AnyShaderConverter: take explicitly set formats into account.

So if we convert foo.blah but explicitly tell it that it's a SPIR-V
file, it actually treats it as such, instead of complaining that `blah`
is not a known extension.

First step towards being able to operate directly on data.

src/MagnumPlugins/AnyShaderConverter/AnyConverter.cpp

@@ -101,7 +101,25 @@ namespace {
 
 using namespace Containers::Literals;
 
-Containers::StringView formatForExtension(const char* prefix, const Containers::StringView filename) {
+Containers::StringView stringForFormat(const Format format) {
+    switch(format) {
+        #define _c(format) case Format::format: return #format ## _s;
+        _c(Glsl)
+        _c(Spirv)
+        _c(SpirvAssembly)
+        _c(Hlsl)
+        _c(Msl)
+        _c(Wgsl)
+        _c(Dxil)
+        #undef _c
+
+        case Format::Unspecified: return {};
+    }
+
+    CORRADE_INTERNAL_ASSERT_UNREACHABLE(); /* LCOV_EXCL_LINE */
+}
+
+Format formatForExtension(const char* prefix, const Containers::StringView filename) {
     /** @todo lowercase only the extension, once Directory::split() is done */
     const std::string normalized = Utility::String::lowercase(filename);
 
@@ -126,7 +144,7 @@ Containers::StringView formatForExtension(const char* prefix, const Containers::
        Utility::String::endsWith(normalized, ".asm.rcall") ||
        Utility::String::endsWith(normalized, ".asm.mesh") ||
        Utility::String::endsWith(normalized, ".asm.task"))
-        return "SpirvAssembly"_s;
+        return Format::SpirvAssembly;
     /* https://github.com/KhronosGroup/glslang/blob/3ce148638bdc3807316e358dee4a5c9583189ae7/StandAlone/StandAlone.cpp#L260-L274 */
     else if(Utility::String::endsWith(normalized, ".glsl") ||
             Utility::String::endsWith(normalized, ".vert") ||
@@ -143,9 +161,9 @@ Containers::StringView formatForExtension(const char* prefix, const Containers::
             Utility::String::endsWith(normalized, ".rcall") ||
             Utility::String::endsWith(normalized, ".mesh") ||
             Utility::String::endsWith(normalized, ".task"))
-        return "Glsl"_s;
+        return Format::Glsl;
     else if(Utility::String::endsWith(normalized, ".spv"))
-        return "Spirv"_s;
+        return Format::Spirv;
 
     Error{} << prefix << "cannot determine the format of" << filename;
     return {};
@@ -156,9 +174,15 @@ Containers::StringView formatForExtension(const char* prefix, const Containers::
 std::pair<bool, Containers::String> AnyConverter::doValidateFile(const Stage stage, const Containers::StringView filename) {
     CORRADE_INTERNAL_ASSERT(manager());
 
-    /* Decide on a plugin name based on the extension */
+    /* Prefer the explicitly set input format. If not set, fall back to
-    const Containers::StringView format = formatForExtension("ShaderTools::AnyConverter::validateFile():", filename);
+       detecting based on extension. */
+    const Containers::StringView format = stringForFormat(
+        _state->inputFormat != Format::Unspecified ? _state->inputFormat :
+        formatForExtension("ShaderTools::AnyConverter::validateFile():", filename)
+    );
     if(format.isEmpty()) return {};
+
+    /* Decide on a plugin name based on the format */
     const std::string plugin = Utility::formatString("{}ShaderConverter", format);
 
     /* Try to load the plugin */
@@ -207,12 +231,19 @@ std::pair<bool, Containers::String> AnyConverter::doValidateFile(const Stage sta
 bool AnyConverter::doConvertFileToFile(const Stage stage, const Containers::StringView from, const Containers::StringView to) {
     CORRADE_INTERNAL_ASSERT(manager());
 
-    /* Decide on a plugin name based on the input and output extension. This
+    /* Prefer the explicitly set input format. If not set, fall back to
-       might result in invalid combinations such as SpirvToGlslShaderConverter
+       detecting based on input and output extension. */
-       which can't be really handled yet but I think that's okay for now */
+    const Containers::StringView formatFrom = stringForFormat(
-    const Containers::StringView formatFrom = formatForExtension("ShaderTools::AnyConverter::convertFileToFile():", from);
+        _state->inputFormat != Format::Unspecified ? _state->inputFormat : formatForExtension("ShaderTools::AnyConverter::convertFileToFile():", from)
-    const Containers::StringView formatTo = formatForExtension("ShaderTools::AnyConverter::convertFileToFile():", to);
+    );
+    const Containers::StringView formatTo = stringForFormat(
+        _state->outputFormat != Format::Unspecified ? _state->outputFormat : formatForExtension("ShaderTools::AnyConverter::convertFileToFile():", to)
+    );
     if(formatFrom.isEmpty() || formatTo.isEmpty()) return {};
+
+    /* Decide on a plugin name based on the format. This might result in
+       invalid combinations such as SpirvToGlslShaderConverter which can't be
+       really handled yet but I think that's okay for now. */
     const std::string plugin = Utility::formatString(
         formatFrom == formatTo ? "{}ShaderConverter" : "{}To{}ShaderConverter",
         formatFrom, formatTo);

src/MagnumPlugins/AnyShaderConverter/AnyConverter.h

@@ -57,8 +57,10 @@ namespace Magnum { namespace ShaderTools {
 
 @m_keywords{AnyShaderConverter}
 
-Detects file type based on file extension, loads corresponding plugin and then
+Loads a plugin corresponding to a format either explicitly set using
-tries to either validate or convert the file with it. Detected file formats:
+@ref setInputFormat() / @ref setOutputFormat() or detected based on input /
+output file extension plugin and then tries to either validate or convert the
+file with it. These formats are detected based on extension:
 
 -   GLSL (`*.glsl`, `*.vert`, `*.frag`, `*.geom`, `*.comp`, `*.tesc`, `*.tese`,
     `*.rgen`, `*.rint`, `*.rahit`, `*.rchit`, `*.rmiss`, `*.rcall`, `*.mesh`,

src/MagnumPlugins/AnyShaderConverter/Test/AnyConverterTest.cpp

@@ -64,7 +64,9 @@ struct AnyConverterTest: TestSuite::Tester {
     void convertPropagateOptimization();
 
     void detectValidate();
+    void detectValidateExplicitFormat();
     void detectConvert();
+    void detectConvertExplicitFormat();
 
     void unknown();
 
@@ -120,9 +122,13 @@ AnyConverterTest::AnyConverterTest() {
     addInstancedTests({&AnyConverterTest::detectValidate},
         Containers::arraySize(DetectValidateData));
 
+    addTests({&AnyConverterTest::detectValidateExplicitFormat});
+
     addInstancedTests({&AnyConverterTest::detectConvert},
         Containers::arraySize(DetectConvertData));
 
+    addTests({&AnyConverterTest::detectConvertExplicitFormat});
+
     addTests({&AnyConverterTest::unknown});
 
     /* Load the plugin directly from the build tree. Otherwise it's static and
@@ -567,6 +573,27 @@ void AnyConverterTest::detectValidate() {
     #endif
 }
 
+void AnyConverterTest::detectValidateExplicitFormat() {
+    Containers::Pointer<AbstractConverter> converter = _manager.instantiate("AnyShaderConverter");
+
+    /* It should pick up this format and not bother with the extension */
+    converter->setInputFormat(Format::Hlsl);
+
+    std::ostringstream out;
+    Error redirectError{&out};
+    CORRADE_COMPARE(converter->validateFile({}, "file.spv"),
+        std::make_pair(false, ""));
+    #ifndef CORRADE_PLUGINMANAGER_NO_DYNAMIC_PLUGIN_SUPPORT
+    CORRADE_COMPARE(out.str(),
+        "PluginManager::Manager::load(): plugin HlslShaderConverter is not static and was not found in nonexistent\n"
+        "ShaderTools::AnyConverter::validateFile(): cannot load the HlslShaderConverter plugin\n");
+    #else
+    CORRADE_COMPARE(out.str(),
+        "PluginManager::Manager::load(): plugin HlslShaderConverter was not found\n"
+        "ShaderTools::AnyConverter::validateFile(): cannot load the HlslShaderConverter plugin\n");
+    #endif
+}
+
 void AnyConverterTest::detectConvert() {
     auto&& data = DetectConvertData[testCaseInstanceId()];
     setTestCaseDescription(data.name);
@@ -587,6 +614,27 @@ void AnyConverterTest::detectConvert() {
     #endif
 }
 
+void AnyConverterTest::detectConvertExplicitFormat() {
+    Containers::Pointer<AbstractConverter> converter = _manager.instantiate("AnyShaderConverter");
+
+    /* It should pick up this format and not bother with the extension */
+    converter->setInputFormat(Format::Hlsl);
+    converter->setOutputFormat(Format::Wgsl);
+
+    std::ostringstream out;
+    Error redirectError{&out};
+    CORRADE_VERIFY(!converter->convertFileToFile({}, "file.spv", Utility::Directory::join(ANYSHADERCONVERTER_TEST_OUTPUT_DIR, "file.glsl")));
+    #ifndef CORRADE_PLUGINMANAGER_NO_DYNAMIC_PLUGIN_SUPPORT
+    CORRADE_COMPARE(out.str(),
+        "PluginManager::Manager::load(): plugin HlslToWgslShaderConverter is not static and was not found in nonexistent\n"
+        "ShaderTools::AnyConverter::convertFileToFile(): cannot load the HlslToWgslShaderConverter plugin\n");
+    #else
+    CORRADE_COMPARE(out.str(),
+        "PluginManager::Manager::load(): plugin HlslToWgslShaderConverter was not found\n"
+        "ShaderTools::AnyConverter::convertFileToFile(): cannot load the HlslToWgslShaderConverter plugin\n");
+    #endif
+}
+
 void AnyConverterTest::unknown() {
     std::ostringstream output;
     Error redirectError{&output};