DebugTools: make CompareImage work with MutableImageView.

And test Image and Trade::ImageData inputs as well while at it, since
they were also not really verified before.

doc/changelog.dox

@@ -525,6 +525,8 @@ See also:
 -   @ref DebugTools::CompareImage now supports comparing half-float pixel
     formats as well, pixel format autodetection for pixel views tries to
     match sRGB and normalization properties of the expected image format
+-   @ref DebugTools::CompareImage now accepts @ref MutableImageView2D as well,
+    in addition to @ref Image2D, @ref ImageView2D and @ref Trade::ImageData2D
 
 @subsubsection changelog-latest-changes-gl GL library
 

src/Magnum/DebugTools/CompareImage.h

@@ -174,7 +174,7 @@ namespace Implementation {
 
 /* Explicit ComparatorTraits specialization because
    Comparator<CompareImage>::operator() is overloaded */
-template<class T> struct ComparatorTraits<Magnum::DebugTools::CompareImage, Magnum::ImageView2D, T> {
+template<class T, class U> struct ComparatorTraits<Magnum::DebugTools::CompareImage, Magnum::ImageView<2, U>, T> {
     typedef Magnum::ImageView2D ActualType;
     typedef Magnum::ImageView2D ExpectedType;
 };
@@ -187,7 +187,7 @@ template<class T, class U> struct ComparatorTraits<Magnum::DebugTools::CompareIm
 
 /* Explicit ComparatorTraits specialization because
    Comparator<CompareImageToFile>::operator() is overloaded */
-template<class T> struct ComparatorTraits<Magnum::DebugTools::CompareImageToFile, Magnum::ImageView2D, T> {
+template<class T, class U> struct ComparatorTraits<Magnum::DebugTools::CompareImageToFile, Magnum::ImageView<2, U>, T> {
     typedef Magnum::ImageView2D ActualType;
     typedef Containers::StringView ExpectedType;
 };

src/Magnum/DebugTools/Test/CompareImageTest.cpp

@@ -40,6 +40,7 @@
 #include <Corrade/Utility/Path.h>
 #include <Corrade/Utility/String.h> /* replaceFirst() */
 
+#include "Magnum/Image.h"
 #include "Magnum/ImageView.h"
 #include "Magnum/PixelFormat.h"
 #include "Magnum/DebugTools/CompareImage.h"
@@ -48,6 +49,7 @@
 #include "Magnum/Math/Half.h"
 #include "Magnum/Trade/AbstractImageConverter.h"
 #include "Magnum/Trade/AbstractImporter.h"
+#include "Magnum/Trade/ImageData.h"
 
 #include "configure.h"
 
@@ -116,6 +118,9 @@ struct CompareImageTest: TestSuite::Tester {
     void fileToImageActualLoadFailed();
     void fileToImageActualIsCompressed();
 
+    void mutableImageViewImageImageData();
+    void mutableImageViewImageImageDataToFile();
+
     template<unsigned dimensions> void pixelFormatFor();
     void pixelFormatForColor();
 
@@ -222,7 +227,13 @@ CompareImageTest::CompareImageTest() {
         &CompareImageTest::setupExternalPluginManager,
         &CompareImageTest::teardownExternalPluginManager);
 
-    addTests({&CompareImageTest::fileToImageActualIsCompressed});
+    addTests({&CompareImageTest::fileToImageActualIsCompressed,
+
+              &CompareImageTest::mutableImageViewImageImageData});
+
+    addTests({&CompareImageTest::mutableImageViewImageImageDataToFile},
+        &CompareImageTest::setupExternalPluginManager,
+        &CompareImageTest::teardownExternalPluginManager);
 
     addTests({&CompareImageTest::pixelFormatFor<1>,
               &CompareImageTest::pixelFormatFor<2>,
@@ -1688,6 +1699,70 @@ void CompareImageTest::fileToImageActualIsCompressed() {
         "Actual image a (.../CompareImageCompressed.dds) is compressed, comparison not possible.\n");
 }
 
+void CompareImageTest::mutableImageViewImageImageData() {
+    /* All other cases use an ImageView, so verify that the other variants all
+       compile too */
+
+    char pixels[]{
+        '\x56', '\xf8', '\x3a', '\x56', '\x47', '\xec', '\0', '\0',
+        '\x23', '\x57', '\x10', '\xab', '\xcd', '\x85', '\0', '\0'
+    };
+    MutableImageView2D view{PixelFormat::RGB8Unorm, {2, 2}, pixels};
+
+    Image2D image{PixelFormat::RGB8Unorm, {2, 2}, Containers::array({
+        '\x56', '\xf8', '\x3a', '\x56', '\x47', '\xec', '\0', '\0',
+        '\x23', '\x57', '\x10', '\xab', '\xcd', '\x85', '\0', '\0'
+    })};
+
+    Trade::ImageData2D data{PixelFormat::RGB8Unorm, {2, 2}, Trade::DataFlags{}, pixels};
+
+    CORRADE_COMPARE_AS(view, view, CompareImage);
+    CORRADE_COMPARE_AS(view, image, CompareImage);
+    CORRADE_COMPARE_AS(view, data, CompareImage);
+    CORRADE_COMPARE_AS(image, view, CompareImage);
+    CORRADE_COMPARE_AS(image, image, CompareImage);
+    CORRADE_COMPARE_AS(image, data, CompareImage);
+    CORRADE_COMPARE_AS(data, view, CompareImage);
+    CORRADE_COMPARE_AS(data, image, CompareImage);
+    CORRADE_COMPARE_AS(data, data, CompareImage);
+}
+
+void CompareImageTest::mutableImageViewImageImageDataToFile() {
+    if(!(_importerManager->loadState("AnyImageImporter") & PluginManager::LoadState::Loaded) ||
+       !(_importerManager->loadState("TgaImporter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnyImageImporter / TgaImporter plugins not found.");
+
+    /* All other cases use an ImageView, so verify that the other variants all
+       compile too */
+
+    char pixels[]{
+        '\x55', '\xf8', '\x3a', '\x56', '\x10', '\xed', '\0', '\0',
+        '\x23', '\x27', '\x10', '\xab', '\xcd', '\xfa', '\0', '\0'
+    };
+    MutableImageView2D view{PixelFormat::RGB8Unorm, {2, 2}, pixels};
+
+    Image2D image{PixelFormat::RGB8Unorm, {2, 2}, Containers::array({
+        '\x55', '\xf8', '\x3a', '\x56', '\x10', '\xed', '\0', '\0',
+        '\x23', '\x27', '\x10', '\xab', '\xcd', '\xfa', '\0', '\0'
+    })};
+
+    Trade::ImageData2D data{PixelFormat::RGB8Unorm, {2, 2}, Trade::DataFlags{}, pixels};
+
+    Containers::String filename = Utility::Path::join(DEBUGTOOLS_TEST_DIR, "CompareImageExpected.tga");
+    CORRADE_COMPARE_WITH(filename, view,
+        CompareFileToImage{*_importerManager});
+    CORRADE_COMPARE_WITH(filename, image,
+        CompareFileToImage{*_importerManager});
+    CORRADE_COMPARE_WITH(filename, data,
+        CompareFileToImage{*_importerManager});
+    CORRADE_COMPARE_WITH(view, filename,
+        CompareImageToFile{*_importerManager});
+    CORRADE_COMPARE_WITH(image, filename,
+        CompareImageToFile{*_importerManager});
+    CORRADE_COMPARE_WITH(data, filename,
+        CompareImageToFile{*_importerManager});
+}
+
 template<UnsignedInt dimensions> void CompareImageTest::pixelFormatFor() {
     setTestCaseTemplateName(Utility::format("{}", dimensions));