mesh_tiny_cad/CCEN.py

   1 # SPDX-FileCopyrightText: 2016-2022 Blender Foundation
   2 #
   3 # SPDX-License-Identifier: GPL-2.0-or-later
   4
   5
   6 import math
   7
   8 import bpy
   9 import bmesh
  10 import mathutils
  11 from mathutils import geometry
  12 from mathutils import Vector
  13
  14
  15 def generate_bmesh_repr(p1, v1, axis, num_verts):
  16     '''
  17         p1:     center of circle (local coordinates)
  18         v1:     first vertex of circle in (local coordinates)
  19         axis:   orientation matrix
  20         origin: obj.location
  21     '''
  22     props = bpy.context.scene.tinycad_props
  23     rescale = props.rescale
  24
  25     # generate geometry up front
  26     chain = []
  27     gamma = 2 * math.pi / num_verts
  28     for i in range(num_verts + 1):
  29         theta = gamma * i
  30         mat_rot = mathutils.Matrix.Rotation(theta, 4, axis)
  31         local_point = (mat_rot @ ((v1 - p1) * rescale))
  32         chain.append(local_point + p1)
  33
  34     obj = bpy.context.edit_object
  35     me = obj.data
  36     bm = bmesh.from_edit_mesh(me)
  37
  38     # add verts
  39     v_refs = []
  40     for p in chain:
  41         v = bm.verts.new(p)
  42         v.select = False  # this might be a default.. redundant?
  43         v_refs.append(v)
  44
  45     # join verts, daisy chain
  46     num_verts = len(v_refs)
  47     for i in range(num_verts):
  48         idx1 = i
  49         idx2 = (i + 1) % num_verts
  50         bm.edges.new([v_refs[idx1], v_refs[idx2]])
  51
  52     bmesh.update_edit_mesh(me, loop_triangles=True)
  53
  54
  55 def generate_3PT(pts, obj, nv, mode=1):
  56     mw = obj.matrix_world
  57     V = Vector
  58     nv = max(3, nv)
  59
  60     # construction
  61     v1, v2, v3, v4 = V(pts[0]), V(pts[1]), V(pts[1]), V(pts[2])
  62     edge1_mid = v1.lerp(v2, 0.5)
  63     edge2_mid = v3.lerp(v4, 0.5)
  64     axis = geometry.normal(v1, v2, v4)
  65     mat_rot = mathutils.Matrix.Rotation(math.radians(90.0), 4, axis)
  66
  67     # triangle edges
  68     v1_ = ((v1 - edge1_mid) @ mat_rot) + edge1_mid
  69     v2_ = ((v2 - edge1_mid) @ mat_rot) + edge1_mid
  70     v3_ = ((v3 - edge2_mid) @ mat_rot) + edge2_mid
  71     v4_ = ((v4 - edge2_mid) @ mat_rot) + edge2_mid
  72
  73     r = geometry.intersect_line_line(v1_, v2_, v3_, v4_)
  74     if r:
  75         p1, _ = r
  76         cp = mw @ p1
  77         bpy.context.scene.cursor.location = cp
  78
  79         if mode == 0:
  80             pass
  81
  82         elif mode == 1:
  83             generate_bmesh_repr(p1, v1, axis, nv)
  84
  85     else:
  86         print('not on a circle')
  87
  88
  89 def get_three_verts_from_selection(obj):
  90     me = obj.data
  91     bm = bmesh.from_edit_mesh(me)
  92
  93     bm.verts.ensure_lookup_table()
  94     bm.edges.ensure_lookup_table()
  95
  96     return [v.co[:] for v in bm.verts if v.select]
  97
  98
  99 def dispatch(context, mode=0):
 100     try:
 101         obj = context.edit_object
 102         pts = get_three_verts_from_selection(obj)
 103         props = context.scene.tinycad_props
 104         generate_3PT(pts, obj, props.num_verts, mode)
 105     except:
 106         print('dispatch failed', mode)
 107
 108
 109 class TCCallBackCCEN(bpy.types.Operator):
 110     bl_idname = 'tinycad.reset_circlescale'
 111     bl_label = 'CCEN circle reset'
 112     bl_options = {'REGISTER'}
 113
 114     def execute(self, context):
 115         context.scene.tinycad_props.rescale = 1
 116         return {'FINISHED'}
 117
 118
 119 class TCCircleCenter(bpy.types.Operator):
 120     '''Recreate a Circle from 3 selected verts, move 3dcursor to its center'''
 121
 122     bl_idname = 'tinycad.circlecenter'
 123     bl_label = 'CCEN circle center from selected'
 124     bl_options = {'REGISTER', 'UNDO'}
 125
 126     def draw(self, context):
 127         scn = context.scene
 128         l = self.layout
 129         col = l.column()
 130
 131         col.prop(scn.tinycad_props, 'num_verts', text='num verts')
 132         row = col.row(align=True)
 133         row.prop(scn.tinycad_props, 'rescale', text='rescale')
 134         row.operator('tinycad.reset_circlescale', text="", icon="PIVOT_CURSOR")
 135
 136     @classmethod
 137     def poll(cls, context):
 138         obj = context.edit_object
 139         return obj is not None and obj.type == 'MESH'
 140
 141     def execute(self, context):
 142         dispatch(context, mode=1)
 143         return {'FINISHED'}