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
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
|
; spyrogimp.scm -*-scheme-*-
; Draws Spirographs, Epitrochoids and Lissajous Curves.
; More info at http://www.wisdom.weizmann.ac.il/~elad/spyrogimp/
; Version 1.2
;
; Copyright (C) 2003 by Elad Shahar <elad@wisdom.weizmann.ac.il>
;
; 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/>.
; This routine is invoked by a dialog.
; It is the main routine in this file.
(define (script-fu-spyrogimp img drw
type shape
oteeth iteeth
margin hole-ratio start-angle
tool brush
color-method color grad)
; Internal function to draw the spyro.
(define (script-fu-spyrogimp-internal img drw
x1 y1 x2 y2 ; Bounding box.
type ; = 0 (Spirograph), 1 (Epitrochoid), 2(Lissajous) .
shape ; = 0 (Circle), 1 (Frame), >2 (Polygons) .
oteeth iteeth ; Outer and inner teeth.
margin hole-ratio
start-angle ; 0 <= start-angle < 360 .
tool ; = 0 (Pencil), 1 (Brush), 2 (Airbrush) .
brush
color-method ; = 0 (Single color), 1 (Grad. Loop Sawtooth),
; 2 (Grad. Loop triangle) .
color ; Used when color-method = Single color .
grad ; Gradient used in Gradient color methods.
)
; This function returns a list of samples according to the gradient.
(define (get-gradient steps color-method grad)
(if (= color-method 1)
; option 1
; Just return the gradient
(gimp-gradient-get-uniform-samples grad (min steps 50) FALSE)
; option 2
; The returned list is such that the gradient appears two times, once
; in the normal order and once in reverse. This way there are no color
; jumps if we go beyond the edge
(let* (
; Sample the gradient into array "gr".
(gr (gimp-gradient-get-uniform-samples grad
(/ (min steps 50) 2)
FALSE))
(grn (car gr)) ; length of sample array.
(gra (cadr gr)) ; array of color samples (R1,G1,B1,A1, R2,....)
; Allocate array gra-new of size (2 * grn) - 8,
; but since each 4 items is actually one (RGBA) tuple,
; it contains 2x - 2 entries.
(grn-new (+ grn grn -8))
(gra-new (cons-array grn-new 'double))
(gr-index 0)
(gr-index2 0)
)
; Copy original array gra to gra_new.
(while (< gr-index grn)
(aset gra-new gr-index (aref gra gr-index))
(set! gr-index (+ 1 gr-index))
)
; Copy second time, but in reverse
(set! gr-index2 (- gr-index 8))
(while (< gr-index grn-new)
(aset gra-new gr-index (aref gra gr-index2))
(set! gr-index (+ 1 gr-index))
(set! gr-index2 (+ 1 gr-index2))
(if (= (fmod gr-index 4) 0)
(set! gr-index2 (- gr-index2 8))
)
)
; Return list.
(list grn-new gra-new)
)
)
)
(let* (
(steps (+ 1 (lcm oteeth iteeth)))
(*points* (cons-array (* steps 2) 'double))
(ot 0) ; current outer tooth
(cx 0) ; Current x,y
(cy 0)
; If its a polygon or frame, how many sides does it have.
(poly (if (= shape 1) 4 ; A frame has four sides.
(if (> shape 1) (+ shape 1) 0)))
(2pi (* 2 *pi*))
(drw-width (- x2 x1))
(drw-height (- y2 y1))
(half-width (/ drw-width 2))
(half-height (/ drw-height 2))
(midx (+ x1 half-width))
(midy (+ y1 half-height))
(hole (* hole-ratio
(- (/ (min drw-width drw-height) 2) margin)
)
)
(irad (+ hole margin))
(radx (- half-width irad)) ;
(rady (- half-height irad)) ;
(gradt (get-gradient steps color-method grad))
(grada (cadr gradt)) ; Gradient array.
(gradn (car gradt)) ; Number of entries of gradients.
; Indexes
(grad-index 0) ; for array: grada
(point-index 0) ; for array: *points*
(index 0)
)
; Do one step of the loop.
(define (calc-and-step!)
(let* (
(oangle (* 2pi (/ ot oteeth)) )
(shifted-oangle (+ oangle (* 2pi (/ start-angle 360))) )
(xfactor (cos shifted-oangle))
(yfactor (sin shifted-oangle))
(lenfactor 1)
(ofactor (/ (+ oteeth iteeth) iteeth))
; The direction of the factor changes according
; to whether the type is a sypro or an epitcorhoid.
(mfactor (if (= type 0) (- ofactor) ofactor))
)
; If we are drawing a polygon then compute a contortion
; factor "lenfactor" which deforms the standard circle.
(if (> poly 2)
(let* (
(pi4 (/ *pi* poly))
(pi2 (* pi4 2))
(oanglemodpi2 (fmod (+ oangle
(if (= 1 (fmod poly 2))
0 ;(/ pi4 2)
0
)
)
pi2))
)
(set! lenfactor (/ ( if (= shape 1) 1 (cos pi4) )
(cos
(if (< oanglemodpi2 pi4)
oanglemodpi2
(- pi2 oanglemodpi2)
)
)
)
)
)
)
(if (= type 2)
(begin ; Lissajous
(set! cx (+ midx
(* half-width (cos shifted-oangle)) ))
(set! cy (+ midy
(* half-height (cos (* mfactor oangle))) ))
)
(begin ; Spyrograph or Epitrochoid
(set! cx (+ midx
(* radx xfactor lenfactor)
(* hole (cos (* mfactor oangle) ) ) ))
(set! cy (+ midy
(* rady yfactor lenfactor)
(* hole (sin (* mfactor oangle) ) ) ))
)
)
;; Advance teeth
(set! ot (+ ot 1))
)
)
;; Draw all the points in *points* with appropriate tool.
(define (flush-points len)
(if (= tool 0)
(gimp-pencil drw len *points*) ; Use pencil
(if (= tool 1)
(gimp-paintbrush-default drw len *points*); use paintbrush
(gimp-airbrush-default drw len *points*) ; use airbrush
)
)
; Reset points array, but copy last point to first
; position so it will connect the next time.
(aset *points* 0 (aref *points* (- point-index 2)))
(aset *points* 1 (aref *points* (- point-index 1)))
(set! point-index 2)
)
;;
;; Execution starts here.
;;
(gimp-context-push)
(gimp-image-undo-group-start img)
; Set new color, brush, opacity, paint mode.
(gimp-context-set-foreground color)
(gimp-context-set-brush (car brush))
(gimp-context-set-opacity (car (cdr brush)))
(gimp-context-set-paint-mode (car (cdr (cdr (cdr brush)))))
(gimp-progress-set-text _"Rendering Spyro")
(while (< index steps)
(calc-and-step!)
(aset *points* point-index cx)
(aset *points* (+ point-index 1) cy)
(set! point-index (+ point-index 2))
; Change color and draw points if using gradient.
(if (< 0 color-method) ; use gradient.
(if (< (/ (+ grad-index 4) gradn) (/ index steps))
(begin
(gimp-context-set-foreground
(list
(* 255 (aref grada grad-index))
(* 255 (aref grada (+ 1 grad-index)) )
(* 255 (aref grada (+ 2 grad-index)) )
)
)
(gimp-context-set-opacity (* 100 (aref grada (+ 3 grad-index) ) ) )
(set! grad-index (+ 4 grad-index))
; Draw points
(flush-points point-index)
)
)
)
(set! index (+ index 1))
(if (= 0 (modulo index 16))
(gimp-progress-update (/ index steps))
)
)
; Draw remaining points.
(flush-points point-index)
(gimp-progress-update 1.0)
(gimp-image-undo-group-end img)
(gimp-displays-flush)
(gimp-context-pop)
)
)
(let* (
; Get current selection to determine where to draw.
(bounds (cdr (gimp-selection-bounds img)))
(x1 (car bounds))
(y1 (cadr bounds))
(x2 (caddr bounds))
(y2 (car (cdddr bounds)))
)
(set! oteeth (trunc (+ oteeth 0.5)))
(set! iteeth (trunc (+ iteeth 0.5)))
(script-fu-spyrogimp-internal img drw
x1 y1 x2 y2
type shape
oteeth iteeth
margin hole-ratio start-angle
tool brush
color-method color grad)
)
)
(script-fu-register "script-fu-spyrogimp"
_"_Spyrogimp (older script-fu version)..."
_"This procedure is deprecated! Use 'plug-in-spyrogimp' instead."
"Elad Shahar <elad@wisdom.weizmann.ac.il>"
"Elad Shahar"
"June 2003"
"RGB*, INDEXED*, GRAY*"
SF-IMAGE "Image" 0
SF-DRAWABLE "Drawable" 0
SF-OPTION _"Type" '(_"Spyrograph"
_"Epitrochoid"
_"Lissajous")
SF-OPTION _"Shape" '(_"Circle"
_"Frame"
_"Triangle"
_"Square"
_"Pentagon"
_"Hexagon"
_"Polygon: 7 sides"
_"Polygon: 8 sides"
_"Polygon: 9 sides"
_"Polygon: 10 sides")
SF-ADJUSTMENT _"Outer teeth" '(86 1 120 1 10 0 0)
SF-ADJUSTMENT _"Inner teeth" '(70 1 120 1 10 0 0)
SF-ADJUSTMENT _"Margin (pixels)" '(0 -10000 10000 1 10 0 1)
SF-ADJUSTMENT _"Hole ratio" '(0.4 0.0 1.0 0.01 0.1 2 0)
SF-ADJUSTMENT _"Start angle" '(0 0 359 1 10 0 0)
SF-OPTION _"Tool" '(_"Pencil"
_"Brush"
_"Airbrush")
SF-BRUSH _"Brush" '("Circle (01)" 100 -1 0)
SF-OPTION _"Color method" '(_"Solid Color"
_"Gradient: Loop Sawtooth"
_"Gradient: Loop Triangle")
SF-COLOR _"Color" "black"
SF-GRADIENT _"Gradient" "Deep Sea"
)
|
