diff --git a/src/main.cpp b/src/main.cpp
index b89cdac..e6450a4 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -110,94 +110,100 @@ struct App {
 	}
 };
 
+struct CLApp {
+	void initialize(){
+		auto context = cl::Context::getDefault();
+		cout << context << endl;
+
+		cl_int err = 0;
+		// build the program
+		auto KernelSource = slurp("Kernel.cl");
+		cl::Program program(context, {KernelSource.c_str(), KernelSource.size()}, true, &err);
+		check(err);
+		cout << program << endl;
+
+		// grab the kernel
+		KernelOp kernel(program, "square", &err);
+		check(err);
+
+		// create a queue
+		cl::CommandQueue queue(context, context.getInfo<CL_CONTEXT_DEVICES>().front());
+
+		// make a lot of data
+		constexpr size_t W = 1280 * 1;
+		constexpr size_t H = 800  * 1;
+		std::vector<cl_float> input_vector(W*H);
+
+		for(int y = 0; y < H; ++y){
+			for(int x = 0; x < W; ++x){
+				input_vector[x + W*y] = 10 * ((x / double(W) - 0.5) + 1.3371337*(y / double(H) - 0.5));
+			}
+		}
 
-int main(){
-	App a;
-
-	NSAppWrapper app;
-
-	app.create_window({
-		[&](ContextParameters){
-			a.initialize();
-		},
-		[&](ContextParameters){
-			a.draw();
-		},
-		nullptr
-	});
-
-	app.run();
-
-	auto context = cl::Context::getDefault();
-	cout << context << endl;
+		// transfer data into buffers
+		cl::Buffer input(context, input_vector.begin(), input_vector.end(), false, true);
 
-	cl_int err = 0;
-	// build the program
-	auto KernelSource = slurp("Kernel.cl");
-	cl::Program program(context, {KernelSource.c_str(), KernelSource.size()}, true, &err);
-	check(err);
-	cout << program << endl;
+		int r = 20, g = 20, b = 20;
 
-	// grab the kernel
-	KernelOp kernel(program, "square", &err);
-	check(err);
+		// DO IT (in place)
+		for(int i = 0; i < r; ++i){
+			check(kernel(queue, W, H, input, W, input));
+		}
 
-	// create a queue
-	cl::CommandQueue queue(context, context.getInfo<CL_CONTEXT_DEVICES>().front());
+		// read back
+		queue.finish();
 
-	// make a lot of data
-	constexpr size_t W = 1280 * 4;
-	constexpr size_t H = 800  * 4;
-	std::vector<cl_float> input_vector(W*H);
+		auto red = input_vector;
 
-	for(int y = 0; y < H; ++y){
-		for(int x = 0; x < W; ++x){
-			input_vector[x + W*y] = 10 * ((x / double(W) - 0.5) + 1.3371337*(y / double(H) - 0.5));
+		// DO IT (in place)
+		for(int i = 0; i < g; ++i){
+			check(kernel(queue, W, H, input, W, input));
 		}
-	}
 
-	// transfer data into buffers
-	cl::Buffer input(context, input_vector.begin(), input_vector.end(), false, true);
+		// read back
+		queue.finish();
 
-	int r = 80, g = 40, b = 20;
+		auto green = input_vector;
 
-	// DO IT (in place)
-	for(int i = 0; i < r; ++i){
-		check(kernel(queue, W, H, input, W, input));
-	}
+		// DO IT (in place)
+		for(int i = 0; i < b; ++i){
+			check(kernel(queue, W, H, input, W, input));
+		}
 
-	// read back
-	queue.finish();
+		// read back
+		queue.finish();
 
-	auto red = input_vector;
+		auto& blue = input_vector;
 
-	// DO IT (in place)
-	for(int i = 0; i < g; ++i){
-		check(kernel(queue, W, H, input, W, input));
+		// test
+		cout << "opencl is done" << endl;
+		png::ostream<> image(W, H, "test.png");
+		for(int i = 0; i < red.size(); ++i){
+			image << png::ostream<>::pixel(blue[i], red[i], green[i]);
+		}
+		cout << "png is saved" << endl;
 	}
+};
 
-	// read back
-	queue.finish();
-
-	auto green = input_vector;
 
-	// DO IT (in place)
-	for(int i = 0; i < b; ++i){
-		check(kernel(queue, W, H, input, W, input));
-	}
+int main() {
+	App a;
+	CLApp b;
 
-	// read back
-	queue.finish();
+	NSAppWrapper app;
 
-	auto& blue = input_vector;
+	app.create_window({
+		[&](ContextParameters){
+			a.initialize();
+			b.initialize();
+		},
+		[&](ContextParameters){
+			a.draw();
+		},
+		nullptr
+	});
 
-	// test
-	cout << "opencl is done" << endl;
-	png::ostream<> image(W, H, "test.png");
-	for(int i = 0; i < red.size(); ++i){
-		image << png::ostream<>::pixel(blue[i], red[i], green[i]);
-	}
-	cout << "png is saved" << endl;
+	app.run();
 }