microwave_inductor.cpp

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2017-2020 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include <base_units.h>
#include <board_commit.h>
#include <board_design_settings.h>
#include <pad.h>
#include <fp_shape.h>
#include <footprint.h>
#include <confirm.h>
#include <dialogs/dialog_text_entry.h>
#include <geometry/geometry_utils.h>
#include <math/util.h> // for KiROUND
#include <microwave/microwave_tool.h>
#include <tool/tool_manager.h>
#include <tools/pcb_actions.h>
#include <pcb_edit_frame.h>
#include <validators.h>

static void gen_arc( std::vector <wxPoint>& aBuffer,
 const wxPoint& aStartPoint,
 const wxPoint& aCenter,
 int a_ArcAngle )
{
 auto first_point = aStartPoint - aCenter;
 auto radius = KiROUND( EuclideanNorm( first_point ) );
 int seg_count = GetArcToSegmentCount( radius, ARC_HIGH_DEF, a_ArcAngle / 10.0 );

 double increment_angle = (double) a_ArcAngle * M_PI / 1800 / seg_count;

 // Creates nb_seg point to approximate arc by segments:
 for( int ii = 1; ii <= seg_count; ii++ )
 {
 double rot_angle = increment_angle * ii;
 double fcos = cos( rot_angle );
 double fsin = sin( rot_angle );
 wxPoint currpt;

 // Rotate current point:
 currpt.x = KiROUND( ( first_point.x * fcos + first_point.y * fsin ) );
 currpt.y = KiROUND( ( first_point.y * fcos - first_point.x * fsin ) );

 auto corner = aCenter + currpt;
 aBuffer.push_back( corner );
 }
}


enum class INDUCTOR_S_SHAPE_RESULT
{
 OK, 
 TOO_LONG, 
 TOO_SHORT, 
 NO_REPR, 
};


static INDUCTOR_S_SHAPE_RESULT BuildCornersList_S_Shape( std::vector<wxPoint>& aBuffer,
 const wxPoint& aStartPoint, const wxPoint& aEndPoint, int aLength, int aWidth )
{
/* We must determine:
 * segm_count = number of segments perpendicular to the direction
 * segm_len = length of a strand
 * radius = radius of rounded parts of the coil
 * stubs_len = length of the 2 stubs( segments parallel to the direction)
 * connecting the start point to the start point of the S shape
 * and the ending point to the end point of the S shape
 * The equations are (assuming the area size of the entire shape is Size:
 * Size.x = 2 * radius + segm_len
 * Size.y = (segm_count + 2 ) * 2 * radius + 2 * stubs_len
 * aInductorPattern.m_length = 2 * delta // connections to the coil
 * + (segm_count-2) * segm_len // length of the strands except 1st and last
 * + (segm_count) * (PI * radius) // length of rounded
 * segm_len + / 2 - radius * 2) // length of 1st and last bit
 *
 * The constraints are:
 * segm_count >= 2
 * radius < m_Size.x
 * Size.y = (radius * 4) + (2 * stubs_len)
 * segm_len > radius * 2
 *
 * The calculation is conducted in the following way:
 * first:
 * segm_count = 2
 * radius = 4 * Size.x (arbitrarily fixed value)
 * Then:
 * Increasing the number of segments to the desired length
 * (radius decreases if necessary)
 */
 wxPoint size;

 // This scale factor adjusts the arc length to handle
 // the arc to segment approximation.
 // because we use SEGM_COUNT_PER_360DEG segment to approximate a circle,
 // the trace len must be corrected when calculated using arcs
 // this factor adjust calculations and must be changed if SEGM_COUNT_PER_360DEG is modified
 // because trace using segment is shorter the corresponding arc
 // ADJUST_SIZE is the ratio between tline len and the arc len for an arc
 // of 360/ADJUST_SIZE angle
 #define ADJUST_SIZE 0.988

 auto pt = aEndPoint - aStartPoint;
 double angle = -ArcTangente( pt.y, pt.x );
 int min_len = KiROUND( EuclideanNorm( pt ) );
 int segm_len = 0; // length of segments
 int full_len; // full len of shape (sum of length of all segments + arcs)


 /* Note: calculations are made for a vertical coil (more easy calculations)
 * and after points are rotated to their actual position
 * So the main direction is the Y axis.
 * the 2 stubs are on the Y axis
 * the others segments are parallel to the X axis.
 */

 // Calculate the size of area (for a vertical shape)
 size.x = min_len / 2;
 size.y = min_len;

 // Choose a reasonable starting value for the radius of the arcs.
 int radius = std::min( aWidth * 5, size.x / 4 );

 int segm_count; // number of full len segments
 // the half size segments (first and last segment) are not counted here
 int stubs_len = 0; // length of first or last segment (half size of others segments)

 for( segm_count = 0; ; segm_count++ )
 {
 stubs_len = ( size.y - ( radius * 2 * (segm_count + 2 ) ) ) / 2;

 if( stubs_len < size.y / 10 ) // Reduce radius.
 {
 stubs_len = size.y / 10;
 radius = ( size.y - (2 * stubs_len) ) / ( 2 * (segm_count + 2) );

 if( radius < aWidth ) // Radius too small.
 {
 // Unable to create line: Requested length value is too large for room
 return INDUCTOR_S_SHAPE_RESULT::TOO_LONG;
 }
 }

 segm_len = size.x - ( radius * 2 );
 full_len = 2 * stubs_len; // Length of coil connections.
 full_len += segm_len * segm_count; // Length of full length segments.
 full_len += KiROUND( ( segm_count + 2 ) * M_PI * ADJUST_SIZE * radius ); // Ard arcs len
 full_len += segm_len - (2 * radius); // Length of first and last segments
 // (half size segments len = segm_len/2 - radius).

 if( full_len >= aLength )
 break;
 }

 // Adjust len by adjusting segm_len:
 int delta_size = full_len - aLength;

 // reduce len of the segm_count segments + 2 half size segments (= 1 full size segment)
 segm_len -= delta_size / (segm_count + 1);

 // at this point, it could still be that the requested length is too
 // short (because 4 quarter-circles are too long)
 // to fix this is a relatively complex numerical problem which probably
 // needs a refactor in this area. For now, just reject these cases:
 {
 const int min_total_length = 2 * stubs_len + 2 * M_PI * ADJUST_SIZE * radius;
 if( min_total_length > aLength )
 {
 // we can't express this inductor with 90-deg arcs of this radius
 return INDUCTOR_S_SHAPE_RESULT::TOO_SHORT;
 }
 }

 if( segm_len - 2 * radius < 0 )
 {
 // we can't represent this exact requested length with this number
 // of segments (using the current algorithm). This stems from when
 // you add a segment, you also add another half-circle, so there's a
 // little bit of "dead" space.
 // It's a bit ugly to just reject the input, as it might be possible
 // to tweak the radius, but, again, that probably needs a refactor.
 return INDUCTOR_S_SHAPE_RESULT::NO_REPR;
 }

 // Generate first line (the first stub) and first arc (90 deg arc)
 pt = aStartPoint;
 aBuffer.push_back( pt );
 pt.y += stubs_len;
 aBuffer.push_back( pt );

 auto centre = pt;
 centre.x -= radius;
 gen_arc( aBuffer, pt, centre, -900 );
 pt = aBuffer.back();

 int half_size_seg_len = segm_len / 2 - radius;

 if( half_size_seg_len )
 {
 pt.x -= half_size_seg_len;
 aBuffer.push_back( pt );
 }

 // Create shape.
 int ii;
 int sign = 1;
 segm_count += 1; // increase segm_count to create the last half_size segment

 for( ii = 0; ii < segm_count; ii++ )
 {
 int arc_angle;

 if( ii & 1 ) // odd order arcs are greater than 0
 sign = -1;
 else
 sign = 1;

 arc_angle = 1800 * sign;
 centre = pt;
 centre.y += radius;
 gen_arc( aBuffer, pt, centre, arc_angle );
 pt = aBuffer.back();
 pt.x += segm_len * sign;
 aBuffer.push_back( pt );
 }

 // The last point is false:
 // it is the end of a full size segment, but must be
 // the end of the second half_size segment. Change it.
 sign *= -1;
 aBuffer.back().x = aStartPoint.x + radius * sign;

 // create last arc
 pt = aBuffer.back();
 centre = pt;
 centre.y += radius;
 gen_arc( aBuffer, pt, centre, 900 * sign );

 // Rotate point
 angle += 900;

 for( unsigned jj = 0; jj < aBuffer.size(); jj++ )
 {
 RotatePoint( &aBuffer[jj], aStartPoint, angle );
 }

 // push last point (end point)
 aBuffer.push_back( aEndPoint );

 return INDUCTOR_S_SHAPE_RESULT::OK;
}


void MICROWAVE_TOOL::createInductorBetween( const VECTOR2I& aStart, const VECTOR2I& aEnd )
{
 PCB_EDIT_FRAME& editFrame = *getEditFrame<PCB_EDIT_FRAME>();

 MICROWAVE_INDUCTOR_PATTERN pattern;

 pattern.m_Width = board()->GetDesignSettings().GetCurrentTrackWidth();

 pattern.m_Start = { aStart.x, aStart.y };
 pattern.m_End = { aEnd.x, aEnd.y };

 wxString errorMessage;

 auto inductorFP = std::unique_ptr<FOOTPRINT>( createMicrowaveInductor( pattern, errorMessage ) );

 // on any error, report if we can
 if ( !inductorFP || !errorMessage.IsEmpty() )
 {
 if ( !errorMessage.IsEmpty() )
 editFrame.ShowInfoBarError( errorMessage );
 }
 else
 {
 // at this point, we can save the footprint
 m_toolMgr->RunAction( PCB_ACTIONS::selectItem, true, inductorFP.get() );

 BOARD_COMMIT commit( this );
 commit.Add( inductorFP.release() );
 commit.Push( _("Add microwave inductor" ) );
 }
}


FOOTPRINT* MICROWAVE_TOOL::createMicrowaveInductor( MICROWAVE_INDUCTOR_PATTERN& aInductorPattern,
 wxString& aErrorMessage )
{
 /* Build a microwave inductor footprint.
 * - Length Mself.lng
 * - Extremities Mself.m_Start and Mself.m_End
 * We must determine:
 * Mself.nbrin = number of segments perpendicular to the direction
 * (The coil nbrin will demicercles + 1 + 2 1 / 4 circle)
 * Mself.lbrin = length of a strand
 * Mself.radius = radius of rounded parts of the coil
 * Mself.delta = segments extremities connection between him and the coil even
 *
 * The equations are
 * Mself.m_Size.x = 2 * Mself.radius + Mself.lbrin
 * Mself.m_Size.y * Mself.delta = 2 + 2 * Mself.nbrin * Mself.radius
 * Mself.lng = 2 * Mself.delta / / connections to the coil
 + (Mself.nbrin-2) * Mself.lbrin / / length of the strands except 1st and last
 + (Mself.nbrin 1) * (PI * Mself.radius) / / length of rounded
 * Mself.lbrin + / 2 - Melf.radius * 2) / / length of 1st and last bit
 *
 * The constraints are:
 * Nbrin >= 2
 * Mself.radius < Mself.m_Size.x
 * Mself.m_Size.y = Mself.radius * 4 + 2 * Mself.raccord
 * Mself.lbrin> Mself.radius * 2
 *
 * The calculation is conducted in the following way:
 * Initially:
 * Nbrin = 2
 * Radius = 4 * m_Size.x (arbitrarily fixed value)
 * Then:
 * Increasing the number of segments to the desired length
 * (Radius decreases if necessary)
 */

 PAD* pad;
 wxString msg;

 PCB_EDIT_FRAME& editFrame = *getEditFrame<PCB_EDIT_FRAME>();

 auto pt = aInductorPattern.m_End - aInductorPattern.m_Start;
 int min_len = KiROUND( EuclideanNorm( pt ) );
 aInductorPattern.m_Length = min_len;

 // Enter the desired length.
 msg = StringFromValue( editFrame.GetUserUnits(), aInductorPattern.m_Length );
 WX_TEXT_ENTRY_DIALOG dlg( &editFrame, _( "Length of Trace:" ), wxEmptyString, msg );

 if( dlg.ShowQuasiModal() != wxID_OK )
 return nullptr; // canceled by user

 msg = dlg.GetValue();
 aInductorPattern.m_Length = ValueFromString( editFrame.GetUserUnits(), msg );

 // Control values (ii = minimum length)
 if( aInductorPattern.m_Length < min_len )
 {
 aErrorMessage = _( "Requested length < minimum length" );
 return nullptr;
 }

 // Calculate the elements.
 std::vector <wxPoint> buffer;
 const INDUCTOR_S_SHAPE_RESULT res = BuildCornersList_S_Shape( buffer, aInductorPattern.m_Start,
 aInductorPattern.m_End,
 aInductorPattern.m_Length,
 aInductorPattern.m_Width );

 switch( res )
 {
 case INDUCTOR_S_SHAPE_RESULT::TOO_LONG:
 aErrorMessage = _( "Requested length too large" );
 return nullptr;
 case INDUCTOR_S_SHAPE_RESULT::TOO_SHORT:
 aErrorMessage = _( "Requested length too small" );
 return nullptr;
 case INDUCTOR_S_SHAPE_RESULT::NO_REPR:
 aErrorMessage = _( "Requested length can't be represented" );
 return nullptr;
 case INDUCTOR_S_SHAPE_RESULT::OK:
 break;
 }

 // Generate footprint. the value is also used as footprint name.
 msg = wxT( "L" );
 WX_TEXT_ENTRY_DIALOG cmpdlg( &editFrame, _( "Component Value:" ), wxEmptyString, msg );
 cmpdlg.SetTextValidator( FOOTPRINT_NAME_VALIDATOR( &msg ) );

 if( ( cmpdlg.ShowQuasiModal() != wxID_OK ) || msg.IsEmpty() )
 return nullptr; // Aborted by user

 FOOTPRINT* footprint = editFrame.CreateNewFootprint( msg, true );

 footprint->SetFPID( LIB_ID( wxEmptyString, wxT( "mw_inductor" ) ) );
 footprint->SetAttributes( FP_EXCLUDE_FROM_POS_FILES | FP_EXCLUDE_FROM_BOM );
 footprint->ClearFlags();
 footprint->SetPosition( aInductorPattern.m_End );

 // Generate segments
 for( unsigned jj = 1; jj < buffer.size(); jj++ )
 {
 FP_SHAPE* seg = new FP_SHAPE( footprint, SHAPE_T::SEGMENT );
 seg->SetStart( buffer[jj - 1] );
 seg->SetEnd( buffer[jj] );
 seg->SetWidth( aInductorPattern.m_Width );
 seg->SetLayer( footprint->GetLayer() );
 seg->SetStart0( seg->GetStart() - footprint->GetPosition() );
 seg->SetEnd0( seg->GetEnd() - footprint->GetPosition() );
 footprint->Add( seg );
 }

 // Place a pad on each end of coil.
 pad = new PAD( footprint );

 footprint->Add( pad );

 pad->SetNumber( wxT( "1" ) );
 pad->SetPosition( aInductorPattern.m_End );
 pad->SetPos0( pad->GetPosition() - footprint->GetPosition() );

 pad->SetSize( wxSize( aInductorPattern.m_Width, aInductorPattern.m_Width ) );

 pad->SetLayerSet( LSET( footprint->GetLayer() ) );
 pad->SetAttribute( PAD_ATTRIB::SMD );
 pad->SetShape( PAD_SHAPE::CIRCLE );

 PAD* newpad = new PAD( *pad );
 const_cast<KIID&>( newpad->m_Uuid ) = KIID();

 footprint->Add( newpad );

 pad = newpad;
 pad->SetNumber( wxT( "2" ) );
 pad->SetPosition( aInductorPattern.m_Start );
 pad->SetPos0( pad->GetPosition() - footprint->GetPosition() );

 // Modify text positions.
 wxPoint refPos( ( aInductorPattern.m_Start.x + aInductorPattern.m_End.x ) / 2,
 ( aInductorPattern.m_Start.y + aInductorPattern.m_End.y ) / 2 );

 wxPoint valPos = refPos;

 refPos.y -= footprint->Reference().GetTextSize().y;
 footprint->Reference().SetPosition( refPos );
 valPos.y += footprint->Value().GetTextSize().y;
 footprint->Value().SetPosition( valPos );

 return footprint;
}