Add back support for 221 VDB files

Signed-off-by: Dan Bailey <danbailey@ilm.com>

Author: danrbailey

openvdb/openvdb/codecs/ScalarLeafCodec.h

@@ -48,6 +48,21 @@ void readScalarLeafBuffers(LeafT& leaf, std::istream& is, bool saveFloatAsHalf,
     if (seekable)   valueMask.seek(is);
     else            valueMask.load(is);
 
+    // Pre-node-mask-compression format stored the origin and buffer count
+    // inline after the value mask.
+    int8_t numBuffers = 1;
+    if (io::getFormatVersion(is) < OPENVDB_FILE_VERSION_NODE_MASK_COMPRESSION) {
+        Coord origin;
+        is.read(reinterpret_cast<char*>(&origin), sizeof(Coord::ValueType) * 3);
+        leaf.setOrigin(origin);
+
+        is.read(reinterpret_cast<char*>(&numBuffers), sizeof(int8_t));
+
+        if (numBuffers > 1) {
+            OPENVDB_THROW(IoError, "Old file format 221 (FLOAT_FRUSTUM_BBOX) with multiple buffers is not supported");
+        }
+    }
+
     if (skip) {
         if (seekable) {
             io::readCompressedValues<StorageValueT, NodeMaskT>(is, nullptr, SIZE, valueMask, saveFloatAsHalf);

openvdb/openvdb/codecs/TopologyCodec.h

@@ -182,7 +182,9 @@ struct ReadTopologyOp
         valueMask.load(is);
         node.setValueMaskUnsafe(valueMask);
 
-        const Index numValues = NodeT::NUM_VALUES;
+        const bool oldVersion =
+            (io::getFormatVersion(is) < OPENVDB_FILE_VERSION_NODE_MASK_COMPRESSION);
+        const Index numValues = (oldVersion ? childMask.countOff() : NodeT::NUM_VALUES);
         {
             // Read in (and uncompress, if necessary) all of this node's values
             // into a contiguous array.
@@ -191,13 +193,27 @@ struct ReadTopologyOp
             io::readCompressedValues(is, values, numValues, valueMask, saveFloatAsHalf);
 
             // Copy values from the array into this node's table.
-            if constexpr (std::is_same_v<ValueT, StorageValueT>) {
-                for (auto iter = node.beginValueAll(); iter; ++iter) {
-                    node.setValueOnlyUnsafe(iter.pos(), values[iter.pos()]);
+            if (oldVersion) {
+                Index n = 0;
+                if constexpr (std::is_same_v<ValueT, StorageValueT>) {
+                    for (auto iter = node.beginValueAll(); iter; ++iter) {
+                        node.setValueOnlyUnsafe(iter.pos(), values[n++]);
+                    }
+                } else {
+                    for (auto iter = node.beginValueAll(); iter; ++iter) {
+                        node.setValueOnlyUnsafe(iter.pos(), static_cast<ValueT>(values[n++]));
+                    }
                 }
+                OPENVDB_ASSERT(n == numValues);
             } else {
-                for (auto iter = node.beginValueAll(); iter; ++iter) {
-                    node.setValueOnlyUnsafe(iter.pos(), static_cast<ValueT>(values[iter.pos()]));
+                if constexpr (std::is_same_v<ValueT, StorageValueT>) {
+                    for (auto iter = node.beginValueAll(); iter; ++iter) {
+                        node.setValueOnlyUnsafe(iter.pos(), values[iter.pos()]);
+                    }
+                } else {
+                    for (auto iter = node.beginValueAll(); iter; ++iter) {
+                        node.setValueOnlyUnsafe(iter.pos(), static_cast<ValueT>(values[iter.pos()]));
+                    }
                 }
             }
         }