[visual-details] get compiling with OIIO C++

src/lib/plot.c

@@ -449,7 +449,7 @@ ncdplot* ncdplot_create(ncplane* n, const ncplot_options* opts, double miny, dou
   ncdplot* ret = malloc(sizeof(*ret));
   if(ret){
     memset(ret, 0, sizeof(*ret));
-    if(create_double(ret, n, opts, miny, maxy, -DBL_MAX, DBL_MAX) == 0){
+    if(create_double(ret, n, opts, miny, maxy, -DBL_MAX, DBL_MAX)){
       return ret;
     }
     free(ret);

src/lib/visual-details.h

@@ -28,7 +28,7 @@ ncvisual_set_data(ncvisual* ncv, void* data, bool owned){
   if(ncv->owndata){
     free(ncv->data);
   }
-  ncv->data = data;
+  ncv->data = (uint32_t*)data;
   ncv->owndata = owned;
 }