From 301c689285d49a969c335cd93132ee84ca064ddb Mon Sep 17 00:00:00 2001
From: Adrian Kummerlaender
Date: Sun, 8 May 2016 20:39:59 +0200
Subject: Adapt example to generate a Voronoi diagram for n points

---
 CMakeLists.txt |  9 +++++++--
 example.cc     | 40 ++++++++++++++++++++++++++++++++++++++++
 test.cc        | 12 ------------
 3 files changed, 47 insertions(+), 14 deletions(-)
 create mode 100644 example.cc
 delete mode 100644 test.cc

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 88200b9..1d543a9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,7 +11,12 @@ include_directories(
 )
 
 add_executable(
-	test
-		test.cc
+	example
+		example.cc
 		src/imgen.cc
 )
+
+target_link_libraries(
+	example
+		m
+)
diff --git a/example.cc b/example.cc
new file mode 100644
index 0000000..e4d7420
--- /dev/null
+++ b/example.cc
@@ -0,0 +1,40 @@
+#include <imgen.h>
+
+#include <cmath>
+#include <algorithm>
+
+double metric(std::size_t refX, std::size_t refY, std::size_t x, std::size_t y) {
+	return std::sqrt(
+		(refX - x)*(refX - x) + (refY - y)*(refY - y)
+	);
+}
+
+int main(int, char*[]) {
+	using refpos = std::tuple<std::size_t, std::size_t, imgen::color>;
+
+	std::array<refpos, 5> ref{
+		refpos(100, 50,  imgen::color(255, 0,   0  )),
+		refpos(500, 300, imgen::color(0,   255, 0  )),
+		refpos(250, 250, imgen::color(0,   0,   255)),
+		refpos(400, 20,  imgen::color(100, 10,  100)),
+		refpos(60,  400, imgen::color(20,  60,  300))
+	};
+
+	imgen::write_ppm(
+		"test.ppm",
+		500,
+		500,
+		[&ref](std::size_t x, std::size_t y) -> imgen::color {
+			const refpos& nearest = *std::min_element(
+				ref.begin(),
+				ref.end(),
+				[x, y](const refpos& a, const refpos& b) -> bool {
+					return   metric(std::get<0>(a), std::get<1>(a), x, y)
+					       < metric(std::get<0>(b), std::get<1>(b), x, y);
+				}
+			);
+
+			return std::get<2>(nearest);
+		}
+	);
+}
diff --git a/test.cc b/test.cc
deleted file mode 100644
index 36f637d..0000000
--- a/test.cc
+++ /dev/null
@@ -1,12 +0,0 @@
-#include <imgen.h>
-
-int main(int, char*[]) {
-	imgen::write_ppm(
-		"test.ppm",
-		500,
-		500,
-		[](std::size_t x, std::size_t y) -> imgen::color {
-			return imgen::color(255, x % 255, y % 255);
-		}
-	);
-}
-- 
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