Text,TextureTools: more SwiftShader XFAILs.

Do I look like I want to deal with broken software on a Sunday? Exactly.

src/Magnum/Text/Test/DistanceFieldGlyphCacheGLTest.cpp

@@ -545,11 +545,17 @@ void DistanceFieldGlyphCacheGLTest::setImageArray() {
 
     /* The format may be three-component, consider just the first channel */
     Containers::StridedArrayView3D<const char> pixels = actual.pixels();
+    {
+        #ifdef MAGNUM_TARGET_GLES
+        CORRADE_EXPECT_FAIL_IF(data.sourceOffset.z() != 0 && GL::Context::current().detectedDriver() >= GL::Context::DetectedDriver::SwiftShader,
+            "SwiftShader is trash and doesn't implement reading from non-zero array layers.");
+        #endif
         CORRADE_COMPARE_WITH((Containers::arrayCast<2, const UnsignedByte>(pixels.prefix({pixels.size()[0], pixels.size()[1], 1})).exceptPrefix(data.offset)),
             Utility::Path::join(TEXTURETOOLS_DISTANCEFIELDGLTEST_DIR, "output.tga"),
             /* Same threshold as in TextureTools DistanceFieldGLTest */
             (DebugTools::CompareImageToFile{_manager, 1.0f, 0.178f}));
     }
+}
 #endif
 
 void DistanceFieldGlyphCacheGLTest::setImageEdgeClamp() {
@@ -603,9 +609,15 @@ void DistanceFieldGlyphCacheGLTest::setImageEdgeClamp() {
 
     /* On the left side the pixels should be completely zero, without the right
        side leaking for example due to accidental repeat clamp */
+    {
+        #if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_GLES2)
+        CORRADE_EXPECT_FAIL_IF(GL::Context::current().detectedDriver() >= GL::Context::DetectedDriver::SwiftShader,
+            "SwiftShader is trash and wraps around out-of-bounds texelFetch().");
+        #endif
         CORRADE_COMPARE(dst[0][0], '\x00');
         CORRADE_COMPARE(dst[1][0], '\x00');
     }
+}
 
 #ifndef MAGNUM_TARGET_GLES2
 void DistanceFieldGlyphCacheGLTest::setImageEdgeClampArray() {
@@ -652,9 +664,15 @@ void DistanceFieldGlyphCacheGLTest::setImageEdgeClampArray() {
 
     /* On the left side the pixels should be completely zero, without the right
        side leaking for example due to accidental repeat clamp */
+    {
+        #ifdef MAGNUM_TARGET_GLES
+        CORRADE_EXPECT_FAIL_IF(GL::Context::current().detectedDriver() >= GL::Context::DetectedDriver::SwiftShader,
+            "SwiftShader is trash and wraps around out-of-bounds texelFetch().");
+        #endif
         CORRADE_COMPARE(dst[0][0], '\x00');
         CORRADE_COMPARE(dst[1][0], '\x00');
     }
+}
 #endif
 
 const UnsignedByte InputData[]{

src/Magnum/TextureTools/Test/DistanceFieldGLTest.cpp

@@ -412,6 +412,10 @@ void DistanceFieldGLTest::run() {
     else
         pixels = Containers::arrayCast<2, UnsignedByte>(pixels3);
 
+    #ifdef MAGNUM_TARGET_GLES
+    CORRADE_EXPECT_FAIL_IF(data.layer != 0 && GL::Context::current().detectedDriver() >= GL::Context::DetectedDriver::SwiftShader,
+        "SwiftShader is trash and doesn't implement reading from non-zero array layers.");
+    #endif
     CORRADE_COMPARE_WITH(
         pixels,
         Utility::Path::join(_testDir, "output.tga"),