AnyImageImporter: recognize WebP extension and header magic.

doc/changelog.dox

@@ -503,7 +503,8 @@ See also:
     when the implementation only neeeds to do a format detection based on file
     extension
 -   Recognizing BMP and TIFF file header magic in @relativeref{Trade,AnyImageImporter}
--   Recognizgin ASTC files and data in @relativeref{Trade,AnyImageImporter}
+-   Recognizing ASTC and WebP files and data in
+    @relativeref{Trade,AnyImageImporter}
 -   Recognizing KTX2 files and data in @relativeref{Trade,AnyImageImporter} and
     @relativeref{Trade,AnyImageConverter} (see also
     [mosra/magnum#529](https://github.com/mosra/magnum/pull/529))

src/MagnumPlugins/AnyImageImporter/AnyImageImporter.cpp

@@ -129,6 +129,8 @@ void AnyImageImporter::doOpenFile(const Containers::StringView filename) {
         plugin = "TgaImporter"_s;
     else if(normalizedExtension == ".vdb"_s)
         plugin = "OpenVdbImporter"_s;
+    else if(normalizedExtension == ".webp"_s)
+        plugin = "WebPImporter"_s;
     else {
         Error{} << "Trade::AnyImageImporter::openFile(): cannot determine the format of" << filename;
         return;
@@ -208,6 +210,11 @@ void AnyImageImporter::doOpenData(Containers::Array<char>&& data, DataFlags) {
     else if(dataString.hasPrefix("II\x2a\x00"_s) ||
             dataString.hasPrefix("MM\x00\x2a"_s))
         plugin = "TiffImporter"_s;
+    /* https://developers.google.com/speed/webp/docs/riff_container#webp_file_header */
+    else if(dataString.size() >= 12 &&
+            dataString.slice(0,  4) == "RIFF"_s &&
+            dataString.slice(8, 12) == "WEBP"_s)
+        plugin = "WebPImporter"_s;
     /* https://github.com/file/file/blob/d04de269e0b06ccd0a7d1bf4974fed1d75be7d9e/magic/Magdir/images#L18-L22
        TGAs are a complete guesswork, so try after everything else fails. */
     else if([dataView]() {

src/MagnumPlugins/AnyImageImporter/AnyImageImporter.h

@@ -101,6 +101,8 @@ Supported formats:
     corresponding signature), loaded with @ref TgaImporter or any other plugin
     that provides it
 -   OpenVDB (`*.vdb`), loaded with any plugin that provides `OpenVdbImporter`
+-   WebP (`*.webp` or data with corresponding signature), loaded with
+    @ref WebPImporter or any other plugin that provides it
 
 Detecting file type through @ref openData() is supported only for a subset of
 formats that are marked as such in the list above.

src/MagnumPlugins/AnyImageImporter/Test/AnyImageImporterTest.cpp

@@ -123,7 +123,9 @@ constexpr struct {
     {"TIFF data", "image.tiff", true, "TiffImporter"},
     {"Basis", "rgb.basis", false, "BasisImporter"},
     {"Basis data", "rgb.basis", true, "BasisImporter"},
-    {"OpenVDB", "volume.vdb", false, "OpenVdbImporter"}
+    {"OpenVDB", "volume.vdb", false, "OpenVdbImporter"},
+    {"WebP", "rgb-lossless.webp", false, "WebPImporter"},
+    {"WebP data", "rgb-lossless.webp", true, "WebPImporter"}
     /* Not testing everything, just the most important ones */
 };
 
@@ -144,7 +146,9 @@ const struct {
     {"DDS, but no space", "DDS!"_s, "44445321"},
     {"TIFF, but too short", "II\x2a"_s, "49492a"},
     {"TIFF, but no zero byte", "MM\xff\x2a"_s, "4d4dff2a"},
-    {"KTX, but wrong version", "\xabKTX 30\xbb\r\n\x1a\n"_s, "ab4b5458"}
+    {"KTX, but wrong version", "\xabKTX 30\xbb\r\n\x1a\n"_s, "ab4b5458"},
+    {"RIFF (for WebP), but only 4 bytes", "RIFF"_s, "52494646"},
+    {"WebP, but only 11 bytes", "RIFF    WEB"_s, "52494646"}
 };
 
 constexpr struct {

src/MagnumPlugins/AnyImageImporter/Test/CMakeLists.txt

@@ -77,7 +77,9 @@ corrade_add_test(AnyImageImporterTest AnyImageImporterTest.cpp
         rgb.hdr
         rgb.png
         rgb.tga
-        rgba_dxt1.dds)
+        rgba_dxt1.dds
+        # From WebPImporter test data
+        rgb-lossless.webp)
 target_include_directories(AnyImageImporterTest PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>)
 if(MAGNUM_ANYIMAGEIMPORTER_BUILD_STATIC)
     target_link_libraries(AnyImageImporterTest PRIVATE AnyImageImporter)