roundrect.cpp

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2017 CERN
 * Copyright The KiCad Developers, see AUTHORS.txt for contributors.
 * @author Tomasz Wlostowski <[email protected]>
 *
 * 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 "geometry/roundrect.h"
 
#include <geometry/shape_poly_set.h>
#include <geometry/shape_utils.h>
 
#include <wx/log.h>
 
 
namespace
{
 
SHAPE_ARC MakeCornerArcCw90( const SHAPE_RECT& aRect, int aRadius, DIRECTION_45::Directions aDir )
{
    const VECTOR2I center = KIGEOM::GetPoint( aRect, aDir );
    return KIGEOM::MakeArcCw90( center, aRadius, aDir );
}
 
 
SHAPE_ARC MakeSideArcCw180( const SHAPE_RECT& aRect, int aRadius, DIRECTION_45::Directions aDir )
{
    const VECTOR2I center = KIGEOM::GetPoint( aRect, aDir );
    return KIGEOM::MakeArcCw180( center, aRadius, aDir );
}
 
} // namespace
 
 
ROUNDRECT::ROUNDRECT( SHAPE_RECT aRect, int aRadius, bool aNormalizeOnCreate ) :
        m_rect( std::move( aRect ) ),
        m_radius( aRadius )
{
    if( aNormalizeOnCreate )
        m_rect.Normalize();
 
    // Ensure radius is compatible with rectangle size:
    int min_radius = std::abs( m_rect.MinorDimension() )/2;
 
    if( m_radius > min_radius )
        m_radius = min_radius;
 
    if( m_radius < 0 )
        m_radius = 0;
}
 
 
ROUNDRECT ROUNDRECT::OutsetFrom( const SHAPE_RECT& aRect, int aOutset )
{
    return ROUNDRECT( aRect.GetInflated( aOutset ), aOutset );
}
 
 
ROUNDRECT ROUNDRECT::GetInflated( int aOutset ) const
{
    return ROUNDRECT( m_rect.GetInflated( aOutset ), m_radius + aOutset );
}
 
 
void ROUNDRECT::TransformToPolygon( SHAPE_POLY_SET& aBuffer, int aMaxError ) const
{
    // Roundrects won't have a gazillion points, so we use a higher definition than the
    // typical maxError.
    int               maxError = aMaxError / 5;
 
    SHAPE_POLY_SET    tmp;
    const int         idx = tmp.NewOutline();
    SHAPE_LINE_CHAIN& outline = tmp.Outline( idx );
 
    const int w = m_rect.GetWidth();
    const int h = m_rect.GetHeight();
 
    // Handle non normalized rect (i.e. w or h < 0 )
    if( w < 0 || h < 0 )
    {
        ROUNDRECT norm_rr( m_rect, m_radius, true );    // build a normalized ROUNDRECT (w,h >= 0)
        norm_rr.TransformToPolygon( aBuffer, aMaxError );
        return;
    }
 
    // This code works fine only with normalized rect (i.e. w or h >= 0 )
    const int x_edge = m_rect.GetWidth() - 2 * m_radius;
    const int y_edge = m_rect.GetHeight() - 2 * m_radius;
 
    // Handle degenerate cases where dimensions are invalid
    // This can happen with negative inflate values or zero-size rectangles
    if( x_edge < 0 || y_edge < 0 || m_radius < 0 || w <= 0 || h <= 0 )
    {
        wxLogDebug( "ROUNDRECT::TransformToPolygon: Degenerate roundrect, skipping polygon generation." );
        return;
    }
 
    const VECTOR2I& m_p0 = m_rect.GetPosition();
 
    if( m_radius == 0 )
    {
        // It's just a rectangle
        outline.Append( m_p0 );
        outline.Append( m_p0 + VECTOR2I( w, 0 ) );
        outline.Append( m_p0 + VECTOR2I( w, h ) );
        outline.Append( m_p0 + VECTOR2I( 0, h ) );
    }
    else if( x_edge == 0 && y_edge == 0 )
    {
        // It's a circle
        outline.Append( SHAPE_ARC( m_p0 + VECTOR2I( m_radius, m_radius ),
                                   m_p0 + VECTOR2I( -m_radius, 0 ), ANGLE_360 ), maxError );
    }
    else
    {
        const SHAPE_RECT inner_rect{ m_p0 + VECTOR2I( m_radius, m_radius ), x_edge, y_edge };
 
        if( x_edge > 0 )
        {
            // Either a normal roundrect or an oval with x_edge > 0
 
            // Start to the right of the top left radius
            outline.Append( m_p0 + VECTOR2I( m_radius, 0 ) );
 
            // Top side
            outline.Append( m_p0 + VECTOR2I( m_radius + x_edge, 0 ) );
 
            if( y_edge > 0 )
            {
                outline.Append( MakeCornerArcCw90( inner_rect, m_radius, DIRECTION_45::NE ), maxError );
                outline.Append( m_p0 + VECTOR2I( w, m_radius + y_edge ) );
                outline.Append( MakeCornerArcCw90( inner_rect, m_radius, DIRECTION_45::SE ), maxError );
            }
            else
            {
                outline.Append( MakeSideArcCw180( inner_rect, m_radius, DIRECTION_45::E ), maxError );
            }
 
            // Bottom side
            outline.Append( m_p0 + VECTOR2I( m_radius, h ) );
 
            if( y_edge > 0 )
            {
                outline.Append( MakeCornerArcCw90( inner_rect, m_radius, DIRECTION_45::SW ), maxError );
                outline.Append( m_p0 + VECTOR2I( 0, m_radius ) );
                outline.Append( MakeCornerArcCw90( inner_rect, m_radius, DIRECTION_45::NW ), maxError );
            }
            else
            {
                outline.Append( MakeSideArcCw180( inner_rect, m_radius, DIRECTION_45::W ), maxError );
            }
        }
        else
        {
            // x_edge is 0 but y_edge is not, so it's an oval the other way up
            outline.Append( m_p0 + VECTOR2I( 0, m_radius ) );
            outline.Append( MakeSideArcCw180( inner_rect, m_radius, DIRECTION_45::N ), maxError );
            outline.Append( m_p0 + VECTOR2I( w, m_radius + y_edge ) );
            outline.Append( MakeSideArcCw180( inner_rect, m_radius, DIRECTION_45::S ), maxError );
        }
    }
 
    outline.SetClosed( true );
    aBuffer = std::move( tmp );
}