[Performous-commit] Lasse Karkkainen : Implement sample iterators and multichannel capture

[Lasse Kärkkäi. <tr...@us...>]

Module: performous
Branch: master
Commit: 07e9e2fa72fc060cf47a0bfc4476b26052689e17

Author: Lasse Karkkainen <tro...@tr...>
Date:   Sun Jul 18 19:08:15 2010 +0300

Implement sample iterators and multichannel capture

---

 game/audio.cc                       |    9 +++++----
 libs/libda/include/libda/sample.hpp |   16 ++++++++++++++++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/game/audio.cc b/game/audio.cc
index b92e325..458ee35 100644
--- a/game/audio.cc
+++ b/game/audio.cc
@@ -273,13 +273,14 @@ struct Device {
 	}
 
 	int operator()(void const* input, void* output, unsigned long frames, const PaStreamCallbackTimeInfo*, PaStreamCallbackFlags) try {
-		float const* in = static_cast<float const*>(input);
-		float* out = static_cast<float*>(output);
+		float const* inbuf = static_cast<float const*>(input);
+		float* outbuf = static_cast<float*>(output);
 		for (std::size_t i = 0; i < mics.size(); ++i) {
 			if (!mics[i]) continue;  // No analyzer? -> Channel not used
-			mics[i]->input(in, in + 1 * frames); // FIXME: needs libda iterators for multiple channel support
+			da::sample_const_iterator it = da::sample_const_iterator(inbuf + i, in);
+			mics[i]->input(it, it + frames);
 		}
-		if (outptr) outptr->callback(out, out + 2 * frames);
+		if (outptr) outptr->callback(outbuf, outbuf + 2 * frames);
 		return paContinue;
 	} catch (std::exception& e) {
 		std::cerr << "Exception in audio callback: " << e.what() << std::endl;
diff --git a/libs/libda/include/libda/sample.hpp b/libs/libda/include/libda/sample.hpp
index 58502e0..29383e7 100644
--- a/libs/libda/include/libda/sample.hpp
+++ b/libs/libda/include/libda/sample.hpp
@@ -49,6 +49,22 @@ namespace da {
 	static inline int conv_to_s16_fast(sample_t s) { return static_cast<int>(s * max_s16); }
 	static inline int conv_to_s24_fast(sample_t s) { return static_cast<int>(s * max_s24); }
 	static inline int conv_to_s32_fast(sample_t s) { return static_cast<int>(s * max_s32); }
+
+	template <typename ValueType> class step_iterator: public std::iterator<std::random_access_iterator_tag, ValueType> {
+		ValueType* m_pos;
+		std::ptrdiff_t m_step;
+	  public:
+		step_iterator(ValueType* pos, std::ptrdiff_t step): m_pos(pos), m_step(step) {}
+		ValueType& operator*() { return *m_pos; }
+		step_iterator operator+(std::ptrdiff_t rhs) { return step_iterator(m_pos + m_step * rhs, m_step); }
+		step_iterator& operator++() { m_pos += m_step; return *this; }
+		bool operator!=(step_iterator const& rhs) const { return m_pos != rhs.m_pos; }
+		std::ptrdiff_t operator-(step_iterator const& rhs) const { return (m_pos - rhs.m_pos) / m_step; }
+		// TODO: more operators
+	};
+
+	typedef step_iterator<sample_t> sample_iterator;
+	typedef step_iterator<sample_t const> sample_const_iterator;
 }
 
 #endif