DebugTools: fuzzy-compare floats in CompareMaterial.

As it should be. It would be silly to compare vectors this way (because
that's what the operator== does by default), but not scalars.

src/Magnum/DebugTools/CompareMaterial.cpp

@@ -91,9 +91,9 @@ bool attributesEqual(const Trade::MaterialAttributeData& a, const Trade::Materia
     CORRADE_INTERNAL_ASSERT(a.type() == b.type());
     switch(a.type()) {
         #define _c(type) case Trade::MaterialAttributeType::type:           \
-            return a.value<type>() == b.value<type>();
+            return Math::TypeTraits<type>::equals(a.value<type>(), b.value<type>());
         #define _ct(name, type) case Trade::MaterialAttributeType::name:    \
-            return a.value<type>() == b.value<type>();
+            return Math::TypeTraits<type>::equals(a.value<type>(), b.value<type>());
         _ct(Bool, bool)
         /* LCOV_EXCL_START */
         _c(Float)

src/Magnum/DebugTools/Test/CompareMaterialTest.cpp

@@ -80,6 +80,18 @@ const struct {
             {Trade::MaterialLayer::ClearCoat},
             {"name", "hello"_s},
         }, {1, 3, 4}}},
+    {"fuzzy compare",
+        Trade::MaterialData{Trade::MaterialType::Phong, {
+            {Trade::MaterialAttribute::Shininess, 2000.0f},
+            {Trade::MaterialAttribute::AlphaMask, 0.5f},
+            {Trade::MaterialAttribute::DiffuseTexture, 3u},
+        }},
+        Trade::MaterialData{Trade::MaterialType::Phong, {
+            {Trade::MaterialAttribute::Shininess, 2000.0f + 0.01f},
+            {Trade::MaterialAttribute::AlphaMask, 0.5f - 1.0e-6f},
+            {Trade::MaterialAttribute::DiffuseTexture, 3u},
+        }},
+    },
 };
 
 const struct {