Extract (some) Writer classes to separate files.

TODO: PNGWriter could probably reuse this stuff too, but...

firmware/application/io_wave.hpp

@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2016 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#pragma once
+
+#include "io_file.hpp"
+
+#include "file.hpp"
+#include "optional.hpp"
+
+#include <cstddef>
+#include <cstdint>
+
+class WAVFileWriter : public FileWriter {
+public:
+	WAVFileWriter(
+		size_t sampling_rate
+	) : header { sampling_rate }
+	{
+	}
+
+
+	WAVFileWriter(const WAVFileWriter&) = delete;
+	WAVFileWriter& operator=(const WAVFileWriter&) = delete;
+	WAVFileWriter(WAVFileWriter&&) = delete;
+	WAVFileWriter& operator=(WAVFileWriter&&) = delete;
+
+	~WAVFileWriter() {
+		update_header();
+	}
+
+	Optional<File::Error> create(
+		const std::filesystem::path& filename
+	) {
+		const auto create_error = FileWriter::create(filename);
+		if( create_error.is_valid() ) {
+			return create_error;
+		} else {
+			return update_header();
+		}
+	}
+
+private:
+	struct fmt_pcm_t {
+		constexpr fmt_pcm_t(
+			const uint32_t sampling_rate
+		) : nSamplesPerSec { sampling_rate },
+			nAvgBytesPerSec { nSamplesPerSec * nBlockAlign }
+		{
+		}
+
+	private:
+		const uint8_t ckID[4] { 'f', 'm', 't', ' ' };
+		const uint32_t cksize { 16 };
+		const uint16_t wFormatTag { 0x0001 };
+		const uint16_t nChannels { 1 };
+		const uint32_t nSamplesPerSec;
+		const uint32_t nAvgBytesPerSec;
+		const uint16_t nBlockAlign { 2 };
+		const uint16_t wBitsPerSample { 16 };
+	};
+
+	struct data_t {
+		void set_size(const uint32_t value) {
+			cksize = value;
+		}
+
+	private:
+		const uint8_t ckID[4] { 'd', 'a', 't', 'a' };
+		uint32_t cksize { 0 };
+	};
+
+	struct header_t {
+		constexpr header_t(
+			const uint32_t sampling_rate
+		) : fmt { sampling_rate }
+		{
+		}
+
+		void set_data_size(const uint32_t value) {
+			data.set_size(value);
+			cksize = sizeof(header_t) + value - 8;
+		}
+
+	private:
+		const uint8_t riff_id[4] { 'R', 'I', 'F', 'F' };
+		uint32_t cksize { 0 };
+		const uint8_t wave_id[4] { 'W', 'A', 'V', 'E' };
+		fmt_pcm_t fmt;
+		data_t data;
+	};
+
+	header_t header;
+
+	Optional<File::Error> update_header() {
+		header.set_data_size(bytes_written);
+		const auto seek_0_result = file.seek(0);
+		if( seek_0_result.is_error() ) {
+			return seek_0_result.error();
+		}
+		const auto old_position = seek_0_result.value();
+		const auto write_result = file.write(&header, sizeof(header));
+		if( write_result.is_error() ) {
+			return write_result.error();
+		}
+		const auto seek_old_result = file.seek(old_position);
+		if( seek_old_result.is_error() ) {
+			return seek_old_result.error();
+		}
+		return { };
+	}
+};