msdfgen/core/Shape.cpp

#include "Shape.h"

#include "arithmetics.hpp"

namespace msdfgen {

Shape::Shape() : inverseYAxis(false) { }

void Shape::addContour(const Contour &contour) {
    contours.push_back(contour);
}

#ifdef MSDFGEN_USE_CPP11
void Shape::addContour(Contour &&contour) {
    contours.push_back((Contour &&) contour);
}
#endif

Contour & Shape::addContour() {
    contours.resize(contours.size()+1);
    return contours.back();
}

bool Shape::validate() const {
    for (std::vector<Contour>::const_iterator contour = contours.begin(); contour != contours.end(); ++contour) {
        if (!contour->edges.empty()) {
            Point2 corner = contour->edges.back()->point(1);
            for (std::vector<EdgeHolder>::const_iterator edge = contour->edges.begin(); edge != contour->edges.end(); ++edge) {
                if (!*edge)
                    return false;
                if ((*edge)->point(0) != corner)
                    return false;
                corner = (*edge)->point(1);
            }
        }
    }
    return true;
}

void Shape::normalize() {
    for (std::vector<Contour>::iterator contour = contours.begin(); contour != contours.end(); ++contour) {
        if (contour->edges.size() == 1) {
            EdgeSegment *parts[3] = { };
            contour->edges[0]->splitInThirds(parts[0], parts[1], parts[2]);
            contour->edges.clear();
            contour->edges.push_back(EdgeHolder(parts[0]));
            contour->edges.push_back(EdgeHolder(parts[1]));
            contour->edges.push_back(EdgeHolder(parts[2]));
        } else {
            EdgeHolder *prevEdge = &contour->edges.back();
            for (std::vector<EdgeHolder>::iterator edge = contour->edges.begin(); edge != contour->edges.end(); ++edge) {
                Vector2 prevDir = (*prevEdge)->direction(1).normalize();
                Vector2 curDir = (*edge)->direction(0).normalize();
                if (dotProduct(prevDir, curDir) < MSDFGEN_CORNER_DOT_EPSILON-1) {
                    Vector2 prevTendency = (*prevEdge)->directionTendency(1, 1);
                    Vector2 curTendency = (*edge)->directionTendency(0, -1);
                    int winding = nonZeroSign(crossProduct(prevTendency, curTendency));
                    EdgeSegment *newEdge = (*prevEdge)->makeDivergent(0, winding);
                    if (newEdge) *prevEdge = newEdge;
                    newEdge = (*edge)->makeDivergent(winding, 0);
                    if (newEdge) *edge = newEdge;
                }
                prevEdge = &*edge;
            }
        }
    }
}

void Shape::bound(double &l, double &b, double &r, double &t) const {
    for (std::vector<Contour>::const_iterator contour = contours.begin(); contour != contours.end(); ++contour)
        contour->bound(l, b, r, t);
}

void Shape::boundMiters(double &l, double &b, double &r, double &t, double border, double miterLimit, int polarity) const {
    for (std::vector<Contour>::const_iterator contour = contours.begin(); contour != contours.end(); ++contour)
        contour->boundMiters(l, b, r, t, border, miterLimit, polarity);
}

Shape::Bounds Shape::getBounds(double border, double miterLimit, int polarity) const {
    static const double LARGE_VALUE = 1e240;
    Shape::Bounds bounds = { +LARGE_VALUE, +LARGE_VALUE, -LARGE_VALUE, -LARGE_VALUE };
    bound(bounds.l, bounds.b, bounds.r, bounds.t);
    if (border > 0) {
        bounds.l -= border, bounds.b -= border;
        bounds.r += border, bounds.t += border;
        if (miterLimit > 0)
            boundMiters(bounds.l, bounds.b, bounds.r, bounds.t, border, miterLimit, polarity);
    }
    return bounds;
}

void Shape::scanline(Scanline &line, double y) const {
    std::vector<Scanline::Intersection> intersections;
    double x[3];
    int dy[3];
    for (std::vector<Contour>::const_iterator contour = contours.begin(); contour != contours.end(); ++contour) {
        for (std::vector<EdgeHolder>::const_iterator edge = contour->edges.begin(); edge != contour->edges.end(); ++edge) {
            int n = (*edge)->scanlineIntersections(x, dy, y);
            for (int i = 0; i < n; ++i) {
                Scanline::Intersection intersection = { x[i], dy[i] };
                intersections.push_back(intersection);
            }
        }
    }
#ifdef MSDFGEN_USE_CPP11
    line.setIntersections((std::vector<Scanline::Intersection> &&) intersections);
#else
    line.setIntersections(intersections);
#endif
}

int Shape::edgeCount() const {
    int total = 0;
    for (std::vector<Contour>::const_iterator contour = contours.begin(); contour != contours.end(); ++contour)
        total += (int) contour->edges.size();
    return total;
}

}