Refactor geometry node arrangement system

- Removed obsolete files: sections.py, semantics.json, and sources.py.
- Introduced new modules: branches.py and layout.py for improved calculation block identification and layout planning.
- Implemented a unified layout strategy for geometry nodes, ensuring consistent spacing and organization.
- Added comprehensive documentation for the new layout design and its goals.
- Established a migration plan for transitioning existing assets to the new layout system.
- Updated tests to validate the new arrangement logic and ensure compatibility with existing geometry node structures.

tests/tools/nodes/test_arrangement.py

@@ -5,18 +5,16 @@ import numpy as np
 import pytest
 
 
-from tools.nodes.groups.image_plane import build_image_plane_group
-from tools.nodes.groups.image_depth_plane import build_image_depth_plane_group
-from tools.nodes.groups.image_cutout import build_image_cutout_group
+from tools.nodes.build import build_node_groups
+from tools.nodes.check import GEOMETRY_NAMES
 from tools.nodes.arrangement.arrange import arrange_nodes
+from tools.nodes.arrangement.dimensions import estimate_node_dimensions
 
 
-@pytest.fixture(params=("depth_plane", "cutout"))
+@pytest.fixture(params=sorted(GEOMETRY_NAMES))
 def node_group(request):
     bpy.ops.wm.read_factory_settings(use_empty=True)
-    if request.param == "depth_plane":
-        return build_image_depth_plane_group(build_image_plane_group())
-    return build_image_cutout_group()
+    return next(group for group in build_node_groups() if group.name == request.param)
 
 
 def _source(socket):
@@ -130,3 +128,17 @@ def test_arrangement_preserves_program_and_geometry(node_group):
     for (before_points, before_faces), (after_points, after_faces) in zip(geometry, evaluate()):
         np.testing.assert_allclose(after_points, before_points, atol=1e-6)
         assert after_faces == before_faces
+
+    display_nodes = [node for node in node_group.nodes if node.bl_idname not in {"NodeFrame", "NodeReroute"}]
+    boxes = []
+    for node in display_nodes:
+        size = estimate_node_dimensions(node)
+        x, y = node.location_absolute
+        box = (x, y - size.height, x + size.width, y)
+        assert all(not (box[0] < other[2] and box[2] > other[0]
+                        and box[1] < other[3] and box[3] > other[1]) for other in boxes), node.name
+        boxes.append(box)
+    input_count = sum(node.bl_idname == "NodeGroupInput" for node in display_nodes)
+    arrange_nodes(node_group)
+    assert _program(node_group) == program
+    assert sum(node.bl_idname == "NodeGroupInput" for node in node_group.nodes) == input_count