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rdkit/Code/GraphMol/MolDraw2D/MolDraw2DDetails.cpp

47 lines
1.4 KiB
C++

//
// Copyright (C) 2015 Greg Landrum
//
// @@ All Rights Reserved @@
// This file is part of the RDKit.
// The contents are covered by the terms of the BSD license
// which is included in the file license.txt, found at the root
// of the RDKit source tree.
//
#include <GraphMol/MolDraw2D/MolDraw2DDetails.h>
#include <cmath>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
// ****************************************************************************
namespace RDKit {
namespace MolDraw2D_detail {
// implementation from $RDBASE/rdkit/sping/pid.py
void arcPoints(const Point2D &cds1,const Point2D &cds2,
std::vector< Point2D > &res,
float startAng,float extent){
// Note: this implementation is simple and not particularly efficient.
float xScale = (cds2.x-cds1.x)/2.0;
float yScale = (cds2.y-cds1.y)/2.0;
if(xScale<0) xScale *= -1;
if(yScale<0) yScale *= -1;
float x = std::min(cds1.x,cds2.x)+xScale;
float y = std::min(cds1.y,cds2.y)+yScale;
int steps = std::max(static_cast<int>(extent*2),5);
float step = M_PI*extent/(180*steps);
float angle = M_PI*startAng/180;
for(unsigned int i=0;i<=steps;++i){
Point2D point(x+xScale*cos(angle),
y-yScale*sin(angle));
res.push_back(point);
angle += step;
}
}
}
}