kicad/pcbnew/zone_filling_algorithm.cpp

313 lines
12 KiB
C++

/**
* @file zone_filling_algorithm.cpp:
* Algorithms used to fill a zone defined by a polygon and a filling starting point.
*/
/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2016 Jean-Pierre Charras, jp.charras at wanadoo.fr
* Copyright (C) 1992-2016 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 <algorithm> // sort
#include <fctsys.h>
#include <trigo.h>
#include <wxPcbStruct.h>
#include <convert_basic_shapes_to_polygon.h>
#include <class_zone.h>
#include <pcbnew.h>
#include <zones.h>
/* Build the filled solid areas data from real outlines (stored in m_Poly)
* The solid areas can be more than one on copper layers, and do not have holes
( holes are linked by overlapping segments to the main outline)
* aPcb: the current board (can be NULL for non copper zones)
* aCornerBuffer: A reference to a buffer to store polygon corners, or NULL
* if aCornerBuffer == NULL:
* - m_FilledPolysList is used to store solid areas polygons.
* - on copper layers, tracks and other items shapes of other nets are
* removed from solid areas
* if not null:
* Only the zone outline (with holes, if any) are stored in aCornerBuffer
* with holes linked. Therefore only one polygon is created
* This function calls AddClearanceAreasPolygonsToPolysList()
* to add holes for pads and tracks and other items not in net.
*/
bool ZONE_CONTAINER::BuildFilledSolidAreasPolygons( BOARD* aPcb, SHAPE_POLY_SET* aOutlineBuffer )
{
/* convert outlines + holes to outlines without holes (adding extra segments if necessary)
* m_Poly data is expected normalized, i.e. NormalizeAreaOutlines was used after building
* this zone
*/
if( GetNumCorners() <= 2 ) // malformed zone. polygon calculations do not like it ...
return false;
// Make a smoothed polygon out of the user-drawn polygon if required
if( m_smoothedPoly )
{
delete m_smoothedPoly;
m_smoothedPoly = NULL;
}
switch( m_cornerSmoothingType )
{
case ZONE_SETTINGS::SMOOTHING_CHAMFER:
m_smoothedPoly = new SHAPE_POLY_SET();
*m_smoothedPoly = m_Poly->Chamfer( m_cornerRadius );
break;
case ZONE_SETTINGS::SMOOTHING_FILLET:
m_smoothedPoly = new SHAPE_POLY_SET();
*m_smoothedPoly = m_Poly->Fillet( m_cornerRadius, m_ArcToSegmentsCount );
break;
default:
// Acute angles between adjacent edges can create issues in calculations,
// in inflate/deflate outlines transforms, especially when the angle is very small.
// We can avoid issues by creating a very small chamfer which remove acute angles,
// or left it without chamfer and use only CPOLYGONS_LIST::InflateOutline to create
// clearance areas
m_smoothedPoly = new SHAPE_POLY_SET();
*m_smoothedPoly = m_Poly->Chamfer( Millimeter2iu( 0.0 ) );
break;
}
if( aOutlineBuffer )
aOutlineBuffer->Append( *m_smoothedPoly );
/* For copper layers, we now must add holes in the Polygon list.
* holes are pads and tracks with their clearance area
* For non copper layers, just recalculate the m_FilledPolysList
* with m_ZoneMinThickness taken in account
*/
else
{
m_FilledPolysList.RemoveAllContours();
if( IsOnCopperLayer() )
{
AddClearanceAreasPolygonsToPolysList_NG( aPcb );
if( m_FillMode ) // if fill mode uses segments, create them:
{
if( !FillZoneAreasWithSegments() )
return false;
}
}
else
{
m_FillMode = 0; // Fill by segments is no more used in non copper layers
// force use solid polygons (usefull only for old boards)
m_FilledPolysList = *m_smoothedPoly;
// The filled areas are deflated by -m_ZoneMinThickness / 2, because
// the outlines are drawn with a line thickness = m_ZoneMinThickness to
// give a good shape with the minimal thickness
m_FilledPolysList.Inflate( -m_ZoneMinThickness / 2, 16 );
m_FilledPolysList.Fracture( SHAPE_POLY_SET::PM_FAST );
}
m_IsFilled = true;
}
return true;
}
/** Helper function fillPolygonWithHorizontalSegments
* fills a polygon with horizontal segments.
* It can be used for any angle, if the zone outline to fill is rotated by this angle
* and the result is rotated by -angle
* @param aPolygon = a SHAPE_LINE_CHAIN polygon to fill
* @param aFillSegmList = a std::vector <SEGMENT> which will be populated by filling segments
* @param aStep = the horizontal grid size
*/
bool fillPolygonWithHorizontalSegments( const SHAPE_LINE_CHAIN& aPolygon,
std::vector <SEGMENT>& aFillSegmList, int aStep );
bool ZONE_CONTAINER::FillZoneAreasWithSegments()
{
bool success = true;
// segments are on something like a grid. Give it a minimal size
// to avoid too many segments, and use the m_ZoneMinThickness when (this is usually the case)
// the size is > mingrid_size.
// This is not perfect, but the actual purpose of this code
// is to allow filling zones on a grid, with grid size > m_ZoneMinThickness,
// in order to have really a grid.
//
// Using a user selectable grid size is for future Kicad versions.
// For now the area is fully filled.
int mingrid_size = Millimeter2iu( 0.05 );
int grid_size = std::max( mingrid_size, m_ZoneMinThickness );
// Make segments slightly overlapping to ensure a good full filling
grid_size -= grid_size/20;
// All filled areas are in m_FilledPolysList
// m_FillSegmList will contain the horizontal and vertical segments
// the segment width is m_ZoneMinThickness.
m_FillSegmList.clear();
// Creates the horizontal segments
for ( int index = 0; index < m_FilledPolysList.OutlineCount(); index++ )
{
const SHAPE_LINE_CHAIN& outline0 = m_FilledPolysList.COutline( index );
success = fillPolygonWithHorizontalSegments( outline0, m_FillSegmList, grid_size );
if( !success )
break;
// Creates the vertical segments. Because the filling algo creates horizontal segments,
// to reuse the fillPolygonWithHorizontalSegments function, we rotate the polygons to fill
// then fill them, then inverse rotate the result
SHAPE_LINE_CHAIN outline90;
outline90.Append( outline0 );
// Rotate 90 degrees the outline:
for( int ii = 0; ii < outline90.PointCount(); ii++ )
{
VECTOR2I& point = outline90.Point( ii );
std::swap( point.x, point.y );
point.y = -point.y;
}
int first_point = m_FillSegmList.size();
success = fillPolygonWithHorizontalSegments( outline90, m_FillSegmList, grid_size );
if( !success )
break;
// Rotate -90 degrees the segments:
for( unsigned ii = first_point; ii < m_FillSegmList.size(); ii++ )
{
SEGMENT& segm = m_FillSegmList[ii];
std::swap( segm.m_Start.x, segm.m_Start.y );
std::swap( segm.m_End.x, segm.m_End.y );
segm.m_Start.x = - segm.m_Start.x;
segm.m_End.x = - segm.m_End.x;
}
}
if( success )
m_IsFilled = true;
else
m_FillSegmList.clear();
return success;
}
bool fillPolygonWithHorizontalSegments( const SHAPE_LINE_CHAIN& aPolygon,
std::vector <SEGMENT>& aFillSegmList, int aStep )
{
std::vector <int> x_coordinates;
bool success = true;
// Creates the horizontal segments
const SHAPE_LINE_CHAIN& outline = aPolygon;
const BOX2I& rect = outline.BBox();
// Calculate the y limits of the zone
for( int refy = rect.GetY(), endy = rect.GetBottom(); refy < endy; refy += aStep )
{
// find all intersection points of an infinite line with polyline sides
x_coordinates.clear();
for( int v = 0; v < outline.PointCount(); v++ )
{
int seg_startX = outline.CPoint( v ).x;
int seg_startY = outline.CPoint( v ).y;
int seg_endX = outline.CPoint( v + 1 ).x;
int seg_endY = outline.CPoint( v + 1 ).y;
/* Trivial cases: skip if ref above or below the segment to test */
if( ( seg_startY > refy ) && ( seg_endY > refy ) )
continue;
// segment below ref point, or its Y end pos on Y coordinate ref point: skip
if( ( seg_startY <= refy ) && (seg_endY <= refy ) )
continue;
/* at this point refy is between seg_startY and seg_endY
* see if an horizontal line at Y = refy is intersecting this segment
*/
// calculate the x position of the intersection of this segment and the
// infinite line this is more easier if we move the X,Y axis origin to
// the segment start point:
seg_endX -= seg_startX;
seg_endY -= seg_startY;
double newrefy = (double) ( refy - seg_startY );
double intersec_x;
if ( seg_endY == 0 ) // horizontal segment on the same line: skip
continue;
// Now calculate the x intersection coordinate of the horizontal line at
// y = newrefy and the segment from (0,0) to (seg_endX,seg_endY) with the
// horizontal line at the new refy position the line slope is:
// slope = seg_endY/seg_endX; and inv_slope = seg_endX/seg_endY
// and the x pos relative to the new origin is:
// intersec_x = refy/slope = refy * inv_slope
// Note: because horizontal segments are already tested and skipped, slope
// exists (seg_end_y not O)
double inv_slope = (double) seg_endX / seg_endY;
intersec_x = newrefy * inv_slope;
x_coordinates.push_back( (int) intersec_x + seg_startX );
}
// A line scan is finished: build list of segments
// Sort intersection points by increasing x value:
// So 2 consecutive points are the ends of a segment
sort( x_coordinates.begin(), x_coordinates.end() );
// An even number of coordinates is expected, because a segment has 2 ends.
// An if this algorithm always works, it must always find an even count.
if( ( x_coordinates.size() & 1 ) != 0 )
{
success = false;
break;
}
// Create segments having the same Y coordinate
int iimax = x_coordinates.size() - 1;
for( int ii = 0; ii < iimax; ii += 2 )
{
wxPoint seg_start, seg_end;
seg_start.x = x_coordinates[ii];
seg_start.y = refy;
seg_end.x = x_coordinates[ii + 1];
seg_end.y = refy;
SEGMENT segment( seg_start, seg_end );
aFillSegmList.push_back( segment );
}
} // End examine segments in one area
return success;
}