precision_drawing_tools/pdt_trig_waves.py

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