1 files changed, 48 insertions, 12 deletions

diff --git a/src/animation/backend/animationutils.cpp b/src/animation/backend/animationutils.cpp
index 7051fd4d4..8308fab34 100644
--- a/src/animation/backend/animationutils.cpp
+++ b/src/animation/backend/animationutils.cpp
@@ -147,6 +147,17 @@ double phaseFromGlobalTime(double t_global, double t_start_global,
     return t_local / duration;
 }
 
+/*!
+    \internal
+
+    Calculates the indices required to map from the component ordering within the
+    provided \a channel, into the standard channel orderings expected by Qt types.
+
+    For example, given a channel representing a rotation with the components ordered
+    as X, Y, Z, Y, this function will return the indices [3, 0, 1, 2] which can then
+    later be used as part of the format vector in the formatClipResults() function to
+    remap the channels into the standard W, X, Y, Z order required by QQuaternion.
+*/
 ComponentIndices channelComponentsToIndices(const Channel &channel, int dataType, int offset)
 {
 #if defined Q_COMPILER_UNIFORM_INIT
@@ -170,9 +181,9 @@ ComponentIndices channelComponentsToIndices(const Channel &channel, int dataType
 }
 
 ComponentIndices channelComponentsToIndicesHelper(const Channel &channel,
-                                              int dataType,
-                                              int offset,
-                                              const QVector<char> &suffixes)
+                                                  int dataType,
+                                                  int offset,
+                                                  const QVector<char> &suffixes)
 {
     const int expectedComponentCount = componentsForType(dataType);
     const int actualComponentCount = channel.channelComponents.size();
@@ -182,15 +193,37 @@ ComponentIndices channelComponentsToIndicesHelper(const Channel &channel,
     }
 
     ComponentIndices indices(expectedComponentCount);
+
+    // Generate the set of channel suffixes
+    QVector<char> channelSuffixes;
+    channelSuffixes.reserve(expectedComponentCount);
     for (int i = 0; i < expectedComponentCount; ++i) {
         const QString &componentName = channel.channelComponents[i].name;
-        char suffix = componentName.at(componentName.length() - 1).toLatin1();
-        int index = suffixes.indexOf(suffix);
+
+        // An unset component name indicates that the no mapping is necessary
+        // and the index can be used as-is.
+        if (componentName.isEmpty()) {
+            indices[i] = i + offset;
+            continue;
+        }
+
+        char channelSuffix = componentName.at(componentName.length() - 1).toLatin1();
+        channelSuffixes.push_back(channelSuffix);
+    }
+
+    // We can short-circuit if the channels were all unnamed (in order)
+    if (channelSuffixes.isEmpty())
+        return indices;
+
+    // Find index of standard index in channel indexes
+    for (int i = 0; i < expectedComponentCount; ++i) {
+        int index = channelSuffixes.indexOf(suffixes[i]);
         if (index != -1)
             indices[i] = index + offset;
         else
             indices[i] = -1;
     }
+
     return indices;
 }
 
@@ -456,16 +489,14 @@ ComponentIndices generateClipFormatIndices(const QVector<ChannelNameAndType> &ta
         const int componentCount = targetIndices[i].size();
 
         if (clipChannelIndex != -1) {
-            // Found a matching channel in the clip. Get the base channel
-            // component index and populate the format indices for this channel.
+            // Found a matching channel in the clip. Populate the corresponding
+            // entries in the format vector with the *source indices*
+            // needed to build the formatted results.
             const int baseIndex = clip->channelComponentBaseIndex(clipChannelIndex);
-
-            // Within this group, match channel names with index ordering
             const auto channelIndices = channelComponentsToIndices(clip->channels()[clipChannelIndex],
                                                                    targetChannel.type,
                                                                    baseIndex);
             std::copy(channelIndices.begin(), channelIndices.end(), formatIt);
-
         } else {
             // No such channel in this clip. We'll use default values when
             // mapping from the clip to the formatted clip results.
@@ -486,11 +517,16 @@ ClipResults formatClipResults(const ClipResults &rawClipResults,
     ClipResults formattedClipResults(elementCount);
 
     // Perform a gather operation to format the data
+
     // TODO: For large numbers of components do this in parallel with
     // for e.g. a parallel_for() like construct
+    // TODO: We could potentially avoid having holes in these intermediate
+    // vectors by adjusting the component indices stored in the MappingData
+    // and format vectors. Needs careful investigation!
     for (int i = 0; i < elementCount; ++i) {
-        const float value = format[i] != -1 ? rawClipResults[format[i]] : 0.0f;
-        formattedClipResults[i] = value;
+        if (format[i] == -1)
+            continue;
+        formattedClipResults[i] = rawClipResults[format[i]];
     }
 
     return formattedClipResults;