add layer multiply and export refactor

Author: HackLinjiuyue

src/preppipe/frontend/vnmodel/passes.py

@@ -8,6 +8,7 @@
 from ...irbase import *
 from .vncodegen import VNCodeGen
 from .vnparser import VNParser
+from .vnprune import prune_unused_asset_declarations
 from ...vnmodel import VNModel
 
 @TransformArgumentGroup('vnparse', 'Options for VNModel source parsing')
@@ -55,3 +56,13 @@ def run(self) -> Operation | list[Operation] | None:
     ast = self.inputs[0]
     model = VNCodeGen.run(ast)
     return model
+
+
+@MiddleEndDecl('vn-prune-unused-decls', input_decl=VNModel, output_decl=VNModel)
+class VNPruneUnusedAssetsTransform(TransformBase):
+  def run(self) -> Operation | list[Operation] | None:
+    assert len(self.inputs) == 1
+    model = self.inputs[0]
+    if isinstance(model, VNModel):
+      prune_unused_asset_declarations(model)
+    return model

src/preppipe/frontend/vnmodel/vnprune.py

@@ -0,0 +1,33 @@
+# SPDX-FileCopyrightText: 2023 PrepPipe's Contributors
+# SPDX-License-Identifier: Apache-2.0
+
+from ...vnmodel import (
+  VNModel,
+  VNNamespace,
+  VNCharacterSymbol,
+  VNSceneSymbol,
+  VNAssetValueSymbol,
+)
+
+
+def _prune_region(symbols):
+  to_remove = [s for s in symbols if isinstance(s, VNAssetValueSymbol) and s.use_empty()]
+  for s in to_remove:
+    s.erase_from_parent()
+
+
+def prune_unused_asset_declarations(model: VNModel) -> None:
+  """原地移除 model 中未被使用的资源声明（依赖 Value 的 uselist）。"""
+  for ns in model.namespace:
+    if not isinstance(ns, VNNamespace):
+      continue
+    for c in ns.characters:
+      if not isinstance(c, VNCharacterSymbol):
+        continue
+      _prune_region(c.sprites)
+      _prune_region(c.sideimages)
+    for scene in ns.scenes:
+      if not isinstance(scene, VNSceneSymbol):
+        continue
+      _prune_region(scene.backgrounds)
+    _prune_region(ns.assets)

src/preppipe/util/imagepack.py

@@ -108,6 +108,26 @@ def clear(self):
     self.layers.clear()
     self.min_cached_layer = 0
 
+
+class LayerBlendMode(enum.Enum):
+  """图层混合模式。NORMAL 为默认 alpha 合成，MULTIPLY 为正片叠底。
+  序列化时使用 name.lower()（如 "normal", "multiply"），反序列化用 LayerBlendMode.from_serialized(str)。"""
+  NORMAL = enum.auto()
+  MULTIPLY = enum.auto()
+
+  def to_serialized(self) -> str:
+    return self.name.lower()
+
+  @classmethod
+  def from_serialized(cls, s : str | None) -> "LayerBlendMode":
+    if s is None or s.strip() == "":
+      return cls.NORMAL
+    try:
+      return cls[s.upper()]
+    except KeyError:
+      raise ValueError("Unsupported layer mode: " + s + " (only normal and multiply are supported)")
+
+
 @AssetClassDecl("imagepack")
 @ToolClassDecl("imagepack")
 class ImagePack(NamedAssetClassBase):
@@ -175,11 +195,13 @@ class LayerInfo:
     base : bool
     # 如果是 True 的话，该层可以不受限制地单独被选取
     toggle : bool
+    # 图层混合模式
+    mode : LayerBlendMode
 
     def __init__(self, patch : ImageWrapper,
                  offset_x : int = 0, offset_y : int = 0,
                  width : int = 0, height : int = 0,
-                 base : bool = False, toggle : bool = False, basename : str = '') -> None:
+                 base : bool = False, toggle : bool = False, basename : str = '', mode : LayerBlendMode | None = None) -> None:
       self.patch = patch
       self.basename = basename
       self.offset_x = offset_x
@@ -188,6 +210,7 @@ def __init__(self, patch : ImageWrapper,
       self.height = height
       self.base = base
       self.toggle = toggle
+      self.mode = mode if mode is not None else LayerBlendMode.NORMAL
       if width == 0 or height == 0:
         raise RuntimeError("Zero-sized layer?")
 
@@ -199,7 +222,7 @@ def get_shrinked(self, ratio : decimal.Decimal):
                                 offset_x=int(self.offset_x * ratio),
                                 offset_y=int(self.offset_y * ratio),
                                 width=newwidth, height=newheight,
-                                base=self.base, toggle=self.toggle, basename=self.basename)
+                                base=self.base, toggle=self.toggle, basename=self.basename, mode=self.mode)
 
   class CompositeInfo:
     # 保存时每个差分的信息
@@ -328,6 +351,8 @@ def collect_layer_group(prefix : str, layers : list[ImagePack.LayerInfo]):
           flags.append("toggle")
         if len(flags) > 0:
           jsonobj["flags"] = flags
+        if l.mode != LayerBlendMode.NORMAL:
+          jsonobj["mode"] = l.mode.to_serialized()
         result.append(jsonobj)
         self._write_image_to_path(l.patch, filename, path)
       return result
@@ -430,11 +455,16 @@ def read_layer_group(prefix, group_name):
           height = layer_info["h"]
           base = "base" in layer_info.get("flags", [])
           toggle = "toggle" in layer_info.get("flags", [])
+          mode_str = layer_info.get("mode", None)
+          try:
+            mode = LayerBlendMode.from_serialized(mode_str)
+          except ValueError as e:
+            raise PPInternalError(str(e))
           layer_img = ImageWrapper(path=os.path.join(path, layer_filename))
           layers.append(ImagePack.LayerInfo(patch=layer_img,
                                             offset_x=offset_x, offset_y=offset_y,
                                             width=width, height=height,
-                                            base=base, toggle=toggle, basename=layer_info["p"]))
+                                            base=base, toggle=toggle, basename=layer_info["p"], mode=mode))
       return layers
 
     self.layers = read_layer_group("l", "layers")
@@ -503,7 +533,11 @@ def get_composed_image_lower(self, layer_indices : list[int], composition_cache:
     for li in layer_indices:
       layer = self.layers[li]
       cur = result.crop((layer.offset_x, layer.offset_y, layer.offset_x + layer.width, layer.offset_y + layer.height))
-      cur = PIL.Image.alpha_composite(cur, layer.patch.get())
+      layer_patch = layer.patch.get()
+      if layer.mode == LayerBlendMode.MULTIPLY:
+        cur = ImagePack.apply_multiply_blend_mode(cur, layer_patch)
+      else:
+        cur = PIL.Image.alpha_composite(cur, layer_patch)
       if composition_cache is not None and li >= composition_cache.min_cached_layer:
         result = result.copy()
       result.paste(cur, (layer.offset_x, layer.offset_y))
@@ -513,6 +547,21 @@ def get_composed_image_lower(self, layer_indices : list[int], composition_cache:
     # print(f"get_composed_image_lower: {end-start} s")
     return ImageWrapper(image=result)
 
+  @staticmethod
+  def apply_multiply_blend_mode(base : PIL.Image.Image, overlay : PIL.Image.Image) -> PIL.Image.Image:
+    base_array = np.array(base, dtype=np.float32)
+    overlay_array = np.array(overlay, dtype=np.float32)
+    overlay_alpha = overlay_array[:, :, 3:4] / 255.0
+    base_alpha = base_array[:, :, 3:4] / 255.0
+    result_rgb = base_array[:, :, :3] * overlay_array[:, :, :3] / 255.0
+    result_alpha = overlay_alpha + base_alpha * (1.0 - overlay_alpha)
+    base_contribution = 1.0 - overlay_alpha
+    final_rgb = result_rgb * overlay_alpha + base_array[:, :, :3] * base_contribution
+    final_rgb = np.clip(final_rgb, 0, 255).astype(np.uint8)
+    final_alpha = np.clip(result_alpha * 255, 0, 255).astype(np.uint8)
+    result_array = np.dstack((final_rgb, final_alpha))
+    return PIL.Image.fromarray(result_array, mode='RGBA')
+
   @staticmethod
   def ndarray_hsv_to_rgb(hsv : np.ndarray) -> np.ndarray:
     #return np.apply_along_axis(ImagePack.hsv_to_rgb, 1, hsv)
@@ -726,7 +775,7 @@ def create_forked_layer(imgwidth : int, imgheight : int, l : LayerInfo, layerind
     return ImagePack.LayerInfo(ImageWrapper(image=newbase.crop(bbox)),
                                     offset_x=offset_x, offset_y=offset_y,
                                     width=xmax-offset_x, height=ymax-offset_y,
-                                    base=True, toggle=l.toggle, basename=l.basename)
+                                    base=True, toggle=l.toggle, basename=l.basename, mode=l.mode)
 
   def fork_applying_mask(self, args : list[Color | PIL.Image.Image | str | tuple[str, Color] | None], enable_parallelization : bool = False):
     # 创建一个新的 imagepack, 将 mask 所影响的部分替换掉
@@ -1336,6 +1385,7 @@ def lookup_file(filename : str) -> str:
       layer_dict[imgpathbase] = layerindex
       flag_base = False
       flag_toggle = False
+      flag_mode : LayerBlendMode = LayerBlendMode.NORMAL
       def add_flag(flag : str):
         nonlocal flag_base
         nonlocal flag_toggle
@@ -1357,6 +1407,13 @@ def add_flag(flag : str):
             elif isinstance(value, list):
               for flag in value:
                 add_flag(flag)
+          elif key in ImagePack.TR_imagepack_yamlparse_mode.get_all_candidates():
+            if not isinstance(value, str):
+              raise PPInternalError("Invalid mode in " + yamlpath + ": expecting a str but got " + str(value))
+            if value in ImagePack.TR_imagepack_yamlparse_multiply.get_all_candidates():
+              flag_mode = LayerBlendMode.MULTIPLY
+            else:
+              raise PPInternalError("Unsupported layer mode: " + value + " (only normal and multiply are supported)")
       imgpath = lookup_file(imgpathbase + ".png")
       if not os.path.exists(os.path.join(basepath, imgpath)):
         raise PPInternalError("Image file not found: " + imgpath)
@@ -1379,7 +1436,7 @@ def add_flag(flag : str):
       newlayer = ImagePack.LayerInfo(patch,
                                       offset_x=offset_x, offset_y=offset_y,
                                       width=img.width, height=img.height,
-                                      base=flag_base, toggle=flag_toggle, basename=imgpathbase)
+                                      base=flag_base, toggle=flag_toggle, basename=imgpathbase, mode=flag_mode)
       result.layers.append(newlayer)
     if composites is None:
       for i, layer in enumerate(result.layers):
@@ -1639,6 +1696,21 @@ class CharacterSpritePartsBased_PartKind(enum.Enum):
     zh_cn="基底简写",
     zh_hk="基底簡寫",
   )
+  TR_imagepack_yamlgen_layer_modes = TR_imagepack.tr("layer_modes",
+    en="layer_modes",
+    zh_cn="图层模式",
+    zh_hk="圖層模式",
+  )
+  TR_imagepack_yamlparse_mode = TR_imagepack.tr("mode",
+    en="mode",
+    zh_cn="模式",
+    zh_hk="模式",
+  )
+  TR_imagepack_yamlparse_multiply = TR_imagepack.tr("multiply",
+    en="multiply",
+    zh_cn="正片叠底",
+    zh_hk="正片疊底",
+  )
 
   @dataclasses.dataclass
   class CharacterSpritePartsBased_PartsDecl:
@@ -1661,6 +1733,9 @@ def yaml_generation_charactersprite_parts_based(data : dict, layers : dict | Non
     # 为了避免基底所用的名称太长（比如每个选区都有独立的图层、立绘有部分需要拆成独立的置顶的图层），我们支持定义基底组合的简称，如果有简称的话所有基底组合都必须有简称
     base_abbreviation : dict[str, tuple[str,...]] | None = None
 
+    # 存储图层模式映射：图层名 -> 模式
+    layer_modes : dict[str, LayerBlendMode] = {}
+
     kinds_enum_map : dict[str, ImagePack.CharacterSpritePartsBased_PartKind] = {}
 
     # 除了装饰部件以外，每种部件类型最多只能声明一次
@@ -1785,11 +1860,22 @@ def add_parsed_info_to_metadata():
           if not isinstance(abbr_list, str):
             raise PPInternalError("Invalid abbreviation list in generation: expecting a str but got " + str(abbr_list) + " (type: " + str(type(abbr_list)) + ")")
           base_abbreviation[abbr_name] = parse_dep_liststr(abbr_list)
+      elif k in ImagePack.TR_imagepack_yamlgen_layer_modes.get_all_candidates():
+        if not isinstance(v, dict):
+          raise PPInternalError("Invalid layer_modes in generation: expecting a dict but got " + str(v) + " (type: " + str(type(v)) + ")")
+        for layer_name, mode in v.items():
+          if not isinstance(mode, str):
+            raise PPInternalError("Invalid layer mode for " + layer_name + ": expecting a str but got " + str(mode) + " (type: " + str(type(mode)) + ")")
+          if mode in ImagePack.TR_imagepack_yamlparse_multiply.get_all_candidates():
+            layer_modes[layer_name] = LayerBlendMode.MULTIPLY
+          else:
+            raise PPInternalError("Unsupported layer mode for " + layer_name + ": " + mode + " (only normal and multiply are supported)")
       else:
         raise PPInternalError("Unknown key in generation: " + k + "(supported keys: "
                               + str(ImagePack.TR_imagepack_yamlgen_parts.get_all_candidates()) + ", "
                               + str(ImagePack.TR_imagepack_yamlgen_parts_kind.get_all_candidates()) + ", "
-                              + str(ImagePack.TR_imagepack_yamlgen_tags.get_all_candidates()) + ")")
+                              + str(ImagePack.TR_imagepack_yamlgen_tags.get_all_candidates()) + ", "
+                              + str(ImagePack.TR_imagepack_yamlgen_layer_modes.get_all_candidates()) + ")")
     # 初步解析完毕，我们将解析结果写入 metadata
     add_parsed_info_to_metadata()
     # 检查一下输入有没有问题，所有标签是否都有定义，所有部件是否都有定义
@@ -1937,6 +2023,8 @@ def try_add_combinations(parts_list : tuple[str, ...]):
       part_dict = {}
       if kinds_enum_map[part.kind] == ImagePack.CharacterSpritePartsBased_PartKind.BASE:
         part_dict[ImagePack.TR_imagepack_yamlparse_flags.get()] = ImagePack.TR_imagepack_yamlparse_base.get()
+      if part.name in layer_modes and layer_modes[part.name] == LayerBlendMode.MULTIPLY:
+        part_dict[ImagePack.TR_imagepack_yamlparse_mode.get()] = ImagePack.TR_imagepack_yamlparse_multiply.get()
       layer_orders[part.name] = len(result_layers)
       result_layers[part.name] = part_dict
     result_composites : dict[str, list[str]] = {}

src/preppipe/util/imagepackexportop.py

@@ -241,7 +241,9 @@ def get_imagepack_layer_filename(self, pack_id : str, layer_index : int) -> str:
 
   def place_imagepack_composite(self, instance_id : str, pack_id : str, composite_code : str) -> str:
     # 组合的图片应该放在哪
-    return os.path.join("images", pack_id, 'E' + instance_id + '_' + composite_code + ".png")
+    # 使用正斜杠以确保跨平台兼容性（RenPy 等引擎需要正斜杠）
+    path = os.path.join("images", pack_id, 'E' + instance_id + '_' + composite_code + ".png")
+    return path.replace("\\", "/")
 
   # 以下是提供给子类使用者的接口
   # ---------------------------------------------------------------------
@@ -334,7 +336,21 @@ def _add_value_impl(self, value : ImagePackElementLiteralExpr, is_require_merged
     target_size_tuple = (value.size.value[0], value.size.value[1])
     composite_code = value.composite_name.value
     composite_index = instance_info.descriptor.get_composite_index_from_code(composite_code)
-    if is_require_merged_image or target_size_tuple != instance_info.descriptor.size:
+    # 检查该组合中是否有图层使用了非默认的混合模式
+    # 如果有，我们需要使用预合成图片，因为 RenPy 的 layeredimage 不支持自定义混合模式
+    has_non_default_blend_mode = False
+    try:
+      imagepack = AssetManager.get_instance().get_asset(pack_id)
+      if isinstance(imagepack, ImagePack) and imagepack.is_imagedata_loaded():
+        for layer_index in instance_info.descriptor.get_layers_from_composite_index(composite_index):
+          layer = imagepack.layers[layer_index]
+          if layer.mode != LayerBlendMode.NORMAL:
+            has_non_default_blend_mode = True
+            break
+    except:
+      # 如果无法访问 ImagePack 或图层信息不可用，保守地假设没有混合模式
+      pass
+    if is_require_merged_image or target_size_tuple != instance_info.descriptor.size or has_non_default_blend_mode:
       # 我们需要生成一个单独的图片
       key_tuple = (composite_index, target_size_tuple)
       if key_tuple in instance_info.composite_export_dict: