feat(live2d): 添加 Pose 处理模块以管理互斥 Part 的显示状态，优化模型加载和参数更新

src/plugins/live2d/model.rs

@@ -64,6 +64,12 @@ pub struct CubismModel {
     pub param_ids: Vec<String>,
     /// 参数索引映射（id → index）
     pub param_index: std::collections::HashMap<String, usize>,
+    /// Part 数量
+    pub part_count: usize,
+    /// Part ID 列表（与 Core 内部顺序一致）
+    pub part_ids: Vec<String>,
+    /// Part 索引映射（id → index）
+    pub part_index: std::collections::HashMap<String, usize>,
     /// drawable 数量
     pub drawable_count: usize,
     /// canvas 信息
@@ -134,6 +140,20 @@ impl CubismModel {
             param_ids.push(id);
         }
 
+        // 读取 part 信息（Pose 会按 PartOpacity 切换互斥部件，如 Haru 的两组手臂）
+        let part_count = unsafe { (core.csm_get_part_count)(model) } as usize;
+        let part_ids_ptr = unsafe { (core.csm_get_part_ids)(model) };
+        let mut part_ids = Vec::with_capacity(part_count);
+        let mut part_index = std::collections::HashMap::new();
+        for i in 0..part_count {
+            let id = unsafe {
+                super::core_ffi::cstr_ptr_to_string(*part_ids_ptr.add(i))
+                    .unwrap_or_default()
+            };
+            part_index.insert(id.clone(), i);
+            part_ids.push(id);
+        }
+
         // 读取 drawable 数量
         let drawable_count = unsafe { (core.csm_get_drawable_count)(model) } as usize;
 
@@ -152,8 +172,8 @@ impl CubismModel {
         };
 
         println!(
-            "[Live2D] 模型加载成功: 参数={} drawable={} canvas={:?} origin=({:.1},{:.1})x{:.0}ppu",
-            param_count, drawable_count, canvas.size, canvas.origin[0], canvas.origin[1], canvas.pixels_per_unit
+            "[Live2D] 模型加载成功: 参数={} part={} drawable={} canvas={:?} origin=({:.1},{:.1})x{:.0}ppu",
+            param_count, part_count, drawable_count, canvas.size, canvas.origin[0], canvas.origin[1], canvas.pixels_per_unit
         );
 
         Ok(Self {
@@ -165,6 +185,9 @@ impl CubismModel {
             param_count,
             param_ids,
             param_index,
+            part_count,
+            part_ids,
+            part_index,
             drawable_count,
             canvas,
         })
@@ -205,19 +228,34 @@ impl CubismModel {
     /// 按参数 ID 设置值
     pub fn set_param(&self, core: &CubismCore, id: &str, value: f32) -> bool {
         if let Some(&idx) = self.param_index.get(id) {
-            let slice = self.param_values_mut(core);
-            slice[idx] = value;
+            self.set_param_by_index(core, idx, value);
             true
         } else {
             false
         }
     }
 
+    /// 按参数索引设置值
+    pub fn set_param_by_index(&self, core: &CubismCore, index: usize, value: f32) {
+        if index < self.param_count {
+            let slice = self.param_values_mut(core);
+            slice[index] = value;
+        }
+    }
+
     /// 按参数 ID 获取值
     pub fn get_param(&self, core: &CubismCore, id: &str) -> Option<f32> {
         let idx = *self.param_index.get(id)?;
+        self.get_param_by_index(core, idx)
+    }
+
+    /// 按参数索引获取值
+    pub fn get_param_by_index(&self, core: &CubismCore, index: usize) -> Option<f32> {
+        if index >= self.param_count {
+            return None;
+        }
         let slice = self.param_values_mut(core);
-        Some(slice[idx])
+        Some(slice[index])
     }
 
     /// 将所有参数重置为默认值
@@ -229,6 +267,36 @@ impl CubismModel {
         }
     }
 
+    /// 获取 PartOpacity 缓冲区（可读写）
+    pub fn part_opacities_mut(&self, core: &CubismCore) -> &mut [f32] {
+        unsafe {
+            let p = (core.csm_get_part_opacities)(self.model);
+            std::slice::from_raw_parts_mut(p, self.part_count)
+        }
+    }
+
+    /// 按 Part ID 获取索引
+    pub fn part_index(&self, id: &str) -> Option<usize> {
+        self.part_index.get(id).copied()
+    }
+
+    /// 按 Part 索引设置 opacity
+    pub fn set_part_opacity_by_index(&self, core: &CubismCore, index: usize, opacity: f32) {
+        if index < self.part_count {
+            let slice = self.part_opacities_mut(core);
+            slice[index] = opacity.clamp(0.0, 1.0);
+        }
+    }
+
+    /// 按 Part 索引获取 opacity
+    pub fn get_part_opacity_by_index(&self, core: &CubismCore, index: usize) -> Option<f32> {
+        if index >= self.part_count {
+            return None;
+        }
+        let slice = self.part_opacities_mut(core);
+        Some(slice[index])
+    }
+
     /// 更新 model（应用参数变化，重新计算顶点/不透明度等）
     pub fn update(&self, core: &CubismCore) {
         unsafe { (core.csm_update_model)(self.model) };