src/Mod/BIM/ArchVRM.py

# SPDX-License-Identifier: LGPL-2.1-or-later

# ***************************************************************************
# *                                                                         *
# *   Copyright (c) 2012 Yorik van Havre <yorik@uncreated.net>              *
# *                                                                         *
# *   This file is part of FreeCAD.                                         *
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# *   FreeCAD is free software: you can redistribute it and/or modify it    *
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# *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
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# *   Lesser General Public License for more details.                       *
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# ***************************************************************************

"The FreeCAD Arch Vector Rendering Module"

## @package ArchVRM
#  \ingroup ARCH
#  \brief The Arch Vector Rendering Module
#
#  This module provides the Renderer Class, that allows one to
#  produce SVG renderings of projected shapes, with filled faces.
#  It is used by the "Solid" mode of Arch views in TechDraw and Drawing,
#  and is called from ArchSectionPlane code.

import math

import FreeCAD
import ArchCommands
import Draft
import DraftVecUtils
import DraftGeomUtils
import Part

from draftutils import params

MAXLOOP = 10  # the max number of loop before abort

# WARNING: in this module, faces are lists whose first item is the actual OCC face, the
# other items being additional information such as color, etc.

DEBUG = params.get_param_arch("ShowVRMDebug")


class Renderer:
    "A renderer object"

    def __init__(self, wp=None):
        """
        Creates a renderer with a default Draft WorkingPlane
        Use like this:

        import ArchVRM
        p = ArchVRM.Renderer()
        p.add(App.ActiveDocument.ActiveObject)
        p.sort()
        p.buildDummy()
        """

        self.reset()
        if wp:
            self.wp = wp
        else:
            import WorkingPlane

            self.wp = WorkingPlane.PlaneBase()

        if DEBUG:
            print("Renderer initialized on " + str(self.wp))

    def __str__(self):
        return "Arch Renderer: " + str(len(self.faces)) + " faces projected on " + str(self.wp)

    def reset(self):
        "removes all faces from this renderer"
        self.objects = []
        self.shapes = []
        self.faces = []
        self.resetFlags()

    def resetFlags(self):
        "resets all flags of this renderer"
        self.oriented = False
        self.trimmed = False
        self.sorted = False
        self.iscut = False
        self.joined = False
        self.sections = []
        self.hiddenEdges = []

    def setWorkingPlane(self, wp):
        "sets a Draft WorkingPlane or Placement for this renderer"
        if isinstance(wp, FreeCAD.Placement):
            self.wp.align_to_placement(wp)
        else:
            self.wp = wp
        if DEBUG:
            print("Renderer set on " + str(self.wp))

    def addFaces(self, faces, color=(0.9, 0.9, 0.9, 1.0)):
        "add individual faces to this renderer, optionally with a color"
        if DEBUG:
            print(
                "adding ",
                len(faces),
                " faces. Warning, these will get lost if using cut() or join()",
            )
        for f in faces:
            self.faces.append([f, color])
        self.resetFlags()

    def addObjects(self, objs):
        "add objects to this renderer"
        for o in objs:
            if o.isDerivedFrom("Part::Feature"):
                self.objects.append(o)
                color = o.ViewObject.ShapeColor
                if o.Shape.Faces:
                    self.shapes.append([o.Shape, color])
                    for f in o.Shape.Faces:
                        self.faces.append([f, color])
        self.resetFlags()
        if DEBUG:
            print("adding ", len(self.objects), " objects, ", len(self.faces), " faces")

    def addShapes(self, shapes, color=(0.9, 0.9, 0.9, 1.0)):
        "add shapes to this renderer, optionally with a color. Warning, these will get lost if using join()"
        if DEBUG:
            print("adding ", len(shapes), " shapes")
        for s in shapes:
            if s.Faces:
                self.shapes.append([s, color])
                for f in s.Faces:
                    self.faces.append([f, color])
        self.resetFlags()

    def info(self):
        "Prints info about the contents of this renderer"
        r = str(self) + "\n"
        r += "oriented: " + str(self.oriented) + "\n"
        r += "trimmed: " + str(self.trimmed) + "\n"
        r += "sorted: " + str(self.sorted) + "\n"
        r += "contains " + str(len(self.faces)) + " faces\n"
        for i in range(len(self.faces)):
            r += "  face " + str(i) + " : center " + str(self.faces[i][0].CenterOfMass)
            r += " : normal " + str(self.faces[i][0].normalAt(0, 0))
            r += ", " + str(len(self.faces[i][0].Vertexes)) + " verts"
            r += ", color: " + self.getFill(self.faces[i][1]) + "\n"
        return r

    def addLabels(self):
        "Add labels on the model to identify faces"
        c = 0
        for f in self.faces:
            l = FreeCAD.ActiveDocument.addObject("App::AnnotationLabel", "facelabel")
            l.BasePosition = f[0].CenterOfMass
            l.LabelText = str(c)
            c += 1

    def isVisible(self, face):
        "returns True if the given face points in the view direction"
        normal = face[0].normalAt(0, 0)
        if DEBUG:
            print(
                "checking face normal ",
                normal,
                " against ",
                self.wp.axis,
                " : ",
                math.degrees(normal.getAngle(self.wp.axis)),
            )
        if normal.getAngle(self.wp.axis) < math.pi / 2:
            return True
        return False

    def reorient(self):
        "reorients the faces on the WP"
        # print("VRM: start reorient")
        if not self.faces:
            return
        self.faces = [self.projectFace(f) for f in self.faces]
        if self.sections:
            self.sections = [self.projectFace(f) for f in self.sections]
        if self.hiddenEdges:
            self.hiddenEdges = [self.projectEdge(e) for e in self.hiddenEdges]
        self.oriented = True
        # print("VRM: end reorient")

    def removeHidden(self):
        "removes faces pointing outwards"
        if not self.faces:
            return
        faces = []
        for f in self.faces:
            if self.isVisible(f):
                faces.append(f)
        if DEBUG:
            print(len(self.faces) - len(faces), " faces removed, ", len(faces), " faces retained")
        self.faces = faces
        self.trimmed = True

    def projectFace(self, face):
        "projects a single face on the WP"
        # print("VRM: projectFace start: ",len(face[0].Vertexes)," verts, ",len(face[0].Edges)," edges")
        wires = []
        if not face[0].Wires:
            if DEBUG:
                print("Error: Unable to project face on the WP")
            return None
        norm = face[0].normalAt(0, 0)
        for w in face[0].Wires:
            verts = []
            edges = Part.__sortEdges__(w.Edges)
            # print(len(edges)," edges after sorting")
            for e in edges:
                v = e.Vertexes[0].Point
                # print(v)
                v = self.wp.get_local_coords(v)
                verts.append(v)
            verts.append(verts[0])
            if len(verts) > 2:
                # print("new wire with ",len(verts))
                wires.append(Part.makePolygon(verts))
        try:
            sh = ArchCommands.makeFace(wires)
        except Exception:
            if DEBUG:
                print("Error: Unable to project face on the WP")
            return None
        else:
            # restoring flipped normals
            vnorm = self.wp.get_local_coords(norm)
            if vnorm.getAngle(sh.normalAt(0, 0)) > 1:
                sh.reverse()
            # print("VRM: projectFace end: ",len(sh.Vertexes)," verts")
            return [sh] + face[1:]

    def projectEdge(self, edge):
        "projects a single edge on the WP"
        if len(edge.Vertexes) > 1:
            v1 = self.wp.get_local_coords(edge.Vertexes[0].Point)
            v2 = self.wp.get_local_coords(edge.Vertexes[-1].Point)
            return Part.LineSegment(v1, v2).toShape()
        return edge

    def flattenFace(self, face):
        "Returns a face where all vertices have Z = 0"
        wires = []
        for w in face[0].Wires:
            verts = []
            edges = Part.__sortEdges__(w.Edges)
            for e in edges:
                v = e.Vertexes[0].Point
                verts.append(FreeCAD.Vector(v.x, v.y, 0))
            verts.append(verts[0])
            wires.append(Part.makePolygon(verts))
        try:
            sh = Part.Face(wires)
        except Part.OCCError:
            if DEBUG:
                print("Error: Unable to flatten face")
            return None
        else:
            return [sh] + face[1:]

    def cut(self, cutplane, hidden=False):
        "Cuts through the shapes with a given cut plane and builds section faces"
        if DEBUG:
            print("\n\n======> Starting cut\n\n")
        if self.iscut:
            return
        if not self.shapes:
            if DEBUG:
                print("No objects to make sections")
        else:
            fill = (1.0, 1.0, 1.0, 1.0)
            shps = []
            for sh in self.shapes:
                shps.append(sh[0])
            cutface, cutvolume, invcutvolume = ArchCommands.getCutVolume(cutplane, shps)
            if cutface and cutvolume:
                shapes = []
                faces = []
                sections = []
                for sh in self.shapes:
                    for sol in sh[0].Solids:
                        c = sol.cut(cutvolume)
                        shapes.append([c] + sh[1:])
                        for f in c.Faces:
                            faces.append([f] + sh[1:])
                            # print("iscoplanar:",f.Vertexes[0].Point,f.normalAt(0,0),cutface.Vertexes[0].Point,cutface.normalAt(0,0))
                            if DraftGeomUtils.isCoplanar([f, cutface]):
                                print("COPLANAR")
                                sections.append([f, fill])
                        if hidden:
                            c = sol.cut(invcutvolume)
                            self.hiddenEdges.extend(c.Edges)
                self.shapes = shapes
                self.faces = faces
                self.sections = sections
                if DEBUG:
                    print(
                        "Built ",
                        len(self.sections),
                        " sections, ",
                        len(self.faces),
                        " faces retained",
                    )
                self.iscut = True
                self.oriented = False
                self.trimmed = False
                self.sorted = False
                self.joined = False
        if DEBUG:
            print("\n\n======> Finished cut\n\n")

    def isInside(self, vert, face):
        "Returns True if the vert is inside the face in Z projection"

        if not face:
            return False

        # http://paulbourke.net/geometry/insidepoly/
        count = 0
        p = self.wp.get_local_coords(vert.Point)
        for e in face[0].Edges:
            p1 = e.Vertexes[0].Point
            p2 = e.Vertexes[-1].Point
            if p.y > min(p1.y, p2.y):
                if p.y <= max(p1.y, p2.y):
                    if p.x <= max(p1.x, p2.x):
                        if p1.y != p2.y:
                            xinters = (p.y - p1.y) * (p2.x - p1.x) / (p2.y - p1.y) + p1.x
                            if (p1.x == p2.x) or (p.x <= xinters):
                                count += 1
        if count % 2 == 0:
            return False
        else:
            return True

    def zOverlaps(self, face1, face2):
        "Checks if face1 overlaps face2 in Z direction"
        face1 = self.flattenFace(face1)
        face2 = self.flattenFace(face2)

        if (not face1) or (not face2):
            return False

        # first we check if one of the verts is inside the other face
        for v in face1[0].Vertexes:
            if self.isInside(v, face2):
                return True

        # even so, faces can still overlap if their edges cross each other
        for e1 in face1[0].Edges:
            for e2 in face2[0].Edges:
                if DraftGeomUtils.findIntersection(e1, e2):
                    return True
        return False

    def compare(self, face1, face2):
        "zsorts two faces. Returns 1 if face1 is closer, 2 if face2 is closer, 0 otherwise"

        # print(face1,face2)

        if not face1:
            if DEBUG:
                print("Warning, undefined face!")
            return 31
        elif not face2:
            if DEBUG:
                print("Warning, undefined face!")
            return 32

        # theory from
        # http://www.siggraph.org/education/materials/HyperGraph/scanline/visibility/painter.htm
        # and practical application http://vrm.ao2.it/ (blender vector renderer)

        b1 = face1[0].BoundBox
        b2 = face2[0].BoundBox

        # test 1: if faces don't overlap, no comparison possible
        if DEBUG:
            print("doing test 1")
        if b1.XMax < b2.XMin:
            return 0
        if b1.XMin > b2.XMax:
            return 0
        if b1.YMax < b2.YMin:
            return 0
        if b1.YMin > b2.YMax:
            return 0
        if DEBUG:
            print("failed, faces bboxes are not distinct")

        # test 2: if Z bounds don't overlap, it's easy to know the closest
        if DEBUG:
            print("doing test 2")
        if b1.ZMax < b2.ZMin:
            return 2
        if b2.ZMax < b1.ZMin:
            return 1
        if DEBUG:
            print("failed, faces Z are not distinct")

        # test 3: all verts of face1 are in front or behind the plane of face2
        if DEBUG:
            print("doing test 3")
        norm = face2[0].normalAt(0, 0)
        behind = 0
        front = 0
        for v in face1[0].Vertexes:
            dv = v.Point.sub(face2[0].Vertexes[0].Point)
            dv = DraftVecUtils.project(dv, norm)
            if DraftVecUtils.isNull(dv):
                behind += 1
                front += 1
            else:
                if dv.getAngle(norm) > 1:
                    behind += 1
                else:
                    front += 1
        if DEBUG:
            print("front: ", front, " behind: ", behind)
        if behind == len(face1[0].Vertexes):
            return 2
        elif front == len(face1[0].Vertexes):
            return 1
        if DEBUG:
            print("failed, cannot say if face 1 is in front or behind")

        # test 4: all verts of face2 are in front or behind the plane of face1
        if DEBUG:
            print("doing test 4")
        norm = face1[0].normalAt(0, 0)
        behind = 0
        front = 0
        for v in face2[0].Vertexes:
            dv = v.Point.sub(face1[0].Vertexes[0].Point)
            dv = DraftVecUtils.project(dv, norm)
            if DraftVecUtils.isNull(dv):
                behind += 1
                front += 1
            else:
                if dv.getAngle(norm) > 1:
                    behind += 1
                else:
                    front += 1
        if DEBUG:
            print("front: ", front, " behind: ", behind)
        if behind == len(face2[0].Vertexes):
            return 1
        elif front == len(face2[0].Vertexes):
            return 2
        if DEBUG:
            print("failed, cannot say if face 2 is in front or behind")

        # test 5: see if faces projections don't overlap, vertexwise
        if DEBUG:
            print("doing test 5")
        if not self.zOverlaps(face1, face2):
            return 0
        elif not self.zOverlaps(face2, face1):
            return 0
        if DEBUG:
            print("failed, faces are overlapping")

        if DEBUG:
            print("Houston, all tests passed, and still no results")
        return 0

    def join(self, otype):
        "joins the objects of same type"
        import Part

        walls = []
        structs = []
        objs = []
        for o in obj.Source.Objects:
            t = Draft.getType(o)
            if t == "Wall":
                walls.append(o)
            elif t == "Structure":
                structs.append(o)
            else:
                objs.append(o)
        for g in [walls, structs]:
            if g:
                print("group:", g)
                col = g[0].ViewObject.DiffuseColor[0]
                s = g[0].Shape
                for o in g[1:]:
                    try:
                        fs = s.fuse(o.Shape)
                        fs = fs.removeSplitter()
                    except Part.OCCError:
                        print("shape fusion failed")
                        objs.append([o.Shape, o.ViewObject.DiffuseColor[0]])
                    else:
                        s = fs
                objs.append([s, col])

    def findPosition(self, f1, faces):
        "Finds the position of a face in a list of faces"
        l = None
        h = None
        for f2 in faces:
            if DEBUG:
                print(
                    "comparing face",
                    str(self.faces.index(f1)),
                    " with face",
                    str(self.faces.index(f2)),
                )
            r = self.compare(f1, f2)
            if r == 1:
                l = faces.index(f2)
            elif r == 2:
                if h is None:
                    h = faces.index(f2)
                else:
                    if faces.index(f2) < h:
                        h = faces.index(f2)
        if l is not None:
            return l + 1
        elif h is not None:
            return h
        else:
            return None

    def sort(self):
        "projects a shape on the WP"
        if DEBUG:
            print("\n\n======> Starting sort\n\n")
        if len(self.faces) <= 1:
            return
        if not self.trimmed:
            self.removeHidden()
            if DEBUG:
                print("Done hidden face removal")
        if len(self.faces) == 1:
            return
        if not self.oriented:
            self.reorient()
            if DEBUG:
                print("Done reorientation")
        faces = self.faces[:]
        if DEBUG:
            print("sorting ", len(self.faces), " faces")
        sfaces = []
        loopcount = 0
        notfoundstack = 0
        while faces:
            if DEBUG:
                print("loop ", loopcount)
            f1 = faces[0]
            if sfaces and (notfoundstack < len(faces)):
                if DEBUG:
                    print("using ordered stack, notfound = ", notfoundstack)
                p = self.findPosition(f1, sfaces)
                if p is None:
                    # no position found, we move the face to the end of the pile
                    faces.remove(f1)
                    faces.append(f1)
                    notfoundstack += 1
                else:
                    # position found, we insert it
                    faces.remove(f1)
                    sfaces.insert(p, f1)
                    notfoundstack = 0
            else:
                # either there is no stack, or no more face can be compared
                # find a root, 2 faces that can be compared
                if DEBUG:
                    print("using unordered stack, notfound = ", notfoundstack)
                for f2 in faces[1:]:
                    if DEBUG:
                        print(
                            "comparing face",
                            str(self.faces.index(f1)),
                            " with face",
                            str(self.faces.index(f2)),
                        )
                    r = self.compare(f1, f2)
                    print("comparison result:", r)
                    if r == 1:
                        faces.remove(f2)
                        sfaces.append(f2)
                        faces.remove(f1)
                        sfaces.append(f1)
                        notfoundstack = 0
                        break
                    elif r == 2:
                        faces.remove(f1)
                        sfaces.append(f1)
                        faces.remove(f2)
                        sfaces.append(f2)
                        notfoundstack = 0
                        break
                    elif r == 31:
                        if f1 in faces:
                            faces.remove(f1)
                    elif r == 32:
                        if f2 in faces:
                            faces.remove(f2)
                else:
                    # nothing found, move the face to the end of the pile
                    if f1 in faces:
                        faces.remove(f1)
                        faces.append(f1)
            loopcount += 1
            if loopcount == MAXLOOP * len(self.faces):
                if DEBUG:
                    print("Too many loops, aborting.")
                break

        if DEBUG:
            print(
                "done Z sorting. ",
                len(sfaces),
                " faces retained, ",
                len(self.faces) - len(sfaces),
                " faces lost.",
            )
        self.faces = sfaces
        self.sorted = True
        if DEBUG:
            print("\n\n======> Finished sort\n\n")

    def buildDummy(self):
        "Builds a dummy object with faces spaced on the Z axis, for visual check"
        z = 0
        if not self.sorted:
            self.sort()
        faces = []
        for f in self.faces[:]:
            ff = self.flattenFace(f)[0]
            ff.translate(FreeCAD.Vector(0, 0, z))
            faces.append(ff)
            z += 1
        if faces:
            c = Part.makeCompound(faces)
            Part.show(c)

    def getFill(self, fill):
        "Returns a SVG fill value"
        r = str(hex(int(fill[0] * 255)))[2:].zfill(2)
        g = str(hex(int(fill[1] * 255)))[2:].zfill(2)
        b = str(hex(int(fill[2] * 255)))[2:].zfill(2)
        col = "#" + r + g + b
        return col

    def getPathData(self, w):
        "Returns a SVG path data string from a 2D wire"

        def tostr(val):
            return str(round(val, Draft.precision()))

        edges = Part.__sortEdges__(w.Edges)
        v = edges[0].Vertexes[0].Point
        svg = "M " + tostr(v.x) + " " + tostr(v.y) + " "
        for e in edges:
            if (DraftGeomUtils.geomType(e) == "Line") or (
                DraftGeomUtils.geomType(e) == "BSplineCurve"
            ):
                v = e.Vertexes[-1].Point
                svg += "L " + tostr(v.x) + " " + tostr(v.y) + " "
            elif DraftGeomUtils.geomType(e) == "Circle":
                r = e.Curve.Radius
                v = e.Vertexes[-1].Point
                svg += "A " + tostr(r) + " " + tostr(r) + " 0 0 1 " + tostr(v.x) + " "
                svg += tostr(v.y) + " "
        if len(edges) > 1:
            svg += "Z "
        return svg

    def getViewSVG(self, linewidth=0.01):
        "Returns a SVG fragment from viewed faces"
        if DEBUG:
            print("Printing ", len(self.faces), " faces")
        if not self.sorted:
            self.sort()
        svg = (
            '<g stroke="#000000" stroke-width="'
            + str(linewidth)
            + '" style="stroke-width:'
            + str(linewidth)
        )
        svg += ';stroke-miterlimit:1;stroke-linejoin:round;stroke-dasharray:none;">\n'
        for f in self.faces:
            if f:
                fill = self.getFill(f[1])
                svg += "    <path "
                svg += 'd="'
                for w in f[0].Wires:
                    svg += self.getPathData(w)
                svg += '" style="fill:' + fill + ';fill-rule: evenodd;"/>\n'
        svg += "</g>\n"
        return svg

    def getSectionSVG(self, linewidth=0.02, fillpattern=None):
        "Returns a SVG fragment from cut faces"
        if DEBUG:
            print("Printing ", len(self.sections), " sections")
        if not self.oriented:
            self.reorient()
        svg = (
            '<g stroke="#000000" stroke-width="'
            + str(linewidth)
            + '" style="stroke-width:'
            + str(linewidth)
        )
        svg += ';stroke-miterlimit:1;stroke-linejoin:round;stroke-dasharray:none;">\n'
        for f in self.sections:
            if f:
                if fillpattern:
                    if "#" in fillpattern:  # color
                        fill = fillpattern
                    else:
                        fill = "url(#" + fillpattern + ")"  # pattern name
                else:
                    fill = "none"  # none
                svg += "<path "
                svg += 'd="'
                for w in f[0].Wires:
                    # print("wire with ",len(w.Vertexes)," verts")
                    svg += self.getPathData(w)
                svg += '" style="fill:' + fill + ';fill-rule: evenodd;"/>\n'
        svg += "</g>\n"
        return svg

    def getHiddenSVG(self, linewidth=0.02):
        "Returns a SVG fragment from cut geometry"
        if DEBUG:
            print("Printing ", len(self.sections), " hidden faces")
        if not self.oriented:
            self.reorient()
        svg = (
            '<g stroke="#000000" stroke-width="'
            + str(linewidth)
            + '" style="stroke-width:'
            + str(linewidth)
        )
        svg += (
            ';stroke-miterlimit:1;stroke-linejoin:round;stroke-dasharray:0.09,0.05;fill:none;">\n'
        )
        for e in self.hiddenEdges:
            svg += "<path "
            svg += 'd="'
            svg += self.getPathData(e)
            svg += '"/>\n'
        svg += "</g>\n"
        return svg