msdfgen/core/edge-selectors.h

119 lines
2.9 KiB
C++

#pragma once
#include "types.h"
#include "Vector2.hpp"
#include "SignedDistance.hpp"
#include "edge-segments.h"
namespace msdfgen {
struct MultiDistance {
real r, g, b;
};
struct MultiAndTrueDistance : MultiDistance {
real a;
};
/// Selects the nearest edge by its true distance.
class TrueDistanceSelector {
public:
typedef real DistanceType;
struct EdgeCache {
Point2 point;
real absDistance;
EdgeCache();
};
void reset(const Point2 &p);
void addEdge(EdgeCache &cache, 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:
struct EdgeCache {
Point2 point;
real absDistance;
real aDomainDistance, bDomainDistance;
real aPseudoDistance, bPseudoDistance;
EdgeCache();
};
static bool getPseudoDistance(real &distance, const Vector2 &ep, const Vector2 &edgeDir);
PseudoDistanceSelectorBase();
void reset(real delta);
bool isEdgeRelevant(const EdgeCache &cache, const EdgeSegment *edge, const Point2 &p) const;
void addEdgeTrueDistance(const EdgeSegment *edge, const SignedDistance &distance, real param);
void addEdgePseudoDistance(real distance);
void merge(const PseudoDistanceSelectorBase &other);
real computeDistance(const Point2 &p) const;
SignedDistance trueDistance() const;
private:
SignedDistance minTrueDistance;
real minNegativePseudoDistance;
real minPositivePseudoDistance;
const EdgeSegment *nearEdge;
real nearEdgeParam;
};
/// Selects the nearest edge by its pseudo-distance.
class PseudoDistanceSelector : public PseudoDistanceSelectorBase {
public:
typedef real DistanceType;
void reset(const Point2 &p);
void addEdge(EdgeCache &cache, 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;
typedef PseudoDistanceSelectorBase::EdgeCache EdgeCache;
void reset(const Point2 &p);
void addEdge(EdgeCache &cache, const EdgeSegment *prevEdge, const EdgeSegment *edge, const EdgeSegment *nextEdge);
void merge(const MultiDistanceSelector &other);
DistanceType distance() const;
SignedDistance trueDistance() const;
private:
Point2 p;
PseudoDistanceSelectorBase r, g, b;
};
/// Selects the nearest edge for each of the three color channels by its pseudo-distance and by true distance for the alpha channel.
class MultiAndTrueDistanceSelector : public MultiDistanceSelector {
public:
typedef MultiAndTrueDistance DistanceType;
DistanceType distance() const;
};
}