api-cpp.md

C++ API

#include "SVGCurveLib.h"

SVGCurveLib::/*some method here*/

PointOnLine

SVGCurveLib::PointGeneric<> SVGCurveLib::PointOnLine(SVGCurveLib::PointGeneric<> p0, SVGCurveLib::PointGeneric<> p1, float t)

• Returns: SVGCurveLib::PointGeneric<>
• Parameters:
  • p0: SVGCurveLib::PointGeneric<> - starting point
  • p1: SVGCurveLib::PointGeneric<> - end point
  • t: float [0-1]

PointOnQuadraticBezierCurve

SVGCurveLib::PointGeneric<> SVGCurveLib::PointOnQuadraticBezierCurve(SVGCurveLib::PointGeneric<> p0, SVGCurveLib::PointGeneric<> p1, SVGCurveLib::PointGeneric<> p2, float t)

• Returns: SVGCurveLib::Point
• Parameters:
  • p0: SVGCurveLib::PointGeneric<> - starting point
  • p1: SVGCurveLib::PointGeneric<> - control point
  • p2: SVGCurveLib::PointGeneric<> - end point
  • t: float [0-1]

PointOnCubicBezierCurve

SVGCurveLib::PointGeneric<> SVGCurveLib::PointOnCubicBezierCurve(SVGCurveLib::PointGeneric<> p0, SVGCurveLib::PointGeneric<> p1, SVGCurveLib::PointGeneric<> p2, SVGCurveLib::PointGeneric<> p3, float t)

• Returns: SVGCurveLib::Point
• Parameters:
  • p0: SVGCurveLib::PointGeneric<> - starting point
  • p1: SVGCurveLib::PointGeneric<> - control point
  • p2: SVGCurveLib::PointGeneric<> - control point
  • p3: SVGCurveLib::PointGeneric<> - end point
  • t: float [0-1]

PointOnEllipticalArc

SVGCurveLib::PointWithEllipticalArcInfo SVGCurveLib::PointOnEllipticalArc(SVGCurveLib::PointGeneric<> p0, double rx, double ry, double xAxisRotation, bool largeArcFlag, bool sweepFlag, SVGCurveLib::PointGeneric<> p1, float t)

• Returns: SVGCurveLib::PointWithEllipticalArcInfo but can be implicitly converted/cast to SVGCurveLib::PointGeneric<>
  • SVGCurveLib::PointWithEllipticalArcInfo members:
    • value: SVGCurveLib::PointGeneric<> - The sampled point on curve. This is what will be returned if this is implicitly converted to SVGCurveLib::PointGeneric<>
    • ellipticalArcStartAngle: float - Curve start angle from x-axis from a full ellipse (in radians)
    • point.ellipticalArcEndAngle: float - Curve end angle from x-axis from a full ellipse (in radians)
    • point.ellipticalArcAngle: float - Angle from x-axis from a full ellipse where the point you are sampling for is at (in radians)
    • point.ellipticalArcCenter: SVGCurveLib::PointGeneric<> - Where the center of the full ellipse would be
    • point.resultantRx: float - Radii of the x-axis
    • point.resultantRy: float - Radii of the y-axis
• Parameters:
  • p0: SVGCurveLib::PointGeneric<> - starting point
  • rx: double - radius of the x-axis
  • ry: double - radius of the y-axis
  • xAxisRotation: double - Angle from the x-axis to rotate the ellipse (in degrees)
  • largeArcFlag: bool - false if an arc spanning less than or equal to 180 degrees is chosen, or true if an arc spanning greater than 180 degrees is chosen. This option is a bit hard to understand without an example.
  • sweepFlag: bool - false if the line joining center to arc sweeps through decreasing angles, or true if it sweeps through increasing angles. This option is a bit hard to understand without an example.
  • p1: SVGCurveLib::PointGeneric<> - end point
  • t: float [0-1]

CalculateQuadraticBezierTOfCriticalPoint

SVGCurveLib::PointGeneric<> SVGCurveLib::CalculateQuadraticBezierTOfCriticalPoint(SVGCurveLib::PointGeneric<> p0, SVGCurveLib::PointGeneric<> p1, SVGCurveLib::PointGeneric<> p2)

Returns the t-value for each axis where the curve can change from negative to positive slope, or vice versa

• Returns: object with format {x: t-value, y: t-value}
• Parameters:
  • p0: SVGCurveLib::PointGeneric<> - starting point
  • p1: SVGCurveLib::PointGeneric<> - control point
  • p2: SVGCurveLib::PointGeneric<> - end point

CalculateCubicBezierTOfCriticalPoint

std::array<SVGCurveLib::Point, 3> SVGCurveLib::CalculateCubicBezierTOfCriticalPoint(SVGCurveLib::PointGeneric<> p0, SVGCurveLib::PointGeneric<> p1, SVGCurveLib::PointGeneric<> p2, SVGCurveLib::PointGeneric<> p3)

Returns the t-value for each axis where the curve can change from negative to positive slope, or vice versa

• Returns: an array of size 3 SVGCurveLib::PointGeneric<>'s' with format { x: t-value, y: t-value }. t-value can be false if not applicable.
• Parameters:
  • p0: SVGCurveLib::PointGeneric<> - starting point
  • p1: SVGCurveLib::PointGeneric<> - control point
  • p2: SVGCurveLib::PointGeneric<> - control point
  • p3: SVGCurveLib::PointGeneric<> - end point

ApproximateArcLengthOfCurve

SVGCurveLib::ArcLengthInfo SVGCurveLib::ApproximateArcLengthOfCurve(unsigned int resolution, SVGCurveLib::PointGeneric<> (*pointOnCurveFunc)(float))

auto/*SVGCurveLib::ArcLengthInfo*/ result = SVGCurveLib::ApproximateArcLengthOfCurve(resolution, [&](float t) {
	return SVGCurveLib::PointOnLine({ 0, 0 }, { 10, 10 }, t);
});

// result.arcLength

• Returns: SVGCurveLib::ArcLengthInfo
  • Members:
    • arcLength: float - length of the curve/arc
    • arcLengthMap: std::vector<SVGCurveLib::ArcLengthMapEntry> - Map of t to arc length

LinearCurve

SVGCurveLib::LinearCurve(unsigned int resolution, SVGCurveLib::PointGeneric<> (*pointOnCurveFunc)(float))

Once initialized, use myLinearCurve.PointOnLinearCurve(float u) to sample the linear curve

SVGCurveLib::LinearCurve myLinearCurve = SVGCurveLib::LinearCurve(50, [&](float t) {
	return SVGCurveLib::PointOnLine({ 0, 0 }, { 10, 10 }, t);
});

// Gets a point exactly halfway, distance-wise along the curve
SVGCurveLib::PointGeneric<> myLinearCurve.PointOnLinearCurve(0.5);

• Returns: SVGCurveLib::LinearCurve
  • Members:
    • SVGCurveLib::ArcLengthInfo resultantInfo
    • SVGCurveLib::PointGeneric<> PointOnLinearCurve(float u)
• Parameters:
  • resolution: float - Number of samples to use to interpolate from
  • pointOnCurveFunc: function that takes t[0, 1] as a parameter and returns a SVGCurveLib::PointGeneric<>
    • Curry PointOnQuadraticBezierCurve, PointOnCubicBezierCurve, or PointOnEllipticalArc to fit the description above.