render_viewport_to_modelspace.py

#  Copyright (c) 2022, Manfred Moitzi
#  License: MIT License
from typing import cast
from pathlib import Path
import ezdxf
from ezdxf import colors
from ezdxf.math import ConstructionBox
from ezdxf.layouts import Paperspace, Modelspace
from ezdxf.entities import Viewport

CWD = Path("~/Desktop/Outbox").expanduser()
if not CWD.exists():
    CWD = Path(".")


def create_2d_modelspace_content(msp: Modelspace):
    msp.add_polyline2d(
        [(5, 5), (10, 5), (10, 10), (5, 10)],
        close=True,
        dxfattribs={"color": colors.RED},
    )
    msp.add_circle((10, 5), 2.5, dxfattribs={"color": colors.GREEN})
    msp.add_polyline2d(
        [(10, 7.5), (15, 5), (15, 10)],
        close=True,
        dxfattribs={"color": colors.CYAN},
    )


def create_viewports(paperspace: Paperspace):
    # Define viewports in paper space:
    # center, size=(width, height) defines the viewport in paper space.
    # view_center_point and view_height defines the area in model space
    # which is displayed in the viewport.
    txt_attribs = dict(
        style="OpenSans-Bold",
        color=colors.BLUE,
    )
    paperspace.add_viewport(
        center=(2.5, 2.5),
        size=(5, 5),
        view_center_point=(10.0, 7.5),
        view_height=10,
        status=2,
    )
    # scale is calculated by:
    # height of model space (view_height=10) / height of viewport (height=5)
    paperspace.add_text(
        "Scale=1:2", height=0.18, dxfattribs=txt_attribs
    ).set_placement((0, 5.2))

    psp = paperspace.add_viewport(
        center=(8.5, 2.5),
        size=(5, 5),
        view_center_point=(10, 5),
        view_height=25,
        status=3,
    )
    psp.dxf.view_twist_angle = 45
    paperspace.add_text(
        "Scale=1:5", height=0.18, dxfattribs=txt_attribs
    ).set_placement((6, 5.2))

    paperspace.add_viewport(
        center=(7.5, 10),
        size=(15, 7.5),
        view_center_point=(10, 6.25),
        view_height=7.5,
        status=4,
    )
    paperspace.add_text(
        "View Scale=1:1", height=0.18, dxfattribs=txt_attribs
    ).set_placement((0, 14))


def make(filename):
    doc = ezdxf.new(setup=True)
    # create/get the default layer for VIEWPORT entities:
    if "VIEWPORTS" not in doc.layers:
        vp_layer = doc.layers.add("VIEWPORTS")
    else:
        vp_layer = doc.layers.get("VIEWPORTS")
    # switch viewport layer off to hide the viewport border lines
    vp_layer.off()
    # the VIEWPORT layer is not fixed:
    # Paperspace.add_viewport(..., dxfattribs={"layer": "MyViewportLayer"})

    create_2d_modelspace_content(doc.modelspace())
    layout = cast(Paperspace, doc.layout("Layout1"))
    layout.page_setup(size=(22, 17), margins=(1, 1, 1, 1), units="inch")
    create_viewports(layout)

    try:
        doc.saveas(CWD / filename)
    except IOError:
        print("Can't write: '%s'" % filename)
    return layout


def render_vp_border(vp: Viewport, msp: Modelspace):
    box = ConstructionBox(vp.dxf.center, vp.dxf.width, vp.dxf.height)
    msp.add_lwpolyline(box.corners, close=True)


def render_viewport(vp: Viewport, msp: Modelspace):
    assert vp.is_top_view is True
    assert vp.get_scale() > 0.0
    m = vp.get_transformation_matrix()
    for entity in vp.doc.modelspace():
        render_vp_border(vp, msp)
        copy = entity.copy()
        copy.transform(m)
        msp.add_foreign_entity(copy, copy=False)


def render_psp_in_msp(psp: Paperspace, filename: str):
    doc = ezdxf.new(setup=True)
    msp = doc.modelspace()
    for viewport in psp.query("VIEWPORT")[1:]:
        # skip the first viewport - defines the paperspace representation in
        # the CAD application
        render_viewport(cast(Viewport, viewport), msp)
    doc.saveas(CWD / filename)


if __name__ == "__main__":
    _layout = make("viewports_in_paperspace.dxf")
    render_psp_in_msp(_layout, "psp2msp.dxf")