# SPDX-License-Identifier: Apache-2.0
"""A lipped channel, its width, depth and lips dimensioned to the outside.

A drawing gives a channel's sizes over the outside of the sheet, and
`length_from="outside"` takes a flange's length that way: the depth runs
outside to outside over both bends, and the lip to the outside at its own
bend. The base is drawn to where the bends start, the outside width less one
outside setback (bend radius plus thickness, at 90 degrees) at each side. Its
flat is 196.096 x 30.000 mm. Build it and unfold it with:

    dxcad run channel.py --output channel.dxcprt
    dxcad flat channel.dxcprt --part channel

Tags: sheet
"""

WIDTH = 100.0
DEPTH = 40.0
LIP = 15.0
LENGTH = 30.0
THICKNESS = 2.0
BEND_RADIUS = 2.0
K_FACTOR = 0.44

spec = SheetSpec(THICKNESS, BEND_RADIUS, K_FACTOR)
setback = BEND_RADIUS + THICKNESS
inside = WIDTH - 2 * setback
channel = base_flange([(0, 0), (inside, 0), (inside, LENGTH), (0, LENGTH)], spec)
for edge in (1, 3):
    channel = flange(channel, edge, DEPTH, return_length=LIP, length_from="outside")

part("channel", channel, color="galvanised")