AnyImageImporter: recognize ASTC files and data.

doc/file-formats.dox

@@ -70,6 +70,16 @@ Together with @ref file-formats-scene-importers "scene importers" derived from
 </tr>
 <tr><td colspan="6"></td></tr>
 
+<tr>
+<th>ASTC (`*.astc`)</th>
+<td>`AstcImporter`</td>
+<td>@relativeref{Trade,AstcImporter}</td>
+<td class="m-text-center m-dim">@ref Trade-AstcImporter-behavior "none"</td>
+<td class="m-text-center">@m_span{m-text m-dim} none @m_endspan </td>
+<td class="m-text-center"></td>
+</tr>
+<tr><td colspan="6"></td></tr>
+
 <tr>
 <th>Basis Universal (`*.basis`)</th>
 <td>`BasisImporter`</td>

src/MagnumPlugins/AnyImageImporter/AnyImageImporter.cpp

@@ -71,7 +71,9 @@ void AnyImageImporter::doOpenFile(const Containers::StringView filename) {
 
     /* Detect the plugin from extension */
     Containers::StringView plugin;
-    if(normalizedExtension == ".basis"_s)
+    if(normalizedExtension == ".astc"_s)
+        plugin = "AstcImporter"_s;
+    else if(normalizedExtension == ".basis"_s)
         plugin = "BasisImporter"_s;
     else if(normalizedExtension == ".bmp"_s)
         plugin = "BmpImporter"_s;
@@ -173,8 +175,12 @@ void AnyImageImporter::doOpenData(Containers::Array<char>&& data, DataFlags) {
     const Containers::StringView dataString = dataView;
 
     Containers::StringView plugin;
+    /* https://stackoverflow.com/questions/22600678/determine-internal-format-of-given-astc-compressed-image-through-its-header
+       unfortunately it being in LE means it's SCALABLE in reverse :) */
+    if(dataString.hasPrefix("\x13\xAB\xA1\x5C"_s))
+        plugin = "AstcImporter"_s;
     /* https://github.com/BinomialLLC/basis_universal/blob/7d784c728844c007d8c95d63231f7adcc0f65364/transcoder/basisu_file_headers.h#L78 */
-    if(dataString.hasPrefix("sB"_s))
+    else if(dataString.hasPrefix("sB"_s))
         plugin = "BasisImporter"_s;
     /* https://en.wikipedia.org/wiki/BMP_file_format#Bitmap_file_header */
     else if(dataString.hasPrefix("BM"_s))

src/MagnumPlugins/AnyImageImporter/AnyImageImporter.h

@@ -57,6 +57,9 @@ Detects file type based on file extension or a signature at the start of the
 file, loads corresponding plugin and then tries to open the file with it.
 Supported formats:
 
+-   Adaptive Scalable Texture Compression (`*.astc` or data with corresponding
+    signature), loaded with @ref AstcImporter or any other plugin that provides
+    it
 -   Basis Universal (`*.basis` or data with corresponding signature), loaded
     with @ref BasisImporter or any other plugin that provides it
 -   Windows Bitmap (`*.bmp` or data with corresponding signature), loaded with

src/MagnumPlugins/AnyImageImporter/Test/AnyImageImporterTest.cpp

@@ -102,6 +102,8 @@ constexpr struct {
     bool asData;
     const char* plugin;
 } DetectData[]{
+    {"ASTC", "8x8.astc", false, "AstcImporter"},
+    {"ASTC data", "8x8.astc", true, "AstcImporter"},
     {"PNG", "rgb.png", false, "PngImporter"},
     {"PNG data", "rgb.png", true, "PngImporter"},
     {"JPEG", "gray.jpg", false, "JpegImporter"},

src/MagnumPlugins/AnyImageImporter/Test/CMakeLists.txt

@@ -61,6 +61,8 @@ file(GENERATE OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>/configure.h
 corrade_add_test(AnyImageImporterTest AnyImageImporterTest.cpp
     LIBRARIES MagnumTrade MagnumDebugTools
     FILES
+        # From AstcImporter test data (in magnum-plugins)
+        8x8.astc
         # Generated by AnyImageConverterTest::propagateConfiguration2D()
         depth32f-custom-channels.exr
         # Generated by AnyImageConverterTest::convert{1D,3D}()