msdfgen/core/edge-selectors.h

84 lines
2.1 KiB
C++

#pragma once
#include "Vector2.h"
#include "SignedDistance.h"
#include "edge-segments.h"
namespace msdfgen {
struct MultiDistance {
double r, g, b;
};
/// Selects the nearest edge by its true distance.
class TrueDistanceSelector {
public:
typedef double DistanceType;
explicit TrueDistanceSelector(const Point2 &p = Point2());
void addEdge(const EdgeSegment *prevEdge, const EdgeSegment *edge, const EdgeSegment *nextEdge);
void merge(const TrueDistanceSelector &other);
DistanceType distance() const;
private:
Point2 p;
SignedDistance minDistance;
};
class PseudoDistanceSelectorBase {
public:
static bool pointFacingEdge(const EdgeSegment *prevEdge, const EdgeSegment *edge, const EdgeSegment *nextEdge, const Point2 &p, double param);
PseudoDistanceSelectorBase();
void addEdgeTrueDistance(const EdgeSegment *edge, const SignedDistance &distance, double param);
void addEdgePseudoDistance(const SignedDistance &distance);
void merge(const PseudoDistanceSelectorBase &other);
double computeDistance(const Point2 &p) const;
private:
SignedDistance minTrueDistance;
SignedDistance minNegativePseudoDistance;
SignedDistance minPositivePseudoDistance;
const EdgeSegment *nearEdge;
double nearEdgeParam;
};
/// Selects the nearest edge by its pseudo-distance.
class PseudoDistanceSelector : public PseudoDistanceSelectorBase {
public:
typedef double DistanceType;
explicit PseudoDistanceSelector(const Point2 &p = Point2());
void addEdge(const EdgeSegment *prevEdge, const EdgeSegment *edge, const EdgeSegment *nextEdge);
DistanceType distance() const;
private:
Point2 p;
};
/// Selects the nearest edge for each of the three channels by its pseudo-distance.
class MultiDistanceSelector {
public:
typedef MultiDistance DistanceType;
explicit MultiDistanceSelector(const Point2 &p = Point2());
void addEdge(const EdgeSegment *prevEdge, const EdgeSegment *edge, const EdgeSegment *nextEdge);
void merge(const MultiDistanceSelector &other);
DistanceType distance() const;
private:
Point2 p;
PseudoDistanceSelectorBase r, g, b;
};
}