fix(xml): handle rational types in ImageSpec roundtrip

src/libOpenImageIO/imagespec_test.cpp

@@ -47,6 +47,7 @@ const char* imagespec_xml_string = R"EOF(
 <attrib name="screenWindowCenter" type="float2">0, 0</attrib>
 <attrib name="screenWindowWidth" type="float">1</attrib>
 <attrib name="oiio:subimages" type="int">1</attrib>
+<attrib name="FramesPerSecond" type="rational">30000/1001</attrib>
 </ImageSpec>
 )EOF";
 
@@ -358,6 +359,20 @@ test_imagespec_from_xml()
     OIIO_CHECK_EQUAL(spec.format, TypeFloat);
     OIIO_CHECK_EQUAL(spec.get_string_attribute("oiio:ColorSpace"),
                      "scene_linear");
+    OIIO_CHECK_EQUAL(spec.getattributetype("FramesPerSecond"), TypeRational);
+    OIIO_CHECK_EQUAL_THRESH(spec.get_float_attribute("FramesPerSecond", -1.0f),
+                            30000.0f / 1001.0f, 1.0e-5f);
+
+    std::string xml = spec.to_xml();
+    OIIO_CHECK_ASSERT(xml.find("name=\"FramesPerSecond\" type=\"rational\"")
+                      != std::string::npos);
+    ImageSpec roundtripped;
+    roundtripped.from_xml(xml.c_str());
+    OIIO_CHECK_EQUAL(roundtripped.getattributetype("FramesPerSecond"),
+                     TypeRational);
+    OIIO_CHECK_EQUAL_THRESH(roundtripped.get_float_attribute("FramesPerSecond",
+                                                             -1.0f),
+                            30000.0f / 1001.0f, 1.0e-5f);
 }
 
 

src/libutil/paramlist.cpp

@@ -130,7 +130,15 @@ parse_elements(string_view value, ParamValue& p)
 ParamValue::ParamValue(string_view name, TypeDesc type, string_view value)
     : ParamValue(name, type, 1, cspan<std::byte>())
 {
-    if (type.basetype == TypeDesc::INT) {
+    if (type == TypeRational || type == TypeURational) {
+        // Accept either "x,y" or "x/y" here
+        std::string rational_values(value);
+        std::replace(rational_values.begin(), rational_values.end(), '/', ',');
+        if (type.basetype == TypeDesc::INT)
+            parse_elements<int>(rational_values, *this);
+        else if (type.basetype == TypeDesc::UINT)
+            parse_elements<unsigned int>(rational_values, *this);
+    } else if (type.basetype == TypeDesc::INT) {
         parse_elements<int>(value, *this);
     } else if (type.basetype == TypeDesc::UINT) {
         parse_elements<unsigned int>(value, *this);

src/libutil/typedesc.cpp

@@ -214,6 +214,14 @@ TypeDesc::c_str() const
             result = Strutil::fmt::format("matrix{}", basetype_code[basetype]);
             break;
         }
+    } else if (vecsemantics == RATIONAL && (*this == TypeRational || *this == TypeURational)) {
+        result = (basetype == TypeDesc::INT) ? "rational" : "urational";
+    } else if (vecsemantics == BOX) {
+        result = Strutil::fmt::format("box{}{}", int(aggregate),
+                                      basetype == FLOAT
+                                          ? ""
+                                          : basetype_code[basetype]);
+        alen   = arraylen > 2 ? (arraylen / 2) : (arraylen < 0 ? -1 : 0);
     } else {
         // Special names for vector semantics
         const char* vec = "";
@@ -237,14 +245,6 @@ TypeDesc::c_str() const
         if (basetype != FLOAT)
             result += basetype_code[basetype];
     }
-    // More unusual cases
-    if (vecsemantics == BOX) {
-        result = Strutil::fmt::format("box{}{}", int(aggregate),
-                                      basetype == FLOAT
-                                          ? ""
-                                          : basetype_code[basetype]);
-        alen   = arraylen > 2 ? (arraylen / 2) : (arraylen < 0 ? -1 : 0);
-    }
     if (alen > 0)
         result += Strutil::fmt::format("[{}]", alen);
     else if (alen < 0)
@@ -323,9 +323,9 @@ TypeDesc::fromstring(string_view typestring)
         t = OIIO::TypeFloat4;
     else if (type == "timecode")
         t = OIIO::TypeTimeCode;
-    else if (type == "rational")
+    else if (type == "rational" || type == "rational2i")
         t = OIIO::TypeRational;
-    else if (type == "urational")
+    else if (type == "urational" || type == "rational2u")
         t = OIIO::TypeURational;
     else if (type == "box2i")
         t = OIIO::TypeBox2i;

src/libutil/typedesc_test.cpp

@@ -202,6 +202,8 @@ main(int /*argc*/, char* /*argv*/[])
                       TypeDesc(TypeDesc::INT, TypeDesc::VEC2,
                                TypeDesc::RATIONAL),
                       TypeRational, i2, "1/2");
+    OIIO_CHECK_EQUAL(TypeDesc("rational"), TypeRational);
+    OIIO_CHECK_EQUAL(TypeDesc("urational"), TypeURational);
     uint32_t ui2[2] = { 1, 2 };
     test_type<uint32_t[2]>("urational",
                            TypeDesc(TypeDesc::UINT32, TypeDesc::VEC2,