Ensure id attr can be set for IIIF tile output #2612

src/pipeline.cc

@@ -1038,6 +1038,7 @@ class PipelineWorker : public Napi::AsyncWorker {
             ->set("angle", CalculateAngleRotation(baton->tileAngle))
             ->set("background", baton->tileBackground)
             ->set("centre", baton->tileCentre)
+            ->set("id", const_cast<char*>(baton->tileId.data()))
             ->set("skip_blanks", baton->tileSkipBlanks);
           // libvips chooses a default depth based on layout. Instead of replicating that logic here by
           // not passing anything - libvips will handle choice
@@ -1438,6 +1439,7 @@ Napi::Value pipeline(const Napi::CallbackInfo& info) {
     vips_enum_from_nick(nullptr, VIPS_TYPE_FOREIGN_DZ_DEPTH,
     sharp::AttrAsStr(options, "tileDepth").data()));
   baton->tileCentre = sharp::AttrAsBool(options, "tileCentre");
+  baton->tileId = sharp::AttrAsStr(options, "tileId");
 
   // Force random access for certain operations
   if (baton->input->access == VIPS_ACCESS_SEQUENTIAL) {

src/pipeline.h

@@ -192,6 +192,7 @@ struct PipelineBaton {
   std::vector<double> tileBackground;
   int tileSkipBlanks;
   VipsForeignDzDepth tileDepth;
+  std::string tileId;
   std::unique_ptr<double[]> recombMatrix;
 
   PipelineBaton():