Trade: add a similar assert check for Phong textureMatrix as well.

src/Magnum/Trade/PhongMaterialData.cpp

@@ -34,6 +34,8 @@ using namespace Math::Literals;
 PhongMaterialData::PhongMaterialData(const Flags flags, const Color4& ambientColor, const UnsignedInt ambientTexture, const UnsignedInt ambientCoordinateSet, const Color4& diffuseColor, const UnsignedInt diffuseTexture, const UnsignedInt diffuseCoordinateSet, const Color4& specularColor, const UnsignedInt specularTexture, const UnsignedInt specularCoordinateSet, const UnsignedInt normalTexture, const UnsignedInt normalCoordinateSet, const Matrix3& textureMatrix, const MaterialAlphaMode alphaMode, const Float alphaMask, const Float shininess, const void* const importerState) noexcept: AbstractMaterialData{MaterialType::Phong, AbstractMaterialData::Flag(UnsignedShort(flags)), alphaMode, alphaMask, importerState}, _ambientColor{ambientColor}, _diffuseColor{diffuseColor}, _specularColor{specularColor}, _shininess{shininess} {
     CORRADE_ASSERT(!(flags & Flag::TextureTransformation) || (flags & (Flag::AmbientTexture|Flag::DiffuseTexture|Flag::SpecularTexture|Flag::NormalTexture)),
         "Trade::PhongMaterialData: texture transformation enabled but the material has no textures", );
+    CORRADE_ASSERT((flags & Flag::TextureTransformation) || textureMatrix == Matrix3{},
+        "PhongMaterialData::PhongMaterialData: non-default texture matrix requires Flag::TextureTransformation to be enabled", );
     CORRADE_ASSERT((flags & Flag::TextureCoordinateSets) || (ambientCoordinateSet == 0 && diffuseCoordinateSet == 0 && specularCoordinateSet == 0 && normalCoordinateSet == 0),
         "PhongMaterialData::PhongMaterialData: non-zero texture coordinate sets require Flag::TextureCoordinateSets to be enabled", );
 

src/Magnum/Trade/PhongMaterialData.h

@@ -110,8 +110,7 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public AbstractMaterialData {
          *      doesn't have @ref Flag::SpecularTexture.
          * @param normalTexture     Normal texture ID. Ignored if @p flags
          *      doesn't have @ref Flag::NormalTexture.
-         * @param textureMatrix     Texture coordinate transformation. Ignored
-         *      if @p flags doesn't have @ref Flag::TextureTransformation.
+         * @param textureMatrix     Texture coordinate transformation
          * @param alphaMode         Alpha mode. Use
          *      @ref MaterialAlphaMode::Opaque for a default value.
          * @param alphaMask         Alpha mask value. Use @cpp 0.5f @ce for a
@@ -122,7 +121,8 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public AbstractMaterialData {
          * @m_since_latest
          *
          * All `*CoordinateSet` accessors are implicitly zero with this
-         * constructor.
+         * constructor. If @p textureMatrix is not default-constructed, expects
+         * @ref Flag::TextureTransformation to be enabled as well.
          */
         explicit PhongMaterialData(Flags flags, const Color4& ambientColor, UnsignedInt ambientTexture, const Color4& diffuseColor, UnsignedInt diffuseTexture, const Color4& specularColor, UnsignedInt specularTexture, UnsignedInt normalTexture, const Matrix3& textureMatrix, MaterialAlphaMode alphaMode, Float alphaMask, Float shininess, const void* importerState = nullptr) noexcept;
 
@@ -155,9 +155,7 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public AbstractMaterialData {
          *      doesn't have @ref Flag::NormalTexture.
          * @param normalCoordinateSet   Normal texture coordinate set. Ignored
          *      if @p flags doesn't have @ref Flag::NormalTexture.
-         * @param textureMatrix         Texture coordinate transformation.
-         *      Ignored if @p flags doesn't have
-         *      @ref Flag::TextureTransformation.
+         * @param textureMatrix         Texture coordinate transformation
          * @param alphaMode             Alpha mode. Use
          *      @ref MaterialAlphaMode::Opaque for a default value.
          * @param alphaMask             Alpha mask value. Use @cpp 0.5f @ce for
@@ -167,8 +165,10 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public AbstractMaterialData {
          * @param importerState         Importer-specific state
          * @m_since_latest
          *
-         * If any `*CoordinateSet` is non-zero, expects
-         * @ref Flag::TextureCoordinateSets to be enabled as well.
+         * If @p textureMatrix is not default-constructed, expects
+         * @ref Flag::TextureTransformation to be enabled as well. If any
+         * `*CoordinateSet` is non-zero, expects @ref Flag::TextureCoordinateSets
+         * to be enabled as well.
          */
         explicit PhongMaterialData(Flags flags, const Color4& ambientColor, UnsignedInt ambientTexture, UnsignedInt ambientCoordinateSet, const Color4& diffuseColor, UnsignedInt diffuseTexture, UnsignedInt diffuseCoordinateSet, const Color4& specularColor, UnsignedInt specularTexture, UnsignedInt specularCoordinateSet, UnsignedInt normalTexture, UnsignedInt normalCoordinateSet, const Matrix3& textureMatrix, MaterialAlphaMode alphaMode, Float alphaMask, Float shininess, const void* importerState = nullptr) noexcept;
 

src/Magnum/Trade/Test/MaterialDataTest.cpp

@@ -40,6 +40,7 @@ class MaterialDataTest: public TestSuite::Tester {
         void constructPhongTexturedTextureTransform();
         void constructPhongTexturedCoordinateSets();
         void constructPhongTextureTransformNoTextures();
+        void constructPhongNoTextureTransformationFlag();
         void constructPhongNoTextureCoordinateSetsFlag();
         void constructCopy();
         void constructMovePhong();
@@ -61,6 +62,7 @@ MaterialDataTest::MaterialDataTest() {
               &MaterialDataTest::constructPhongTexturedTextureTransform,
               &MaterialDataTest::constructPhongTexturedCoordinateSets,
               &MaterialDataTest::constructPhongTextureTransformNoTextures,
+              &MaterialDataTest::constructPhongNoTextureTransformationFlag,
               &MaterialDataTest::constructPhongNoTextureCoordinateSetsFlag,
               &MaterialDataTest::constructCopy,
               &MaterialDataTest::constructMovePhong,
@@ -204,6 +206,24 @@ void MaterialDataTest::constructPhongTextureTransformNoTextures() {
         "Trade::PhongMaterialData: texture transformation enabled but the material has no textures\n");
 }
 
+void MaterialDataTest::constructPhongNoTextureTransformationFlag() {
+    using namespace Math::Literals;
+
+    #ifdef CORRADE_NO_ASSERT
+    CORRADE_SKIP("CORRADE_NO_ASSERT defined, can't test assertions");
+    #endif
+
+    std::ostringstream out;
+    Error redirectError{&out};
+    PhongMaterialData a{{},
+        {}, {},
+        {}, {},
+        {}, {}, {}, Matrix3::rotation(90.0_degf),
+        {}, 0.5f, 80.0f};
+    CORRADE_COMPARE(out.str(),
+        "PhongMaterialData::PhongMaterialData: non-default texture matrix requires Flag::TextureTransformation to be enabled\n");
+}
+
 void MaterialDataTest::constructPhongNoTextureCoordinateSetsFlag() {
     #ifdef CORRADE_NO_ASSERT
     CORRADE_SKIP("CORRADE_NO_ASSERT defined, can't test assertions");