"""
Buffer/Inverter symbol for JITX Standard Library
"""
from __future__ import annotations
from dataclasses import dataclass, replace
import math
from typing import TYPE_CHECKING, cast
from jitx.shapes import Shape
from jitx.shapes.primitive import Polygon, Polyline
from jitx.symbol import Direction, Pin
from ..common import (
DEF_FILLED,
DEF_LINE_WIDTH,
DEF_PIN_LENGTH,
DEF_PAD_NAME_SIZE,
)
from ..decorators import (
ActiveLow,
OpenCollector,
OpenCollectorType,
draw,
)
from ..label import LabelConfigurable, LabelledSymbol
if TYPE_CHECKING:
from ..context import SymbolStyleContext
DEF_BUFFER_TRI_HEIGHT = 3.0
DEF_BUFFER_TRI_WIDTH = 2.0
[docs]
@dataclass
class BufferConfig(LabelConfigurable):
"""
Configuration for buffer/inverter symbols
Defines the geometric and visual parameters for buffer symbols.
"""
tri_height: float = DEF_BUFFER_TRI_HEIGHT
"""Triangle height (vertical dimension)"""
tri_width: float = DEF_BUFFER_TRI_WIDTH
"""Triangle width (horizontal dimension)"""
filled: bool = DEF_FILLED
"""Whether to fill the triangle body"""
line_width: float = DEF_LINE_WIDTH
"""Width of the triangle lines"""
pin_length: int = DEF_PIN_LENGTH
"""Length of the pin extensions"""
pad_name_size: float | None = DEF_PAD_NAME_SIZE
"""Size of the pad name text"""
inverter: bool = False
"""Whether to add inversion bubble (creates inverter)"""
open_collector: OpenCollectorType | None = None
"""Whether to add open-collector symbol on output pin"""
def __post_init__(self):
if self.tri_height <= 0:
raise ValueError("Buffer tri_height must be positive")
if self.tri_width <= 0:
raise ValueError("Buffer tri_width must be positive")
if self.pin_length < 0:
raise ValueError("Buffer pin_length must be non-negative")
if self.pad_name_size is not None and self.pad_name_size < 0:
raise ValueError("Buffer pad_name_size must be non-negative")
[docs]
class BufferSymbol[T: BufferConfig](LabelledSymbol):
"""
Buffer symbol with graphics and pins.
Can be configured as buffer or inverter.
"""
config: T
triangle_body: Shape[Polyline] | Shape[Polygon]
p: dict[int, Pin]
def _symbol_style_config(self, context: SymbolStyleContext | None = None) -> T:
"""Symbol style config for this buffer symbol."""
if context is None:
config = BufferConfig()
else:
config = context.buffer_config
# Casting necessary because BufferSymbol is both a generic and a concrete class.
return cast(T, config)
def _lookup_config(
self, config: T | None = None, context: SymbolStyleContext | None = None
) -> T:
"""Lookup the config for this symbol."""
if config is None:
return self._symbol_style_config(context)
return config
def __init__(self, config: T | None = None, **kwargs):
"""
Initialize buffer symbol
Args:
config: Config object, or None to use defaults
**kwargs: Individual parameters to override defaults
"""
# Apparently this needs to be imported here, even though SymbolStyleContext is imported in TYPE_CHECKING.
from ..context import SymbolStyleContext
context = SymbolStyleContext.get()
config = self._lookup_config(config, context)
self.config = replace(config, **kwargs)
self._build_triangle_body()
self._build_pins()
self._build_labels(ref=Direction.Up, value=Direction.Up)
self.pad_name_size = self.config.pad_name_size
def _build_triangle_body(self) -> None:
"""Build the triangular buffer body shape."""
th = self.config.tri_height
tw = self.config.tri_width
th2 = th / 2.0
tw2 = tw / 2.0
# Triangle points: output tip, top input, bottom input, back to output tip
body_points = [
(tw2, 0.0), # Output tip (right point)
(-tw2, th2), # Top left point
(-tw2, -th2), # Bottom left point
(tw2, 0.0), # Back to output tip (closes triangle)
]
if self.config.filled:
# Use Polygon for filled triangle
self.triangle_body = Polygon(
body_points[:-1]
) # Remove duplicate closing point
else:
# Use Polyline for outline triangle
self.triangle_body = Polyline(self.config.line_width, body_points)
def _build_pins(self) -> None:
"""Build input and output pins for the buffer."""
tw2 = math.floor(self.config.tri_width / 2)
# Input and output pins
in_pos = (-tw2, 0)
out_pos = (tw2, 0)
in_dir = Direction.Left
out_dir = Direction.Right
self.p = {
1: Pin(at=in_pos, direction=in_dir, length=self.config.pin_length),
2: Pin(at=out_pos, direction=out_dir, length=self.config.pin_length),
}
self.pin_decorators = []
if self.config.inverter:
self.pin_decorators.append(draw(ActiveLow(), out_dir, out_pos))
if self.config.open_collector is not None:
self.pin_decorators.append(
draw(
OpenCollector(oc_type=self.config.open_collector),
out_dir,
out_pos,
)
)
# Convenience properties to access config values
@property
def tri_height(self) -> float:
"""See :attr:`~.BufferConfig.tri_height`."""
return self.config.tri_height
@property
def tri_width(self) -> float:
"""See :attr:`~.BufferConfig.tri_width`."""
return self.config.tri_width
@property
def filled(self) -> bool:
"""See :attr:`~.BufferConfig.filled`."""
return self.config.filled
@property
def line_width(self) -> float:
"""See :attr:`~.BufferConfig.line_width`."""
return self.config.line_width
@property
def pin_length(self) -> float:
"""See :attr:`~.BufferConfig.pin_length`."""
return self.config.pin_length
@property
def inverter(self) -> bool:
"""See :attr:`~.BufferConfig.inverter`."""
return self.config.inverter
@property
def label_config(self) -> LabelConfigurable:
"""Configuration object that provides label configuration"""
return self.config
