Deprecate passing nullptr to images.

Causes too much pain. Ugh.

doc/changelog.dox

@@ -550,6 +550,9 @@ See also:
     use the non-templated version together with
     @ref Corrade::Containers::arrayCast() instead for properly bounds-checked
     type conversion
+-   Passing @cpp nullptr @ce to @ref ImageView constructors is deprecated and
+    will print a warning at runtime. Use a constructor without the @p data
+    parameter instead.
 
 @subsection changelog-latest-compatibility Potential compatibility breakages, removed APIs
 

src/Magnum/DebugTools/Test/CompareImageTest.cpp

@@ -493,8 +493,9 @@ void CompareImageTest::pixelDeltaSpecials() {
 void CompareImageTest::compareDifferentSize() {
     std::stringstream out;
 
-    ImageView2D a{PixelFormat::RG8UI, {3, 4}, nullptr};
+    char data[8*5];
-    ImageView2D b{PixelFormat::RG8UI, {3, 5}, nullptr};
+    ImageView2D a{PixelFormat::RG8UI, {3, 4}, data};
+    ImageView2D b{PixelFormat::RG8UI, {3, 5}, data};
 
     {
         TestSuite::Comparator<CompareImage> compare{{}, {}};
@@ -511,8 +512,9 @@ void CompareImageTest::compareDifferentSize() {
 void CompareImageTest::compareDifferentFormat() {
     std::stringstream out;
 
-    ImageView2D a{PixelFormat::RGBA32F, {3, 4}, nullptr};
+    char data[16*12];
-    ImageView2D b{PixelFormat::RGB32F, {3, 4}, nullptr};
+    ImageView2D a{PixelFormat::RGBA32F, {3, 4}, data};
+    ImageView2D b{PixelFormat::RGB32F, {3, 4}, data};
 
     {
         TestSuite::Comparator<CompareImage> compare{{}, {}};

src/Magnum/ImageView.cpp

@@ -35,7 +35,15 @@ template<UnsignedInt dimensions, class T> ImageView<dimensions, T>::ImageView(co
 template<UnsignedInt dimensions, class T> ImageView<dimensions, T>::ImageView(const PixelStorage storage, const UnsignedInt format, const UnsignedInt formatExtra, const UnsignedInt pixelSize, const VectorTypeFor<dimensions, Int>& size, const Containers::ArrayView<ErasedType> data) noexcept: ImageView{storage, pixelFormatWrap(format), formatExtra, pixelSize, size, data} {}
 
 template<UnsignedInt dimensions, class T> ImageView<dimensions, T>::ImageView(const PixelStorage storage, const PixelFormat format, const UnsignedInt formatExtra, const UnsignedInt pixelSize, const VectorTypeFor<dimensions, Int>& size, const Containers::ArrayView<ErasedType> data) noexcept: _storage{storage}, _format{format}, _formatExtra{formatExtra}, _pixelSize{pixelSize}, _size{size}, _data{reinterpret_cast<Type*>(data.data()), data.size()} {
+    #ifdef MAGNUM_BUILD_DEPRECATED
+    #ifndef CORRADE_NO_ASSERT
+    if(size.product() && !_data && !_data.size())
+        Warning{} << "ImageView::ImageView(): passing empty data to a non-empty view is deprecated, use a constructor without the data parameter instead";
+    #endif
     CORRADE_ASSERT(!_data || Implementation::imageDataSize(*this) <= _data.size(), "ImageView::ImageView(): data too small, got" << _data.size() << "but expected at least" << Implementation::imageDataSize(*this) << "bytes", );
+    #else
+    CORRADE_ASSERT(Implementation::imageDataSize(*this) <= _data.size(), "ImageView::ImageView(): data too small, got" << _data.size() << "but expected at least" << Implementation::imageDataSize(*this) << "bytes", );
+    #endif
 }
 
 template<UnsignedInt dimensions, class T> ImageView<dimensions, T>::ImageView(const PixelStorage storage, const PixelFormat format, const VectorTypeFor<dimensions, Int>& size) noexcept: ImageView{storage, format, {}, Magnum::pixelSize(format), size} {}

src/Magnum/Test/ImageViewTest.cpp

@@ -39,10 +39,8 @@ struct ImageViewTest: TestSuite::Tester {
 
     template<class T> void constructGeneric();
     template<class T> void constructGenericEmpty();
-    template<class T> void constructGenericEmptyNullptr();
     template<class T> void constructImplementationSpecific();
     template<class T> void constructImplementationSpecificEmpty();
-    template<class T> void constructImplementationSpecificEmptyNullptr();
     template<class T> void constructCompressedGeneric();
     template<class T> void constructCompressedGenericEmpty();
     template<class T> void constructCompressedImplementationSpecific();
@@ -51,6 +49,7 @@ struct ImageViewTest: TestSuite::Tester {
     void constructFromMutable();
     void constructCompressedFromMutable();
 
+    void constructNullptr();
     void constructInvalidSize();
     void constructCompressedInvalidSize();
 
@@ -81,14 +80,10 @@ ImageViewTest::ImageViewTest() {
               &ImageViewTest::constructGeneric<char>,
               &ImageViewTest::constructGenericEmpty<const char>,
               &ImageViewTest::constructGenericEmpty<char>,
-              &ImageViewTest::constructGenericEmptyNullptr<const char>,
-              &ImageViewTest::constructGenericEmptyNullptr<char>,
               &ImageViewTest::constructImplementationSpecific<const char>,
               &ImageViewTest::constructImplementationSpecific<char>,
               &ImageViewTest::constructImplementationSpecificEmpty<const char>,
               &ImageViewTest::constructImplementationSpecificEmpty<char>,
-              &ImageViewTest::constructImplementationSpecificEmptyNullptr<const char>,
-              &ImageViewTest::constructImplementationSpecificEmptyNullptr<char>,
               &ImageViewTest::constructCompressedGeneric<const char>,
               &ImageViewTest::constructCompressedGeneric<char>,
               &ImageViewTest::constructCompressedGenericEmpty<const char>,
@@ -101,6 +96,7 @@ ImageViewTest::ImageViewTest() {
               &ImageViewTest::constructFromMutable,
               &ImageViewTest::constructCompressedFromMutable,
 
+              &ImageViewTest::constructNullptr,
               &ImageViewTest::constructInvalidSize,
               &ImageViewTest::constructCompressedInvalidSize,
 
@@ -205,34 +201,6 @@ template<class T> void ImageViewTest::constructGenericEmpty() {
     }
 }
 
-template<class T> void ImageViewTest::constructGenericEmptyNullptr() {
-    setTestCaseTemplateName(MutabilityTraits<T>::name());
-
-    /* This should be deprecated/removed, as it doesn't provide anything over
-       the above and can lead to silent errors */
-
-    {
-        ImageView<2, T> a{PixelFormat::RG32F, {2, 6}, nullptr};
-
-        CORRADE_COMPARE(a.storage().alignment(), 4);
-        CORRADE_COMPARE(a.format(), PixelFormat::RG32F);
-        CORRADE_COMPARE(a.formatExtra(), 0);
-        CORRADE_COMPARE(a.pixelSize(), 8);
-        CORRADE_COMPARE(a.size(), (Vector2i{2, 6}));
-        CORRADE_COMPARE(a.data(), nullptr);
-    } {
-        ImageView<2, T> a{PixelStorage{}.setAlignment(1),
-            PixelFormat::RGB16F, {8, 3}, nullptr};
-
-        CORRADE_COMPARE(a.storage().alignment(), 1);
-        CORRADE_COMPARE(a.format(), PixelFormat::RGB16F);
-        CORRADE_COMPARE(a.formatExtra(), 0);
-        CORRADE_COMPARE(a.pixelSize(), 6);
-        CORRADE_COMPARE(a.size(), (Vector2i{8, 3}));
-        CORRADE_COMPARE(a.data(), nullptr);
-    }
-}
-
 template<class T> void ImageViewTest::constructImplementationSpecific() {
     setTestCaseTemplateName(MutabilityTraits<T>::name());
 
@@ -361,68 +329,6 @@ template<class T> void ImageViewTest::constructImplementationSpecificEmpty() {
     }
 }
 
-template<class T> void ImageViewTest::constructImplementationSpecificEmptyNullptr() {
-    setTestCaseTemplateName(MutabilityTraits<T>::name());
-
-    /* This should be deprecated/removed, as it doesn't provide anything over
-       the above and can lead to silent errors */
-
-    /* Single format */
-    {
-        ImageView<2, T> a{Vk::PixelFormat::R32G32B32F, {2, 16}, nullptr};
-
-        CORRADE_COMPARE(a.storage().alignment(), 4);
-        CORRADE_COMPARE(a.format(), pixelFormatWrap(Vk::PixelFormat::R32G32B32F));
-        CORRADE_COMPARE(a.formatExtra(), 0);
-        CORRADE_COMPARE(a.pixelSize(), 12);
-        CORRADE_COMPARE(a.size(), (Vector2i{2, 16}));
-        CORRADE_COMPARE(a.data(), nullptr);
-    } {
-        ImageView<2, T> a{PixelStorage{}.setAlignment(1),
-            Vk::PixelFormat::R32G32B32F, {1, 2}, nullptr};
-
-        CORRADE_COMPARE(a.storage().alignment(), 1);
-        CORRADE_COMPARE(a.format(), pixelFormatWrap(Vk::PixelFormat::R32G32B32F));
-        CORRADE_COMPARE(a.formatExtra(), 0);
-        CORRADE_COMPARE(a.pixelSize(), 12);
-        CORRADE_COMPARE(a.size(), (Vector2i{1, 2}));
-        CORRADE_COMPARE(a.data(), nullptr);
-    }
-
-    /* Format + extra */
-    {
-        ImageView<2, T> a{GL::PixelFormat::RGB, GL::PixelType::UnsignedShort, {1, 3}, nullptr};
-
-        CORRADE_COMPARE(a.storage().alignment(), 4);
-        CORRADE_COMPARE(a.format(), pixelFormatWrap(GL::PixelFormat::RGB));
-        CORRADE_COMPARE(a.formatExtra(), UnsignedInt(GL::PixelType::UnsignedShort));
-        CORRADE_COMPARE(a.pixelSize(), 6);
-        CORRADE_COMPARE(a.size(), (Vector2i{1, 3}));
-        CORRADE_COMPARE(a.data(), nullptr);
-    } {
-        ImageView<2, T> a{PixelStorage{}.setAlignment(1),
-            GL::PixelFormat::RGB, GL::PixelType::UnsignedShort, {8, 2}, nullptr};
-
-        CORRADE_COMPARE(a.format(), pixelFormatWrap(GL::PixelFormat::RGB));
-        CORRADE_COMPARE(a.formatExtra(), UnsignedInt(GL::PixelType::UnsignedShort));
-        CORRADE_COMPARE(a.pixelSize(), 6);
-        CORRADE_COMPARE(a.size(), (Vector2i{8, 2}));
-        CORRADE_COMPARE(a.data(), nullptr);
-    }
-
-    /* Manual pixel size */
-    {
-        ImageView<2, T> a{PixelStorage{}.setAlignment(1), 666, 1337, 6, {3, 3}, nullptr};
-
-        CORRADE_COMPARE(a.storage().alignment(), 1);
-        CORRADE_COMPARE(a.format(), pixelFormatWrap(GL::PixelFormat::RGB));
-        CORRADE_COMPARE(a.formatExtra(), UnsignedInt(GL::PixelType::UnsignedShort));
-        CORRADE_COMPARE(a.pixelSize(), 6);
-        CORRADE_COMPARE(a.size(), (Vector2i{3, 3}));
-        CORRADE_COMPARE(a.data(), nullptr);
-    }
-}
-
 template<class T> void ImageViewTest::constructCompressedGeneric() {
     setTestCaseTemplateName(MutabilityTraits<T>::name());
 
@@ -566,6 +472,17 @@ void ImageViewTest::constructCompressedFromMutable() {
     CORRADE_COMPARE(b.data().size(), 8);
 }
 
+void ImageViewTest::constructNullptr() {
+    #ifdef CORRADE_BUILD_DEPRECATED
+    CORRADE_SKIP("This is still allowed on a deprecated build, can't test.");
+    #endif
+
+    std::ostringstream out;
+    Error redirectError{&out};
+    ImageView2D{PixelFormat::RGB8Unorm, {1, 3},  nullptr};
+    CORRADE_COMPARE(out.str(), "ImageView::ImageView(): data too small, got 0 but expected at least 12 bytes\n");
+}
+
 void ImageViewTest::constructInvalidSize() {
     std::ostringstream out;
     Error redirectError{&out};

src/Magnum/Text/Test/AbstractGlyphCacheTest.cpp

@@ -127,7 +127,7 @@ void AbstractGlyphCacheTest::setImage() {
         Vector2i imageOffset, imageSize;
     } cache{{100, 200}};
 
-    cache.setImage({80, 175}, ImageView2D{{}, {20, 25}, nullptr});
+    cache.setImage({80, 175}, ImageView2D{{}, {20, 25}});
 
     CORRADE_COMPARE(cache.imageOffset, (Vector2i{80, 175}));
     CORRADE_COMPARE(cache.imageSize, (Vector2i{20, 25}));
@@ -138,9 +138,9 @@ void AbstractGlyphCacheTest::setImageOutOfBounds() {
 
     std::ostringstream out;
     Error redirectError{&out};
-    cache.setImage({80, 175}, ImageView2D{{}, {20, 25}, nullptr});
+    cache.setImage({80, 175}, ImageView2D{{}, {20, 25}});
-    cache.setImage({81, 175}, ImageView2D{{}, {20, 25}, nullptr});
+    cache.setImage({81, 175}, ImageView2D{{}, {20, 25}});
-    cache.setImage({80, -1}, ImageView2D{{}, {20, 25}, nullptr});
+    cache.setImage({80, -1}, ImageView2D{{}, {20, 25}});
 
     CORRADE_COMPARE(out.str(),
         "Text::AbstractGlyphCache::setImage(): Range({81, 175}, {101, 200}) out of bounds for texture size Vector(100, 200)\n"

src/Magnum/Trade/Test/AbstractImageConverterTest.cpp

@@ -188,7 +188,7 @@ void AbstractImageConverterTest::exportToImageNotImplemented() {
     Error redirectError{&out};
 
     Converter converter;
-    converter.exportToImage(ImageView2D{PixelFormat::R8Unorm, {4, 6}, Containers::ArrayView<char>{nullptr, 24}});
+    converter.exportToImage(ImageView2D{PixelFormat::R8Unorm, {4, 6}, Containers::ArrayView<char>{nullptr, 128}});
     CORRADE_COMPARE(out.str(), "Trade::AbstractImageConverter::exportToImage(): feature advertised but not implemented\n");
 }
 
@@ -201,7 +201,7 @@ void AbstractImageConverterTest::exportToCompressedImage() {
     };
 
     Converter converter;
-    Containers::Optional<CompressedImage2D> actual = converter.exportToCompressedImage(ImageView2D{PixelFormat::R8Unorm, {16, 8}, Containers::ArrayView<char>{nullptr, 24}});
+    Containers::Optional<CompressedImage2D> actual = converter.exportToCompressedImage(ImageView2D{PixelFormat::R8Unorm, {16, 8}, Containers::ArrayView<char>{nullptr, 128}});
     CORRADE_VERIFY(actual);
     CORRADE_COMPARE(actual->data().size(), 64);
     CORRADE_COMPARE(actual->size(), (Vector2i{16, 8}));
@@ -216,7 +216,7 @@ void AbstractImageConverterTest::exportToCompressedImageNotSupported() {
     Error redirectError{&out};
 
     Converter converter;
-    converter.exportToCompressedImage(ImageView2D{PixelFormat::R8Unorm, {16, 8}, Containers::ArrayView<char>{nullptr, 24}});
+    converter.exportToCompressedImage(ImageView2D{PixelFormat::R8Unorm, {16, 8}, Containers::ArrayView<char>{nullptr, 128}});
     CORRADE_COMPARE(out.str(), "Trade::AbstractImageConverter::exportToCompressedImage(): feature not supported\n");
 }
 
@@ -229,7 +229,7 @@ void AbstractImageConverterTest::exportToCompressedImageNotImplemented() {
     Error redirectError{&out};
 
     Converter converter;
-    converter.exportToCompressedImage(ImageView2D{PixelFormat::R8Unorm, {16, 8}, Containers::ArrayView<char>{nullptr, 24}});
+    converter.exportToCompressedImage(ImageView2D{PixelFormat::R8Unorm, {16, 8}, Containers::ArrayView<char>{nullptr, 128}});
     CORRADE_COMPARE(out.str(), "Trade::AbstractImageConverter::exportToCompressedImage(): feature advertised but not implemented\n");
 }