer& speed_override_backup() 
	{
		m_gcode += "M220 B\n";
		return *this;
	};

	// Let the firmware restore the active speed override value.
	Writer& speed_override_restore() 
	{
		m_gcode += "M220 R\n";
		return *this;
	};

	// Set digital trimpot motor
	Writer& set_extruder_trimpot(int current) 
	{
		char buf[128];
        if (m_gcode_flavor == gcfRepRap)
            sprintf(buf, "M906 E%d\n", current);
        else
            sprintf(buf, "M907 E%d\n", current);
		m_gcode += buf;
		return *this;
	};

	Writer& flush_planner_queue() 
	{ 
		m_gcode += "G4 S0\n"; 
		return *this;
	}

	// Reset internal extruder counter.
	Writer& reset_extruder()
	{ 
		m_gcode += "G92 E0\n";
		return *this;
	}

	Writer& comment_with_value(const char *comment, int value)
	{
		char strvalue[64];
		sprintf(strvalue, "%d", value);
		m_gcode += std::string(";") + comment + strvalue + "\n";
		return *this;
	};


	Writer& set_fan(unsigned int speed)
	{
		if (speed == m_last_fan_speed)
			return *this;
				
		if (speed == 0)
			m_gcode += "M107\n";
		else
		{
			m_gcode += "M106 S";
			char buf[128];
			sprintf(buf,"%u\n",(unsigned int)(255.0 * speed / 100.0));
			m_gcode += buf;
		}
		m_last_fan_speed = speed;
		return *this;
	}

	Writer& comment_material(WipeTowerPrusaMM::material_type material)
	{
		m_gcode += "; material : ";
		m_gcode += WipeTowerPrusaMM::to_string(material) + "\n";
		return *this;
	};

	Writer& append(const char *text) { m_gcode += text; return *this; }

private:
	WipeTower::xy m_start_pos;
	WipeTower::xy m_current_pos;
	float    	  m_current_z;
	float 	  	  m_current_feedrate;
	unsigned int  m_current_tool;
	float 		  m_layer_height;
	float 	  	  m_extrusion_flow;
	bool		  m_preview_suppressed;
	std::string   m_gcode;
	std::vector<WipeTower::Extrusion> m_extrusions;
	float         m_elapsed_time;
	float   	  m_internal_angle = 0.f;
	float		  m_y_shift = 0.f;
	float 		  m_wipe_tower_width = 0.f;
	float		  m_wipe_tower_depth = 0.f;
	float		  m_last_fan_speed = 0.f;
    int           current_temp = -1;
    const float   m_default_analyzer_line_width;
    float         m_used_filament_length = 0.f;
    GCodeFlavor   m_gcode_flavor;
    const std::vector<WipeTowerPrusaMM::FilamentParameters>& m_filpar;

	std::string   set_format_X(float x)
	{
		char buf[64];
		sprintf(buf, " X%.3f", x);
		m_current_pos.x = x;
		return buf;
	}

	std::string   set_format_Y(float y) {
		char buf[64];
		sprintf(buf, " Y%.3f", y);
		m_current_pos.y = y;
		return buf;
	}

	std::string   set_format_Z(float z) {
		char buf[64];
		sprintf(buf, " Z%.3f", z);
		return buf;
	}

	std::string   set_format_E(float e) {
		char buf[64];
		sprintf(buf, " E%.4f", e);
		return buf;
	}

	std::string   set_format_F(float f) {
		char buf[64];
		sprintf(buf, " F%d", int(floor(f + 0.5f)));
		m_current_feedrate = f;
		return buf;
	}

	Writer& operator=(const Writer &rhs);
}; // class Writer

}; // namespace PrusaMultiMaterial



WipeTowerPrusaMM::material_type WipeTowerPrusaMM::parse_material(const char *name)
{
	if (strcasecmp(name, "PLA") == 0)
		return PLA;
	if (strcasecmp(name, "ABS") == 0)
		return ABS;
	if (strcasecmp(name, "PET") == 0)
		return PET;
	if (strcasecmp(name, "HIPS") == 0)
		return HIPS;
	if (strcasecmp(name, "FLEX") == 0)
		return FLEX;
	if (strcasecmp(name, "SCAFF") == 0)
		return SCAFF;
	if (strcasecmp(name, "EDGE") == 0)
		return EDGE;
	if (strcasecmp(name, "NGEN") == 0)
		return NGEN;
	if (strcasecmp(name, "PVA") == 0)
		return PVA;
	if (strcasecmp(name, "PC") == 0)
		return PC;
	return INVALID;
}

std::string WipeTowerPrusaMM::to_string(material_type material)
{
	switch (material) {
	case PLA:		return "PLA";
	case ABS:		return "ABS";
	case PET:		return "PET";
	case HIPS:		return "HIPS";
	case FLEX:		return "FLEX";
	case SCAFF:		return "SCAFF";
	case EDGE:		return "EDGE";
	case NGEN:		return "NGEN";
	case PVA:		return "PVA";
	case PC:		return "PC";
	case INVALID: 	
	default: 		return "INVALID";
	}
}

// Returns gcode to prime the nozzles at the front edge of the print bed.
WipeTower::ToolChangeResult WipeTowerPrusaMM::prime(
	// print_z of the first layer.
	float 						first_layer_height, 
	// Extruder indices, in the order to be primed. The last extruder will later print the wipe tower brim, print brim and the object.
	const std::vector<unsigned int> &tools,
	// If true, the last priming are will be the same as the other priming areas, and the rest of the wipe will be performed inside the wipe tower.
	// If false, the last priming are will be large enough to wipe the last extruder sufficiently.
	bool 						last_wipe_inside_wipe_tower)
{
	this->set_layer(first_layer_height, first_layer_height, tools.size(), true, false);
	this->m_current_tool 		= tools.front();
    
    // The Prusa i3 MK2 has a working space of [0, -2.2] to [250, 210].
    // Due to the XYZ calibration, this working space may shrink slightly from all directions,
    // therefore the homing position is shifted inside the bed by 0.2 in the firmware to [0.2, -2.0].
//	box_coordinates cleaning_box(xy(0.5f, - 1.5f), m_wipe_tower_width, wipe_area);

	const float prime_section_width = std::min(240.f / tools.size(), 60.f);
	box_coordinates cleaning_box(xy(5.f, 0.01f + m_perimeter_width/2.f), prime_section_width, 100.f);

	PrusaMultiMaterial::Writer writer(m_layer_height, m_perimeter_width, m_gcode_flavor, m_filpar);
	writer.set_extrusion_flow(m_extrusion_flow)
		  .set_z(m_z_pos)
		  .set_initial_tool(m_current_tool)
		  .append(";--------------------\n"
			 	  "; CP PRIMING START\n")
		  .append(";--------------------\n");
	writer.speed_override_backup();
	writer.speed_override(100);

	writer.set_initial_position(xy(0.f, 0.f))	// Always move to the starting position
		.travel(cleaning_box.ld, 7200);
	if (m_set_extruder_trimpot)
		writer.set_extruder_trimpot(750); 			// Increase the extruder driver current to allow fast ramming.

    for (size_t idx_tool = 0; idx_tool < tools.size(); ++ idx_tool) {
        unsigned int tool = tools[idx_tool];
        m_left_to_right = true;
        toolchange_Change(writer, tool, m_filpar[tool].material); // Select the tool, set a speed override for soluble and flex materials.
        toolchange_Load(writer, cleaning_box); // Prime the tool.
        if (idx_tool + 1 == tools.size()) {
            // Last tool should not be unloaded, but it should be wiped enough to become of a pure color.
            toolchange_Wipe(writer, cleaning_box, wipe_volumes[tools[idx_tool-1]][tool]);
        } else {
            // Ram the hot material out of the melt zone, retract the filament into the cooling tubes and let it cool.
            //writer.travel(writer.x(), writer.y() + m_perimeter_width, 7200);
            toolchange_Wipe(writer, cleaning_box , 20.f);
            box_coordinates box = cleaning_box;
            box.translate(0.f, writer.y() - cleaning_box.ld.y + m_perimeter_width);
            toolchange_Unload(writer, box , m_filpar[m_current_tool].material, m_filpar[tools[idx_tool + 1]].first_layer_temperature);
            cleaning_box.translate(prime_section_width, 0.f);
            writer.travel(cleaning_box.ld, 7200);
        }
        ++ m_num_tool_changes;
    }

    m_old_temperature = -1; // If the priming is turned off in config, the temperature changing commands will not actually appear
                            // in the output gcode - we should not remember emitting them (we will output them twice in the worst case)

	// Reset the extruder current to a normal value.
	if (m_set_extruder_trimpot)
		writer.set_extruder_trimpot(550);
	writer.speed_override_restore();
	writer.feedrate(6000)
		  .flush_planner_queue()
		  .reset_extruder()
		  .append("; CP PRIMING END\n"
	 		      ";------------------\n"
				  "\n\n");

	// so that tool_change() will know to extrude the wipe tower brim:
	m_print_brim = true;

    // Ask our writer about how much material was consumed:
    if (m_current_tool < m_used_filament_length.size())
    	m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();

	ToolChangeResult result;
    result.priming      = true;
	result.print_z 	  	= this->m_z_pos;
	result.layer_height = this->m_layer_height;
	result.gcode   	  	= writer.gcode();
	result.elapsed_time = writer.elapsed_time();
	result.extrusions 	= writer.extrusions();
	result.start_pos  	= writer.start_pos_rotated();
	result.end_pos 	  	= writer.pos_rotated();
	return result;
}

WipeTower::ToolChangeResult WipeTowerPrusaMM::tool_change(unsigned int tool, bool last_in_layer)
{
	if ( m_print_brim )
		return toolchange_Brim();

	float wipe_area = 0.f;
	bool last_change_in_layer = false;
	float wipe_volume = 0.f;
	
	// Finds this toolchange info
	if (tool != (unsigned int)(-1))
	{
		for (const auto &b : m_layer_info->tool_changes)
			if ( b.new_tool == tool ) {
				wipe_volume = b.wipe_volume;
				if (tool == m_layer_info->tool_changes.back().new_tool)
					last_change_in_layer = true;
				wipe_area = b.required_depth * m_layer_info->extra_spacing;
				break;
			}
	}
	else {
		// Otherwise we are going to Unload only. And m_layer_info would be invalid.
	}

	box_coordinates cleaning_box(
		xy(m_perimeter_width / 2.f, m_perimeter_width / 2.f),
		m_wipe_tower_width - m_perimeter_width,
		(tool != (unsigned int)(-1) ? /*m_layer_info->depth*/wipe_area+m_depth_traversed-0.5*m_perimeter_width
                                    : m_wipe_tower_depth-m_perimeter_width));

	PrusaMultiMaterial::Writer writer(m_layer_height, m_perimeter_width, m_gcode_flavor, m_filpar);
	writer.set_extrusion_flow(m_extrusion_flow)
		.set_z(m_z_pos)
		.set_initial_tool(m_current_tool)
		.set_y_shift(m_y_shift + (tool!=(unsigned int)(-1) && (m_current_shape == SHAPE_REVERSED && !m_peters_wipe_tower) ? m_layer_info->depth - m_layer_info->toolchanges_depth(): 0.f))
		.append(";--------------------\n"
				"; CP TOOLCHANGE START\n")
		.comment_with_value(" toolchange #", m_num_tool_changes + 1) // the number is zero-based
		.comment_material(m_filpar[m_current_tool].material)
		.append(";--------------------\n");
	writer.speed_override_backup();
	writer.speed_override(100);

	xy initial_position = cleaning_box.ld + WipeTower::xy(0.f,m_depth_traversed);
    writer.set_initial_position(initial_position, m_wipe_tower_width, m_wipe_tower_depth, m_internal_rotation);

    // Increase the extruder driver current to allow fast ramming.
	if (m_set_extruder_trimpot)
		writer.set_extruder_trimpot(750);

    // Ram the hot material out of the melt zone, retract the filament into the cooling tubes and let it cool.
    if (tool != (unsigned int)-1){ 			// This is not the last change.
        toolchange_Unload(writer, cleaning_box, m_filpar[m_current_tool].material,
                          m_is_first_layer ? m_filpar[tool].first_layer_temperature : m_filpar[tool].temperature);
        toolchange_Change(writer, tool, m_filpar[tool].material); // Change the tool, set a speed override for soluble and flex materials.
        toolchange_Load(writer, cleaning_box);
        writer.travel(writer.x(),writer.y()-m_perimeter_width); // cooling and loading were done a bit down the road
        toolchange_Wipe(writer, cleaning_box, wipe_volume);     // Wipe the newly loaded filament until the end of the assigned wipe area.
        ++ m_num_tool_changes;
    } else
        toolchange_Unload(writer, cleaning_box, m_filpar[m_current_tool].material, m_filpar[m_current_tool].temperature);

    m_depth_traversed += wipe_area;

    if (last_change_in_layer) {// draw perimeter line
        writer.set_y_shift(m_y_shift);
        if (m_peters_wipe_tower)
            writer.rectangle(WipeTower::xy(0.f, 0.f),m_layer_info->depth + 3*m_perimeter_width,m_wipe_tower_depth);
        else {
            writer.rectangle(WipeTower::xy(0.f, 0.f),m_wipe_tower_width, m_layer_info->depth + m_perimeter_width);
            if (layer_finished()) { // no finish_layer will be called, we must wipe the nozzle
                writer.travel(writer.x()> m_wipe_tower_width / 2.f ? 0.f : m_wipe_tower_width, writer.y());
            }
        }
    }

	if (m_set_extruder_trimpot)
		writer.set_extruder_trimpot(550);    // Reset the extruder current to a normal value.
	writer.speed_override_restore();
    writer.feedrate(6000)
          .flush_planner_queue()
          .reset_extruder()
          .append("; CP TOOLCHANGE END\n"
                  ";------------------\n"
                  "\n\n");

    // Ask our writer about how much material was consumed:
    if (m_current_tool < m_used_filament_length.size())
        m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();

	ToolChangeResult result;
    result.priming      = false;
	result.print_z 	  	= this->m_z_pos;
	result.layer_height = this->m_layer_height;
	result.gcode   	  	= writer.gcode();
	result.elapsed_time = writer.elapsed_time();
	result.extrusions 	= writer.extrusions();
	result.start_pos  	= writer.start_pos_rotated();
	result.end_pos 	  	= writer.pos_rotated();
	return result;
}

WipeTower::ToolChangeResult WipeTowerPrusaMM::toolchange_Brim(bool sideOnly, float y_offset)
{
	const box_coordinates wipeTower_box(
		WipeTower::xy(0.f, 0.f),
		m_wipe_tower_width,
		m_wipe_tower_depth);

	PrusaMultiMaterial::Writer writer(m_layer_height, m_perimeter_width, m_gcode_flavor, m_filpar);
	writer.set_extrusion_flow(m_extrusion_flow * 1.1f)
		  .set_z(m_z_pos) // Let the writer know the current Z position as a base for Z-hop.
		  .set_initial_tool(m_current_tool)
		  .append(";-------------------------------------\n"
				  "; CP WIPE TOWER FIRST LAYER BRIM START\n");

	xy initial_position = wipeTower_box.lu - xy(m_perimeter_width * 6.f, 0);
	writer.set_initial_position(initial_position, m_wipe_tower_width, m_wipe_tower_depth, m_internal_rotation);

    writer.extrude_explicit(wipeTower_box.ld - xy(m_perimeter_width * 6.f, 0), // Prime the extruder left of the wipe tower.
        1.5f * m_extrusion_flow * (wipeTower_box.lu.y - wipeTower_box.ld.y), 2400);

    // The tool is supposed to be active and primed at the time when the wipe tower brim is extruded.
    // Extrude 4 rounds of a brim around the future wipe tower.
    box_coordinates box(wipeTower_box);
    for (size_t i = 0; i < 4; ++ i) {
        box.expand(m_perimeter_width - m_layer_height*(1.f-M_PI_4)); // the brim shall have 'normal' spacing with no extra void space
        writer.travel (box.ld, 7000)
                .extrude(box.lu, 2100).extrude(box.ru)
                .extrude(box.rd      ).extrude(box.ld);
    }

    writer.travel(wipeTower_box.ld, 7000); // Move to the front left corner.
    writer.travel(wipeTower_box.rd) // Always wipe the nozzle with a long wipe to reduce stringing when moving away from the wipe tower.
          .travel(wipeTower_box.ld);
    writer.append("; CP WIPE TOWER FIRST LAYER BRIM END\n"
                  ";-----------------------------------\n");

    m_print_brim = false;  // Mark the brim as extruded

    // Ask our writer about how much material was consumed:
    if (m_current_tool < m_used_filament_length.size())
    	m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();

	ToolChangeResult result;
    result.priming      = false;
	result.print_z 	  	= this->m_z_pos;
	result.layer_height = this->m_layer_height;
	result.gcode   	  	= writer.gcode();
	result.elapsed_time = writer.elapsed_time();
	result.extrusions 	= writer.extrusions();
	result.start_pos  	= writer.start_pos_rotated();
	result.end_pos 	  	= writer.pos_rotated();
	return result;
}



// Ram the hot material out of the melt zone, retract the filament into the cooling tubes and let it cool.
void WipeTowerPrusaMM::toolchange_Unload(
	PrusaMultiMaterial::Writer &writer,
	const box_coordinates 	&cleaning_box,
	const material_type		 current_material,
	const int 				 new_temperature)
{
	float xl = cleaning_box.ld.x + 1.f * m_perimeter_width;
	float xr = cleaning_box.rd.x - 1.f * m_perimeter_width;
	
	const float line_width = m_perimeter_width * m_filpar[m_current_tool].ramming_line_width_multiplicator;       // desired ramming line thickness
	const float y_step = line_width * m_filpar[m_current_tool].ramming_step_multiplicator * m_extra_spacing; // spacing between lines in mm

    writer.append("; CP TOOLCHANGE UNLOAD\n")
          .change_analyzer_line_width(line_width);

	unsigned i = 0;										// iterates through ramming_speed
	m_left_to_right = true;								// current direction of ramming
	float remaining = xr - xl ;							// keeps track of distance to the next turnaround
	float e_done = 0;									// measures E move done from each segment

	writer.travel(xl, cleaning_box.ld.y + m_depth_traversed + y_step/2.f ); // move to starting position

    // if the ending point of the ram would end up in mid air, align it with the end of the wipe tower:
    if (m_layer_info > m_plan.begin() && m_layer_info < m_plan.end() && (m_layer_info-1!=m_plan.begin() || !m_adhesion )) {

        // this is y of the center of previous sparse infill border
        float sparse_beginning_y = 0.f;
        if (m_current_shape == SHAPE_REVERSED)
            sparse_beginning_y += ((m_layer_info-1)->depth - (m_layer_info-1)->toolchanges_depth())
                                      - ((m_layer_info)->depth-(m_layer_info)->toolchanges_depth()) ;
        else
            sparse_beginning_y += (m_layer_info-1)->toolchanges_depth() + m_perimeter_width;

        //debugging:
        /* float oldx = writer.x();
        float oldy = writer.y();
        writer.travel(xr,sparse_beginning_y);
        writer.extrude(xr+5,writer.y());
        writer.travel(oldx,oldy);*/

        float sum_of_depths = 0.f;
        for (const auto& tch : m_layer_info->tool_changes) {  // let's find this toolchange
            if (tch.old_tool == m_current_tool) {
                sum_of_depths += tch.ramming_depth;
                float ramming_end_y = sum_of_depths;
                ramming_end_y -= (y_step/m_extra_spacing-m_perimeter_width) / 2.f;   // center of final ramming line

                // debugging:
                /*float oldx = writer.x();
                float oldy = writer.y();
                writer.travel(xl,ramming_end_y);
                writer.extrude(xl-15,writer.y());
                writer.travel(oldx,oldy);*/

                if ( (m_current_shape == SHAPE_REVERSED   && ramming_end_y < sparse_beginning_y - 0.5f*m_perimeter_width  ) ||
                     (m_current_shape == SHAPE_NORMAL && ramming_end_y > sparse_beginning_y + 0.5f*m_perimeter_width  )  )
                {
                    writer.extrude(xl + tch.first_wipe_line-1.f*m_perimeter_width,writer.y());
                    remaining -= tch.first_wipe_line-1.f*m_perimeter_width;
                }
                break;
            }
            sum_of_depths += tch.required_depth;
        }
    }

    // now the ramming itself:
    while (i < m_filpar[m_current_tool].ramming_speed.size())
    {
        const float x = volume_to_length(m_filpar[m_current_tool].ramming_speed[i] * 0.25f, line_width, m_layer_height);
        const float e = m_filpar[m_current_tool].ramming_speed[i] * 0.25f / Filament_Area; // transform volume per sec to E move;
        const float dist = std::min(x - e_done, remaining);		  // distance to travel for either the next 0.25s, or to the next turnaround
        const float actual_time = dist/x * 0.25;
        writer.ram(writer.x(), writer.x() + (m_left_to_right ? 1.f : -1.f) * dist, 0, 0, e * (dist / x), std::hypot(dist, e * (dist / x)) / (actual_time / 60.));
        remaining -= dist;

		if (remaining < WT_EPSILON)	{ // we reached a turning point
			writer.travel(writer.x(), writer.y() + y_step, 7200);
			m_left_to_right = !m_left_to_right;
			remaining = xr - xl;
		}
		e_done += dist; // subtract what was actually done
		if (e_done > x - WT_EPSILON) { // current segment finished
			++i;
			e_done = 0;
		}
	}
	WipeTower::xy end_of_ramming(writer.x(),writer.y());
    writer.change_analyzer_line_width(m_perimeter_width);   // so the next lines are not affected by ramming_line_width_multiplier

    // Retraction:
    float old_x = writer.x();
    float turning_point = (!m_left_to_right ? xl : xr );
    float total_retraction_distance = m_cooling_tube_retraction + m_cooling_tube_length/2.f - 15.f; // the 15mm is reserved for the first part after ramming
    writer.suppress_preview()
          .retract(15.f, m_filpar[m_current_tool].unloading_speed_start * 60.f) // feedrate 5000mm/min = 83mm/s
          .retract(0.70f * total_retraction_distance, 1.0f * m_filpar[m_current_tool].unloading_speed * 60.f)
          .retract(0.20f * total_retraction_distance, 0.5f * m_filpar[m_current_tool].unloading_speed * 60.f)
          .retract(0.10f * total_retraction_distance, 0.3f * m_filpar[m_current_tool].unloading_speed * 60.f)
          
          /*.load_move_x_advanced(turning_point, -15.f, 83.f, 50.f) // this is done at fixed speed
          .load_move_x_advanced(old_x,         -0.70f * total_retraction_distance, 1.0f * m_filpar[m_current_tool].unloading_speed)
          .load_move_x_advanced(turning_point, -0.20f * total_retraction_distance, 0.5f * m_filpar[m_current_tool].unloading_speed)
          .load_move_x_advanced(old_x,         -0.10f * total_retraction_distance, 0.3f * m_filpar[m_current_tool].unloading_speed)
          .travel(old_x, writer.y()) // in case previous move was shortened to limit feedrate*/
          .resume_preview();
    if (new_temperature != 0 && (new_temperature != m_old_temperature || m_is_first_layer) ) { 	// Set the extruder temperature, but don't wait.
        // If the required temperature is the same as last time, don't emit the M104 again (if user adjusted the value, it would be reset)
        // However, always change temperatures on the first layer (this is to avoid issues with priming lines turned off).
		writer.set_extruder_temp(new_temperature, false);
        m_old_temperature = new_temperature;
    }

    // Cooling:
    const int& number_of_moves = m_filpar[m_current_tool].cooling_moves;
    if (number_of_moves > 0) {
        const float& initial_speed = m_filpar[m_current_tool].cooling_initial_speed;
        const float& final_speed   = m_filpar[m_current_tool].cooling_final_speed;

        float speed_inc = (final_speed - initial_speed) / (2.f * number_of_moves - 1.f);

        writer.suppress_preview()
              .travel(writer.x(), writer.y() + y_step);
        old_x = writer.x();
        turning_point = xr-old_x > old_x-xl ? xr : xl;
        for (int i=0; i<number_of_moves; ++i) {
            float speed = initial_speed + speed_inc * 2*i;
            writer.load_move_x_advanced(turning_point, m_cooling_tube_length, speed);
            speed += speed_inc;
            writer.load_move_x_advanced(old_x, -m_cooling_tube_length, speed);
        }
    }

    // let's wait is necessary:
    writer.wait(m_filpar[m_current_tool].delay);
    // we should be at the beginning of the cooling tube again - let's move to parking position:
    writer.retract(-m_cooling_tube_length/2.f+m_parking_pos_retraction-m_cooling_tube_retraction, 2000);

	// this is to align ramming and future wiping extrusions, so the future y-steps can be uniform from the start:
    // the perimeter_width will later be subtracted, it is there to not load while moving over just extruded material
	writer.travel(end_of_ramming.x, end_of_ramming.y + (y_step/m_extra_spacing-m_perimeter_width) / 2.f + m_perimeter_width, 2400.f);

	writer.resume_preview()
		  .flush_planner_queue();
}

// Change the tool, set a speed override for soluble and flex materials.
void WipeTowerPrusaMM::toolchange_Change(
	PrusaMultiMaterial::Writer &writer,
	const unsigned int 	new_tool, 
	material_type 		new_material)
{
    // Ask the writer about how much of the old filament we consumed:
    if (m_current_tool < m_used_filament_length.size())
    	m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();

	writer.set_tool(new_tool);
	writer.flush_planner_queue();
	m_current_tool = new_tool;
}

void WipeTowerPrusaMM::toolchange_Load(
	PrusaMultiMaterial::Writer &writer,
	const box_coordinates  &cleaning_box)
{	
	float xl = cleaning_box.ld.x + m_perimeter_width * 0.75f;
	float xr = cleaning_box.rd.x - m_perimeter_width * 0.75f;
	float oldx = writer.x();	// the nozzle is in place to do the first wiping moves, we will remember the position

    // Load the filament while moving left / right, so the excess material will not create a blob at a single position.
    float turning_point = ( oldx-xl < xr-oldx ? xr : xl );
    float edist = m_parking_pos_retraction+m_extra_loading_move;

    writer.append("; CP TOOLCHANGE LOAD\n")
		  .suppress_preview()
		  /*.load_move_x_advanced(turning_point, 0.2f * edist, 0.3f * m_filpar[m_current_tool].loading_speed)  // Acceleration
		  .load_move_x_advanced(oldx,          0.5f * edist,        m_filpar[m_current_tool].loading_speed)  // Fast phase
		  .load_move_x_advanced(turning_point, 0.2f * edist, 0.3f * m_filpar[m_current_tool].loading_speed)  // Slowing down
		  .load_move_x_advanced(oldx,          0.1f * edist, 0.1f * m_filpar[m_current_tool].loading_speed)  // Super slow*/

          .load(0.2f * edist, 60.f * m_filpar[m_current_tool].loading_speed_start)
          .load_move_x_advanced(turning_point, 0.7f * edist,        m_filpar[m_current_tool].loading_speed)  // Fast phase
		  .load_move_x_advanced(oldx,          0.1f * edist, 0.1f * m_filpar[m_current_tool].loading_speed)  // Super slow*/

          .travel(oldx, writer.y()) // in case last move was shortened to limit x feedrate
		  .resume_preview();

	// Reset the extruder current to the normal value.
	if (m_set_extruder_trimpot)
		writer.set_extruder_trimpot(550);
}

// Wipe the newly loaded filament until the end of the assigned wipe area.
void WipeTowerPrusaMM::toolchange_Wipe(
	PrusaMultiMaterial::Writer &writer,
	const box_coordinates  &cleaning_box,
	float wipe_volume)
{
	// Increase flow on first layer, slow down print.
	writer.set_extrusion_flow(m_extrusion_flow * (m_is_first_layer ? 1.18f : 1.f))
		  .append("; CP TOOLCHANGE WIPE\n");
	float wipe_coeff = m_is_first_layer ? 0.5f : 1.f;
	const float& xl = cleaning_box.ld.x;
	const float& xr = cleaning_box.rd.x;

	// Variables x_to_wipe and traversed_x are here to be able to make sure it always wipes at least
    //   the ordered volume, even if it means violating the box. This can later be removed and simply
    // wipe until the end of the assigned area.

	float x_to_wipe = volume_to_length(wipe_volume, m_perimeter_width, m_layer_height);
	float dy = m_extra_spacing*m_perimeter_width;
	float wipe_speed = 1600.f;

    // if there is less than 2.5*m_perimeter_width to the edge, advance straightaway (there is likely a blob anyway)
    if ((m_left_to_right ? xr-writer.x() : writer.x()-xl) < 2.5f*m_perimeter_width) {
        writer.travel((m_left_to_right ? xr-m_perimeter_width : xl+m_perimeter_width),writer.y()+dy);
        m_left_to_right = !m_left_to_right;
    }
    
    // now the wiping itself:
	for (int i = 0; true; ++i)	{
		if (i!=0) {
			if (wipe_speed < 1610.f) wipe_speed = 1800.f;
			else if (wipe_speed < 1810.f) wipe_speed = 2200.f;
			else if (wipe_speed < 2210.f) wipe_speed = 4200.f;
			else wipe_speed = std::min(4800.f, wipe_speed + 50.f);
		}

		float traversed_x = writer.x();
		if (m_left_to_right)
			writer.extrude(xr - (i % 4 == 0 ? 0 : 1.5*m_perimeter_width), writer.y(), wipe_speed * wipe_coeff);
		else
			writer.extrude(xl + (i % 4 == 1 ? 0 : 1.5*m_perimeter_width), writer.y(), wipe_speed * wipe_coeff);

        if (writer.y()+EPSILON > cleaning_box.lu.y-0.5f*m_perimeter_width)
            break;		// in case next line would not fit

		traversed_x -= writer.x();
		x_to_wipe -= fabs(traversed_x);
		if (x_to_wipe < WT_EPSILON) {
			writer.travel(m_left_to_right ? xl + 1.5*m_perimeter_width : xr - 1.5*m_perimeter_width, writer.y(), 7200);
			break;
		}
		// stepping to the next line:
		writer.extrude(writer.x() + (i % 4 == 0 ? -1.f : (i % 4 == 1 ? 1.f : 0.f)) * 1.5*m_perimeter_width, writer.y() + dy);
		m_left_to_right = !m_left_to_right;
	}

    // this is neither priming nor not the last toolchange on this layer - we are going back to the model - wipe the nozzle
    if (m_layer_info != m_plan.end() && m_current_tool != m_layer_info->tool_changes.back().new_tool) {
        m_left_to_right = !m_left_to_right;
        writer.travel(writer.x(), writer.y() - dy)
        .travel(m_left_to_right ? m_wipe_tower_width : 0.f, writer.y());
    }

	writer.set_extrusion_flow(m_extrusion_flow); // Reset the extrusion flow.
}




WipeTower::ToolChangeResult WipeTowerPrusaMM::finish_layer()
{
	// This should only be called if the layer is not finished yet.
	// Otherwise the caller would likely travel to the wipe tower in vain.
	assert(! this->layer_finished());

	PrusaMultiMaterial::Writer writer(m_layer_height, m_perimeter_width, m_gcode_flavor, m_filpar);
	writer.set_extrusion_flow(m_extrusion_flow)
		.set_z(m_z_pos)
		.set_initial_tool(m_current_tool)
		.set_y_shift(m_y_shift - (m_current_shape == SHAPE_REVERSED && !m_peters_wipe_tower ? m_layer_info->toolchanges_depth() : 0.f))
		.append(";--------------------\n"
				"; CP EMPTY GRID START\n")
		.comment_with_value(" layer #", m_num_layer_changes + 1);

	// Slow down on the 1st layer.
	float speed_factor = m_is_first_layer ? 0.5f : 1.f;
	float current_depth = m_layer_info->depth - m_layer_info->toolchanges_depth();
	box_coordinates fill_box(xy(m_perimeter_width, m_depth_traversed + m_perimeter_width),
							 m_wipe_tower_width - 2 * m_perimeter_width, current_depth-m_perimeter_width);


    writer.set_initial_position((m_left_to_right ? fill_box.ru : fill_box.lu), // so there is never a diagonal travel
                                 m_wipe_tower_width, m_wipe_tower_depth, m_internal_rotation);

	box_coordinates box = fill_box;
    for (int i=0;i<2;++i) {
        if (m_layer_info->toolchanges_depth() < WT_EPSILON) { // there were no toolchanges on this layer
            if (i==0) box.expand(m_perimeter_width);
            else box.expand(-m_perimeter_width);
        }
        else i=2;	// only draw the inner perimeter, outer has been already drawn by tool_change(...)
        writer.rectangle(box.ld,box.rd.x-box.ld.x,box.ru.y-box.rd.y,2900*speed_factor);
    }

    // we are in one of the corners, travel to ld along the perimeter:
    if (writer.x() > fill_box.ld.x+EPSILON) writer.travel(fill_box.ld.x,writer.y());
    if (writer.y() > fill_box.ld.y+EPSILON) writer.travel(writer.x(),fill_box.ld.y);

    if (m_is_first_layer && m_adhesion) {
        // Extrude a dense infill at the 1st layer to improve 1st layer adhesion of the wipe tower.
        box.expand(-m_perimeter_width/2.f);
        int nsteps = int(floor((box.lu.y - box.ld.y) / (2*m_perimeter_width)));
        float step   = (box.lu.y - box.ld.y) / nsteps;
        writer.travel(box.ld-xy(m_perimeter_width/2.f,m_perimeter_width/2.f));
        if (nsteps >= 0)
            for (int i = 0; i < nsteps; ++i)	{
                writer.extrude(box.ld.x+m_perimeter_width/2.f, writer.y() + 0.5f * step);
                writer.extrude(box.rd.x - m_perimeter_width / 2.f, writer.y());
                writer.extrude(box.rd.x - m_perimeter_width / 2.f, writer.y() + 0.5f * step);
                writer.extrude(box.ld.x + m_perimeter_width / 2.f, writer.y());
            }
            writer.travel(box.rd.x-m_perimeter_width/2.f,writer.y()); // wipe the nozzle
    }
    else {  // Extrude a sparse infill to support the material to be printed above.
        const float dy = (fill_box.lu.y - fill_box.ld.y - m_perimeter_width);
        const float left = fill_box.lu.x+2*m_perimeter_width;
        const float right = fill_box.ru.x - 2 * m_perimeter_width;
        if (dy > m_perimeter_width)
        {
            // Extrude an inverse U at the left of the region.
            writer.travel(fill_box.ld + xy(m_perimeter_width * 2, 0.f))
                  .extrude(fill_box.lu + xy(m_perimeter_width * 2, 0.f), 2900 * speed_factor);

            const int n = 1+(right-left)/(m_bridging);
            const float dx = (right-left)/n;
            for (int i=1;i<=n;++i) {
                float x=left+dx*i;
                writer.travel(x,writer.y());
                writer.extrude(x,i%2 ? fill_box.rd.y : fill_box.ru.y);
            }
            writer.travel(left,writer.y(),7200); // wipes the nozzle before moving away from the wipe tower
        }
        else
            writer.travel(right,writer.y(),7200); // wipes the nozzle before moving away from the wipe tower
    }
    writer.append("; CP EMPTY GRID END\n"
                  ";------------------\n\n\n\n\n\n\n");

    m_depth_traversed = m_wipe_tower_depth-m_perimeter_width;

    // Ask our writer about how much material was consumed:
    if (m_current_tool < m_used_filament_length.size())
        m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();

	ToolChangeResult result;
    result.priming      = false;
	result.print_z 	  	= this->m_z_pos;
	result.layer_height = this->m_layer_height;
	result.gcode   	  	= writer.gcode();
	result.elapsed_time = writer.elapsed_time();
	result.extrusions 	= writer.extrusions();
	result.start_pos 	= writer.start_pos_rotated();
	result.end_pos 	  	= writer.pos_rotated();
	return result;
}

// Appends a toolchange into m_plan and calculates neccessary depth of the corresponding box
void WipeTowerPrusaMM::plan_toolchange(float z_par, float layer_height_par, unsigned int old_tool, unsigned int new_tool, bool brim, float wipe_volume)
{
	assert(m_plan.empty() || m_plan.back().z <= z_par + WT_EPSILON);	// refuses to add a layer below the last one

	if (m_plan.empty() || m_plan.back().z + WT_EPSILON < z_par) // if we moved to a new layer, we'll add it to m_plan first
		m_plan.push_back(WipeTowerInfo(z_par, layer_height_par));

	if (brim) {	// this toolchange prints brim - we must add it to m_plan, but not to count its depth
		m_plan.back().tool_changes.push_back(WipeTowerInfo::ToolChange(old_tool, new_tool));
		return;
	}

	if (old_tool==new_tool)	// new layer without toolchanges - we are done
		return;

	// this is an actual toolchange - let's calculate depth to reserve on the wipe tower
	float depth = 0.f;			
	float width = m_wipe_tower_width - 3*m_perimeter_width; 
	float length_to_extrude = volume_to_length(0.25f * std::accumulate(m_filpar[old_tool].ramming_speed.begin(), m_filpar[old_tool].ramming_speed.end(), 0.f),
										m_perimeter_width * m_filpar[old_tool].ramming_line_width_multiplicator,
										layer_height_par);
	depth = (int(length_to_extrude / width) + 1) * (m_perimeter_width * m_filpar[old_tool].ramming_line_width_multiplicator * m_filpar[old_tool].ramming_step_multiplicator);
    float ramming_depth = depth;
    length_to_extrude = width*((length_to_extrude / width)-int(length_to_extrude / width)) - width;
    float first_wipe_line = -length_to_extrude;
    length_to_extrude += volume_to_length(wipe_volume, m_perimeter_width, layer_height_par);
    length_to_extrude = std::max(length_to_extrude,0.f);

	depth += (int(length_to_extrude / width) + 1) * m_perimeter_width;
	depth *= m_extra_spacing;

	m_plan.back().tool_changes.push_back(WipeTowerInfo::ToolChange(old_tool, new_tool, depth, ramming_depth, first_wipe_line, wipe_volume));
}



void WipeTowerPrusaMM::plan_tower()
{
	// Calculate m_wipe_tower_depth (maximum depth for all the layers) and propagate depths downwards
	m_wipe_tower_depth = 0.f;
	for (auto& layer : m_plan)
		layer.depth = 0.f;
	
	for (int layer_index = m_plan.size() - 1; layer_index >= 0; --layer_index)
	{
		float this_layer_depth = std::max(m_plan[layer_index].depth, m_plan[layer_index].toolchanges_depth());
		m_plan[layer_index].depth = this_layer_depth;
		
		if (this_layer_depth > m_wipe_tower_depth - m_perimeter_width)
			m_wipe_tower_depth = this_layer_depth + m_perimeter_width;

		for (int i = layer_index - 1; i >= 0 ; i--)
		{
			if (m_plan[i].depth - this_layer_depth < 2*m_perimeter_width )
				m_plan[i].depth = this_layer_depth;
		}
	}
}

void WipeTowerPrusaMM::save_on_last_wipe()
{
    for (m_layer_info=m_plan.begin();m_layer_info<m_plan.end();++m_layer_info) {
        set_layer(m_layer_info->z, m_layer_info->height, 0, m_layer_info->z == m_plan.front().z, m_layer_info->z == m_plan.back().z);
        if (m_layer_info->tool_changes.size()==0)   // we have no way to save anything on an empty layer
            continue;

        for (const auto &toolchange : m_layer_info->tool_changes)
            tool_change(toolchange.new_tool, false);

        float width = m_wipe_tower_width - 3*m_perimeter_width; // width we draw into
        float length_to_save = 2*(m_wipe_tower_width+m_wipe_tower_depth) + (!layer_finished() ? finish_layer().total_extrusion_length_in_plane() : 0.f);
        float length_to_wipe = volume_to_length(m_layer_info->tool_changes.back().wipe_volume,
                              m_perimeter_width,m_layer_info->height)  - m_layer_info->tool_changes.back().first_wipe_line - length_to_save;

        length_to_wipe = std::max(length_to_wipe,0.f);
        float depth_to_wipe = m_perimeter_width * (std::floor(length_to_wipe/width) + ( length_to_wipe > 0.f ? 1.f : 0.f ) ) * m_extra_spacing;

        //depth += (int(length_to_extrude / width) + 1) * m_perimeter_width;
        m_layer_info->tool_changes.back().required_depth = m_layer_info->tool_changes.back().ramming_depth + depth_to_wipe;
    }
}

// Processes vector m_plan and calls respective functions to generate G-code for the wipe tower
// Resulting ToolChangeResults are appended into vector "result"
void WipeTowerPrusaMM::generate(std::vector<std::vector<WipeTower::ToolChangeResult>> &result)
{
	if (m_plan.empty())

        return;

    m_extra_spacing = 1.f;

	plan_tower();
    for (int i=0;i<5;++i) {
        save_on_last_wipe();
        plan_tower();
    }

	if (m_peters_wipe_tower)
			make_wipe_tower_square();

    m_layer_info = m_plan.begin();
    m_current_tool = (unsigned int)(-2); // we don't know which extruder to start with - we'll set it according to the first toolchange
    for (auto& used : m_used_filament_length) // reset used filament stats
        used = 0.f;

    std::vector<WipeTower::ToolChangeResult> layer_result;
	for (auto layer : m_plan)
	{
		set_layer(layer.z,layer.height,0,layer.z == m_plan.front().z,layer.z == m_plan.back().z);
		if (m_peters_wipe_tower)
			m_internal_rotation += 90.f;
		else
            m_internal_rotation += 180.f;

		if (!m_peters_wipe_tower && m_layer_info->depth < m_wipe_tower_depth - m_perimeter_width)
			m_y_shift = (m_wipe_tower_depth-m_layer_info->depth-m_perimeter_width)/2.f;

		for (const auto &toolchange : layer.tool_changes) {
            if (m_current_tool == (unsigned int)(-2))
                m_current_tool = toolchange.old_tool;
			layer_result.emplace_back(tool_change(toolchange.new_tool, false));
        }

		if (! layer_finished()) {
            auto finish_layer_toolchange = finish_layer();
            if ( ! layer.tool_changes.empty() ) { // we will merge it to the last toolchange
                auto& last_toolchange = layer_result.back();
                if (last_toolchange.end_pos != finish_layer_toolchange.start_pos) {
                    char buf[2048];     // Add a travel move from tc1.end_pos to tc2.start_pos.
					sprintf(buf, "G1 X%.3f Y%.3f F7200\n", finish_layer_toolchange.start_pos.x, finish_layer_toolchange.start_pos.y);
					last_toolchange.gcode += buf;
				}
                last_toolchange.gcode += finish_layer_toolchange.gcode;
                last_toolchange.extrusions.insert(last_toolchange.extrusions.end(), finish_layer_toolchange.extrusions.begin(), finish_layer_toolchange.extrusions.end());
                last_toolchange.end_pos = finish_layer_toolchange.end_pos;
            }
            else
                layer_result.emplace_back(std::move(finish_layer_toolchange));
        }

		result.emplace_back(std::move(layer_result));
		m_is_first_layer = false;
	}
}

void WipeTowerPrusaMM::make_wipe_tower_square()
{
	const float width = m_wipe_tower_width - 3 * m_perimeter_width;
	const float depth = m_wipe_tower_depth - m_perimeter_width;
	// area that we actually print into is width*depth
	float side = sqrt(depth * width);

	m_wipe_tower_width = side + 3 * m_perimeter_width;
	m_wipe_tower_depth = side + 2 * m_perimeter_width;
	// For all layers, find how depth changed and update all toolchange depths
	for (auto &lay : m_plan)
	{
		side = sqrt(lay.depth * width);
		float width_ratio = width / side;

		//lay.extra_spacing = width_ratio;
		for (auto &tch : lay.tool_changes)
			tch.required_depth *= width_ratio;
	}

	plan_tower();				// propagates depth downwards again (width has changed)
	for (auto& lay : m_plan)	// depths set, now the spacing
		lay.extra_spacing = lay.depth / lay.toolchanges_depth();
}

}; // namespace Slic3r