ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/rxvt-unicode/src/perl/background
(Generate patch)

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.33 by root, Thu Jun 7 16:30:58 2012 UTC vs.
Revision 1.51 by sf-exg, Sun Jun 10 19:01:03 2012 UTC

1#! perl 1#! perl
2 2
3#:META:X_RESOURCE:%.expr:string:background expression 3#:META:X_RESOURCE:%.expr:string:background expression
4#:META:X_RESOURCE:%.border.:boolean:respect the terminal border 4#:META:X_RESOURCE:%.border:boolean:respect the terminal border
5#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
5 6
7=head1 NAME
8
6=head1 background - manage terminal background 9 background - manage terminal background
7 10
8=head2 SYNOPSIS 11=head1 SYNOPSIS
9 12
10 rxvt -background-expr 'background expression' 13 urxvt --background-expr 'background expression'
11 -background-border 14 --background-border
15 --background-interval seconds
12 16
13=head2 DESCRIPTION 17=head1 DESCRIPTION
14 18
19This extension manages the terminal background by creating a picture that
20is behind the text, replacing the normal background colour.
21
22It does so by evaluating a Perl expression that I<calculates> the image on
23the fly, for example, by grabbing the root background or loading a file.
24
25While the full power of Perl is available, the operators have been design
26to be as simple as possible.
27
28For example, to load an image and scale it to the window size, you would
29use:
30
31 urxvt --background-expr 'scale load "/path/to/mybg.png"'
32
33Or specified as a X resource:
34
35 URxvt.background-expr: scale load "/path/to/mybg.png"
36
37=head1 THEORY OF OPERATION
38
39At startup, just before the window is mapped for the first time, the
40expression is evaluated and must yield an image. The image is then
41extended as necessary to cover the whole terminal window, and is set as a
42background pixmap.
43
44If the image contains an alpha channel, then it will be used as-is in
45visuals that support alpha channels (for example, for a compositing
46manager). In other visuals, the terminal background colour will be used to
47replace any transparency.
48
49When the expression relies, directly or indirectly, on the window size,
50position, the root pixmap, or a timer, then it will be remembered. If not,
51then it will be removed.
52
53If any of the parameters that the expression relies on changes (when the
54window is moved or resized, its position or size changes; when the root
55pixmap is replaced by another one the root background changes; or when the
56timer elapses), then the expression will be evaluated again.
57
58For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
59image to the window size, so it relies on the window size and will
60be reevaluated each time it is changed, but not when it moves for
61example. That ensures that the picture always fills the terminal, even
62after its size changes.
63
64=head2 EXPRESSIONS
65
66Expressions are normal Perl expressions, in fact, they are Perl blocks -
67which means you could use multiple lines and statements:
68
69 again 3600;
70 if (localtime now)[6]) {
71 return scale load "$HOME/weekday.png";
72 } else {
73 return scale load "$HOME/sunday.png";
74 }
75
76This expression gets evaluated once per hour. It will set F<sunday.png> as
77background on Sundays, and F<weekday.png> on all other days.
78
79Fortunately, we expect that most expressions will be much simpler, with
80little Perl knowledge needed.
81
82Basically, you always start with a function that "generates" an image
83object, such as C<load>, which loads an image from disk, or C<root>, which
84returns the root window background image:
85
86 load "$HOME/mypic.png"
87
88The path is usually specified as a quoted string (the exact rules can be
89found in the L<perlop> manpage). The F<$HOME> at the beginning of the
90string is expanded to the home directory.
91
92Then you prepend one or more modifiers or filtering expressions, such as
93C<scale>:
94
95 scale load "$HOME/mypic.png"
96
97Just like a mathematical expression with functions, you should read these
98expressions from right to left, as the C<load> is evaluated first, and
99its result becomes the argument to the C<scale> function.
100
101Many operators also allow some parameters preceding the input image
102that modify its behaviour. For example, C<scale> without any additional
103arguments scales the image to size of the terminal window. If you specify
104an additional argument, it uses it as a scale factor (multiply by 100 to
105get a percentage):
106
107 scale 2, load "$HOME/mypic.png"
108
109This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
110has now two arguments, the C<200> and the C<load> expression, while
111C<load> only has one argument. Arguments are separated from each other by
112commas.
113
114Scale also accepts two arguments, which are then separate factors for both
115horizontal and vertical dimensions. For example, this halves the image
116width and doubles the image height:
117
118 scale 0.5, 2, load "$HOME/mypic.png"
119
120Other effects than scaling are also readily available, for example, you can
121tile the image to fill the whole window, instead of resizing it:
122
123 tile load "$HOME/mypic.png"
124
125In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator
126is kind of superfluous.
127
128Another common effect is to mirror the image, so that the same edges touch:
129
130 mirror load "$HOME/mypic.png"
131
132This is also a typical background expression:
133
134 rootalign root
135
136It first takes a snapshot of the screen background image, and then
137moves it to the upper left corner of the screen - the result is
138pseudo-transparency, as the image seems to be static while the window is
139moved around.
140
141=head2 CYCLES AND CACHING
142
143As has been mentioned before, the expression might be evaluated multiple
144times. Each time the expression is reevaluated, a new cycle is said to
145have begun. Many operators cache their results till the next cycle.
146
147For example, the C<load> operator keeps a copy of the image. If it is
148asked to load the same image on the next cycle it will not load it again,
149but return the cached copy.
150
151This only works for one cycle though, so as long as you load the same
152image every time, it will always be cached, but when you load a different
153image, it will forget about the first one.
154
155This allows you to either speed things up by keeping multiple images in
156memory, or conserve memory by loading images more often.
157
158For example, you can keep two images in memory and use a random one like
159this:
160
161 my $img1 = load "img1.png";
162 my $img2 = load "img2.png";
163 (0.5 > rand) ? $img1 : $img2
164
165Since both images are "loaded" every time the expression is evaluated,
166they are always kept in memory. Contrast this version:
167
168 my $path1 = "img1.png";
169 my $path2 = "img2.png";
170 load ((0.5 > rand) ? $path1 : $path2)
171
172Here, a path is selected randomly, and load is only called for one image,
173so keeps only one image in memory. If, on the next evaluation, luck
174decides to use the other path, then it will have to load that image again.
175
15=head2 REFERENCE 176=head1 REFERENCE
16 177
17=cut 178=head2 COMMAND LINE SWITCHES
18 179
19our $EXPR; 180=over 4
20#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';
21$EXPR = 'move -TX, -TY, load "argb.png"';
22#$EXPR = '
23# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,
24# clip X, Y, W, H, repeat_mirror,
25# load "/root/pix/das_fette_schwein.jpg"
26#';
27#$EXPR = 'solid "red"';
28#$EXPR = 'blur root, 10, 10'
29#$EXPR = 'blur move (root, -x, -y), 5, 5'
30#resize load "/root/pix/das_fette_schwein.jpg", w, h
31 181
182=item --background-expr perl-expression
183
184Specifies the Perl expression to evaluate.
185
186=item --background-border
187
188By default, the expression creates an image that fills the full window,
189overwriting borders and any other areas, such as the scrollbar.
190
191Specifying this flag changes the behaviour, so that the image only
192replaces the background of the character area.
193
194=item --background-interval seconds
195
196Since some operations in the underlying XRender extension can effectively
197freeze your X-server for prolonged time, this extension enforces a minimum
198time between updates, which is normally about 0.1 seconds.
199
200If you want to do updates more often, you can decrease this safety
201interval with this switch.
202
203=back
204
205=cut
206
207our %_IMGCACHE;
208our $HOME;
32our ($self, $old, $new); 209our ($self, $old, $new);
33our ($x, $y, $w, $h); 210our ($x, $y, $w, $h);
34 211
35# enforce at least this interval between updates 212# enforce at least this interval between updates
36our $MIN_INTERVAL = 1/100; 213our $MIN_INTERVAL = 6/59.951;
37 214
38{ 215{
39 package urxvt::bgdsl; # background language 216 package urxvt::bgdsl; # background language
217
218 use List::Util qw(min max sum shuffle);
40 219
41=head2 PROVIDERS/GENERATORS 220=head2 PROVIDERS/GENERATORS
42 221
43These functions provide an image, by loading it from disk, grabbing it 222These functions provide an image, by loading it from disk, grabbing it
44from the root screen or by simply generating it. They are used as starting 223from the root screen or by simply generating it. They are used as starting
81=item solid $width, $height, $colour 260=item solid $width, $height, $colour
82 261
83Creates a new image and completely fills it with the given colour. The 262Creates a new image and completely fills it with the given colour. The
84image is set to tiling mode. 263image is set to tiling mode.
85 264
86If <$width> and C<$height> are omitted, it creates a 1x1 image, which is 265If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
87useful for solid backgrounds or for use in filtering effects. 266useful for solid backgrounds or for use in filtering effects.
88 267
89=cut 268=cut
90 269
91 sub solid($$;$) { 270 sub solid($;$$) {
92 my $colour = pop; 271 my $colour = pop;
93 272
94 my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] || 1, $_[1] || 1); 273 my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] || 1, $_[1] || 1);
95 $img->fill ($colour); 274 $img->fill ($colour);
96 $img 275 $img
97 } 276 }
98 277
278=item clone $img
279
280Returns an exact copy of the image. This is useful if you want to have
281multiple copies of the same image to apply different effects to.
282
283=cut
284
285 sub clone($) {
286 $_[0]->clone
287 }
288
99=back 289=back
100 290
291=head2 TILING MODES
292
293The following operators modify the tiling mode of an image, that is, the
294way that pixels outside the image area are painted when the image is used.
295
296=over 4
297
298=item tile $img
299
300Tiles the whole plane with the image and returns this new image - or in
301other words, it returns a copy of the image in plane tiling mode.
302
303Example: load an image and tile it over the background, without
304resizing. The C<tile> call is superfluous because C<load> already defaults
305to tiling mode.
306
307 tile load "mybg.png"
308
309=item mirror $img
310
311Similar to tile, but reflects the image each time it uses a new copy, so
312that top edges always touch top edges, right edges always touch right
313edges and so on (with normal tiling, left edges always touch right edges
314and top always touch bottom edges).
315
316Example: load an image and mirror it over the background, avoiding sharp
317edges at the image borders at the expense of mirroring the image itself
318
319 mirror load "mybg.png"
320
321=item pad $img
322
323Takes an image and modifies it so that all pixels outside the image area
324become transparent. This mode is most useful when you want to place an
325image over another image or the background colour while leaving all
326background pixels outside the image unchanged.
327
328Example: load an image and display it in the upper left corner. The rest
329of the space is left "empty" (transparent or whatever your compositor does
330in alpha mode, else background colour).
331
332 pad load "mybg.png"
333
334=item extend $img
335
336Extends the image over the whole plane, using the closest pixel in the
337area outside the image. This mode is mostly useful when you use more complex
338filtering operations and want the pixels outside the image to have the
339same values as the pixels near the edge.
340
341Example: just for curiosity, how does this pixel extension stuff work?
342
343 extend move 50, 50, load "mybg.png"
344
345=cut
346
347 sub pad($) {
348 my $img = $_[0]->clone;
349 $img->repeat_mode (urxvt::RepeatNone);
350 $img
351 }
352
353 sub tile($) {
354 my $img = $_[0]->clone;
355 $img->repeat_mode (urxvt::RepeatNormal);
356 $img
357 }
358
359 sub mirror($) {
360 my $img = $_[0]->clone;
361 $img->repeat_mode (urxvt::RepeatReflect);
362 $img
363 }
364
365 sub extend($) {
366 my $img = $_[0]->clone;
367 $img->repeat_mode (urxvt::RepeatPad);
368 $img
369 }
370
371=back
372
101=head2 VARIABLES 373=head2 VARIABLE VALUES
102 374
103The following functions provide variable data such as the terminal 375The following functions provide variable data such as the terminal window
376dimensions. They are not (Perl-) variables, they just return stuff that
104window dimensions. Most of them make your expression sensitive to some 377varies. Most of them make your expression sensitive to some events, for
105events, for example using C<TW> (terminal width) means your expression is 378example using C<TW> (terminal width) means your expression is evaluated
106evaluated again when the terminal is resized. 379again when the terminal is resized.
107 380
108=over 4 381=over 4
109 382
110=item TX 383=item TX
111 384
158 431
159When this function is used the expression will be reevaluated again in 432When this function is used the expression will be reevaluated again in
160C<$seconds> seconds. 433C<$seconds> seconds.
161 434
162Example: load some image and rotate it according to the time of day (as if it were 435Example: load some image and rotate it according to the time of day (as if it were
163the hour pointer of a clock). update this image every minute. 436the hour pointer of a clock). Update this image every minute.
164 437
165 again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png" 438 again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
166 439
167=item counter $seconds 440=item counter $seconds
168 441
182 $self->{counter} + 0 455 $self->{counter} + 0
183 } 456 }
184 457
185=back 458=back
186 459
187=head2 TILING MODES 460=head2 SHAPE CHANGING OPERATORS
188 461
189The following operators modify the tiling mode of an image, that is, the 462The following operators modify the shape, size or position of the image.
190way that pixels outside the image area are painted when the image is used.
191 463
192=over 4 464=over 4
193
194=item tile $img
195
196Tiles the whole plane with the image and returns this new image - or in
197other words, it returns a copy of the image in plane tiling mode.
198
199=item mirror $img
200
201Similar to tile, but reflects the image each time it uses a new copy, so
202that top edges always touch top edges, right edges always touch right
203edges and so on (with normal tiling, left edges always touch right edges
204and top always touch bottom edges).
205
206=item pad $img
207
208Takes an image and modifies it so that all pixels outside the image area
209become transparent. This mode is most useful when you want to place an
210image over another image or the background colour while leaving all
211background pixels outside the image unchanged.
212
213=item extend $img
214
215Extends the image over the whole plane, using the closest pixel in the
216area outside the image. This mode is mostly useful when you more complex
217filtering operations and want the pixels outside the image to have the
218same values as the pixels near the edge.
219
220=cut
221
222 sub pad($) {
223 my $img = $_[0]->clone;
224 $img->repeat_mode (urxvt::RepeatNone);
225 $img
226 }
227
228 sub tile($) {
229 my $img = $_[0]->clone;
230 $img->repeat_mode (urxvt::RepeatNormal);
231 $img
232 }
233
234 sub mirror($) {
235 my $img = $_[0]->clone;
236 $img->repeat_mode (urxvt::RepeatReflect);
237 $img
238 }
239
240 sub extend($) {
241 my $img = $_[0]->clone;
242 $img->repeat_mode (urxvt::RepeatPad);
243 $img
244 }
245
246=back
247
248=head2 PIXEL OPERATORS
249
250The following operators modify the image pixels in various ways.
251
252=over 4
253
254=item clone $img
255
256Returns an exact copy of the image.
257
258=cut
259
260 sub clone($) {
261 $_[0]->clone
262 }
263 465
264=item clip $img 466=item clip $img
265 467
266=item clip $width, $height, $img 468=item clip $width, $height, $img
267 469
291 $img->sub_rect ($_[0], $_[1], $w, $h) 493 $img->sub_rect ($_[0], $_[1], $w, $h)
292 } 494 }
293 495
294=item scale $img 496=item scale $img
295 497
296=item scale $size_percent, $img 498=item scale $size_factor, $img
297 499
298=item scale $width_percent, $height_percent, $img 500=item scale $width_factor, $height_factor, $img
299 501
300Scales the image by the given percentages in horizontal 502Scales the image by the given factors in horizontal
301(C<$width_percent>) and vertical (C<$height_percent>) direction. 503(C<$width>) and vertical (C<$height>) direction.
302 504
303If only one percentage is give, it is used for both directions. 505If only one factor is give, it is used for both directions.
304 506
305If no percentages are given, scales the image to the window size without 507If no factors are given, scales the image to the window size without
306keeping aspect. 508keeping aspect.
307 509
308=item resize $width, $height, $img 510=item resize $width, $height, $img
309 511
310Resizes the image to exactly C<$width> times C<$height> pixels. 512Resizes the image to exactly C<$width> times C<$height> pixels.
311 513
312=cut 514=item fit $img
313 515
314#TODO: maximise, maximise_fill? 516=item fit $width, $height, $img
517
518Fits the image into the given C<$width> and C<$height> without changing
519aspect, or the terminal size. That means it will be shrunk or grown until
520the whole image fits into the given area, possibly leaving borders.
521
522=item cover $img
523
524=item cover $width, $height, $img
525
526Similar to C<fit>, but shrinks or grows until all of the area is covered
527by the image, so instead of potentially leaving borders, it will cut off
528image data that doesn't fit.
529
530=cut
315 531
316 sub scale($;$;$) { 532 sub scale($;$;$) {
317 my $img = pop; 533 my $img = pop;
318 534
319 @_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01) 535 @_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
320 : @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01) 536 : @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
321 : $img->scale (TW, TH) 537 : $img->scale (TW, TH)
322 } 538 }
323 539
324 sub resize($$$) { 540 sub resize($$$) {
325 my $img = pop; 541 my $img = pop;
326 $img->scale ($_[0], $_[1]) 542 $img->scale ($_[0], $_[1])
327 } 543 }
544
545 sub fit($;$$) {
546 my $img = pop;
547 my $w = ($_[0] || TW) / $img->w;
548 my $h = ($_[1] || TH) / $img->h;
549 scale +(min $w, $h), $img
550 }
551
552 sub cover($;$$) {
553 my $img = pop;
554 my $w = ($_[0] || TW) / $img->w;
555 my $h = ($_[1] || TH) / $img->h;
556 scale +(max $w, $h), $img
557 }
558
559=item move $dx, $dy, $img
560
561Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
562the vertical.
563
564Example: move the image right by 20 pixels and down by 30.
565
566 move 20, 30, ...
567
568=item align $xalign, $yalign, $img
569
570Aligns the image according to a factor - C<0> means the image is moved to
571the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
572exactly centered and C<1> means it touches the right or bottom edge.
573
574Example: remove any visible border around an image, center it vertically but move
575it to the right hand side.
576
577 align 1, 0.5, pad $img
578
579=item center $img
580
581=item center $width, $height, $img
582
583Centers the image, i.e. the center of the image is moved to the center of
584the terminal window (or the box specified by C<$width> and C<$height> if
585given).
586
587Example: load an image and center it.
588
589 center pad load "mybg.png"
590
591=item rootalign $img
592
593Moves the image so that it appears glued to the screen as opposed to the
594window. This gives the illusion of a larger area behind the window. It is
595exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
596top left of the screen.
597
598Example: load a background image, put it in mirror mode and root align it.
599
600 rootalign mirror load "mybg.png"
601
602Example: take the screen background and align it, giving the illusion of
603transparency as long as the window isn't in front of other windows.
604
605 rootalign root
606
607=cut
328 608
329 sub move($$;$) { 609 sub move($$;$) {
330 my $img = pop->clone; 610 my $img = pop->clone;
331 $img->move ($_[0], $_[1]); 611 $img->move ($_[0], $_[1]);
332 $img 612 $img
333 } 613 }
334 614
615 sub align($;$$) {
616 my $img = pop;
617
618 move $_[0] * (TW - $img->w),
619 $_[1] * (TH - $img->h),
620 $img
621 }
622
623 sub center($;$$) {
624 my $img = pop;
625 my $w = $_[0] || TW;
626 my $h = $_[1] || TH;
627
628 move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
629 }
630
631 sub rootalign($) {
632 move -TX, -TY, $_[0]
633 }
634
635=back
636
637=head2 COLOUR MODIFICATIONS
638
639The following operators change the pixels of the image.
640
641=over 4
642
643=item contrast $factor, $img
644
645=item contrast $r, $g, $b, $img
646
647=item contrast $r, $g, $b, $a, $img
648
649Adjusts the I<contrast> of an image.
650
651The first form applies a single C<$factor> to red, green and blue, the
652second form applies separate factors to each colour channel, and the last
653form includes the alpha channel.
654
655Values from 0 to 1 lower the contrast, values higher than 1 increase the
656contrast.
657
658Due to limitations in the underlying XRender extension, lowering contrast
659also reduces brightness, while increasing contrast currently also
660increases brightness.
661
662=item brightness $bias, $img
663
664=item brightness $r, $g, $b, $img
665
666=item brightness $r, $g, $b, $a, $img
667
668Adjusts the brightness of an image.
669
670The first form applies a single C<$bias> to red, green and blue, the
671second form applies separate biases to each colour channel, and the last
672form includes the alpha channel.
673
674Values less than 0 reduce brightness, while values larger than 0 increase
675it. Useful range is from -1 to 1 - the former results in a black, the
676latter in a white picture.
677
678Due to idiosyncrasies in the underlying XRender extension, biases less
679than zero can be I<very> slow.
680
681=cut
682
683 sub contrast($$;$$;$) {
684 my $img = pop;
685 my ($r, $g, $b, $a) = @_;
686
687 ($g, $b) = ($r, $r) if @_ < 3;
688 $a = 1 if @_ < 4;
689
690 $img = $img->clone;
691 $img->contrast ($r, $g, $b, $a);
692 $img
693 }
694
695 sub brightness($$;$$;$) {
696 my $img = pop;
697 my ($r, $g, $b, $a) = @_;
698
699 ($g, $b) = ($r, $r) if @_ < 3;
700 $a = 1 if @_ < 4;
701
702 $img = $img->clone;
703 $img->brightness ($r, $g, $b, $a);
704 $img
705 }
706
707=item blur $radius, $img
708
709=item blur $radius_horz, $radius_vert, $img
710
711Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
712can also be specified separately.
713
714Blurring is often I<very> slow, at least compared or other
715operators. Larger blur radii are slower than smaller ones, too, so if you
716don't want to freeze your screen for long times, start experimenting with
717low values for radius (<5).
718
719=cut
720
721 sub blur($$;$) {
722 my $img = pop;
723 $img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
724 }
725
726=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
727
728Rotates the image by C<$degrees> degrees, counter-clockwise, around the
729pointer at C<$center_x> and C<$center_y> (specified as factor of image
730width/height), generating a new image with width C<$new_width> and height
731C<$new_height>.
732
733#TODO# new width, height, maybe more operators?
734
735Example: rotate the image by 90 degrees
736
737=cut
738
335 sub rotate($$$$$$) { 739 sub rotate($$$$$$) {
336 my $img = pop; 740 my $img = pop;
337 $img->rotate ( 741 $img->rotate (
338 $_[0], 742 $_[0],
339 $_[1], 743 $_[1],
340 $_[2] * $img->w * .01, 744 $_[2] * $img->w,
341 $_[3] * $img->h * .01, 745 $_[3] * $img->h,
342 $_[4] * (3.14159265 / 180), 746 $_[4] * (3.14159265 / 180),
343 ) 747 )
344 }
345
346 sub blur($$;$) {
347 my $img = pop;
348 $img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
349 }
350
351 sub contrast($$;$$;$) {
352 my $img = pop;
353 my ($r, $g, $b, $a) = @_;
354
355 ($g, $b) = ($r, $r) if @_ < 4;
356 $a = 1 if @_ < 5;
357
358 $img = $img->clone;
359 $img->contrast ($r, $g, $b, $a);
360 $img
361 }
362
363 sub brightness($$;$$;$) {
364 my $img = pop;
365 my ($r, $g, $b, $a) = @_;
366
367 ($g, $b) = ($r, $r) if @_ < 4;
368 $a = 1 if @_ < 5;
369
370 $img = $img->clone;
371 $img->brightness ($r, $g, $b, $a);
372 $img
373 } 748 }
374 749
375=back 750=back
376 751
377=cut 752=cut
409 784
410 # set environment to evaluate user expression 785 # set environment to evaluate user expression
411 786
412 local $self = $arg_self; 787 local $self = $arg_self;
413 788
789 local $HOME = $ENV{HOME};
414 local $old = $self->{state}; 790 local $old = $self->{state};
415 local $new = my $state = $self->{state} = {}; 791 local $new = my $state = $self->{state} = {};
416 792
417 ($x, $y, $w, $h) = 793 ($x, $y, $w, $h) =
418 $self->background_geometry ($self->{border}); 794 $self->background_geometry ($self->{border});
419 795
420 # evaluate user expression 796 # evaluate user expression
421 797
422 my $img = eval { $self->{expr}->() }; 798 my $img = eval { $self->{expr}->() };
423 warn $@ if $@;#d# 799 warn $@ if $@;#d#
424 die if !UNIVERSAL::isa $img, "urxvt::img"; 800 die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
801
802 $state->{size_sensitive} = 1
803 if $img->repeat_mode != urxvt::RepeatNormal;
425 804
426 # if the expression is sensitive to external events, prepare reevaluation then 805 # if the expression is sensitive to external events, prepare reevaluation then
427 806
428 my $repeat; 807 my $repeat;
429 808
430 if (my $again = $state->{again}) { 809 if (my $again = $state->{again}) {
431 $repeat = 1; 810 $repeat = 1;
811 my $self = $self;
432 $state->{timer} = $again == $old->{again} 812 $state->{timer} = $again == $old->{again}
433 ? $old->{timer} 813 ? $old->{timer}
434 : urxvt::timer->new->after ($again)->interval ($again)->cb (sub { 814 : urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
435 ++$self->{counter}; 815 ++$self->{counter};
436 $self->recalculate 816 $self->recalculate
465 unless ($repeat) { 845 unless ($repeat) {
466 delete $self->{state}; 846 delete $self->{state};
467 delete $self->{expr}; 847 delete $self->{expr};
468 } 848 }
469 849
470 # prepare and set background pixmap 850 # set background pixmap
471
472 $img = $img->sub_rect (0, 0, $w, $h)
473 if $img->w != $w || $img->h != $h;
474 851
475 $self->set_background ($img, $self->{border}); 852 $self->set_background ($img, $self->{border});
476 $self->scr_recolour (0); 853 $self->scr_recolour (0);
477 $self->want_refresh; 854 $self->want_refresh;
478} 855}
479 856
480sub on_start { 857sub on_start {
481 my ($self) = @_; 858 my ($self) = @_;
482 859
483 my $expr = $self->x_resource ("background.expr") 860 my $expr = $self->x_resource ("%.expr")
484 or return; 861 or return;
485 862
863 $self->has_render
864 or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
865
486 $self->set_expr (parse_expr $expr); 866 $self->set_expr (parse_expr $expr);
487 $self->{border} = $self->x_resource_boolean ("background.border"); 867 $self->{border} = $self->x_resource_boolean ("%.border");
868
869 $MIN_INTERVAL = $self->x_resource ("%.interval");
488 870
489 () 871 ()
490} 872}
491 873

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines