Support particle simulation point cache data

Also see https://developer.blender.org/T53562

.gitignore

@@ -7,3 +7,4 @@ __pycache__
 /.coverage
 
 /tests/blendfiles/cache_ocean/
+/tests/blendfiles/T53562/blendcache_bam_pack_bug/

blender_asset_tracer/tracer/block_walkers.py

@@ -12,7 +12,7 @@ import typing
 
 from blender_asset_tracer import blendfile, bpathlib
 from blender_asset_tracer.blendfile import iterators
-from . import result, cdefs
+from . import result, cdefs, modifier_walkers
 
 log = logging.getLogger(__name__)
 
@@ -105,20 +105,14 @@ def _from_block_ob(block: blendfile.BlendFileBlock) -> typing.Iterator[result.Bl
     mods = block.get_pointer((b'modifiers', b'first'))
     for mod_idx, block_mod in enumerate(iterators.listbase(mods, next_path=(b'modifier', b'next'))):
         block_name = b'%s.modifiers[%d]' % (ob_idname, mod_idx)
-        log.debug('Tracing modifier %s', block_name.decode())
-
         mod_type = block_mod[b'modifier', b'type']
-        if mod_type == cdefs.eModifierType_Ocean:
-            if block_mod[b'cached']:
-                path, field = block_mod.get(b'cachepath', return_field=True)
-                # The path indicates the directory containing the cached files.
-                yield result.BlockUsage(block_mod, path, is_sequence=True, path_full_field=field,
-                                        block_name=block_name)
+        log.debug('Tracing modifier %s, type=%d', block_name.decode(), mod_type)
 
-        elif mod_type == cdefs.eModifierType_MeshCache:
-            path, field = block_mod.get(b'filepath', return_field=True)
-            yield result.BlockUsage(block_mod, path, is_sequence=False, path_full_field=field,
-                                    block_name=block_name)
+        try:
+            mod_handler = modifier_walkers.modifier_handlers[mod_type]
+        except KeyError:
+            continue
+        yield from mod_handler(block_mod, block_name)
 
 
 def _from_block_sc(block: blendfile.BlendFileBlock) -> typing.Iterator[result.BlockUsage]:

blender_asset_tracer/tracer/cdefs.py

@@ -34,6 +34,7 @@ IMA_SRC_SEQUENCE = 2
 IMA_SRC_MOVIE = 3
 
 # DNA_modifier_types.h
+eModifierType_ParticleSystem = 19
 eModifierType_Ocean = 39
 eModifierType_MeshCache = 46
 
@@ -45,4 +46,10 @@ PART_DRAW_GR = 8
 # Object.transflag
 OB_DUPLIGROUP = 1 << 8
 
-CACHE_LIBRARY_SOURCE_CACHE = 1
+# DNA_object_force_types.h
+PTCACHE_DISK_CACHE = 64
+PTCACHE_EXTERNAL = 512
+
+# BKE_pointcache.h
+PTCACHE_EXT = b'.bphys'
+PTCACHE_PATH = b'blendcache_'

blender_asset_tracer/tracer/modifier_walkers.py

@@ -0,0 +1,64 @@
+"""Modifier handling code used in block_walkers.py
+
+The _modifier_xxx() functions all yield result.BlockUsage objects for external
+files used by the modifiers.
+"""
+import typing
+
+from blender_asset_tracer import blendfile, bpathlib
+from . import result, cdefs
+
+
+def _modifier_filepath(modifier: blendfile.BlendFileBlock, block_name: bytes) \
+        -> typing.Iterator[result.BlockUsage]:
+    """Just yield the 'filepath' field."""
+    path, field = modifier.get(b'filepath', return_field=True)
+    yield result.BlockUsage(modifier, path, path_full_field=field, block_name=block_name)
+
+
+def _modifier_ocean(modifier: blendfile.BlendFileBlock, block_name: bytes) \
+        -> typing.Iterator[result.BlockUsage]:
+    if not modifier[b'cached']:
+        return
+
+    path, field = modifier.get(b'cachepath', return_field=True)
+    # The path indicates the directory containing the cached files.
+    yield result.BlockUsage(modifier, path, is_sequence=True, path_full_field=field,
+                            block_name=block_name)
+
+
+def _modifier_particle_system(modifier: blendfile.BlendFileBlock, block_name: bytes) \
+        -> typing.Iterator[result.BlockUsage]:
+    psys = modifier.get_pointer(b'psys')
+    if psys is None:
+        return
+
+    pointcache = psys.get_pointer(b'pointcache')
+    if pointcache is None:
+        return
+
+    flag = pointcache[b'flag']
+
+    if flag & cdefs.PTCACHE_DISK_CACHE:
+        # See ptcache_path() in pointcache.c
+        name, field = pointcache.get(b'name', return_field=True)
+        path = b'//%b%b/%b_*%b' % (
+            cdefs.PTCACHE_PATH,
+            modifier.bfile.filepath.stem.encode(),
+            name,
+            cdefs.PTCACHE_EXT)
+        bpath = bpathlib.BlendPath(path)
+        yield result.BlockUsage(pointcache, bpath, path_full_field=field,
+                                is_sequence=True, block_name=block_name)
+
+    if flag & cdefs.PTCACHE_EXTERNAL:
+        path, field = pointcache.get(b'path', return_field=True)
+        yield result.BlockUsage(pointcache, path, path_full_field=field,
+                                is_sequence=True, block_name=block_name)
+
+
+modifier_handlers = {
+    cdefs.eModifierType_ParticleSystem: _modifier_particle_system,
+    cdefs.eModifierType_Ocean: _modifier_ocean,
+    cdefs.eModifierType_MeshCache: _modifier_filepath,
+}

blender_asset_tracer/tracer/result.py

@@ -8,7 +8,9 @@ class BlockUsage:
     :ivar block_name: an identifying name for this block. Defaults to the ID
         name of the block.
     :ivar block:
-    :ivar asset_path:
+    :ivar asset_path: The path of the asset, if is_sequence=False. Otherwise
+        it can be either a glob pattern (must contain a * byte), a directory,
+        or the path of the first file in the sequence.
     :ivar is_sequence: Indicates whether this file is alone (False), the
         first of a sequence (True, and the path points to a file), or a
         directory containing a sequence (True, and path points to a directory).

tests/test_tracer.py

@@ -196,3 +196,10 @@ class DepsTest(AbstractTracerTest):
                 'Image', 'name[1024]', None, None,
                 b'//textures/Textures/Buildings/buildings_roof_04-color.png', False),
         }, recursive=True)
+
+    def test_sim_data(self):
+        self.assert_deps('T53562/bam_pack_bug.blend', {
+            b'OBEmitter.modifiers[0]': Expect(
+                'PointCache', 'name[64]', None, None,
+                b'//blendcache_bam_pack_bug/particles_*.bphys', True),
+        })