{Material,Mesh,SceneTools}: use Utility::copyMasked() in filter*().

It's not really implemented in a fast way yet, but that doesn't mean the
custom loops were any better.

src/Magnum/MaterialTools/Filter.cpp

@@ -28,6 +28,7 @@
 #include <Corrade/Containers/BitArray.h>
 #include <Corrade/Containers/StridedBitArrayView.h>
 #include <Corrade/Utility/Algorithms.h>
+#include <Corrade/Utility/BitAlgorithms.h>
 
 #include "Magnum/Trade/MaterialData.h"
 
@@ -99,13 +100,7 @@ Trade::MaterialData filterAttributesLayersImplementation(const Trade::MaterialDa
     /* Copy attributes that aren't filtered away. Not using NoInit in order to
        use the default deleter and have this usable from plugins. */
     Containers::Array<Trade::MaterialAttributeData> attributes{patchedInputAttributesToKeep.count()};
-    /** @todo some copyMasked() utility */
-    UnsignedInt attributeOffset = 0;
-    for(UnsignedInt i = 0; i != totalAttributeCount; ++i) {
-        if(!patchedInputAttributesToKeep[i]) continue;
-        attributes[attributeOffset++] = material.attributeData()[i];
-    }
-    CORRADE_INTERNAL_ASSERT(attributeOffset == attributes.size());
+    Utility::copyMasked(material.attributeData(), patchedInputAttributesToKeep, attributes);
 
     return Trade::MaterialData{material.types() & typesToKeep, std::move(attributes), std::move(layers)};
 }

src/Magnum/MeshTools/Filter.cpp

@@ -27,6 +27,7 @@
 
 #include <Corrade/Containers/BitArray.h>
 #include <Corrade/Containers/BitArrayView.h>
+#include <Corrade/Utility/BitAlgorithms.h>
 
 #include "Magnum/Trade/MeshData.h"
 
@@ -43,14 +44,8 @@ Trade::MeshData filterAttributes(const Trade::MeshData& mesh, const Containers::
 
     /* Copy attributes that aren't filtered away. Not using NoInit in order to
        use the default deleter and have this usable from plugins. */
-    Containers::Array<Trade::MeshAttributeData> filtered{attributesToKeep.count()};
-    /** @todo some copyMasked() utility */
-    UnsignedInt attributeOffset = 0;
-    for(UnsignedInt i = 0; i != attributesToKeep.size(); ++i) {
-        if(!attributesToKeep[i]) continue;
-        filtered[attributeOffset++] = mesh.attributeData()[i];
-    }
-    CORRADE_INTERNAL_ASSERT(attributeOffset == filtered.size());
+    Containers::Array<Trade::MeshAttributeData> filtered{ValueInit, attributesToKeep.count()};
+    Utility::copyMasked(mesh.attributeData(), attributesToKeep, filtered);
 
     /* Can't do just Trade::MeshIndexData{data.indices()} as that would discard
        implementation-specific types. And can't do

src/Magnum/SceneTools/Filter.cpp

@@ -42,14 +42,10 @@ Trade::SceneData filterFields(const Trade::SceneData& scene, const Containers::B
     CORRADE_ASSERT(fieldsToKeep.size() == scene.fieldCount(),
         "SceneTools::filterFields(): expected" << scene.fieldCount() << "bits but got" << fieldsToKeep.size(), (Trade::SceneData{Trade::SceneMappingType::UnsignedInt, 0, nullptr, {}}));
 
+    /* Copy fields that aren't filtered away. Not using NoInit in order to use
+       the default deleter and have this usable from plugins. */
     Containers::Array<Trade::SceneFieldData> filtered{ValueInit, fieldsToKeep.count()};
-    std::size_t offset = 0;
-    /** @todo some "iterate set bits" API */
-    for(std::size_t i = 0; i != fieldsToKeep.size(); ++i) {
-        if(!fieldsToKeep[i]) continue;
-        filtered[offset++] = scene.fieldData(i);
-    }
-    CORRADE_INTERNAL_ASSERT(offset == filtered.size());
+    Utility::copyMasked(scene.fieldData(), fieldsToKeep, filtered);
 
     return Trade::SceneData{scene.mappingType(), scene.mappingBound(),
         {}, scene.data(), std::move(filtered)};