d3d10: Implement ID3D10EffectVariable::GetAnnotationByIndex().

dlls/d3d10/effect.c

@@ -1650,9 +1650,22 @@ static HRESULT STDMETHODCALLTYPE d3d10_effect_variable_GetDesc(ID3D10EffectVaria
 static struct ID3D10EffectVariable * STDMETHODCALLTYPE d3d10_effect_variable_GetAnnotationByIndex(
         ID3D10EffectVariable *iface, UINT index)
 {
-    FIXME("iface %p, index %u stub!\n", iface, index);
+    struct d3d10_effect_variable *This = (struct d3d10_effect_variable *)iface;
+    struct d3d10_effect_variable *a;
 
-    return NULL;
+    TRACE("iface %p, index %u\n", iface, index);
+
+    if (index >= This->annotation_count)
+    {
+        WARN("Invalid index specified\n");
+        return (ID3D10EffectVariable *)&null_variable;
+    }
+
+    a = &This->annotations[index];
+
+    TRACE("Returning annotation %p, %s\n", a, debugstr_a(a->name));
+
+    return (ID3D10EffectVariable *)a;
 }
 
 static struct ID3D10EffectVariable * STDMETHODCALLTYPE d3d10_effect_variable_GetAnnotationByName(