greasepencil_tools/line_reshape.py

   1 # SPDX-FileCopyrightText: 2020-2022 Blender Foundation
   2 #
   3 # SPDX-License-Identifier: GPL-2.0-or-later
   4
   5 '''Based on GP_refine_stroke 0.2.4 - Author: Samuel Bernou'''
   6
   7 import bpy
   8
   9 ### --- Vector utils
  10
  11 def mean(*args):
  12     '''
  13     return mean of all passed value (multiple)
  14     If it's a list or tuple return mean of it (only on first list passed).
  15     '''
  16     if isinstance(args[0], list) or isinstance(args[0], tuple):
  17         return mean(*args[0])#send the first list UNPACKED (else infinite recursion as it always evaluate as list)
  18     return sum(args) / len(args)
  19
  20 def vector_len_from_coord(a, b):
  21     '''
  22     Get two points (that has coordinate 'co' attribute) or Vectors (2D or 3D)
  23     Return length as float
  24     '''
  25     from mathutils import Vector
  26     if type(a) is Vector:
  27         return (a - b).length
  28     else:
  29         return (a.co - b.co).length
  30
  31 def point_from_dist_in_segment_3d(a, b, ratio):
  32     '''return the tuple coords of a point on 3D segment ab according to given ratio (some distance divided by total segment length)'''
  33     ## ref:https://math.stackexchange.com/questions/175896/finding-a-point-along-a-line-a-certain-distance-away-from-another-point
  34     # ratio = dist / seglength
  35     return ( ((1 - ratio) * a[0] + (ratio*b[0])), ((1 - ratio) * a[1] + (ratio*b[1])), ((1 - ratio) * a[2] + (ratio*b[2])) )
  36
  37 def get_stroke_length(s):
  38     '''return 3D total length of the stroke'''
  39     all_len = 0.0
  40     for i in range(0, len(s.points)-1):
  41         #print(vector_len_from_coord(s.points[i],s.points[i+1]))
  42         all_len += vector_len_from_coord(s.points[i],s.points[i+1])
  43     return (all_len)
  44
  45 ### --- Functions
  46
  47 def to_straight_line(s, keep_points=True, influence=100, straight_pressure=True):
  48     '''
  49     keep points : if false only start and end point stay
  50     straight_pressure : (not available with keep point) take the mean pressure of all points and apply to stroke.
  51     '''
  52
  53     p_len = len(s.points)
  54     if p_len <= 2: # 1 or 2 points only, cancel
  55         return
  56
  57     if not keep_points:
  58         if straight_pressure: mean_pressure = mean([p.pressure for p in s.points])#can use a foreach_get but might not be faster.
  59         for i in range(p_len-2):
  60             s.points.pop(index=1)
  61         if straight_pressure:
  62             for p in s.points:
  63                 p.pressure = mean_pressure
  64
  65     else:
  66         A = s.points[0].co
  67         B = s.points[-1].co
  68         # ab_dist = vector_len_from_coord(A,B)
  69         full_dist = get_stroke_length(s)
  70         dist_from_start = 0.0
  71         coord_list = []
  72
  73         for i in range(1, p_len-1):#all but first and last
  74             dist_from_start += vector_len_from_coord(s.points[i-1],s.points[i])
  75             ratio = dist_from_start / full_dist
  76             # dont apply directly (change line as we measure it in loop)
  77             coord_list.append( point_from_dist_in_segment_3d(A, B, ratio) )
  78
  79         # apply change
  80         for i in range(1, p_len-1):
  81             ## Direct super straight 100%
  82             #s.points[i].co = coord_list[i-1]
  83
  84             ## With influence
  85             s.points[i].co = point_from_dist_in_segment_3d(s.points[i].co, coord_list[i-1], influence / 100)
  86
  87     return
  88
  89 def get_last_index(context=None):
  90     if not context:
  91         context = bpy.context
  92     return 0 if context.tool_settings.use_gpencil_draw_onback else -1
  93
  94 ### --- OPS
  95
  96 class GPENCIL_OT_straight_stroke(bpy.types.Operator):
  97     bl_idname = "gpencil.straight_stroke"
  98     bl_label = "Straight Stroke"
  99     bl_description = "Make stroke a straight line between first and last point,\
 100         \nTweak influence in the redo panel\
 101         \nShift+click to reset infuence to 100%"
 102     bl_options = {"REGISTER", "UNDO"}
 103
 104     @classmethod
 105     def poll(cls, context):
 106         return context.active_object is not None and context.object.type == 'GPENCIL'
 107         #and context.mode in ('PAINT_GPENCIL', 'EDIT_GPENCIL')
 108
 109     influence_val : bpy.props.FloatProperty(name="Straight force", description="Straight interpolation percentage",
 110     default=100, min=0, max=100, step=2, precision=1, subtype='PERCENTAGE', unit='NONE')
 111
 112     def execute(self, context):
 113         gp = context.object.data
 114         gpl = gp.layers
 115         if not gpl:
 116             return {"CANCELLED"}
 117
 118         if context.mode == 'PAINT_GPENCIL':
 119             if not gpl.active or not gpl.active.active_frame:
 120                 self.report({'ERROR'}, 'No Grease pencil frame found')
 121                 return {"CANCELLED"}
 122
 123             if not len(gpl.active.active_frame.strokes):
 124                 self.report({'ERROR'}, 'No strokes found.')
 125                 return {"CANCELLED"}
 126
 127             s = gpl.active.active_frame.strokes[get_last_index(context)]
 128             to_straight_line(s, keep_points=True, influence=self.influence_val)
 129
 130         elif context.mode == 'EDIT_GPENCIL':
 131             ct = 0
 132             for l in gpl:
 133                 if l.lock or l.hide or not l.active_frame:
 134                     # avoid locked, hidden, empty layers
 135                     continue
 136                 if gp.use_multiedit:
 137                     target_frames = [f for f in l.frames if f.select]
 138                 else:
 139                     target_frames = [l.active_frame]
 140
 141                 for f in target_frames:
 142                     for s in f.strokes:
 143                         if s.select:
 144                             ct += 1
 145                             to_straight_line(s, keep_points=True, influence=self.influence_val)
 146
 147             if not ct:
 148                 self.report({'ERROR'}, 'No selected stroke found.')
 149                 return {"CANCELLED"}
 150
 151         ## filter method
 152         # if context.mode == 'PAINT_GPENCIL':
 153         #     L, F, S = 'ACTIVE', 'ACTIVE', 'LAST'
 154         # elif context.mode == 'EDIT_GPENCIL'
 155         #     L, F, S = 'ALL', 'ACTIVE', 'SELECT'
 156         #     if gp.use_multiedit: F = 'SELECT'
 157         # else : return {"CANCELLED"}
 158         # for s in strokelist(t_layer=L, t_frame=F, t_stroke=S):
 159         #     to_straight_line(s, keep_points=True, influence = self.influence_val)#, straight_pressure=True
 160
 161         return {"FINISHED"}
 162
 163     def draw(self, context):
 164         layout = self.layout
 165         layout.prop(self, "influence_val")
 166
 167     def invoke(self, context, event):
 168         if context.mode not in ('PAINT_GPENCIL', 'EDIT_GPENCIL'):
 169             return {"CANCELLED"}
 170         if event.shift:
 171             self.influence_val = 100
 172         return self.execute(context)
 173
 174
 175 def register():
 176     bpy.utils.register_class(GPENCIL_OT_straight_stroke)
 177
 178 def unregister():
 179     bpy.utils.unregister_class(GPENCIL_OT_straight_stroke)