feat: generate resource pack overlays

    - add dependency pillow

TODO.md

@@ -1,5 +1,5 @@
 ## TODO:
-- generate resource pack overlays
 - add worldgen support
 - merge nested overlays (overlays in the target pack)
 - create more tests
+- allow separate dp and rp default formats

beet_observer/resource_pack.py

@@ -1,5 +1,151 @@
-from beet import Context
+from typing import Any
 
+from beet import Context, NamespaceProxy
 
-def gen_rp_overlays(ctx: Context, ctx_overlay: Context, directory: str):
-    return
+
+def gen_rp_overlays(ctx: Context, ctx_overlay: Context, overlay_dir: str) -> None:
+    """
+    Generates overlays between two resource packs.
+
+    Keyword arguments:</br>
+    `ctx` -- the build context</br>
+    `ctx_overlay` -- the overlay context</br>
+    `overlay_dir` -- the directory of the overlay</br>
+    """
+    # create list of all resource pack file types
+    file_types: list[tuple[NamespaceProxy[Any], NamespaceProxy[Any]]] = [
+        (ctx.assets.blockstates, ctx_overlay.assets.blockstates),
+        (ctx.assets.models, ctx_overlay.assets.models),
+        (ctx.assets.languages, ctx_overlay.assets.languages),
+        (ctx.assets.fonts, ctx_overlay.assets.fonts),
+        (ctx.assets.glyph_sizes, ctx_overlay.assets.glyph_sizes),
+        (ctx.assets.true_type_fonts, ctx_overlay.assets.true_type_fonts),
+        (ctx.assets.shader_posts, ctx_overlay.assets.shader_posts),
+        (ctx.assets.shaders, ctx_overlay.assets.shaders),
+        (ctx.assets.fragment_shaders, ctx_overlay.assets.fragment_shaders),
+        (ctx.assets.vertex_shaders, ctx_overlay.assets.vertex_shaders),
+        (ctx.assets.glsl_shaders, ctx_overlay.assets.glsl_shaders),
+        (ctx.assets.texts, ctx_overlay.assets.texts),
+        (ctx.assets.textures_mcmeta, ctx_overlay.assets.textures_mcmeta),
+        (ctx.assets.textures, ctx_overlay.assets.textures),
+        (ctx.assets.sounds, ctx_overlay.assets.sounds),
+        (ctx.assets.particles, ctx_overlay.assets.particles),
+        (ctx.assets.atlases, ctx_overlay.assets.atlases),
+    ]
+    # for each file type, check for required overlays
+    for registry, registry_overlay in file_types:
+        check_registry(ctx, ctx_overlay, overlay_dir, registry, registry_overlay)
+
+    # get pack.mcmeta overlay entries
+    mcmeta: dict[str, dict[str, list[dict[str, Any]]]] = ctx.assets.mcmeta.data.copy()
+    if "overlays" not in mcmeta:
+        mcmeta["overlays"] = {}
+    if "entries" not in mcmeta["overlays"]:
+        mcmeta["overlays"]["entries"] = []
+    entries = mcmeta["overlays"]["entries"]
+
+    # add overlays to pack.mcmeta
+    for overlay in ctx.assets.overlays:
+        # check if it's the top-level overlay
+        if overlay == ctx.meta["observer"]["default_dir_rp"]:
+            # delete pack.mcmeta from overlay (required for tests)
+            default_dir = ctx.meta["observer"]["default_dir_rp"]
+            if ctx.assets.overlays[default_dir].mcmeta:
+                del ctx.assets.overlays[default_dir].mcmeta
+
+            # get pack format from build context
+            if "default_format" in ctx.meta["observer"]:
+                formats = ctx.meta["observer"]["default_format"]
+            else:
+                formats = ctx.assets.mcmeta.data["pack"]["pack_format"]
+        else:
+            # get formats from overlay pack
+            if "supported_formats" in ctx_overlay.assets.mcmeta.data["pack"]:
+                formats = ctx_overlay.assets.mcmeta.data["pack"]["supported_formats"]
+            else:
+                formats = ctx_overlay.assets.mcmeta.data["pack"]["pack_format"]
+
+        # update pack.mcmeta overlay entries
+        entries.append(
+            {
+                "formats": formats,
+                "directory": overlay,
+            }
+        )
+
+    # save overlay entries in pack.mcmeta
+    if len(entries) > 0:
+        ctx.assets.mcmeta.data.update({"overlays": {"entries": entries}})
+
+
+def check_registry(
+    ctx: Context,
+    ctx_overlay: Context,
+    overlay_dir: str,
+    registry: NamespaceProxy[Any],
+    registry_overlay: NamespaceProxy[Any],
+) -> None:
+    """
+    Generates overlays for each namespace proxy.
+
+    Keyword arguments:</br>
+    `ctx` -- the build context</br>
+    `ctx_overlay` -- the overlay context</br>
+    `overlay_dir` -- the directory of the overlay</br>
+    `registry` -- the namespace proxy from the build context</br>
+    `registry_overlay` -- the namespace proxy from the overlay context</br>
+    """
+    # check each file in the build pack
+    for name in list(registry):
+        if name in registry_overlay:
+            # exists in both, so check if an overlay is needed
+            gen_registry_overlay(ctx, overlay_dir, name, registry, registry_overlay)
+        else:
+            # exists only in overlay, so create a deletion overlay
+            gen_registry_overlay(
+                ctx, overlay_dir, name, registry, registry_overlay, "deletion"
+            )
+
+    # for all remaining files (of this type) in the overlay pack, add to build pack as an overlay
+    for name in list(registry_overlay):
+        gen_registry_overlay(
+            ctx, overlay_dir, name, registry, registry_overlay, "addition"
+        )
+
+
+def gen_registry_overlay(
+    ctx: Context,
+    overlay_dir: str,
+    name: str,
+    registry: NamespaceProxy[Any],
+    registry_overlay: NamespaceProxy[Any],
+    type: str = "",
+) -> None:
+    """
+    Checks if two functions have the same contents and generate an overlay if they don't.
+
+    Keyword arguments:</br>
+    `ctx` -- the build context</br>
+    `overlay_dir` -- the directory of the generated overlay</br>
+    `name` -- the name of the file</br>
+    `registry` -- the namespace proxy from the build context</br>
+    `registry_overlay` -- the namespace proxy from the overlay context</br>
+    `type` -- either "deletion" or "addition" (default: `""`)</br>
+    """
+    if type == "deletion":
+        # move file from build pack to overlay in build pack
+        default_dir = ctx.meta["observer"]["default_dir_rp"]
+        ctx.assets.overlays[default_dir][name] = registry[name]
+        del registry[name]
+    elif type == "addition":
+        # move function from overlay pack to overlay in build pack
+        ctx.assets.overlays[overlay_dir][name] = registry_overlay[name]
+    else:
+        # check if files are exactly the same
+        if registry[name] != registry_overlay[name]:
+            # move function from overlay pack to overlay in build pack
+            ctx.assets.overlays[overlay_dir][name] = registry_overlay[name]
+
+    # remove file from overlay pack
+    if name in registry_overlay:
+        del registry_overlay[name]

examples/overlay_adds_texture1/beet.yaml

@@ -0,0 +1,12 @@
+resource_pack:
+  load: src
+  pack_format: 42
+  supported_formats: [34,42]
+
+pipeline:
+  - beet_observer
+
+meta:
+  observer:
+    overlays:
+      - process: proc

examples/overlay_adds_texture1/proc/pack.mcmeta

@@ -0,0 +1,6 @@
+{
+  "pack": {
+    "pack_format": 34,
+    "description": ""
+  }
+}

examples/overlay_deletes_texture1/beet.yaml

@@ -0,0 +1,13 @@
+resource_pack:
+  load: src
+  pack_format: 42
+  supported_formats: [34,42]
+
+pipeline:
+  - beet_observer
+
+meta:
+  observer:
+    default_format: 42
+    overlays:
+      - process: proc

examples/overlay_deletes_texture1/proc/pack.mcmeta

@@ -0,0 +1,6 @@
+{
+  "pack": {
+    "pack_format": 34,
+    "description": ""
+  }
+}

examples/overlay_replaces_texture1/beet.yaml

@@ -0,0 +1,12 @@
+resource_pack:
+  load: src
+  pack_format: 42
+  supported_formats: [34,42]
+
+pipeline:
+  - beet_observer
+
+meta:
+  observer:
+    overlays:
+      - process: proc

examples/overlay_replaces_texture1/proc/pack.mcmeta

@@ -0,0 +1,6 @@
+{
+  "pack": {
+    "pack_format": 34,
+    "description": ""
+  }
+}

pyproject.toml

@@ -9,6 +9,7 @@ readme = "README.md"
 [tool.poetry.dependencies]
 python = "^3.10"
 beet = ">=0.108.5"
+pillow = "^11.0.0"
 
 [tool.poetry.group.dev.dependencies]
 pytest = "^8.3.3"