diff --git a/testspr/test.sh b/testspr/test.sh
index db9b89c5..dd7eb7a5 100755
--- a/testspr/test.sh
+++ b/testspr/test.sh
@@ -11,6 +11,8 @@ gcc_version="4.7.0 4.7.1 4.7.2 4.7.3 4.8.0 4.8.1"
 clang_version="3.2 3.3"
 declare -a user_macros
 user_macros=()
+declare -a include_paths
+include_paths=()
 force=0
 declare -A version_specific_options
 version_specific_options=(
@@ -36,9 +38,9 @@ execute() {
 	fi
 }
 
-args=`getopt -o S:D:f -l stagedir:,gcc-version:,clang-version:,define:,force -- "$@"`
+args=`getopt -o S:D:I:f -l stagedir:,gcc-version:,clang-version:,define:,include:,force -- "$@"`
 if [ "$?" -ne 0 ]; then
-	echo >&2 -e ": \e[31musage: $0 [-S|--stagedir=path] [--gcc-version=versions] [--clang-version=versions] [-D|--define=identifier]* [-f|-force]\e[m"
+	echo >&2 -e ": \e[31musage: $0 [-S|--stagedir=path] [--gcc-version=versions] [--clang-version=versions] [-D|--define=identifier]* [-I|--include=path]* [-f|-force]\e[m"
 	exit 1
 fi
 eval set -- ${args}
@@ -48,6 +50,7 @@ while [ -n "$1" ]; do
 		--gcc-version) gcc_version="$2"; shift 2;;
 		--clang-version) clang_version="$2"; shift 2;;
 		-D|--define) user_macros=(${user_macros[@]} "$2"); shift 2;;
+		-I|--include) include_paths=(${include_paths[@]} "$2"); shift 2;;
 		-f|--force) force=1; shift;;
 		--) shift; break;;
 		*) echo >&2 -e ": \e[31munknown option($1) used.\e[m"; exit 1;;
@@ -58,6 +61,7 @@ echo ":   stagedir = \"${stagedir}\""
 echo ":   gcc-version = (${gcc_version})"
 echo ":   clang-version = (${clang_version})"
 echo ":   user-macros = (${user_macros[*]})"
+echo ":   include-paths = (${include_paths[*]})"
 echo ":   force = ${force}"
 
 if [ -d "${stagedir}" ]; then
@@ -75,12 +79,16 @@ for user_macro in ${user_macros}; do
 	define_options="${define_options} -D${user_macro}"
 done
 
+for include_path in ${include_paths}; do
+	include_options="${include_options} -I${include_path}"
+done
+
 for version in ${gcc_version}; do
-	compile gcc ${version} $(cd $(dirname $0); pwd)/sprout.cpp "${define_options} ${version_specific_options[gcc-${version}]}"
+	compile gcc ${version} $(cd $(dirname $0); pwd)/sprout.cpp "${define_options} ${include_options} ${version_specific_options[gcc-${version}]}"
 done
 
 for version in ${clang_version}; do
-	compile clang ${version} $(cd $(dirname $0); pwd)/sprout.cpp "${define_options} ${version_specific_options[clang-${version}]}"
+	compile clang ${version} $(cd $(dirname $0); pwd)/sprout.cpp "${define_options} ${include_options} ${version_specific_options[clang-${version}]}"
 done
 
 for version in ${gcc_version}; do
diff --git a/tools/compost/wavconv.cpp b/tools/compost/wavconv.cpp
index d54ca12c..d47636ea 100644
--- a/tools/compost/wavconv.cpp
+++ b/tools/compost/wavconv.cpp
@@ -15,23 +15,25 @@
 #include <iostream>
 #include <fstream>
 
-template<std::size_t N = 4, typename InputIterator>
-std::string read_chunk(InputIterator& it) {
-	std::string s;
-	for (std::size_t i = 0; i != N; ++i, ++it) {
-		s.push_back(*it);
+namespace toolspr {
+	template<std::size_t N = 4, typename InputIterator>
+	std::string read_chunk(InputIterator& it) {
+		std::string s;
+		for (std::size_t i = 0; i != N; ++i, ++it) {
+			s.push_back(*it);
+		}
+		return s;
 	}
-	return s;
-}
 
-template<typename IntType, typename InputIterator>
-IntType read_int(InputIterator& it) {
-	IntType n = 0;
-	for (std::size_t i = 0; i != sizeof(IntType); ++i, ++it) {
-		n |= static_cast<IntType>(static_cast<unsigned char>(*it)) << (i * CHAR_BIT);
+	template<typename IntType, typename InputIterator>
+	IntType read_int(InputIterator& it) {
+		IntType n = 0;
+		for (std::size_t i = 0; i != sizeof(IntType); ++i, ++it) {
+			n |= static_cast<IntType>(static_cast<unsigned char>(*it)) << (i * CHAR_BIT);
+		}
+		return n;
 	}
-	return n;
-}
+}	// namespace toolspr
 
 int main(int argc, char* argv[]) {
 	if (argc < 2) {
@@ -54,15 +56,15 @@ int main(int argc, char* argv[]) {
 			"\n"
 		;
 
-	if (read_chunk(it) != "RIFF") {
+	if (toolspr::read_chunk(it) != "RIFF") {
 		std::cerr
 			<< "#error not RIFF file.\n"
 			<< std::flush
 			;
 		return EXIT_FAILURE;
 	}
-	/*auto file_size = */read_int<std::uint32_t>(it);
-	if (read_chunk(it) != "WAVE") {
+	/*auto file_size = */toolspr::read_int<std::uint32_t>(it);
+	if (toolspr::read_chunk(it) != "WAVE") {
 		std::cerr
 			<< "#error not WAVE format.\n"
 			<< std::flush
@@ -70,17 +72,17 @@ int main(int argc, char* argv[]) {
 		return EXIT_FAILURE;
 	}
 
-	while (read_chunk(it) != "fmt ") {
-		auto chunk_size = read_int<std::uint32_t>(it);
+	while (toolspr::read_chunk(it) != "fmt ") {
+		auto chunk_size = toolspr::read_int<std::uint32_t>(it);
 		std::advance(it, chunk_size);
 	}
-	auto fmt_size = read_int<std::uint32_t>(it);
-	auto format_tag = read_int<std::uint16_t>(it);
-	auto channels = read_int<std::uint16_t>(it);
-	auto samples_per_sec = read_int<std::uint32_t>(it);
-	auto bytes_per_sec = read_int<std::uint32_t>(it);
-	auto block_size = read_int<std::uint16_t>(it);
-	auto bits_per_sample = read_int<std::uint16_t>(it);
+	auto fmt_size = toolspr::read_int<std::uint32_t>(it);
+	auto format_tag = toolspr::read_int<std::uint16_t>(it);
+	auto channels = toolspr::read_int<std::uint16_t>(it);
+	auto samples_per_sec = toolspr::read_int<std::uint32_t>(it);
+	auto bytes_per_sec = toolspr::read_int<std::uint32_t>(it);
+	auto block_size = toolspr::read_int<std::uint16_t>(it);
+	auto bits_per_sample = toolspr::read_int<std::uint16_t>(it);
 	std::cout
 		<< format_tag << ",\n"
 		<< channels << ",\n"
@@ -91,11 +93,11 @@ int main(int argc, char* argv[]) {
 		;
 	std::advance(it, fmt_size - 16);
 
-	while (read_chunk(it) != "data") {
-		auto chunk_size = read_int<std::uint32_t>(it);
+	while (toolspr::read_chunk(it) != "data") {
+		auto chunk_size = toolspr::read_int<std::uint32_t>(it);
 		std::advance(it, chunk_size);
 	}
-	auto data_size = read_int<std::uint32_t>(it);
+	auto data_size = toolspr::read_int<std::uint32_t>(it);
 	std::size_t size = data_size / (bits_per_sample / CHAR_BIT);
 	std::cout
 		<< size << "\n"
@@ -107,20 +109,20 @@ int main(int argc, char* argv[]) {
 		if (bits_per_sample == 16) {
 			for (std::size_t i = 1; i != size; ++i) {
 				std::cout
-					<< read_int<std::int16_t>(it) << ",\n"
+					<< toolspr::read_int<std::int16_t>(it) << ",\n"
 					;
 			}
 			std::cout
-				<< read_int<std::int16_t>(it) << "\n"
+				<< toolspr::read_int<std::int16_t>(it) << "\n"
 				;
 		} else if (bits_per_sample == 8) {
 			for (std::size_t i = 1; i != size; ++i) {
 				std::cout
-					<< read_int<std::uint8_t>(it) << ",\n"
+					<< toolspr::read_int<std::uint8_t>(it) << ",\n"
 					;
 			}
 			std::cout
-				<< read_int<std::uint8_t>(it) << "\n"
+				<< toolspr::read_int<std::uint8_t>(it) << "\n"
 				;
 		}
 	}
@@ -131,4 +133,3 @@ int main(int argc, char* argv[]) {
 		<< std::flush
 		;
 }
-
diff --git a/tools/compost/wave_io.hpp b/tools/compost/wave_io.hpp
new file mode 100644
index 00000000..c8cc611f
--- /dev/null
+++ b/tools/compost/wave_io.hpp
@@ -0,0 +1,176 @@
+/*=============================================================================
+  Copyright (c) 2011-2013 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef TOOLS_COMPOST_WAVE_IO_HPP
+#define TOOLS_COMPOST_WAVE_IO_HPP
+
+#include <climits>
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <algorithm>
+#include <ios>
+#include <iostream>
+#include <fstream>
+#include <type_traits>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <linux/soundcard.h>
+
+namespace toolspr {
+	//
+	// output_plot
+	//
+	//	output for gnuplot
+	//
+	template<typename Elem, typename Traits, typename InputRange>
+	std::basic_ostream<Elem, Traits>& output_plot(std::basic_ostream<Elem, Traits>& os, InputRange const& range) {
+		os << std::fixed;
+		unsigned x = 0;
+		for (auto const& e : range) {
+			os << x++ << ',' << e << '\n';
+		}
+		return os;
+	}
+	template<typename InputRange>
+	std::basic_ostream<Elem, Traits>& output_plot(std::string const& filename, InputRange const& range) {
+		std::ofstream os(filename);
+		output_plot(os, range);
+	}
+
+	//
+	// output_plot_real
+	//
+	//	output for gnuplot (only real part)
+	//
+	template<typename Elem, typename Traits, typename InputRange>
+	std::basic_ostream<Elem, Traits>& output_plot_real(std::basic_ostream<Elem, Traits>& os, InputRange const& range) {
+		os << std::fixed;
+		unsigned x = 0;
+		for (auto const& e : range) {
+			os << x++ << ',' << real(e) << '\n';
+		}
+		return os;
+	}
+	template<typename InputRange>
+	std::basic_ostream<Elem, Traits>& output_plot_real(std::string const& filename, InputRange const& range) {
+		std::ofstream os(filename);
+		output_plot_real(os, range);
+	}
+
+	//
+	// write_chunk
+	// write_int
+	// write_wav
+	//
+	//	write data for wav format
+	//
+	template<typename OutputIterator>
+	void write_chunk(OutputIterator& it, std::string const& s) {
+		it = std::copy(s.begin(), s.end(), it);
+	}
+	template<typename IntType, typename OutputIterator>
+	void write_int(OutputIterator& it, IntType const& n) {
+		for (std::size_t i = 0; i != sizeof(IntType); ++i, ++it) {
+			*it = static_cast<char>((static_cast<typename std::make_unsigned<IntType>::type>(n) >> (i * CHAR_BIT)) & 0xFF);
+		}
+	}
+	template<typename OutputIterator, typename InputRange>
+	void write_wav(OutputIterator& it, sprout::compost::sources::info_type const& info, InputRange const& data) {
+		std::size_t data_size = info.size * info.bits_per_sample / CHAR_BIT;
+
+		write_chunk(it, "RIFF");
+		write_int(it, 36 + data_size);
+		write_chunk(it, "WAVE");
+		write_chunk(it, "fmt ");
+		write_int(it, 16);
+		write_int(it, info.format_tag);
+		write_int(it, info.channels);
+		write_int(it, info.samples_per_sec);
+		write_int(it, info.bytes_per_sec);
+		write_int(it, info.block_size);
+		write_int(it, info.bits_per_sample);
+		write_chunk(it, "data");
+		write_int(it, data_size);
+		if (info.bits_per_sample == 16) {
+			for (auto e : data) {
+				write_int<std::int16_t>(it, e);
+			}
+		} else if (info.bits_per_sample == 8) {
+			for (auto e : data) {
+				write_int<std::uint8_t>(it, e);
+			}
+		}
+	}
+
+	//
+	// output_wav
+	//
+	//	output for wav format
+	//
+	template<typename Elem, typename Traits, typename InputRange>
+	void output_wav(std::basic_ostream<Elem, Traits>& os, sprout::compost::sources::info_type const& info, InputRange const& data) {
+		std::ostreambuf_iterator<Elem> it(os);
+		write_wav(it, info, data);
+	}
+	template<typename InputRange>
+	void output_wav(std::string const& filename, sprout::compost::sources::info_type const& info, InputRange const& data) {
+		std::ofstream os(filename, std::ios_base::out | std::ios_base::binary);
+		output_wav(os, info, data);
+	}
+
+	//
+	// setup_dev_dsp
+	//
+	//	Setting up dsp device
+	//
+	int setup_dev_dsp(sprout::compost::sources::info_type const& info) {
+		/* open of dsp device */
+		int fd = open("/dev/dsp", O_RDWR);
+		if (fd < 0) {
+			std::cerr << "open of /dev/dsp failed" << std::endl;
+			return -1;
+		}
+
+		/* initializations of dsp device */
+		int arg = 0;
+		int status = 0;
+		/* sampling bit rate */
+		arg = info.bits_per_sample;
+		status = ioctl(fd, SOUND_PCM_WRITE_BITS, &arg);
+		if (status == -1 || arg != info.bits_per_sample) {
+			return -1;
+		}
+		/* stereo or monoral */
+		arg = info.channels;
+		status = ioctl(fd, SOUND_PCM_WRITE_CHANNELS, &arg);
+		if (status == -1 || arg != info.channels) {
+			return -1;
+		}
+		/* sampling frequency */
+		arg = info.samples_per_sec;
+		status = ioctl(fd, SOUND_PCM_WRITE_RATE, &arg);
+		if (status == -1 || arg != static_cast<int>(info.samples_per_sec)) {
+			return -1;
+		}
+
+		return fd;
+	}
+
+	//
+	// write_dev_dsp
+	//
+	//	write to dsp device
+	//
+	ssize_t write_dev_dsp(int fd, void const* buf, std::size_t n) {
+		return write(fd, buf, n);
+	}
+}	// namespace toolspr
+
+#endif	// #ifndef TOOLS_COMPOST_WAVE_IO_HPP
diff --git a/tools/darkroom/darkcult.sh b/tools/darkroom/darkcult.sh
index 2b05dbff..263b9fd8 100755
--- a/tools/darkroom/darkcult.sh
+++ b/tools/darkroom/darkcult.sh
@@ -7,7 +7,7 @@
 # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 # =============================================================================
 #
-# requires: ImageMagick (http://www.imagemagick.org/script/index.php)
+# requires: Netpbm (http://netpbm.sourceforge.net/)
 #
 src="../../example/darkroom/two_spheres.hpp"
 stagedir="darkroom"
@@ -15,11 +15,13 @@ width=16
 height=16
 tile_width=16
 tile_height=16
+declare -a include_paths
+include_paths=()
 force=0
 
-args=`getopt -o s:S:w:h:W:H:f -l source:,stagedir:,width:,height:,tile-width:,tile-height:,force -- "$@"`
+args=`getopt -o s:S:w:h:W:H:I:f -l source:,stagedir:,width:,height:,tile-width:,tile-height:,include:,force -- "$@"`
 if [ "$?" -ne 0 ]; then
-	echo >&2 -e ": \e[31musage: $0 [-s|--source=file] [-S|--stagedir=path] [-w|--width=value] [-h|--height=value] [-W|--tile-width=value] [-H|--tile-height=value] [-f|-force]\e[m"
+	echo >&2 -e ": \e[31musage: $0 [-s|--source=file] [-S|--stagedir=path] [-w|--width=value] [-h|--height=value] [-W|--tile-width=value] [-H|--tile-height=value] [-I|--include=path]* [-f|-force]\e[m"
 	exit 1
 fi
 eval set -- ${args}
@@ -31,6 +33,7 @@ while [ -n "$1" ]; do
 		-h|--height) height=$2; shift 2;;
 		-W|--tile-width) tile_width=$2; shift 2;;
 		-H|--tile-height) tile_height=$2; shift 2;;
+		-I|--include) include_paths=(${include_paths[@]} "$2"); shift 2;;
 		-f|--force) force=1; shift;;
 		--) shift; break;;
 		*) echo >&2 -e ": \e[31munknown option($1) used.\e[m"; exit 1;;
@@ -44,6 +47,7 @@ echo ":   width = ${width}"
 echo ":   height = ${height}"
 echo ":   tile-width = ${tile_width}"
 echo ":   tile-height = ${tile_height}"
+echo ":   include-paths = (${include_paths[*]})"
 echo ":   force = ${force}"
 
 if [ ! -f "${src}" -a ! -f "$(cd $(dirname $0); pwd)/${src}" ]; then
@@ -62,6 +66,10 @@ else
 	mkdir -p ${stagedir}
 fi
 
+for include_path in ${include_paths}; do
+	include_options="${include_options} -I${include_path}"
+done
+
 echo ": start."
 start=${SECONDS}
 
@@ -73,6 +81,7 @@ for ((y=0; y<height; y+=tile_height)); do
 		mkdir -p ${stagedir}/${y}/
 		binname=${stagedir}/${y}/${x}.out
 		g++ -o ${binname} -std=c++11 \
+			${include_options} \
 			-DDARKROOM_SOURCE="\"${src}\"" \
 			-DDARKROOM_TOTAL_WIDTH=${width} \
 			-DDARKROOM_TOTAL_HEIGHT=${height} \
@@ -81,17 +90,18 @@ for ((y=0; y<height; y+=tile_height)); do
 			-DDARKROOM_OFFSET_X=${x} \
 			-DDARKROOM_OFFSET_Y=${y} \
 			$(cd $(dirname $0); pwd)/darkcult.cpp && ${binname} > ${stagedir}/${y}/${x}.ppm
-#		rm ${binname}
 	done
 	pushd ${stagedir}/${y}/ > /dev/null
-	convert +append $(ls *.ppm | sort -n) ../${y}.ppm
+#	convert +append $(ls *.ppm | sort -n) ../${y}.ppm
+	pnmcat -lr $(ls *.ppm | sort -n) > ../${y}.ppm
 	popd > /dev/null
 
 	let "y_elapsed=${SECONDS}-${y_start}"
 	echo ":   elapsed = ${y_elapsed}s"
 done
 pushd ${stagedir} > /dev/null
-convert -append $(ls *.ppm | sort -n) out.ppm
+#convert -append $(ls *.ppm | sort -n) out.ppm
+pnmcat -tb $(ls *.ppm | sort -n) > out.ppm
 popd > /dev/null
 
 let "elapsed=${SECONDS}-${start}"
diff --git a/tools/darkroom/texconv.cpp b/tools/darkroom/texconv.cpp
index ce2e7f17..5a07d014 100644
--- a/tools/darkroom/texconv.cpp
+++ b/tools/darkroom/texconv.cpp
@@ -69,4 +69,3 @@ int main(int argc, char* argv[]) {
 		<< std::flush
 		;
 }
-