Adding additional word offsets to SpvReflectBlockVariable

[alister-chowdhury]

Hey there,

It would be useful to be able to reflect the word offset of offset in UBOs, this allows you to reorder and compact structs.
(This is mostly for dealing with floating hlsl $Globals)

This was a very trivial patch for me to implement locally, if it's something you wouldn't be against I can quickly put together a PR.

--- aspirv_reflect/spirv_reflect.c
+++ bspirv_reflect/spirv_reflect.c
@@ -2272,6 +2272,8 @@ static SpvReflectResult ParseDescriptorBlockVariable(
         ApplyArrayTraits(p_member_type, &p_member_var->array);
       }

+      p_member_var->word_offset.offset = p_type_node->member_decorations[member_index].offset.word_offset;
+
       p_member_var->type_description = p_member_type;
     }
   }

--- aspirv_reflect/spirv_reflect.h
+++ bspirv_reflect/spirv_reflect.h
@@ -378,6 +378,10 @@ typedef struct SpvReflectBlockVariable {
   uint32_t                          member_count;
   struct SpvReflectBlockVariable*   members;

+  struct {
+    uint32_t                          offset;
+  } word_offset;
+
   SpvReflectTypeDescription*        type_description;
 } SpvReflectBlockVariable;

[chaoticbob]

Hi apologies for the late reply. Definitely not against it if it's useful to you - so definitely would love a PR. Just a couple of things:

1. Looking at SpvReflectBlockVariable - it seems like embedded struct isn't necessary, so a member called word_offset should be sufficient. I don't have a strong opinion on this.
2. Can you add it to the end of the struct?

Thanks!

[alister-chowdhury]

That sounds fine, will put something together hopefully sooner rather than later.
The word offset part was just to match the existing convention (since I suppose, it might be desirable in the future to have the word offsets of other things such as alignment and whatknot)