1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
#!/usr/bin/env python2
# Gimp-Python - allows the writing of Gimp plugins in Python.
# Copyright (C) 1997 James Henstridge <james@daa.com.au>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
# Algorithms stolen from the whirl and pinch plugin distributed with Gimp,
# by Federico Mena Quintero and Scott Goehring
#
# This version does the same thing, except there is no preview, and it is
# written in python and is slower.
import math, struct
from gimpfu import *
class pixel_fetcher:
def __init__(self, drawable):
self.col = -1
self.row = -1
self.img_width = drawable.width
self.img_height = drawable.height
self.img_bpp = drawable.bpp
self.img_has_alpha = drawable.has_alpha
self.tile_width = gimp.tile_width()
self.tile_height = gimp.tile_height()
self.bg_colour = '\0\0\0\0'
self.bounds = drawable.mask_bounds
self.drawable = drawable
self.tile = None
def set_bg_colour(self, r, g, b, a):
self.bg_colour = struct.pack('BBB', r,g,b)
if self.img_has_alpha:
self.bg_colour = self.bg_colour + chr(a)
def get_pixel(self, x, y):
sel_x1, sel_y1, sel_x2, sel_y2 = self.bounds
if x < sel_x1 or x >= sel_x2 or y < sel_y1 or y >= sel_y2:
return self.bg_colour
col = x / self.tile_width
coloff = x % self.tile_width
row = y / self.tile_height
rowoff = y % self.tile_height
if col != self.col or row != self.row or self.tile == None:
self.tile = self.drawable.get_tile(False, row, col)
self.col = col
self.row = row
return self.tile[coloff, rowoff]
class Dummy:
pass
def whirl_pinch(image, drawable, whirl, pinch, radius):
self = Dummy()
self.width = drawable.width
self.height = drawable.height
self.bpp = drawable.bpp
self.has_alpha = drawable.has_alpha
self.bounds = drawable.mask_bounds
self.sel_x1, self.sel_y1, self.sel_x2, self.sel_y2 = \
drawable.mask_bounds
self.sel_w = self.sel_x2 - self.sel_x1
self.sel_h = self.sel_y2 - self.sel_y1
self.cen_x = (self.sel_x1 + self.sel_x2 - 1) / 2.0
self.cen_y = (self.sel_y1 + self.sel_y2 - 1) / 2.0
xhsiz = (self.sel_w - 1) / 2.0
yhsiz = (self.sel_h - 1) / 2.0
if xhsiz < yhsiz:
self.scale_x = yhsiz / xhsiz
self.scale_y = 1.0
elif xhsiz > yhsiz:
self.scale_x = 1.0
self.scale_y = xhsiz / yhsiz
else:
self.scale_x = 1.0
self.scale_y = 1.0
self.radius = max(xhsiz, yhsiz);
if not drawable.is_rgb and not drawable.is_grey:
return
gimp.tile_cache_ntiles(2 * (1 + self.width / gimp.tile_width()))
whirl = whirl * math.pi / 180
dest_rgn = drawable.get_pixel_rgn(self.sel_x1, self.sel_y1,
self.sel_w, self.sel_h, True, True)
pft = pixel_fetcher(drawable)
pfb = pixel_fetcher(drawable)
bg_colour = gimp.get_background()
pft.set_bg_colour(bg_colour[0], bg_colour[1], bg_colour[2], 0)
pfb.set_bg_colour(bg_colour[0], bg_colour[1], bg_colour[2], 0)
progress = 0
max_progress = self.sel_w * self.sel_h
gimp.progress_init("Whirling and pinching")
self.radius2 = self.radius * self.radius * radius
pixel = ['', '', '', '']
values = [0,0,0,0]
for row in range(self.sel_y1, (self.sel_y1+self.sel_y2)/2+1):
top_p = ''
bot_p = ''
for col in range(self.sel_x1, self.sel_x2):
q, cx, cy = calc_undistorted_coords(self, col,
row, whirl, pinch,
radius)
if q:
if cx >= 0: ix = int(cx)
else: ix = -(int(-cx) + 1)
if cy >= 0: iy = int(cy)
else: iy = -(int(-cy) + 1)
pixel[0] = pft.get_pixel(ix, iy)
pixel[1] = pft.get_pixel(ix+1, iy)
pixel[2] = pft.get_pixel(ix, iy+1)
pixel[3] = pft.get_pixel(ix+1, iy+1)
for i in range(self.bpp):
values[0] = ord(pixel[0][i])
values[1] = ord(pixel[1][i])
values[2] = ord(pixel[2][i])
values[3] = ord(pixel[3][i])
top_p = top_p + bilinear(cx,cy, values)
cx = self.cen_x + (self.cen_x - cx)
cy = self.cen_y + (self.cen_y - cy)
if cx >= 0: ix = int(cx)
else: ix = -(int(-cx) + 1)
if cy >= 0: iy = int(cy)
else: iy = -(int(-cy) + 1)
pixel[0] = pfb.get_pixel(ix, iy)
pixel[1] = pfb.get_pixel(ix+1, iy)
pixel[2] = pfb.get_pixel(ix, iy+1)
pixel[3] = pfb.get_pixel(ix+1, iy+1)
tmp = ''
for i in range(self.bpp):
values[0] = ord(pixel[0][i])
values[1] = ord(pixel[1][i])
values[2] = ord(pixel[2][i])
values[3] = ord(pixel[3][i])
tmp = tmp + bilinear(cx,cy, values)
bot_p = tmp + bot_p
else:
top_p = top_p + pft.get_pixel(col, row)
bot_p = pfb.get_pixel((self.sel_x2 - 1) -
(col - self.sel_x1), (self.sel_y2-1) -
(row - self.sel_y1)) + bot_p
dest_rgn[self.sel_x1:self.sel_x2, row] = top_p
dest_rgn[self.sel_x1:self.sel_x2, (self.sel_y2 - 1)
- (row - self.sel_y1)] = bot_p
progress = progress + self.sel_w * 2
gimp.progress_update(float(progress) / max_progress)
drawable.flush()
drawable.merge_shadow(True)
drawable.update(self.sel_x1,self.sel_y1,self.sel_w,self.sel_h)
def calc_undistorted_coords(self, wx, wy, whirl, pinch, radius):
dx = (wx - self.cen_x) * self.scale_x
dy = (wy - self.cen_y) * self.scale_y
d = dx * dx + dy * dy
inside = d < self.radius2
if inside:
dist = math.sqrt(d / radius) / self.radius
if (d == 0.0):
factor = 1.0
else:
factor = math.pow(math.sin(math.pi / 2 * dist),
-pinch)
dx = dx * factor
dy = dy * factor
factor = 1 - dist
ang = whirl * factor * factor
sina = math.sin(ang)
cosa = math.cos(ang)
x = (cosa * dx - sina * dy) / self.scale_x + self.cen_x
y = (sina * dx + cosa * dy) / self.scale_y + self.cen_y
else:
x = wx
y = wy
return inside, float(x), float(y)
def bilinear(x, y, values):
x = x % 1.0
y = y % 1.0
m0 = values[0] + x * (values[1] - values[0])
m1 = values[2] + x * (values[3] - values[2])
return chr(int(m0 + y * (m1 - m0)))
register(
"python-fu-whirl-pinch",
"Distorts an image by whirling and pinching",
"Distorts an image by whirling and pinching",
"James Henstridge (translated from C plugin)",
"James Henstridge",
"1997-1999",
"_Whirl and Pinch...",
"RGB*, GRAY*",
[
(PF_IMAGE, "image", "Input image", None),
(PF_DRAWABLE, "drawable", "Input drawable", None),
(PF_SLIDER, "whirl", "Whirl angle", 90, (-360, 360, 1)),
(PF_FLOAT, "pinch", "Pinch amount", 0),
(PF_FLOAT, "radius", "radius", 1)
],
[],
whirl_pinch, menu="<Image>/Filters/Distorts")
main()
|