1 files changed, 49 insertions, 0 deletions
diff --git a/extern/draco/draco/src/draco/compression/bit_coders/symbol_bit_decoder.cc b/extern/draco/draco/src/draco/compression/bit_coders/symbol_bit_decoder.cc
new file mode 100644
index 00000000000..8ed50ef92ec
--- /dev/null
+++ b/extern/draco/draco/src/draco/compression/bit_coders/symbol_bit_decoder.cc
@@ -0,0 +1,49 @@
+#include "draco/compression/bit_coders/symbol_bit_decoder.h"
+
+#include "draco/compression/entropy/symbol_decoding.h"
+
+namespace draco {
+
+bool SymbolBitDecoder::StartDecoding(DecoderBuffer *source_buffer) {
+  uint32_t size;
+  if (!source_buffer->Decode(&size)) {
+    return false;
+  }
+
+  symbols_.resize(size);
+  if (!DecodeSymbols(size, 1, source_buffer, symbols_.data())) {
+    return false;
+  }
+  std::reverse(symbols_.begin(), symbols_.end());
+  return true;
+}
+
+bool SymbolBitDecoder::DecodeNextBit() {
+  uint32_t symbol;
+  DecodeLeastSignificantBits32(1, &symbol);
+  DRACO_DCHECK(symbol == 0 || symbol == 1);
+  return symbol == 1;
+}
+
+void SymbolBitDecoder::DecodeLeastSignificantBits32(int nbits,
+                                                    uint32_t *value) {
+  DRACO_DCHECK_LE(1, nbits);
+  DRACO_DCHECK_LE(nbits, 32);
+  DRACO_DCHECK_NE(value, nullptr);
+  // Testing: check to make sure there is something to decode.
+  DRACO_DCHECK_GT(symbols_.size(), 0);
+
+  (*value) = symbols_.back();
+  symbols_.pop_back();
+
+  const int discarded_bits = 32 - nbits;
+  (*value) <<= discarded_bits;
+  (*value) >>= discarded_bits;
+}
+
+void SymbolBitDecoder::Clear() {
+  symbols_.clear();
+  symbols_.shrink_to_fit();
+}
+
+}  // namespace draco