precision_drawing_tools/pdt_trig_waves.py

   1 # SPDX-FileCopyrightText: 2019-2022 Alan Odom (Clockmender)
   2 # SPDX-FileCopyrightText: 2019-2022 Rune Morling (ermo)
   3 #
   4 # SPDX-License-Identifier: GPL-2.0-or-later
   5
   6 import bpy
   7 import bmesh
   8 from math import sin, cos, tan, pi
   9 from mathutils import Vector
  10 from .pdt_functions import (
  11     set_mode,
  12     view_coords,
  13 )
  14
  15 class PDT_OT_WaveGenerator(bpy.types.Operator):
  16     """Generate Trig Waves in Active Object"""
  17     bl_idname = "pdt.wave_generator"
  18     bl_label = "Generate Waves"
  19     bl_options = {"REGISTER", "UNDO"}
  20
  21     @classmethod
  22     def poll(cls, context):
  23         pg = context.scene.pdt_pg
  24         return pg.trig_obj is not None
  25
  26     def execute(self, context):
  27         """Generate Trig Waves in Active Object.
  28
  29         Note:
  30             Uses all the PDT trig_* variables.
  31
  32             This function will draw a trigonometrical wave based upon cycle length
  33             One cycle is assumed to be 180 degrees, so half a revolution of an imaginary
  34             rotating object. If a full cycle from 0 to 360 degrees is required, the cycles
  35             number should be set to 2.
  36
  37         Args:
  38             context: Blender bpy.context instance.
  39
  40         Returns:
  41             Nothing.
  42         """
  43
  44         pg = context.scene.pdt_pg
  45         plane = pg.plane
  46         # Find the horizontal, vertical and depth axes in the view from working plane.
  47         # Order is: H, V, D.
  48         #
  49         a1, a2, a3 = set_mode(plane)
  50         # Make sure object selected in the UI is the active object.
  51         #
  52         for obj in bpy.data.objects:
  53             obj.select_set(state=False)
  54         context.view_layer.objects.active = pg.trig_obj
  55         # x_inc is the increase in X (Horiz axis) per unit of resolution of the wave, so if
  56         # resolution is 9, nine points will be drawn in each cycle representing increases of
  57         # 20 degrees and 1/9th of the cycle length.
  58         #
  59         x_inc = pg.trig_len / pg.trig_res
  60
  61         if pg.trig_del:
  62             # Delete all existing vertices first.
  63             #
  64             bpy.ops.object.mode_set(mode='EDIT')
  65             for v in pg.trig_obj.data.vertices:
  66                 v.select = True
  67             bpy.ops.mesh.delete(type='VERT')
  68             bpy.ops.object.mode_set(mode='OBJECT')
  69
  70         if pg.trig_obj.mode != "EDIT":
  71             bpy.ops.object.mode_set(mode='EDIT')
  72         bm = bmesh.from_edit_mesh(pg.trig_obj.data)
  73
  74         # Loop for each point in the number of cycles times the resolution value.
  75         # Uses basic trigonomtry to calculate the wave locations.
  76         # If Absolute has been set, all values are made positive.
  77         # z_val is assumed to be the offset from the horizontal axis of the wave.
  78         # These values will be offset by the Offset Vector given in the UI.
  79         #
  80         for i in range((pg.trig_res * pg.trig_cycles) + 1):
  81             # Uses a calculation of trig function angle of imaginary object times maximum amplitude
  82             # of wave. So with reolution at 9, angular increments are 20 degrees.
  83             # Angles must be in Radians for this calcultion.
  84             #
  85             if pg.trig_type == "sin":
  86                 if pg.trig_abs:
  87                     z_val = abs(sin((i / pg.trig_res) * pi) * pg.trig_amp)
  88                 else:
  89                     z_val = sin((i / pg.trig_res) * pi) * pg.trig_amp
  90             elif pg.trig_type == "cos":
  91                 if pg.trig_abs:
  92                     z_val = abs(cos((i / pg.trig_res) * pi) * pg.trig_amp)
  93                 else:
  94                     z_val = cos((i / pg.trig_res) * pi) * pg.trig_amp
  95             else:
  96                 if pg.trig_abs:
  97                     z_val = abs(tan((i / pg.trig_res) * pi) * pg.trig_amp)
  98                 else:
  99                     z_val = tan((i / pg.trig_res) * pi) * pg.trig_amp
 100
 101                 if abs(z_val) > pg.trig_tanmax:
 102                     if z_val >= 0:
 103                         z_val = pg.trig_tanmax
 104                     else:
 105                         if pg.trig_abs:
 106                             z_val = pg.trig_tanmax
 107                         else:
 108                             z_val = -pg.trig_tanmax
 109
 110             # Start with Offset Vector from UI and add wave offsets to it.
 111             # Axis a3 (depth) is never changed from offset vector in UI.
 112             #
 113             vert_loc = Vector(pg.trig_off)
 114             vert_loc[a1] = vert_loc[a1] + (i * x_inc)
 115             vert_loc[a2] = vert_loc[a2] + z_val
 116             if plane == "LO":
 117                 # Translate view local coordinates (horiz, vert, depth) into World XYZ
 118                 #
 119                 vert_loc = view_coords(vert_loc[a1], vert_loc[a2], vert_loc[a3])
 120             vertex_new = bm.verts.new(vert_loc)
 121             # Refresh Vertices list in object data.
 122             #
 123             bm.verts.ensure_lookup_table()
 124             if i > 0:
 125                 # Make an edge from last two vertices in object data.
 126                 #
 127                 bm.edges.new([bm.verts[-2], vertex_new])
 128
 129         bmesh.update_edit_mesh(pg.trig_obj.data)
 130         bpy.ops.object.mode_set(mode='OBJECT')
 131
 132         return {"FINISHED"}