Makefile

@@ -1,21 +1,13 @@
 .PHONY: default
-default: dashing dashing.omp
+default: dashing
 
 .PHONY: bench
 bench: dashing
 	perf stat --log-fd=2 ./dashing -b -s .1 data/HWOOD6E1.pat data/sf.seg
 
 dashing: main.cc dashing.cc dashing.hh parse_numbers.hh contours_and_segments.hh
-	+g++ -W -Wall -O2 -g -std=c++20 $(filter %.cc, $^) -o $@ -flto -DNDEBUG
+	g++ -W -Wall -O2 -g -std=c++11 $(filter %.cc, $^) -o $@ -lboost_random
 dashing-noopt: main.cc dashing.cc dashing.hh parse_numbers.hh contours_and_segments.hh
-	+g++ -W -Wall -O0 -g -std=c++20 $(filter %.cc, $^) -o $@
+	g++ -W -Wall -O0 -g -std=c++11 $(filter %.cc, $^) -o $@ -lboost_random
 dashing-clang: main.cc dashing.cc dashing.hh parse_numbers.hh
-	+clang++ -W -Wall -O2 -g -std=c++20 $(filter %.cc, $^) -o $@ -flto -DNDEBUG
-dashing.pgo.0: main.cc dashing.cc dashing.hh parse_numbers.hh contours_and_segments.hh
-	+g++ -W -Wall -O2 -g -std=c++20 $(filter %.cc, $^) -o $@ -flto -DNDEBUG -fprofile-generate
-dashing.pgo.1: dashing.pgo.0 main.cc dashing.cc dashing.hh parse_numbers.hh contours_and_segments.hh
-	./dashing.pgo.0 -b -s .002 data/HWOOD6E1.pat  data/sf.seg
-	+g++ -W -Wall -O2 -g -std=c++20 $(filter %.cc, $^) -o $@ -flto -DNDEBUG -fprofile-use
-
-dashing.omp: main.cc dashing.cc dashing.hh parse_numbers.hh contours_and_segments.hh
-	+g++ -W -Wall -O2 -g -std=c++20 $(filter %.cc, $^) -o $@ -flto -DNDEBUG -fopenmp -DDASHING_OMP
+	clang++ -W -Wall -O2 -g -std=c++11 $(filter %.cc, $^) -o $@ -lboost_random

README.md

@@ -2,11 +2,11 @@
 
 License: permissive (zlib); see source files for additional details.
 
-On a i5-1235U in multithreaded benchmark mode, it runs at over 3.3 billion dashes per second:
+On a i5-3320M in benchmark mode, it runs at over 175 million dashes per second:
 ```
-$ time ./dashing.omp -b -s .002 data/HWOOD6E1.pat  data/sf.seg
-2822685873
-real	0m0.851s
+$ time ./dashing -b -s .01 data/HWOOD6E1.pat  data/sf.seg
+111430525
+user    0m0.616s
 ```
 
 ![Example image](data/sf.png)
@@ -31,7 +31,7 @@ I would be interested in passing this project to a new maintainer.
     The winding rule `wr` defines which regions are in the interior of the contours.
     For each dash or dot in the resulting hatch, `cb` is called with the output segment.
 
-`xyhatch(const HatchPattern&, const C &segments, Cb cb, const char *wr)`:
+`xyhatch(const HatchPattern&, const C &segments, Cb cb, const char \*wr)`:
     The container C holds segments which must define a set of closed
     contours.
     The winding rule `wr` defines which regions are in the interior of the contours.
@@ -39,7 +39,7 @@ I would be interested in passing this project to a new maintainer.
 
 `HatchPattern::FromFile`: Read a hatch pattern from a file.
 
-`parse_numbers(std::string line)`: Read a comma and/or space-separated
+`parse\_numbers(std::string line)`: Read a comma and/or space-separated
     sequence of numbers into a vector
 
 `SegmentsFromFile`, `ContoursFromFile`, `ContourToSegments`, `ContoursToSegments`: Read and convert segments and contours
@@ -51,22 +51,6 @@ Useful winding rules include:
  
 but any predicate of a single integer may be used.
 
-### Parallel API
-These APIs are available if built with `-fopenmp -DDASHING_OMP`
-
-`xyhatch_omp(const HatchPattern&, It start, It end, Cb cb, Wr wr)`:
-    Iterators `start`..`end` define a range of segments, which must define a set of closed contours.
-    The winding rule `wr` defines which regions are in the interior of the contours.
-    For each dash or dot in the resulting hatch, `cb` is called with the output segment and the thread ID.
-
-`xyhatch_omp(const HatchPattern&, const C &segments, Cb cb, Wr wr)`:
-    The container C holds segments which must define a set of closed
-    contours.
-    The winding rule `wr` defines which regions are in the interior of the contours.
-    For each dash or dot in the resulting hatch, `cb` is called with the output segment and the thread ID.
-
-### Other APIs
-
 Other items in the header files are implementation details.
 
 ## Demo program

contours_and_segments.hh

@@ -12,7 +12,7 @@ typedef std::vector<Contour> Contours;
 
 void ContourToSegments(Segments &dest,
         /* EXPLICIT COPY */ Contour src,
-        F jitter = 0)
+        double jitter = 0)
 {
     if(jitter)
     {
@@ -32,7 +32,7 @@ void ContourToSegments(Segments &dest,
     dest.emplace_back(Segment{src[i-1], src[0], false});
 }
 
-void ContoursToSegments(Segments &dest, Contours const &src, F jitter=0)
+void ContoursToSegments(Segments &dest, Contours const &src, double jitter=0)
 {
     dest.clear();
 
@@ -62,14 +62,14 @@ Contours ContoursFromFile(std::istream &fi)
     return result;
 }
 
-Segments SegmentsFromFile(std::istream &fi, F jitter) {
+Segments SegmentsFromFile(std::istream &fi, double jitter) {
     auto && contours = ContoursFromFile(fi);
     auto result = Segments{};
     ContoursToSegments(result, contours, jitter);
     return result;
 }
 
-std::vector<Segment> SegmentsFromFile(const char *filename, F jitter) {
+std::vector<Segment> SegmentsFromFile(const char *filename, double jitter) {
     std::fstream fi(filename);
     return SegmentsFromFile(fi, jitter);
 }

dashing.cc

@@ -2,41 +2,37 @@
 #include "dashing.hh"
 namespace dashing
 {
-std::vector<F> parse_numbers(std::string line) {
+std::vector<double> parse_numbers(std::string line) {
+    boost::algorithm::replace_all(line, ",", " ");
     std::istringstream fi(line);
-    std::vector<F> result;
-    F d;
-    while((fi >> d)) {
-        result.push_back(d);
-        for (auto p = fi.peek(); p == ',' || isspace(p); p = fi.peek()) {
-            fi.get();
-        }
-    }
+    std::vector<double> result;
+    double d;
+    while((fi >> d)) result.push_back(d);
     return result;
 }
 
 PSMatrix PSMatrix::inverse() const {
-    auto i = F(1.) / determinant();
+    auto i = 1. / determinant();
     return PSMatrix{d*i, -b*i, -c*i, a*i, i*(c*f-e*d), i*(b*e-a*f)};
 }
 
-PSMatrix Translation(F x, F y) {
+PSMatrix Translation(double x, double y) {
     PSMatrix r{1.,0.,0.,1.,x,y};
     return r;
 }
 
-PSMatrix Rotation(F theta) {
-    F c = cos(theta), s = sin(theta);
+PSMatrix Rotation(double theta) {
+    double c = cos(theta), s = sin(theta);
     PSMatrix r{c,s,-s,c,0.,0.};
     return r;
 }
 
-PSMatrix XSkew(F xk) {
+PSMatrix XSkew(double xk) {
     PSMatrix r{1.,0.,xk,1.,0.,0.};
     return r;
 }
 
-PSMatrix YScale(F ys) {
+PSMatrix YScale(double ys) {
     PSMatrix r{1.,0.,0.,ys,0.,0.};
     return r;
 }
@@ -52,31 +48,21 @@ PSMatrix operator*(const PSMatrix &m1, const PSMatrix m2) {
     return r;
 }
 
-static F radians(F degrees) { return degrees * acos(0) / 90.; }
+static double radians(double degrees) { return degrees * acos(0) / 90.; }
 
-Dash::Dash(F th, F x0, F y0, F dx, F dy,
-        const std::vector<F>::const_iterator dbegin,
-        const std::vector<F>::const_iterator dend)
-    : dash{dbegin, dend} {
+Dash::Dash(double th, double x0, double y0, double dx, double dy,
+        const std::vector<double>::const_iterator dbegin,
+        const std::vector<double>::const_iterator dend) : dash(dbegin, dend) {
     auto s = 0.;
-    for(size_t i = 0; i < dash.size(); i++) {
-        bool is_negative = std::signbit(dash[i]);
-        bool index_is_odd = (i % 2) != 0;
-        if(is_negative != index_is_odd) {
-            throw std::invalid_argument("not a supported dash specification (but probably valid)");
-        }
-        dash[i] = std::abs(dash[i]);
-    }
-    if (dash.size() % 2) dash.push_back(0);
-    for(auto d : dash) { sum.push_back(s); s += d; }
+    for(auto d : dash) { sum.push_back(s); s += fabs(d); }
     sum.push_back(s);
 
     tr = Translation(x0, y0) * Rotation(th) * XSkew(dx / dy) * YScale(dy);
     tf = tr.inverse();
 }
 
-Dash Dash::FromString(const std::string &line, F scale) {
-    std::vector<F> words = parse_numbers(line);
+Dash Dash::FromString(const std::string &line, double scale) {
+    std::vector<double> words = parse_numbers(line);
     if(words.size() < 5)
         throw std::invalid_argument("not a valid dash specification");
     for(auto i = words.begin() + 1; i != words.end(); i++) *i *= scale;

dashing.hh

@@ -18,47 +18,43 @@ freely, subject to the following restrictions:
 3. This notice may not be removed or altered from any source distribution.
 */
 
-#pragma once
+#ifndef DASHING_H
+#define DASHING_H
 
-#include <algorithm>
 #include <cmath>
 #include <cassert>
 #include <vector>
 #include <string>
 #include <fstream>
 #include <stdexcept>
-#include <span>
-#if defined(DASHING_OMP)
-#include <omp.h>
-#endif
-
-#include "dashing_F.hh"
+#include <boost/algorithm/string/replace.hpp>
+#include <boost/algorithm/string/trim.hpp>
 
 namespace dashing
 {
 
 struct PSMatrix {
-    F a, b, c, d, e, f;
+    double a, b, c, d, e, f;
 
     PSMatrix inverse() const;
-    F determinant() const { return a * d - b * c; }
+    double determinant() const { return a * d - b * c; }
 };
 
-PSMatrix Translation(F x, F y);
-PSMatrix Rotation(F theta);
-PSMatrix XSkew(F xk);
-PSMatrix YScale(F ys);
+PSMatrix Translation(double x, double y);
+PSMatrix Rotation(double theta);
+PSMatrix XSkew(double xk);
+PSMatrix YScale(double ys);
 
-struct Point { F x, y; };
+struct Point { double x, y; };
 inline Point operator*(const Point &p, const PSMatrix &m) {
     return Point{ p.x*m.a + p.y*m.c + m.e,
                   p.x*m.b + p.y*m.d + m.f };
 }
-inline Point operator*(const Point &p, F d)
+inline Point operator*(const Point &p, double d)
 {
     return Point{ p.x * d, p.y * d };
 }
-inline Point operator*(F d, const Point &p)
+inline Point operator*(double d, const Point &p)
 {
     return Point{ p.x * d, p.y * d };
 }
@@ -71,17 +67,17 @@ PSMatrix operator*(const PSMatrix &m1, const PSMatrix m2);
 
 struct Dash {
     PSMatrix tr, tf;
-    std::vector<F> dash, sum;
+    std::vector<double> dash, sum;
 
-    Dash(F th, F x0, F y0, F dx, F dy,
-            const std::vector<F>::const_iterator dbegin,
-            const std::vector<F>::const_iterator dend);
+    Dash(double th, double x0, double y0, double dx, double dy,
+            const std::vector<double>::const_iterator dbegin,
+            const std::vector<double>::const_iterator dend);
 
-    static Dash FromString(const std::string &line, F scale);
+    static Dash FromString(const std::string &line, double scale);
 };
 
 struct Segment { Point p, q; bool swapped; };
-struct Intersection { F u; bool positive; };
+struct Intersection { double u; bool positive; };
 inline bool operator<(const Intersection &a, const Intersection &b)
 {
     return a.u < b.u;
@@ -94,16 +90,16 @@ inline void ysort(Segment &s) {
     std::swap(s.p, s.q);
 }
 
-inline int intceil(F x) { return int(ceil(x)); }
-inline int intfloor(F x) { return int(floor(x)); }
+inline double intceil(double x) { return int(ceil(x)); }
+inline double intfloor(double x) { return int(floor(x)); }
 
-inline F pythonmod(F a, F b) {
+inline double pythonmod(double a, double b) {
     auto r = a - floor(a / b) * b;
     if(r == b) return 0;
     return r;
 }
 
-inline size_t utoidx(const Dash &d, F u, F &o) {
+inline size_t utoidx(const Dash &d, double u, double &o) {
     u = pythonmod(u, d.sum.back());
     for(size_t i = 1; i != d.sum.size(); i++) {
         if(u < d.sum[i]) { o = u - d.sum[i-1]; return i-1; }
@@ -112,30 +108,26 @@ inline size_t utoidx(const Dash &d, F u, F &o) {
 }
 
 template<class Cb>
-void uvdraw(const Dash &pattern, F v, F u1, F u2, Cb cb) {
+void uvdraw(const Dash &pattern, double v, double u1, double u2, Cb cb) {
     if(pattern.dash.empty()) { cb(v, u1, u2); return;  }
-    F o;
+    double o;
     auto i = utoidx(pattern, u1, o);
-    const auto pi = pattern.dash[i];
-    if(i % 2 == 0) { cb(v, u1, std::min(u2, u1+pi-o)); u1 += pi-o; }
+    const auto &pi = pattern.dash[i];
+    if(pi >= 0) { cb(v, u1, std::min(u2, u1+pi-o)); u1 += pi-o; }
     else { u1 -= pi+o; }
-    i++;
-    if(i % 2) {
-        u1 += pattern.dash[i];
-        i++;
-    }
+    i = i + 1;
+    if(i == pattern.dash.size()) i = 0;
     for(auto u = u1; u < u2;) {
-        if(i >= pattern.dash.size()) i = 0;
-        const auto pi = pattern.dash[i];
-        cb(v, u, std::min(u2, u+pi));
-        u += pi;
-        u += pattern.dash[i+1];
-        i+=2;
+        const auto &pi = pattern.dash[i];
+        if(pi >= 0) { cb(v, u, std::min(u2, u+pi)); u += pi; }
+        else { u -= pi; }
+        i = i + 1;
+        if(i == pattern.dash.size()) i = 0;
     }
 }
 
 template<class Cb, class Wr>
-void uvspans(const Dash &pattern, std::vector<Segment> & segments, Cb cb, std::vector<Intersection> &uu, Wr wr) {
+void uvspans(const Dash &pattern, std::vector<Segment> && segments, Cb cb, std::vector<Intersection> &uu, Wr wr) {
     if(segments.empty()) return; // no segments
 
     for(auto &s : segments) ysort(s);
@@ -181,16 +173,16 @@ void uvspans(const Dash &pattern, std::vector<Segment> & segments, Cb cb, std::v
             segments_begin ++;
         }
 
-        for(const auto &s : std::span(heap_begin, heap_end)) {
+        for(const auto &s : boost::make_iterator_range(heap_begin, heap_end)) {
             auto du = s.q.x - s.p.x;
             auto dv = s.q.y - s.p.y;
             assert(dv);
-            uu.push_back(
+            if(dv) uu.push_back(
                     Intersection{s.p.x + du * (v - s.p.y) / dv,s.swapped});
         }
         std::sort(uu.begin(), uu.end());
         int winding = 0;
-        F old_u = -std::numeric_limits<F>::infinity();
+        double old_u = -std::numeric_limits<double>::infinity();
         for(const auto &isect : uu) {
             if(wr(winding)) uvdraw(pattern, v, old_u, isect.u, cb);
             winding += 2*isect.positive - 1;
@@ -201,16 +193,14 @@ void uvspans(const Dash &pattern, std::vector<Segment> & segments, Cb cb, std::v
 
 struct HatchPattern {
     std::vector<Dash> d;
-    static HatchPattern FromFile(std::istream &fi, F scale) {
+    static HatchPattern FromFile(std::istream &fi, double scale) {
         HatchPattern result;
 
         std::string line;
         while(getline(fi, line)) {
             auto i = line.find(";");
             if(i != line.npos) line.erase(i, line.npos);
-            while(!line.empty() && isspace(line.back())) {
-                line.pop_back();
-            }
+            boost::algorithm::trim(line);
             if(line.empty()) continue;
             if(line[0] == '*') continue;
             result.d.push_back(Dash::FromString(line, scale));
@@ -218,34 +208,34 @@ struct HatchPattern {
         return result;
     }
 
-    static HatchPattern FromFile(const char *filename, F scale) {
+    static HatchPattern FromFile(const char *filename, double scale) {
         std::ifstream fi(filename);
         return FromFile(fi, scale);
     }
 };
 
 template<class It, class Cb, class Wr>
-void xyhatch(const Dash &pattern, It start, It end, Cb cb, Wr wr) {
-    std::vector<Segment> uvsegments;
-    uvsegments.reserve(end-start);
-
-    std::vector<Intersection> uu;
-    uu.reserve(8);
-
+void xyhatch(const Dash &pattern, It start, It end, Cb cb, std::vector<Segment> &uvsegments, std::vector<Intersection> &uu, Wr wr) {
+    uvsegments.clear();
     bool swapped = pattern.tf.determinant() < 0;
     std::transform(start, end, std::back_inserter(uvsegments),
         [&](const Segment &s)
         { return Segment{s.p * pattern.tf, s.q * pattern.tf, swapped != s.swapped };
     });
-    uvspans(pattern, uvsegments, [&](F v, F u1, F u2) {
+    uvspans(pattern, std::move(uvsegments), [&](double v, double u1, double u2) {
         Point p{u1, v}, q{u2, v};
-        cb(Segment{ p * pattern.tr, q * pattern.tr, false });
+        Segment xy{ p * pattern.tr, q * pattern.tr, false };
+        cb(xy);
     }, uu, wr);
 }
 
 template<class It, class Cb, class Wr>
 void xyhatch(const HatchPattern &pattern, It start, It end, Cb cb, Wr wr) {
-    for(const auto &i : pattern.d) xyhatch(i, start, end, cb, wr);
+    std::vector<Segment> uvsegments;
+    uvsegments.reserve(end-start);
+    std::vector<Intersection> uu;
+    uu.reserve(8);
+    for(const auto &i : pattern.d) xyhatch(i, start, end, cb, uvsegments, uu, wr);
 }
 
 template<class C, class Cb, class Wr>
@@ -253,20 +243,5 @@ void xyhatch(const HatchPattern &pattern, const C &c, Cb cb, Wr wr) {
     xyhatch(pattern, c.begin(), c.end(), cb, wr);
 }
 
-#if defined(DASHING_OMP)
-template<class It, class Cb, class Wr>
-void xyhatch_omp(const HatchPattern &pattern, It start, It end, Cb cb, Wr wr) {
-    #pragma omp parallel for
-    for(const auto &i : pattern.d) {
-        int iam = omp_get_thread_num();
-        xyhatch(i, start, end, [iam, &cb](Segment s) { cb(s, iam); }, wr);
 }
-}
-template<class C, class Cb, class Wr>
-void xyhatch_omp(const HatchPattern &pattern, const C &c, Cb cb, Wr wr) {
-    xyhatch_omp(pattern, c.begin(), c.end(), cb, wr);
-}
-
 #endif
-
-}

dashing_F.hh

@@ -1,26 +0,0 @@
-/*
-Copyright (c) 2015 Jeff Epler
-
-This software is provided 'as-is', without any express or implied
-warranty. In no event will the authors be held liable for any damages
-arising from the use of this software.
-
-Permission is granted to anyone to use this software for any purpose,
-including commercial applications, and to alter it and redistribute it
-freely, subject to the following restrictions:
-
-1. The origin of this software must not be misrepresented; you must not
-   claim that you wrote the original software. If you use this software
-   in a product, an acknowledgement in the product documentation would be
-   appreciated but is not required.
-2. Altered source versions must be plainly marked as such, and must not be
-   misrepresented as being the original software.
-3. This notice may not be removed or altered from any source distribution.
-*/
-
-#pragma once
-namespace dashing
-{
-
-typedef float F;
-}

main.cc

@@ -20,12 +20,6 @@ freely, subject to the following restrictions:
 
 // demo and benchmark program for dashing
 
-#include <new>
-#include <atomic>
-#include <cstring>
-#if defined(DASHING_OMP)
-#include <omp.h>
-#endif
 #include "dashing.hh"
 #include "contours_and_segments.hh"
 
@@ -91,20 +85,9 @@ int main(int argc, char **argv) {
     if(xit) return 0;
 
     if(bench) {
-#if defined(DASHING_OMP)
-        struct per_thread_count_type {
-            alignas(std::hardware_destructive_interference_size) size_t n;
-        };
-        auto max_threads = omp_get_max_threads();
-        std::vector<per_thread_count_type> thread_nseg(max_threads, per_thread_count_type{0});
-        auto count_seg = [&thread_nseg](const Segment &s, int iam) { (void)s; thread_nseg[iam].n++; };
-        xyhatch_omp(h, s, count_seg, [](int i) { return i != 0; } );
-        size_t nseg = std::accumulate(thread_nseg.begin(), thread_nseg.end(), size_t{}, [](size_t a, const per_thread_count_type &b) { return a + b.n; });
-#else
-        size_t nseg{};
-        auto count_seg = [&nseg](const Segment &s) { (void)s; nseg ++; };
-        xyhatch(h, s, count_seg, [](int i) { return i != 0; } );
-#endif
+        int nseg = 0;
+        auto print_seg = [&nseg](const Segment &s) { (void)s; nseg ++; };
+        xyhatch(h, s, print_seg, [](int i) { return i != 0; } );
         std::cout << nseg << "\n";
         return 0;
     }

parse_numbers.hh

@@ -3,9 +3,9 @@
 #include <vector>
 #include <string>
 #include <sstream>
-#include "dashing_F.hh"
+#include <boost/algorithm/string/replace.hpp>
 namespace dashing
 {
-std::vector<F> parse_numbers(std::string line);
+std::vector<double> parse_numbers(std::string line);
 }
 #endif