custom levels: support vanilla skies and texture remapping tables (#3691)

This adds some new JSON entries to custom levels so they can support
vanilla sky textures and the texture remapping tables, allowing for
proper textures on objects that use `generic`, like dark eco pools or
dying enemies.

The comments explain it in more detail, but the gist is:

For skies:
- `sky` needs to be a vanilla level that has sky textures.
- The alpha tpage (fourth entry in `tpages`) needs to be that vanilla
level's alpha tpage (if `tex_remap` is the same level as `sky`, this
will be handled automatically).
- The tpage needs to be added to the custom level `.gd` and to
`textures` in the JSON.
- In `level-info.gc`, `sky` needs to be `#t`, your level's mood needs to
call `update-mood-sky-texture` (the default mood, `update-mood-default`,
handles this as an example) and `sun-fade` needs to be nonzero for the
sun to show up.

For `generic` textures:
- `tex_remap` needs to be the name of a vanilla level.
- When using a vanilla level's remap table, you need to adhere to the
order of the files in that level's `.gd` in your own level.
  - Code files are first.
- Then the tpages (in the order `tfrag`, `pris`, `shrub`, `alpha`,
`water`).
  - Then the art groups.
  - Lastly, the level file.
- The tpages need to be added to the `textures` in the JSON.

decompiler/level_extractor/BspHeader.cpp

@@ -1987,6 +1987,13 @@ void HFragment::read_from_file(TypedRef ref, const decompiler::DecompilerTypeSys
   size = read_plain_data_field<u32>(ref, "size", dts);
 }
 
+void AdgifShaderArray::read_from_file(TypedRef ref, const decompiler::DecompilerTypeSystem& dts) {
+  auto length = read_plain_data_field<s32>(ref, "length", dts);
+  adgifs.resize(length);
+  memcpy_plain_data((u8*)adgifs.data(), get_field_ref(ref, "data", dts),
+                    sizeof(AdGifData) * length);
+}
+
 void BspHeader::read_from_file(const decompiler::LinkedObjectFile& file,
                                const decompiler::DecompilerTypeSystem& dts,
                                GameVersion version,
@@ -2001,6 +2008,19 @@ void BspHeader::read_from_file(const decompiler::LinkedObjectFile& file,
   bsphere.read_from_file(get_field_ref(ref, "bsphere", dts));
   name = read_symbol_field(ref, "name", dts);
 
+  if (version == GameVersion::Jak1) {
+    adgifs.read_from_file(get_and_check_ref_to_basic(ref, "adgifs", "adgif-shader-array", dts),
+                          dts);
+  }
+
+  texture_page_count = read_plain_data_field<s32>(ref, "texture-page-count", dts);
+  if (texture_page_count > 0) {
+    auto tex_id_ptr = deref_label(get_field_ref(ref, "texture-ids", dts));
+    for (int i = 0; i < texture_page_count; i++) {
+      texture_ids.push_back(deref_u32(tex_id_ptr, i));
+    }
+  }
+
   texture_remap_table.clear();
   s32 tex_remap_len = read_plain_data_field<s32>(ref, "texture-remap-table-len", dts);
   if (tex_remap_len > 0) {