Trade: non-random defaults for PhongMaterialData.

src/Magnum/Trade/PhongMaterialData.cpp

@@ -29,6 +29,25 @@
 
 namespace Magnum { namespace Trade {
 
+using namespace Math::Literals;
+
+PhongMaterialData::PhongMaterialData(const Flags flags, const Float shininess, const void* const importerState) noexcept: AbstractMaterialData{MaterialType::Phong, importerState}, _flags{flags}, _shininess{shininess} {
+    if(_flags & Flag::AmbientTexture)
+        _ambient.texture = {};
+    else
+        _ambient.color = 0x000000ff_rgbaf;
+
+    if(_flags & Flag::DiffuseTexture)
+        _diffuse.texture = {};
+    else
+        _diffuse.color = 0xffffffff_rgbaf;
+
+    if(_flags & Flag::SpecularTexture)
+        _specular.texture = {};
+    else
+        _specular.color = 0xffffffff_rgbaf;
+}
+
 PhongMaterialData::PhongMaterialData(PhongMaterialData&& other) noexcept: AbstractMaterialData{std::move(other)}, _flags{other._flags}, _shininess{other._shininess} {
     if(_flags & Flag::AmbientTexture)
         _ambient.texture = other._ambient.texture;

src/Magnum/Trade/PhongMaterialData.h

@@ -71,9 +71,12 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public AbstractMaterialData {
          * @param importerState     Importer-specific state
          *
          * Colors and textures should be specified using member functions based
-         * on what flags are set.
+         * on what flags are set. Ambient color (if set) is by default
+         * @cpp 0x000000ff_rgbaf @ce, diffuse and specular color is by default
+         * @cpp 0xffffffff_rgbaf @ce, all texture IDs (if any) are by default
+         * set to @cpp 0 @ce.
          */
-        explicit PhongMaterialData(Flags flags, Float shininess, const void* importerState = nullptr) noexcept: AbstractMaterialData{MaterialType::Phong, importerState}, _flags{flags}, _shininess{shininess} {}
+        explicit PhongMaterialData(Flags flags, Float shininess, const void* importerState = nullptr) noexcept;
 
         /** @brief Copying is not allowed */
         PhongMaterialData(const PhongMaterialData&) = delete;