fix(openexr): modernize dwa compression level setting

Starting with OpenEXR 3.1.3, the preferred API call for setting
DWAA/DWAB compression level has changed. We never changed the OIIO
side. Luckily, OpenEXR seems to have kept respecting the old API calls
we were making (passing as an attribute). But this modernizes the
approach, now that we don't have OpenEXR 2.x suppor to maintain.

But in the process, we also fixed a bug! Turns out we weren't
propagating the compression properly -- if the compression name
was plain "dwaa", we ignored any "openexr:dwaCompressionLevel"
attribute, effectively.

Signed-off-by: Larry Gritz <[email protected]>

src/openexr.imageio/exroutput.cpp

@@ -22,9 +22,6 @@
 #include <OpenEXR/ImfTiledOutputFile.h>
 
 #include "exr_pvt.h"
-#define OPENEXR_CODED_VERSION                                    \
-    (OPENEXR_VERSION_MAJOR * 10000 + OPENEXR_VERSION_MINOR * 100 \
-     + OPENEXR_VERSION_PATCH)
 
 // The way that OpenEXR uses dynamic casting for attributes requires
 // temporarily suspending "hidden" symbol visibility mode.
@@ -734,16 +731,20 @@ OpenEXROutput::spec_to_header(ImageSpec& spec, int subimage,
             || !ispow2(spec.tile_width) || !ispow2(spec.tile_height))) {
         comp = "zip";
     }
-    if (Strutil::istarts_with(comp, "dwa")) {
-        spec.attribute("openexr:dwaCompressionLevel",
-                       qual > 0 ? float(qual) : 45.0f);
-    }
     spec.attribute("compression", comp);
 #if OPENEXR_CODED_VERSION >= 30103
     if (Strutil::istarts_with(comp, "zip")) {
         header.zipCompressionLevel() = (qual >= 1 && qual <= 9) ? qual : 4;
     }
 #endif
+    if (Strutil::istarts_with(comp, "dwa") && qual > 0) {
+        spec.attribute("openexr:dwaCompressionLevel", float(qual));
+                    //    qual > 0 ? float(qual) : 45.0f);
+#if OPENEXR_CODED_VERSION >= 30103
+        // header.dwaCompressionLevel() = qual > 0 ? float(qual) : 45.0f;
+        header.dwaCompressionLevel() = float(qual);
+#endif
+    }
 
     // Default to increasingY line order
     if (!spec.find_attribute("openexr:lineOrder"))