testing/api: Add test for filter values and 'filter_list' query (#4140)

Add testsuite/filters that verifies that the filter shapes are correct
and don't change if we make future changes to the filter code.

Along the way, add a new global getattribute query 'filter_list', that
returns a semicolon-separated list of all the 2D filters it knows about.

---------

Signed-off-by: Larry Gritz <lg@larrygritz.com>

src/cmake/testing.cmake

@@ -221,6 +221,7 @@ macro (oiio_add_all_tests)
             python-roi
             python-texturesys
             python-typedesc
+            filters
             )
         # These Python tests also need access to oiio-images
         oiio_add_tests (

src/include/OpenImageIO/imageio.h

@@ -3079,6 +3079,11 @@ inline bool attribute (string_view name, string_view val) {
 ///   full paths), and all the directories that OpenImageIO will search for
 ///   fonts.  (Added in OpenImageIO 2.5)
 ///
+/// - `string filter_list`
+///
+///   A semicolon-separated list of all built-in 2D filters. (Added in
+///   OpenImageIO 2.5.9)
+///
 /// - int64_t IB_local_mem_current
 /// - int64_t IB_local_mem_peak
 ///

src/libOpenImageIO/imageio.cpp

@@ -9,6 +9,7 @@
 
 #include <OpenImageIO/color.h>
 #include <OpenImageIO/dassert.h>
+#include <OpenImageIO/filter.h>
 #include <OpenImageIO/fmath.h>
 #include <OpenImageIO/hash.h>
 #include <OpenImageIO/imageio.h>
@@ -539,6 +540,13 @@ getattribute(string_view name, TypeDesc type, void* val)
         *(ustring*)val = ustring(Strutil::join(font_list(), ";"));
         return true;
     }
+    if (name == "filter_list" && type == TypeString) {
+        std::vector<string_view> filternames;
+        for (int i = 0, e = Filter2D::num_filters(); i < e; ++i)
+            filternames.emplace_back(Filter2D::get_filterdesc(i).name);
+        *(ustring*)val = ustring(Strutil::join(filternames, ";"));
+        return true;
+    }
     if (name == "exr_threads" && type == TypeInt) {
         *(int*)val = oiio_exr_threads;
         return true;

src/oiiotool/oiiotool.cpp

@@ -6496,12 +6496,11 @@ print_help_end(Oiiotool& ot, std::ostream& out)
     print(out, "    Run `oiiotool --colorconfiginfo` for a "
                "full color management inventory.\n");
 
-    std::vector<string_view> filternames;
-    for (int i = 0, e = Filter2D::num_filters(); i < e; ++i)
-        filternames.emplace_back(Filter2D::get_filterdesc(i).name);
     print(out, "{}\n",
           Strutil::wordwrap("Filters available: "
-                                + Strutil::join(filternames, ", "),
+                                + Strutil::replace(OIIO::get_string_attribute(
+                                                       "filter_list"),
+                                                   ";", ", ", true),
                             columns, 4));
 
     print_build_info(ot, out);

testsuite/filters/ref/out.txt

@@ -0,0 +1,34 @@
+Comparing "box.exr" and "ref/box.exr"
+PASS
+Comparing "triangle.exr" and "ref/triangle.exr"
+PASS
+Comparing "gaussian.exr" and "ref/gaussian.exr"
+PASS
+Comparing "sharp-gaussian.exr" and "ref/sharp-gaussian.exr"
+PASS
+Comparing "catmull-rom.exr" and "ref/catmull-rom.exr"
+PASS
+Comparing "blackman-harris.exr" and "ref/blackman-harris.exr"
+PASS
+Comparing "sinc.exr" and "ref/sinc.exr"
+PASS
+Comparing "lanczos3.exr" and "ref/lanczos3.exr"
+PASS
+Comparing "radial-lanczos3.exr" and "ref/radial-lanczos3.exr"
+PASS
+Comparing "nuke-lanczos6.exr" and "ref/nuke-lanczos6.exr"
+PASS
+Comparing "mitchell.exr" and "ref/mitchell.exr"
+PASS
+Comparing "bspline.exr" and "ref/bspline.exr"
+PASS
+Comparing "disk.exr" and "ref/disk.exr"
+PASS
+Comparing "cubic.exr" and "ref/cubic.exr"
+PASS
+Comparing "keys.exr" and "ref/keys.exr"
+PASS
+Comparing "simon.exr" and "ref/simon.exr"
+PASS
+Comparing "rifman.exr" and "ref/rifman.exr"
+PASS

testsuite/filters/run.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+
+# Copyright Contributors to the OpenImageIO project.
+# SPDX-License-Identifier: Apache-2.0
+# https://github.com/AcademySoftwareFoundation/OpenImageIO
+
+# Test the filters
+
+import OpenImageIO as oiio
+
+filters = oiio.get_string_attribute("filter_list").split(";")
+print ("all filters: ", filters)
+i = 0
+outputs = [ ]
+
+delta = oiio.ImageBuf(oiio.ImageSpec(16, 16, 1, "float"))
+oiio.ImageBufAlgo.render_point(delta, 8, 8)
+
+for f in filters:
+    buf = oiio.ImageBufAlgo.resize(delta, f, roi=oiio.ROI(0, 80, 0, 80, 0, 1))
+    # Make a marker different for each filter so they dont compare against
+    # each other
+    oiio.ImageBufAlgo.render_point(buf, i, 0)
+    i += 1
+    buf.write("{}.exr".format(f), "half")
+    outputs += [ "{}.exr".format(f) ]
+
+outputs += [ "out.txt" ]