code: end

svg.cpp

@@ -0,0 +1,56 @@
+#include "svg.h"
+#include <algorithm>
+#include <string>
+
+using namespace std;
+
+namespace svg {
+    void begin(ostream& out, double width, double height) {
+        out << "<?xml version='1.0' encoding='UTF-8'?>\n";
+        out << "<svg width='" << width << "' height='" << height << "' "
+            << "viewBox='0 0 " << width << " " << height << "' "
+            << "xmlns='http://www.w3.org/2000/svg'>\n";
+    }
+
+    void end(ostream& out) {
+        out << "</svg>\n";
+    }
+
+    void text(ostream& out, double left, double baseline, const string& text) {
+        out << "<text x='" << left << "' y='" << baseline << "'>" << text << "</text>\n";
+    }
+
+    void rect(ostream& out, double x, double y, double width, double height,
+              const string& stroke, const string& fill) {
+        out << "<rect x='" << x << "' y='" << y << "' width='" << width
+            << "' height='" << height << "' stroke='" << stroke
+            << "' fill='" << fill << "' />\n";
+    }
+
+    void show_histogram_svg(ostream& out, const vector<size_t>& bins) {
+        begin(out, IMAGE_WIDTH, IMAGE_HEIGHT);
+
+        if (bins.empty()) {
+            end(out);
+            return;
+        }
+
+
+        size_t max_count = *max_element(bins.begin(), bins.end());
+        double scale = (max_count > 0) ? (IMAGE_WIDTH - TEXT_WIDTH) / static_cast<double>(max_count) : 1.0;
+
+        double top = 0;
+        for (size_t bin : bins) {
+            const double bin_width = bin * scale;
+            text(out, TEXT_LEFT, top + TEXT_BASELINE, to_string(bin));
+
+
+            string fill_color = (static_cast<int>(top / BIN_HEIGHT) % 2 == 0) ? "#aaffaa" : "#aaaaff";
+            rect(out, TEXT_WIDTH, top, bin_width, BIN_HEIGHT, "black", fill_color);
+
+            top += BIN_HEIGHT;
+        }
+
+        end(out);
+    }
+}

svg.h

@@ -0,0 +1,27 @@
+#ifndef SVG_H
+#define SVG_H
+
+#include <vector>
+#include <string>
+#include <iostream>
+
+
+const size_t IMAGE_WIDTH = 400;
+const size_t IMAGE_HEIGHT = 300;
+const size_t TEXT_LEFT = 20;
+const size_t TEXT_BASELINE = 20;
+const size_t TEXT_WIDTH = 50;
+const size_t BIN_HEIGHT = 30;
+const size_t BLOCK_WIDTH = 10;
+
+namespace svg {
+    void begin(std::ostream& out, double width, double height);
+    void end(std::ostream& out);
+    void text(std::ostream& out, double left, double baseline, const std::string& text);
+    void rect(std::ostream& out, double x, double y, double width, double height,
+              const std::string& stroke = "black", const std::string& fill = "#dddddd");
+
+    void show_histogram_svg(std::ostream& out, const std::vector<size_t>& bins);
+}
+
+#endif