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Fixes problems with Helmert curves
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@RickBrice
RickBrice committed Apr 11, 2024
1 parent 4807e5b commit a1d8aaf
Showing 1 changed file with 49 additions and 24 deletions.
73 changes: 49 additions & 24 deletions src/ifcgeom/mapping/IfcCurveSegment.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -389,10 +389,9 @@ class curve_segment_evaluator {
auto position = spiral->Position()->as<IfcSchema::IfcAxis2Placement2D>();
auto location = position->Location()->as<IfcSchema::IfcCartesianPoint>();

// center point of the parent curve
// this is the inflection point of the spiral
auto pcCenterX = location->Coordinates()[0];
auto pcCenterY = location->Coordinates()[1];
// parent curve placement information
auto pcX = location->Coordinates()[0];
auto pcY = location->Coordinates()[1];

// orientation of the coordinate system at the center point
// normalize the direction ratios
Expand All @@ -408,50 +407,76 @@ class curve_segment_evaluator {
pcDy = dr[1];
}

// start of trimmed curve
double pcStartX = 0.0, pcStartY = 0.0;
double pcStartDx = 1.0, pcStartDy = 0.0;
if (start)
{
// the spiral doesn't start at the inflection point
// compute the point where it starts
pcStartX = boost::math::quadrature::trapezoidal(fnX, 0.0, start / s);
pcStartY = boost::math::quadrature::trapezoidal(fnY, 0.0, start / s);
auto x = boost::math::quadrature::trapezoidal(fnX, 0.0, start / s);
auto y = boost::math::quadrature::trapezoidal(fnY, 0.0, start / s);

// compute the slope of the spiral at the start point
pcStartDx = s ? fnX(start/s) / s : 1.0;
pcStartDy = s ? fnY(start/s) / s : 0.0;
auto dx = s ? fnX(start/s) / s : 1.0;
auto dy = s ? fnY(start/s) / s : 0.0;

pcStartX = x * pcDx - y * pcDy + pcX;
pcStartY = x * pcDy + y * pcDx + pcY;
pcStartDx = dx * pcDx - dy * pcDy;
pcStartDy = dx * pcDy + dy * pcDx;
}

geometry_adjuster_ = std::make_shared<GEOMETRY_ADJUSTER>(mapping_, inst_, next_inst_);
eval_ = [start, s, pcStartX, pcStartY, pcStartDx, pcStartDy, pcCenterX, pcCenterY, pcDx, pcDy, fnX, fnY, geometry_adjuster = geometry_adjuster_](double u) {
eval_ = [start, s, pcX, pcY, pcDx, pcDy, pcStartX, pcStartY, pcStartDx, pcStartDy, fnX, fnY, geometry_adjuster = geometry_adjuster_](double u) {

u += start;

// integration limits, integrate from a to b
auto a = 0.0;
auto b = s ? u / s : 0.0;

// point on parent curve
auto pcX = boost::math::quadrature::trapezoidal(fnX, a, b) + pcCenterX - pcStartX;
auto pcY = boost::math::quadrature::trapezoidal(fnY, a, b) + pcCenterY - pcStartY;

auto angle1 = atan2(pcStartDy, pcStartDx);
auto angle2 = atan2(pcDy, pcDx);
auto angle = angle2 - angle1;
auto csX = pcX * cos(angle) - pcY * sin(angle);
auto csY = pcX * sin(angle) + pcY * cos(angle);

// From https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/HTML/lexical/IfcSpiral.htm, x = Integral(fnX du), y = Integral(fnY du)
// The tangent slope of a curve is the derivate of the curve, so the derivitive of an integral, is just the function
auto x = boost::math::quadrature::trapezoidal(fnX, 0.0, b);
auto y = boost::math::quadrature::trapezoidal(fnY, 0.0, b);
auto dx = s ? fnX(b) / s : 1.0;
auto dy = s ? fnY(b) / s : 0.0;

auto x1 = x * pcDx - y * pcDy + pcX;
auto y1 = x * pcDy + y * pcDx + pcY;
auto dx1 = dx * pcDx - dy * pcDy;
auto dy1 = dx * pcDy + dy * pcDx;

auto x2 = (x1 - pcStartX) * pcStartDx - (y1 - pcStartY) * (-pcStartDy);
auto y2 = (x1 - pcStartX) * (-pcStartDy) + (y1 - pcStartY) * pcStartDx;
auto dx2 = dx1 * pcStartDx + dy1 * (-pcStartDy);
auto dy2 = dx1 * (-pcStartDy) + dy1 * pcStartDx;

Eigen::Matrix4d m = Eigen::Matrix4d::Identity();
m.col(0) = Eigen::Vector4d(dx, dy, 0, 0);
m.col(1) = Eigen::Vector4d(-dy, dx, 0, 0);
m.col(3) = Eigen::Vector4d(csX, csY, 0.0, 1.0);
m.col(0) = Eigen::Vector4d(dx2, dy2, 0, 0);
m.col(1) = Eigen::Vector4d(-dy2, dx2, 0, 0);
m.col(3) = Eigen::Vector4d(x2, y2, 0.0, 1.0);
return geometry_adjuster->transform_and_adjust(u, m);

//auto pcX = boost::math::quadrature::trapezoidal(fnX, 0.0, b) + pcCenterX - pcStartX;
//auto pcY = boost::math::quadrature::trapezoidal(fnY, 0.0, b) + pcCenterY - pcStartY;

//auto angle1 = atan2(pcStartDy, pcStartDx);
//auto angle2 = atan2(pcDy, pcDx);
//auto angle = angle2 - angle1;
//auto csX = pcX * cos(angle) - pcY * sin(angle);
//auto csY = pcX * sin(angle) + pcY * cos(angle);

//// From https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/HTML/lexical/IfcSpiral.htm, x = Integral(fnX du), y = Integral(fnY du)
//// The tangent slope of a curve is the derivate of the curve, so the derivitive of an integral, is just the function
//auto dx = s ? fnX(b) / s : 1.0;
//auto dy = s ? fnY(b) / s : 0.0;


//Eigen::Matrix4d m = Eigen::Matrix4d::Identity();
//m.col(0) = Eigen::Vector4d(dx, dy, 0, 0);
//m.col(1) = Eigen::Vector4d(-dy, dx, 0, 0);
//m.col(3) = Eigen::Vector4d(csX, csY, 0.0, 1.0);
//return geometry_adjuster->transform_and_adjust(u, m);
};
} else if (segment_type_ == ST_VERTICAL) {

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