feat: expr constant w/viz fixes

Driven solely by the Expr socket, we've completely replaced the
dedicated NumberConstant and PhysicalConstant nodes. We also
demonstrated symbolic variable operations w/visualization and
end-node realization, validating that this approach to Expr sockets is
key.

We prepared for a new `BLPropType`, namely dynamic lists of dataclasses,
which will represent dynamic user-adjustable lists. This is the only
proper UI design for declaring symbols directly in an Expr node.
For now, we'll do without symbols, but will be a core feature for design
space exploration (aka. batch-run a bunch of sims), and for inverse
design.

Else, a few fixes: Naming of `ManagedBLImage` was updated, the expr
socket info display was fixed to display even when only output
information is available,

A few TODOs remain in the Expr Constant, but they are less important
before dynamic symbol declarations are in place.

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/node_types.py

@@ -38,8 +38,6 @@ class NodeType(blender_type_enum.BlenderTypeEnum):
 	Scene = enum.auto()
 	## Inputs / Constants
 	ExprConstant = enum.auto()
-	NumberConstant = enum.auto()
-	PhysicalConstant = enum.auto()
 	ScientificConstant = enum.auto()
 	UnitSystemConstant = enum.auto()
 	BlenderConstant = enum.auto()

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/sim_types.py

@@ -21,9 +21,11 @@ import enum
 import typing as typ
 
 import jax.numpy as jnp
+import sympy as sp
 import tidy3d as td
 
 from blender_maxwell.services import tdcloud
+from blender_maxwell.utils import extra_sympy_units as spux
 
 
 ####################

src/blender_maxwell/node_trees/maxwell_sim_nodes/managed_objs/managed_bl_image.py

@@ -47,8 +47,13 @@ class ManagedBLImage(base.ManagedObj):
 	managed_obj_type = ct.ManagedObjType.ManagedBLImage
 	_bl_image_name: str
 
-	def __init__(self, name: str):
+	def __init__(self, name: str, prev_name: str | None = None):
-		self._bl_image_name = name
+		if prev_name is not None:
+			self._bl_image_name = prev_name
+		else:
+			self._bl_image_name = name
+
+		self.name = name
 
 	@property
 	def name(self):
@@ -57,26 +62,29 @@ class ManagedBLImage(base.ManagedObj):
 	@name.setter
 	def name(self, value: str):
 		log.info(
-			'Setting ManagedBLImage from "%s" to "%s"',
+			'Changing ManagedBLImage from "%s" to "%s"',
 			self.name,
 			value,
 		)
-		current_bl_image = bpy.data.images.get(self._bl_image_name)
+		existing_bl_image = bpy.data.images.get(self.name)
-		wanted_bl_image = bpy.data.images.get(value)
 
-		# Yoink Image Name
+		# No Existing Image: Set Value to Name
-		if current_bl_image is None and wanted_bl_image is None:
+		if existing_bl_image is None:
 			self._bl_image_name = value
 
-		# Alter Image Name
+		# Existing Image: Rename to New Name
-		elif current_bl_image is not None and wanted_bl_image is None:
+		else:
+			existing_bl_image.name = value
 			self._bl_image_name = value
-			current_bl_image.name = value
 
-		# Overlapping Image Name
+			# Check: Blender Rename -> Synchronization Error
-		elif wanted_bl_image is not None:
+			## -> We can't do much else than report to the user & free().
-			msg = f'ManagedBLImage "{self._bl_image_name}" could not change its name to "{value}", since it already exists.'
+			if existing_bl_image.name != self._bl_image_name:
-			raise ValueError(msg)
+				log.critical(
+					'BLImage: Failed to set name of %s to %s, as %s already exists.'
+				)
+				self._bl_image_name = existing_bl_image.name
+				self.free()
 
 	def free(self):
 		bl_image = bpy.data.images.get(self.name)

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/inputs/constants/expr_constant.py

@@ -16,6 +16,8 @@
 
 import typing as typ
 
+import sympy as sp
+
 from .... import contracts as ct
 from .... import sockets
 from ... import base, events
@@ -26,27 +28,69 @@ class ExprConstantNode(base.MaxwellSimNode):
 	bl_label = 'Expr Constant'
 
 	input_sockets: typ.ClassVar = {
-		'Expr': sockets.ExprSocketDef(),
+		'Expr': sockets.ExprSocketDef(
+			active_kind=ct.FlowKind.LazyValueFunc,
+		),
 	}
 	output_sockets: typ.ClassVar = {
-		'Expr': sockets.ExprSocketDef(),
+		'Expr': sockets.ExprSocketDef(
+			active_kind=ct.FlowKind.LazyValueFunc,
+			show_info_columns=True,
+		),
 	}
 
-	## TODO: Symbols (defined w/props?)
+	## TODO: Allow immediately realizing any symbol, or just passing it along.
-	## - Currently expr constant isn't excessively useful, since there are no variables.
+	## TODO: Alter output physical_type when the input PhysicalType changes.
-	## - We'll define the #, type, name with props.
-	## - We'll add loose-socket inputs as int/real/complex/physical socket (based on type) for Param.
-	## - We the output expr would support `Value` (just the expression), `LazyValueFunc` (evaluate w/symbol support), `Param` (example values for symbols).
 
 	####################
-	# - Callbacks
+	# - FlowKinds
 	####################
 	@events.computes_output_socket(
-		'Expr', kind=ct.FlowKind.Value, input_sockets={'Expr'}
+		# Trigger
+		'Expr',
+		kind=ct.FlowKind.Value,
+		# Loaded
+		input_sockets={'Expr'},
 	)
 	def compute_value(self, input_sockets: dict) -> typ.Any:
 		return input_sockets['Expr']
 
+	@events.computes_output_socket(
+		# Trigger
+		'Expr',
+		kind=ct.FlowKind.LazyValueFunc,
+		# Loaded
+		input_sockets={'Expr'},
+		input_socket_kinds={'Expr': ct.FlowKind.LazyValueFunc},
+	)
+	def compute_lazy_value_func(self, input_sockets: dict) -> typ.Any:
+		return input_sockets['Expr']
+
+	####################
+	# - FlowKinds: Auxiliary
+	####################
+	@events.computes_output_socket(
+		# Trigger
+		'Expr',
+		kind=ct.FlowKind.Info,
+		# Loaded
+		input_sockets={'Expr'},
+		input_socket_kinds={'Expr': ct.FlowKind.Info},
+	)
+	def compute_info(self, input_sockets: dict) -> typ.Any:
+		return input_sockets['Expr']
+
+	@events.computes_output_socket(
+		# Trigger
+		'Expr',
+		kind=ct.FlowKind.Params,
+		# Loaded
+		input_sockets={'Expr'},
+		input_socket_kinds={'Expr': ct.FlowKind.Params},
+	)
+	def compute_params(self, input_sockets: dict) -> typ.Any:
+		return input_sockets['Expr']
+
 
 ####################
 # - Blender Registration

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/inputs/constants/number_constant.py

@@ -1,90 +0,0 @@
-# blender_maxwell
-# Copyright (C) 2024 blender_maxwell Project Contributors
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Affero General Public License for more details.
-#
-# You should have received a copy of the GNU Affero General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-import typing as typ
-
-import bpy
-
-from blender_maxwell.utils import bl_cache
-from blender_maxwell.utils import extra_sympy_units as spux
-
-from .... import contracts as ct
-from .... import sockets
-from ... import base, events
-
-
-class NumberConstantNode(base.MaxwellSimNode):
-	"""A unitless number of configurable math type ex. integer, real, etc. .
-
-	Attributes:
-		mathtype: The math type to specify the number as.
-	"""
-
-	node_type = ct.NodeType.NumberConstant
-	bl_label = 'Numerical Constant'
-
-	input_sockets: typ.ClassVar = {
-		'Value': sockets.ExprSocketDef(),
-	}
-	output_sockets: typ.ClassVar = {
-		'Value': sockets.ExprSocketDef(),
-	}
-
-	####################
-	# - Properties
-	####################
-	mathtype: spux.MathType = bl_cache.BLField(
-		spux.MathType.Integer,
-		prop_ui=True,
-	)
-
-	size: spux.NumberSize1D = bl_cache.BLField(
-		spux.NumberSize1D.Scalar,
-		prop_ui=True,
-	)
-
-	####################
-	# - UI
-	####################
-	def draw_props(self, _, col: bpy.types.UILayout) -> None:
-		row = col.row(align=True)
-		row.prop(self, self.blfields['mathtype'], text='')
-		row.prop(self, self.blfields['size'], text='')
-
-	####################
-	# - Events
-	####################
-	@events.on_value_changed(prop_name={'mathtype', 'size'}, props={'mathtype', 'size'})
-	def on_mathtype_size_changed(self, props) -> None:
-		"""Change the input/output expression sockets to match the mathtype declared in the node."""
-		self.inputs['Value'].mathtype = props['mathtype']
-		self.inputs['Value'].shape = props['size'].shape
-
-	####################
-	# - FlowKind
-	####################
-	@events.computes_output_socket('Value', input_sockets={'Value'})
-	def compute_value(self, input_sockets) -> typ.Any:
-		return input_sockets['Value']
-
-
-####################
-# - Blender Registration
-####################
-BL_REGISTER = [
-	NumberConstantNode,
-]
-BL_NODES = {ct.NodeType.NumberConstant: (ct.NodeCategory.MAXWELLSIM_INPUTS_CONSTANTS)}

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/inputs/constants/physical_constant.py

@@ -1,143 +0,0 @@
-# blender_maxwell
-# Copyright (C) 2024 blender_maxwell Project Contributors
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Affero General Public License for more details.
-#
-# You should have received a copy of the GNU Affero General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-import typing as typ
-
-import bpy
-import sympy as sp
-
-from blender_maxwell.utils import bl_cache
-from blender_maxwell.utils import extra_sympy_units as spux
-
-from .... import contracts, sockets
-from ... import base, events
-
-
-class PhysicalConstantNode(base.MaxwellSimNode):
-	"""A number of configurable unit dimension, ex. time, length, etc. .
-
-	Attributes:
-		physical_type: The physical type to specify.
-		size: The size of the physical type, if it can be a vector.
-	"""
-
-	node_type = contracts.NodeType.PhysicalConstant
-	bl_label = 'Physical Constant'
-
-	input_sockets: typ.ClassVar = {
-		'Value': sockets.ExprSocketDef(),
-	}
-	output_sockets: typ.ClassVar = {
-		'Value': sockets.ExprSocketDef(),
-	}
-
-	####################
-	# - Properties
-	####################
-	physical_type: spux.PhysicalType = bl_cache.BLField(
-		spux.PhysicalType.Time,
-		prop_ui=True,
-	)
-
-	mathtype: spux.MathType = bl_cache.BLField(
-		enum_cb=lambda self, _: self.search_mathtypes(),
-		prop_ui=True,
-	)
-
-	size: spux.NumberSize1D = bl_cache.BLField(
-		enum_cb=lambda self, _: self.search_sizes(),
-	)
-
-	####################
-	# - Searchers
-	####################
-	def search_mathtypes(self):
-		return [
-			mathtype.bl_enum_element(i)
-			for i, mathtype in enumerate(self.physical_type.valid_mathtypes)
-		]
-
-	def search_sizes(self):
-		return [
-			spux.NumberSize1D.from_shape(shape).bl_enum_element(i)
-			for i, shape in enumerate(self.physical_type.valid_shapes)
-			if spux.NumberSize1D.has_shape(shape)
-		]
-
-	####################
-	# - UI
-	####################
-	def draw_props(self, _, col: bpy.types.UILayout) -> None:
-		col.prop(self, self.blfields['physical_type'], text='')
-
-		row = col.row(align=True)
-		row.prop(self, self.blfields['mathtype'], text='')
-		row.prop(self, self.blfields['size'], text='')
-
-	####################
-	# - Events
-	####################
-	@events.on_value_changed(
-		# Trigger
-		prop_name={'physical_type'},
-		run_on_init=True,
-		# Loaded
-		props={'physical_type'},
-	)
-	def on_physical_type_changed(self, props) -> None:
-		"""Change the input/output expression sockets to match the mathtype and size declared in the node."""
-		# Set Input Socket Physical Type
-		if self.inputs['Value'].physical_type != props['physical_type']:
-			self.inputs['Value'].physical_type = props['physical_type']
-			self.mathtype = bl_cache.Signal.ResetEnumItems
-			self.size = bl_cache.Signal.ResetEnumItems
-
-	@events.on_value_changed(
-		# Trigger
-		prop_name={'mathtype', 'size'},
-		run_on_init=True,
-		# Loaded
-		props={'physical_type', 'mathtype', 'size'},
-	)
-	def on_mathtype_or_size_changed(self, props) -> None:
-		# Set Input Socket Math Type
-		if self.inputs['Value'].mathtype != props['mathtype']:
-			self.inputs['Value'].mathtype = props['mathtype']
-
-		# Set Input Socket Shape
-		shape = props['size'].shape
-		if self.inputs['Value'].shape != shape:
-			self.inputs['Value'].shape = shape
-
-	####################
-	# - Callbacks
-	####################
-	@events.computes_output_socket('Value', input_sockets={'Value'})
-	def compute_value(self, input_sockets) -> sp.Expr:
-		return input_sockets['Value']
-
-
-####################
-# - Blender Registration
-####################
-BL_REGISTER = [
-	PhysicalConstantNode,
-]
-BL_NODES = {
-	contracts.NodeType.PhysicalConstant: (
-		contracts.NodeCategory.MAXWELLSIM_INPUTS_CONSTANTS
-	)
-}

src/blender_maxwell/node_trees/maxwell_sim_nodes/sockets/expr.py

@@ -116,13 +116,22 @@ class ExprBLSocket(base.MaxwellSimSocket):
 	size: spux.NumberSize1D = bl_cache.BLField(spux.NumberSize1D.Scalar)
 	mathtype: spux.MathType = bl_cache.BLField(spux.MathType.Real)
 	physical_type: spux.PhysicalType = bl_cache.BLField(spux.PhysicalType.NonPhysical)
+
+	# Symbols
+	# active_symbols: list[sim_symbols.SimSymbol] = bl_cache.BLField([])
 	symbols: frozenset[sp.Symbol] = bl_cache.BLField(frozenset())
 
+	# @property
+	# def symbols(self) -> set[sp.Symbol]:
+	# """Current symbols as an unordered set."""
+	# return {sim_symbol.sp_symbol for sim_symbol in self.active_symbols}
+
 	@bl_cache.cached_bl_property(depends_on={'symbols'})
 	def sorted_symbols(self) -> list[sp.Symbol]:
-		"""Name-sorted symbols."""
+		"""Current symbols as a sorted list."""
 		return sorted(self.symbols, key=lambda sym: sym.name)
 
+	# Unit
 	active_unit: enum.StrEnum = bl_cache.BLField(
 		enum_cb=lambda self, _: self.search_valid_units(),
 		cb_depends_on={'physical_type'},
@@ -672,16 +681,16 @@ class ExprBLSocket(base.MaxwellSimSocket):
 			Whether information about the expression passing through a linked socket is shown is governed by `self.show_info_columns`.
 		"""
 		info = self.compute_data(kind=ct.FlowKind.Info)
-		has_dims = not ct.FlowSignal.check(info) and info.dim_names
+		has_info = not ct.FlowSignal.check(info)
 
-		if has_dims:
+		if has_info:
 			split = row.split(factor=0.85, align=True)
 			_row = split.row(align=False)
 		else:
 			_row = row
 
 		_row.label(text=text)
-		if has_dims:
+		if has_info:
 			if self.show_info_columns:
 				_row.prop(self, self.blfields['info_columns'])
 
@@ -735,9 +744,17 @@ class ExprBLSocket(base.MaxwellSimSocket):
 	# - UI: Active FlowKind
 	####################
 	def draw_value(self, col: bpy.types.UILayout) -> None:
-		"""Draw the socket body for a single values/expression.
+		"""Draw the socket body for a single value/expression.
 
-		Drawn when `self.active_kind == FlowKind.Value`.
+		This implements the base UI for `ExprSocket`, for when `self.size`, `self.mathtype`, `self.physical_type`, and `self.symbols` are set.
+
+		Notes:
+			Drawn when `self.active_kind == FlowKind.Value`.
+
+			Alone, `draw_value` provides no mechanism for altering expression constraints like size.
+			Thus, `FlowKind.Value` is a good choice for when the expression must be of a very particular type.
+
+			However, `draw_value` may also be called by the `draw_*` methods of other `FlowKinds`, who may choose to layer more flexibility around this base UI.
 		"""
 		if self.symbols:
 			col.prop(self, self.blfields['raw_value_spstr'], text='')
@@ -819,23 +836,43 @@ class ExprBLSocket(base.MaxwellSimSocket):
 			col.prop(self, self.blfields['steps'], text='')
 
 	def draw_lazy_value_func(self, col: bpy.types.UILayout) -> None:
-		"""Draw the socket body for a value/expression meant for use in a lazy function composition chain.
+		"""Draw the socket body for a single flexible value/expression, for down-chain lazy evaluation.
 
-		Drawn when `self.active_kind == FlowKind.LazyValueFunc`.
+		This implements the most flexible variant of the `ExprSocket` UI, providing the user with full runtime-configuration of the exact `self.size`, `self.mathtype`, `self.physical_type`, and `self.symbols` of the expression.
+
+		Notes:
+			Drawn when `self.active_kind == FlowKind.LazyValueFunc`.
+
+			This is an ideal choice for ex. math nodes that need to accept arbitrary expressions as inputs, with an eye towards lazy evaluation of ex. symbolic terms.
+
+			Uses `draw_value` to draw the base UI
 		"""
+		# Physical Type Selector
+		## -> Determines whether/which unit-dropdown will be shown.
 		col.prop(self, self.blfields['physical_type'], text='')
+
+		# Non-Symbolic: Size/Mathtype Selector
+		## -> Symbols imply str expr input.
+		## -> For arbitrary str exprs, size/mathtype are derived from the expr.
+		## -> Otherwise, size/mathtype must be pre-specified for a nice UI.
 		if not self.symbols:
 			row = col.row(align=True)
 			row.prop(self, self.blfields['size'], text='')
 			row.prop(self, self.blfields['mathtype'], text='')
 
+		# Base UI
+		## -> Draws the UI appropriate for the above choice of constraints.
 		self.draw_value(col)
 
+		# Symbol UI
+		## -> Draws the UI appropriate for the above choice of constraints.
+		## -> TODO
+
 	####################
 	# - UI: InfoFlow
 	####################
 	def draw_info(self, info: ct.InfoFlow, col: bpy.types.UILayout) -> None:
-		if self.active_kind == ct.FlowKind.Array and self.show_info_columns:
+		if self.active_kind == ct.FlowKind.LazyValueFunc and self.show_info_columns:
 			row = col.row()
 			box = row.box()
 			grid = box.grid_flow(
@@ -899,7 +936,8 @@ class ExprSocketDef(base.SocketDef):
 	physical_type: spux.PhysicalType = spux.PhysicalType.NonPhysical
 
 	default_unit: spux.Unit | None = None
-	symbols: frozenset[spux.Symbol] = frozenset()
+	# symbols: list[sim_symbols.SimSymbol] = frozenset()
+	symbols: frozenset[spux.SympyExpr] = frozenset()
 
 	# FlowKind: Value
 	default_value: spux.SympyExpr = 0

src/blender_maxwell/utils/sim_symbols.py

@@ -0,0 +1,76 @@
+# blender_maxwell
+# Copyright (C) 2024 blender_maxwell Project Contributors
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import dataclasses
+import enum
+import typing as typ
+
+import sympy as sp
+
+from . import extra_sympy_units as spux
+
+
+class SimSymbolNames(enum.StrEnum):
+	LowerA = enum.auto()
+	LowerLambda = enum.auto()
+
+	@staticmethod
+	def to_name(v: typ.Self) -> str:
+		"""Convert the enum value to a human-friendly name.
+
+		Notes:
+			Used to print names in `EnumProperty`s based on this enum.
+
+		Returns:
+			A human-friendly name corresponding to the enum value.
+		"""
+		SSN = SimSymbolNames
+		return {
+			SSN.LowerA: 'a',
+			SSN.LowerLambda: 'λ',
+		}[v]
+
+	@staticmethod
+	def to_icon(_: typ.Self) -> str:
+		"""Convert the enum value to a Blender icon.
+
+		Notes:
+			Used to print icons in `EnumProperty`s based on this enum.
+
+		Returns:
+			A human-friendly name corresponding to the enum value.
+		"""
+		return ''
+
+
+@dataclasses.dataclass(kw_only=True, frozen=True)
+class SimSymbol:
+	name: SimSymbolNames = SimSymbolNames.LowerLambda
+	mathtype: spux.MathType = spux.MathType.Real
+
+	## TODO:
+	## -> Physical Type: Track unit dimension information on the side.
+	## -> Domain: Ability to constrain mathtype ex. (-pi,pi]
+	## -> Shape: For using sp.MatrixSymbol w/predefined rows/cols.
+
+	@property
+	def sp_symbol(self):
+		mathtype_kwarg = {}
+		match self.mathtype:
+			case spux.MathType.Real:
+				mathtype_kwarg = {}
+
+		return sp.Symbol(self.name, **mathtype_kwarg)