add raw version of getting parameters in helium, demonstrate in helide

libs/helide/camera/Perspective.cpp

@@ -11,7 +11,10 @@ void Perspective::commit()
 {
   Camera::commit();
 
-  float fovy = getParam<float>("fovy", radians(60.f));
+  // NOTE: demonstrate alternative 'raw' method for getting parameter values
+  float fovy = 0.f;
+  if (!getParam("fovy", ANARI_FLOAT32, &fovy))
+    fovy = radians(60.f);
   float aspect = getParam<float>("aspect", 1.f);
 
   float2 imgPlaneSize;

libs/helium/utility/ParameterizedObject.cpp

@@ -2,6 +2,8 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "ParameterizedObject.h"
+// std
+#include <cstring>
 
 namespace helium {
 
@@ -16,6 +18,20 @@ void ParameterizedObject::setParam(
   findParam(name, true)->second = AnariAny(type, v);
 }
 
+bool ParameterizedObject::getParam(
+    const std::string &name, ANARIDataType type, void *v)
+{
+  if (type == ANARI_STRING || anari::isObject(type))
+    return false;
+
+  auto *p = findParam(name, false);
+  if (!p || !p->second.is(type))
+    return false;
+
+  std::memcpy(v, p->second.data(), anari::sizeOf(type));
+  return true;
+}
+
 std::string ParameterizedObject::getParamString(
     const std::string &name, const std::string &valIfNotFound)
 {

libs/helium/utility/ParameterizedObject.h

@@ -35,6 +35,12 @@ struct ParameterizedObject
   template <typename T>
   T getParam(const std::string &name, T valIfNotFound);
 
+  // Get the value of the parameter associated with 'name' and write it to
+  // location 'v', returning whether the was actually read. Just like the
+  // templated version above, this requires that 'type' exactly match what the
+  // application set. This function also cannot get objects or strings.
+  bool getParam(const std::string &name, ANARIDataType type, void *v);
+
   // Get the pointer to an object parameter (returns null if not present). While
   // ParameterizedObject will track object lifetime appropriately, accessing
   // an object parameter does _not_ influence lifetime considerations -- devices

tests/unit/test_helium_ParameterizedObject.cpp

@@ -57,6 +57,11 @@ SCENARIO(
       REQUIRE(obj.hasParam(name));
       REQUIRE(obj.getParam<int>(name, 4) == v);
       REQUIRE(obj.getParam<short>(name, 4) == 4);
+
+      int v2 = 0;
+      bool success = obj.getParam(name, ANARI_INT32, &v2);
+      REQUIRE(success == true);
+      REQUIRE(v2 == v);
     }
 
     WHEN("The parameter is removed")
@@ -68,6 +73,11 @@ SCENARIO(
         REQUIRE(!obj.hasParam(name));
         REQUIRE(obj.getParam<int>(name, 4) == 4);
         REQUIRE(obj.getParam<short>(name, 4) == 4);
+
+        int v2 = 0;
+        bool success = obj.getParam(name, ANARI_INT32, &v2);
+        REQUIRE(success == false);
+        REQUIRE(v2 == 0);
       }
     }
   }