De-duplicate LoadSampleArray and FmtTypeTraits

1 files changed, 81 insertions, 0 deletions

diff --git a/alc/fmt_traits.h b/alc/fmt_traits.h
new file mode 100644
index 00000000..c3bf5fa5
--- /dev/null
+++ b/alc/fmt_traits.h
@@ -0,0 +1,81 @@
+#ifndef ALC_FMT_TRAITS_H
+#define ALC_FMT_TRAITS_H
+
+#include <cstddef>
+#include <cstdint>
+
+#include "albyte.h"
+#include "buffer_formats.h"
+
+
+namespace al {
+
+extern const int16_t muLawDecompressionTable[256];
+extern const int16_t aLawDecompressionTable[256];
+
+
+template<FmtType T>
+struct FmtTypeTraits { };
+
+template<>
+struct FmtTypeTraits<FmtUByte> {
+    using Type = uint8_t;
+
+    template<typename OutT>
+    static constexpr inline OutT to(const Type val) noexcept
+    { return val*OutT{1.0/128.0} - OutT{1.0}; }
+};
+template<>
+struct FmtTypeTraits<FmtShort> {
+    using Type = int16_t;
+
+    template<typename OutT>
+    static constexpr inline OutT to(const Type val) noexcept { return val*OutT{1.0/32768.0}; }
+};
+template<>
+struct FmtTypeTraits<FmtFloat> {
+    using Type = float;
+
+    template<typename OutT>
+    static constexpr inline OutT to(const Type val) noexcept { return val; }
+};
+template<>
+struct FmtTypeTraits<FmtDouble> {
+    using Type = double;
+
+    template<typename OutT>
+    static constexpr inline OutT to(const Type val) noexcept { return static_cast<OutT>(val); }
+};
+template<>
+struct FmtTypeTraits<FmtMulaw> {
+    using Type = uint8_t;
+
+    template<typename OutT>
+    static constexpr inline OutT to(const Type val) noexcept
+    { return muLawDecompressionTable[val] * OutT{1.0/32768.0}; }
+};
+template<>
+struct FmtTypeTraits<FmtAlaw> {
+    using Type = uint8_t;
+
+    template<typename OutT>
+    static constexpr inline OutT to(const Type val) noexcept
+    { return aLawDecompressionTable[val] * OutT{1.0/32768.0}; }
+};
+
+
+template<FmtType SrcType, typename DstT>
+inline void LoadSampleArray(DstT *RESTRICT dst, const al::byte *src, const size_t srcstep,
+    const size_t samples) noexcept
+{
+    using TypeTraits = FmtTypeTraits<SrcType>;
+    using SampleType = typename TypeTraits::Type;
+
+    const SampleType *RESTRICT ssrc{reinterpret_cast<const SampleType*>(src)};
+    for(size_t i{0u};i < samples;i++)
+        dst[i] = TypeTraits::template to<DstT>(ssrc[i*srcstep]);
+}
+
+} // namespace al
+
+#endif /* ALC_FMT_TRAITS_H */