new file mode 100644

@@ -0,0 +1,32 @@

+#include "samplecache.h"

+

+static inline constexpr uint64_t makeKey(uint32_t base, uint16_t loop, uint32_t length)

+{

+  return

+    // has to be 32-bit aligned, so 2 low bits aren't needed

+    // has to fit in the memory map, so high 7 bits aren't needed

+    (uint64_t(base & 0x01FFFFFC) >> 2) |

+    // loop uses the full 16 bits

+    uint64_t(loop << 23) |

+    // max length is 21 bits

+    (uint64_t(length & 0x1FFFFF) << 39);

+}

+

+const SampleData& SampleCache::getSample(uint32_t baseAddr, uint16_t loopStartWords, uint32_t loopLengthWords, SampleData::Format format)

+{

+  uint64_t key = makeKey(baseAddr, loopStartWords, loopLengthWords);

+  auto iter = samples.find(key);

+  if (iter == samples.end()) {

+    iter = samples.emplace(

+      std::piecewise_construct,

+      std::forward_as_tuple(key),

+      std::forward_as_tuple(baseAddr, loopStartWords << 2, (loopStartWords + loopLengthWords) << 2, format)

+    ).first;

+  }

+  return iter->second;

+}

+

+void SampleCache::clear()

+{

+  samples.clear();

+}