Triangles with fill instead of stroke

main.cpp

@@ -10,6 +10,14 @@ struct pt {
 	ld x = 0, y = 0;
 };
 
+bool operator<(pt lhs, pt rhs) {
+	return make_pair(lhs.x, lhs.y) < make_pair(rhs.x, rhs.y);
+}
+
+ostream& operator<<(ostream& out, pt p) {
+	return out << p.x << ',' << p.y;
+}
+
 constexpr pt zero = pt{0, 0};
 
 pt operator+(pt a, pt b) {
@@ -103,16 +111,11 @@ int main() {
 	pt p31b = unit_triangle(p31a, {0, 0}, c1) * c1;
 	cone c31{p31a, c3, p31b, c1};
 
-	// we keep track of all lines in the construction
-	vector<pair<pt, pt>> rays;
-	rays.emplace_back(zero, c1);
-	rays.emplace_back(zero, c2);
-	rays.emplace_back(zero, c3);
-
-	vector<pair<pt, pt>> lines;
-	lines.emplace_back(p12a, p12b);
-	lines.emplace_back(p23a, p23b);
-	lines.emplace_back(p31a, p31b);
+	// we keep track of all triangles in the construction
+	vector<tuple<pt, pt, pt>> triangles;
+	triangles.emplace_back(p12a, p12b, zero);
+	triangles.emplace_back(p23a, p23b, zero);
+	triangles.emplace_back(p31a, p31b, zero);
 
 	// I use a priority queue to pick the closest cone
 	priority_queue<cone_d> work;
@@ -121,7 +124,7 @@ int main() {
 	work.push(c31);
 
 	// we pick the closest cone to expand
-	while(!work.empty() && lines.size() < 2000) {
+	while(!work.empty() && triangles.size() < 2000) {
 		auto c = work.top().c;
 		work.pop();
 
@@ -139,15 +142,13 @@ int main() {
 			const auto l = sqrt(lensqr(c.p1, c.p2));
 			const auto wiggle = l - 4;
 			const auto r0 = unif01(gen);
-			const auto r = 2.0 / l + pow(r0, 1.5) * wiggle / l;
+			const auto r = 2.0 / l + pow(r0, 1.1) * wiggle / l;
 			const auto pm = (1.0 - r) * c.p1 + r * c.p2;
 
 			const auto r20 = unif01(gen);
-			const auto r2 = 0.001 + 0.998 * pow(r20, 1.2);
+			const auto r2 = 0.001 + 0.998 * pow(r20, 1.1);
 			const auto dm = r2 * c.d1 + (1.0 - r2) * c.d2;
 
-			rays.emplace_back(pm, dm);
-
 			cone c1{c.p1, c.d1, pm, dm};
 			cone c2{pm, dm, c.p2, c.d2};
 			work.push(c1);
@@ -165,49 +166,31 @@ int main() {
 			// the one with a shorter edge, sounds fine to me. I reintroduce
 			// some randomness for artistic reasons. Increase 20 for wild
 			// results.
-			if (lensqr(c.p1, p2b) + 20*unif01(gen) < lensqr(p1b, c.p2) + 20*unif01(gen)) {
+			if (lensqr(c.p1, p2b) + 34*unif01(gen) < lensqr(p1b, c.p2) + 34*unif01(gen)) {
 				cone c2{c.p1, c.d1, p2b, c.d2};
 				work.push(c2);
-				lines.emplace_back(c.p1, p2b);
+				triangles.emplace_back(c.p1, p2b, c.p2);
 			} else {
 				cone c2{p1b, c.d1, c.p2, c.d2};
 				work.push(c2);
-				lines.emplace_back(p1b, c.p2);
+				triangles.emplace_back(c.p1, p1b, c.p2);
 			}
 		}
 	}
 
-	// the print an svg attribute
-	const auto p = [](auto str, auto v) {
-		cout << ' ' << str << "=\"" << v << "\"";
-	};
-
-	// I roughly estimate the maximal distance from zero
-	ld max_l = 0;
-
-	shuffle(lines.begin(), lines.end(), gen);
-
 	cout << "<svg>\n";
-	for(auto && l : lines) {
-		max_l = 0.5 * max_l + 0.5 * max(max_l, max(norm(l.first), norm(l.second)));
-		cout << "<line";
-		p("x1", l.first.x);
-		p("y1", l.first.y);
-		p("x2", l.second.x);
-		p("y2", l.second.y);
-		p("style", "stroke:#000;stroke-width:0.1");
-		cout << "/>\n";
-	}
-	for(auto && l : rays) {
-		const auto p1 = l.first;
-		const auto l_left = max(ld(1.0), max_l - norm(p1));
-		const auto p2 = p1 + (l_left / norm(l.second)) * l.second;
-		cout << "<line";
-		p("x1", p1.x);
-		p("y1", p1.y);
-		p("x2", p2.x);
-		p("y2", p2.y);
-		p("style", "stroke:#000;stroke-width:0.1");
+	for(auto && t : triangles) {
+		auto p1 = get<0>(t), p2 = get<1>(t), p3 = get<2>(t);
+		vector<ld> lengths{{norm(p2 - p1), norm(p3 - p2), norm(p1 - p3)}};
+		sort(lengths.begin(), lengths.end());
+		auto r = max(0.0l, min(255.0l, 70 * lengths[2]));
+		auto g = max(0.0l, min(255.0l, 70 * lengths[1]));
+		auto b = max(0.0l, min(255.0l, 256 - 100 * lengths[0]));
+		cout << "<polygon";
+		cout << " points=\"" << get<0>(t) << ' ' << get<1>(t) << ' ' << get<2>(t) << "\"";
+		cout << " style=\"" << "stroke-width:0.01;"
+		     << "fill:rgb(" << r << ", " << g << ", " << b << ");"
+		     << "stroke:rgb(" << max(0.0l, r-100) << ", " << max(0.0l, g-100) << ", " << max(0.0l, b-100) << ");" << "\"";
 		cout << "/>\n";
 	}
 	cout << "</svg>" << endl;