From 63f9e43e176010377f3ec3a8c67b38747b4015bd Mon Sep 17 00:00:00 2001
From: William Herald Snyder <will.herald.snyder@gmail.com>
Date: Fri, 6 Jan 2023 21:30:16 -0500
Subject: [PATCH] Read SHDW chunks

---
 addons/io_scene_swbf_msh/msh_model.py      | 15 +++++++++++++++
 addons/io_scene_swbf_msh/msh_scene_read.py | 22 ++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/addons/io_scene_swbf_msh/msh_model.py b/addons/io_scene_swbf_msh/msh_model.py
index 3c6daf0..f83fb0b 100644
--- a/addons/io_scene_swbf_msh/msh_model.py
+++ b/addons/io_scene_swbf_msh/msh_model.py
@@ -39,6 +39,20 @@ class VertexWeight:
     weight: float = 1.0
     bone: int = 0
 
+
+@dataclass 
+class ShadowGeometry:
+    """ Class representing 'SHDW' chunks. """
+
+    # Perhaps I could just use the positions list in the segment
+    # class, but I don't know if SHDW info can coexist with 
+    # a normal geometry segment...
+    positions: List[Vector] = field(default_factory=list)
+   
+    # The second two entries may not be necessary...
+    edges: List[Tuple[int,int,int,int]] = field(default_factory=list)
+
+
 @dataclass
 class GeometrySegment:
     """ Class representing a 'SEGM' section in a .msh file. """
@@ -56,6 +70,7 @@ class GeometrySegment:
     triangles: List[List[int]] = field(default_factory=list)
     triangle_strips: List[List[int]] = None
 
+    shadow_geometry: ShadowGeometry = None
 
 @dataclass
 class CollisionPrimitive:
diff --git a/addons/io_scene_swbf_msh/msh_scene_read.py b/addons/io_scene_swbf_msh/msh_scene_read.py
index d4f9802..964eae0 100644
--- a/addons/io_scene_swbf_msh/msh_scene_read.py
+++ b/addons/io_scene_swbf_msh/msh_scene_read.py
@@ -387,7 +387,29 @@ def _read_segm(segm: Reader, materials_list: List[Material]) -> GeometrySegment:
             # TODO: Dont know if/how to handle trailing 0 bug yet: https://schlechtwetterfront.github.io/ze_filetypes/msh.html#STRP
             #if segm.read_u16 != 0: 
             #    segm.skip_bytes(-2)
+       
+        elif next_header == "SHDW":
+            
+            shadow_geometry = ShadowGeometry()
 
+            with segm.read_child() as shdw:
+                #print("Found shadow chunk")
+
+                num_positions = shdw.read_u32()
+                #print(f"  Num verts in shadow mesh: {num_positions}")
+                shadow_geometry.positions = [shdw.read_vec() for _ in range(num_positions)]
+
+                num_edges = shdw.read_u32()
+                #print(f" Num edges in shadow mesh: {num_edges}")
+                edges = []
+                for i in range(num_edges):
+                    edges.append(tuple(shdw.read_u16(4)))
+                    #print("    " + str(edges[-1]))
+                shadow_geometry.edges = edges
+
+            geometry_seg.shadow_geometry = shadow_geometry    
+
+                
         elif next_header == "WGHT":
             with segm.read_child() as wght: