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Revision 1.41 by root, Fri Jun 8 22:21:48 2012 UTC vs.
Revision 1.48 by root, Sun Jun 10 15:01:14 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
6#TODO: once, rootalign 7#TODO: once, rootalign
7 8
8=head1 NAME 9=head1 NAME
9 10
… …
11 12
12=head1 SYNOPSIS 13=head1 SYNOPSIS
13 14
14 urxvt --background-expr 'background expression' 15 urxvt --background-expr 'background expression'
15 --background-border 16 --background-border
17 --background-interval seconds
16 18
17=head1 DESCRIPTION 19=head1 DESCRIPTION
18 20
19This extension manages the terminal background by creating a picture that 21This extension manages the terminal background by creating a picture that
20is behind the text, replacing the normal background colour. 22is behind the text, replacing the normal background colour.
… …
99its result becomes the argument to the C<scale> function. 101its result becomes the argument to the C<scale> function.
100 102
101Many operators also allow some parameters preceding the input image 103Many operators also allow some parameters preceding the input image
102that modify its behaviour. For example, C<scale> without any additional 104that modify its behaviour. For example, C<scale> without any additional
103arguments scales the image to size of the terminal window. If you specify 105arguments scales the image to size of the terminal window. If you specify
104an additional argument, it uses it as a percentage: 106an additional argument, it uses it as a scale factor (multiply by 100 to
107get a percentage):
105 108
106 scale 200, load "$HOME/mypic.png" 109 scale 2, load "$HOME/mypic.png"
107 110
108This enlarges the image by a factor of 2 (200%). As you can see, C<scale> 111This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
109has now two arguments, the C<200> and the C<load> expression, while 112has now two arguments, the C<200> and the C<load> expression, while
110C<load> only has one argument. Arguments are separated from each other by 113C<load> only has one argument. Arguments are separated from each other by
111commas. 114commas.
112 115
113Scale also accepts two arguments, which are then separate factors for both 116Scale also accepts two arguments, which are then separate factors for both
114horizontal and vertical dimensions. For example, this halves the image 117horizontal and vertical dimensions. For example, this halves the image
115width and doubles the image height: 118width and doubles the image height:
116 119
117 scale 50, 200, load "$HOME/mypic.png" 120 scale 0.5, 2, load "$HOME/mypic.png"
118 121
119Other effects than scalign are also readily available, for exmaple, you can 122Other effects than scalign are also readily available, for exmaple, you can
120tile the image to fill the whole window, instead of resizing it: 123tile the image to fill the whole window, instead of resizing it:
121 124
122 tile load "$HOME/mypic.png" 125 tile load "$HOME/mypic.png"
… …
188overwriting borders and any other areas, such as the scrollbar. 191overwriting borders and any other areas, such as the scrollbar.
189 192
190Specifying this flag changes the behaviour, so that the image only 193Specifying this flag changes the behaviour, so that the image only
191replaces the background of the character area. 194replaces the background of the character area.
192 195
196=item --background-interval seconds
197
198Since some operations in the underlying XRender extension can effetively
199freeze your X-server for prolonged time, this extension enforces a minimum
200time between updates, which is normally about 0.1 seconds.
201
202If you want to do updates more often, you can decrease this safety
203interval with this switch.
204
193=back 205=back
194 206
195=cut 207=cut
196 208
197our $HOME; 209our $HOME;
198our ($self, $old, $new); 210our ($self, $old, $new);
199our ($x, $y, $w, $h); 211our ($x, $y, $w, $h);
200 212
201# enforce at least this interval between updates 213# enforce at least this interval between updates
202our $MIN_INTERVAL = 1/100; 214our $MIN_INTERVAL = 6/59.951;
203 215
204{ 216{
205 package urxvt::bgdsl; # background language 217 package urxvt::bgdsl; # background language
218
219 use List::Util qw(min max sum shuffle);
206 220
207=head2 PROVIDERS/GENERATORS 221=head2 PROVIDERS/GENERATORS
208 222
209These functions provide an image, by loading it from disk, grabbing it 223These functions provide an image, by loading it from disk, grabbing it
210from the root screen or by simply generating it. They are used as starting 224from the root screen or by simply generating it. They are used as starting
… …
252If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is 266If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
253useful for solid backgrounds or for use in filtering effects. 267useful for solid backgrounds or for use in filtering effects.
254 268
255=cut 269=cut
256 270
257 sub solid($$;$) { 271 sub solid($;$$) {
258 my $colour = pop; 272 my $colour = pop;
259 273
260 my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] || 1, $_[1] || 1); 274 my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] || 1, $_[1] || 1);
261 $img->fill ($colour); 275 $img->fill ($colour);
262 $img 276 $img
263 } 277 }
264 278
279=item clone $img
280
281Returns an exact copy of the image. This is useful if you want to have
282multiple copies of the same image to apply different effects to.
283
284=cut
285
286 sub clone($) {
287 $_[0]->clone
288 }
289
265=back 290=back
266 291
292=head2 TILING MODES
293
294The following operators modify the tiling mode of an image, that is, the
295way that pixels outside the image area are painted when the image is used.
296
297=over 4
298
299=item tile $img
300
301Tiles the whole plane with the image and returns this new image - or in
302other words, it returns a copy of the image in plane tiling mode.
303
304Example: load an image and tile it over the background, without
305resizing. The C<tile> call is superfluous because C<load> already defaults
306to tiling mode.
307
308 tile load "mybg.png"
309
310=item mirror $img
311
312Similar to tile, but reflects the image each time it uses a new copy, so
313that top edges always touch top edges, right edges always touch right
314edges and so on (with normal tiling, left edges always touch right edges
315and top always touch bottom edges).
316
317Example: load an image and mirror it over the background, avoiding sharp
318edges at the image borders at the expense of mirroring the image itself
319
320 mirror load "mybg.png"
321
322=item pad $img
323
324Takes an image and modifies it so that all pixels outside the image area
325become transparent. This mode is most useful when you want to place an
326image over another image or the background colour while leaving all
327background pixels outside the image unchanged.
328
329Example: load an image and display it in the upper left corner. The rest
330of the space is left "empty" (transparent or wahtever your compisotr does
331in alpha mode, else background colour).
332
333 pad load "mybg.png"
334
335=item extend $img
336
337Extends the image over the whole plane, using the closest pixel in the
338area outside the image. This mode is mostly useful when you more complex
339filtering operations and want the pixels outside the image to have the
340same values as the pixels near the edge.
341
342Example: just for curiosity, how does this pixel extension stuff work?
343
344 extend move 50, 50, load "mybg.png"
345
346=cut
347
348 sub pad($) {
349 my $img = $_[0]->clone;
350 $img->repeat_mode (urxvt::RepeatNone);
351 $img
352 }
353
354 sub tile($) {
355 my $img = $_[0]->clone;
356 $img->repeat_mode (urxvt::RepeatNormal);
357 $img
358 }
359
360 sub mirror($) {
361 my $img = $_[0]->clone;
362 $img->repeat_mode (urxvt::RepeatReflect);
363 $img
364 }
365
366 sub extend($) {
367 my $img = $_[0]->clone;
368 $img->repeat_mode (urxvt::RepeatPad);
369 $img
370 }
371
372=back
373
267=head2 VARIABLES 374=head2 VARIABLE VALUES
268 375
269The following functions provide variable data such as the terminal window 376The following functions provide variable data such as the terminal window
270dimensions. They are not (Perl-) variables, they jsut return stuff that 377dimensions. They are not (Perl-) variables, they just return stuff that
271varies. Most of them make your expression sensitive to some events, for 378varies. Most of them make your expression sensitive to some events, for
272example using C<TW> (terminal width) means your expression is evaluated 379example using C<TW> (terminal width) means your expression is evaluated
273again when the terminal is resized. 380again when the terminal is resized.
274 381
275=over 4 382=over 4
… …
349 $self->{counter} + 0 456 $self->{counter} + 0
350 } 457 }
351 458
352=back 459=back
353 460
354=head2 TILING MODES 461=head2 SHAPE CHANGING OPERATORS
355 462
356The following operators modify the tiling mode of an image, that is, the 463The following operators modify the shape, size or position of the image.
357way that pixels outside the image area are painted when the image is used.
358 464
359=over 4 465=over 4
360
361=item tile $img
362
363Tiles the whole plane with the image and returns this new image - or in
364other words, it returns a copy of the image in plane tiling mode.
365
366Example: load an image and tile it over the background, without
367resizing. The C<tile> call is superfluous because C<load> already defaults
368to tiling mode.
369
370 tile load "mybg.png"
371
372=item mirror $img
373
374Similar to tile, but reflects the image each time it uses a new copy, so
375that top edges always touch top edges, right edges always touch right
376edges and so on (with normal tiling, left edges always touch right edges
377and top always touch bottom edges).
378
379Example: load an image and mirror it over the background, avoiding sharp
380edges at the image borders at the expense of mirroring the image itself
381
382 mirror load "mybg.png"
383
384=item pad $img
385
386Takes an image and modifies it so that all pixels outside the image area
387become transparent. This mode is most useful when you want to place an
388image over another image or the background colour while leaving all
389background pixels outside the image unchanged.
390
391Example: load an image and display it in the upper left corner. The rest
392of the space is left "empty" (transparent or wahtever your compisotr does
393in alpha mode, else background colour).
394
395 pad load "mybg.png"
396
397=item extend $img
398
399Extends the image over the whole plane, using the closest pixel in the
400area outside the image. This mode is mostly useful when you more complex
401filtering operations and want the pixels outside the image to have the
402same values as the pixels near the edge.
403
404Example: just for curiosity, how does this pixel extension stuff work?
405
406 extend move 50, 50, load "mybg.png"
407
408=cut
409
410 sub pad($) {
411 my $img = $_[0]->clone;
412 $img->repeat_mode (urxvt::RepeatNone);
413 $img
414 }
415
416 sub tile($) {
417 my $img = $_[0]->clone;
418 $img->repeat_mode (urxvt::RepeatNormal);
419 $img
420 }
421
422 sub mirror($) {
423 my $img = $_[0]->clone;
424 $img->repeat_mode (urxvt::RepeatReflect);
425 $img
426 }
427
428 sub extend($) {
429 my $img = $_[0]->clone;
430 $img->repeat_mode (urxvt::RepeatPad);
431 $img
432 }
433
434=back
435
436=head2 PIXEL OPERATORS
437
438The following operators modify the image pixels in various ways.
439
440=over 4
441
442=item clone $img
443
444Returns an exact copy of the image.
445
446=cut
447
448 sub clone($) {
449 $_[0]->clone
450 }
451 466
452=item clip $img 467=item clip $img
453 468
454=item clip $width, $height, $img 469=item clip $width, $height, $img
455 470
… …
479 $img->sub_rect ($_[0], $_[1], $w, $h) 494 $img->sub_rect ($_[0], $_[1], $w, $h)
480 } 495 }
481 496
482=item scale $img 497=item scale $img
483 498
484=item scale $size_percent, $img 499=item scale $size_factor, $img
485 500
486=item scale $width_percent, $height_percent, $img 501=item scale $width_factor, $height_factor, $img
487 502
488Scales the image by the given percentages in horizontal 503Scales the image by the given factors in horizontal
489(C<$width_percent>) and vertical (C<$height_percent>) direction. 504(C<$width>) and vertical (C<$height>) direction.
490 505
491If only one percentage is give, it is used for both directions. 506If only one factor is give, it is used for both directions.
492 507
493If no percentages are given, scales the image to the window size without 508If no factors are given, scales the image to the window size without
494keeping aspect. 509keeping aspect.
495 510
496=item resize $width, $height, $img 511=item resize $width, $height, $img
497 512
498Resizes the image to exactly C<$width> times C<$height> pixels. 513Resizes the image to exactly C<$width> times C<$height> pixels.
499 514
500=cut 515=item fit $img
501 516
502#TODO: maximise, maximise_fill? 517=item fit $width, $height, $img
518
519Fits the image into the given C<$width> and C<$height> without changing
520aspect, or the terminal size. That means it will be shrunk or grown until
521the whole image fits into the given area, possibly leaving borders.
522
523=item cover $img
524
525=item cover $width, $height, $img
526
527Similar to C<fit>, but shrinks or grows until all of the area is covered
528by the image, so instead of potentially leaving borders, it will cut off
529image data that doesn't fit.
530
531=cut
503 532
504 sub scale($;$;$) { 533 sub scale($;$;$) {
505 my $img = pop; 534 my $img = pop;
506 535
507 @_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01) 536 @_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
508 : @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01) 537 : @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
509 : $img->scale (TW, TH) 538 : $img->scale (TW, TH)
510 } 539 }
511 540
512 sub resize($$$) { 541 sub resize($$$) {
513 my $img = pop; 542 my $img = pop;
514 $img->scale ($_[0], $_[1]) 543 $img->scale ($_[0], $_[1])
544 }
545
546 sub fit($;$$) {
547 my $img = pop;
548 my $w = ($_[0] || TW) / $img->w;
549 my $h = ($_[1] || TH) / $img->h;
550 scale +(min $w, $h), $img
551 }
552
553 sub cover($;$$) {
554 my $img = pop;
555 my $w = ($_[0] || TW) / $img->w;
556 my $h = ($_[1] || TH) / $img->h;
557 scale +(max $w, $h), $img
515 } 558 }
516 559
517=item move $dx, $dy, $img 560=item move $dx, $dy, $img
518 561
519Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in 562Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
520the vertical. 563the vertical.
521 564
522Example: move the image right by 20 pixels and down by 30. 565Example: move the image right by 20 pixels and down by 30.
523 566
524 move 20, 30, ... 567 move 20, 30, ...
568
569=item align $xalign, $yalign, $img
570
571Aligns the image according to a factor - C<0> means the image is moved to
572the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
573exactly centered and C<1> means it touches the right or bottom edge.
574
575Example: remove any visible border around an image, center it vertically but move
576it to the right hand side.
577
578 align 1, 0.5, pad $img
579
580=item center $img
581
582=item center $width, $height, $img
583
584Centers the image, i.e. the center of the image is moved to the center of
585the terminal window (or the box specified by C<$width> and C<$height> if
586given).
587
588Example: load an image and center it.
589
590 center pad load "mybg.png"
525 591
526=item rootalign $img 592=item rootalign $img
527 593
528Moves the image so that it appears glued to the screen as opposed to the 594Moves the image so that it appears glued to the screen as opposed to the
529window. This gives the illusion of a larger area behind the window. It is 595window. This gives the illusion of a larger area behind the window. It is
… …
535 rootalign mirror load "mybg.png" 601 rootalign mirror load "mybg.png"
536 602
537Example: take the screen background and align it, giving the illusion of 603Example: take the screen background and align it, giving the illusion of
538transparency as long as the window isn't in front of other windows. 604transparency as long as the window isn't in front of other windows.
539 605
540 rootalign root 606 rootalign root
541 607
542=cut 608=cut
543 609
544 sub move($$;$) { 610 sub move($$;$) {
545 my $img = pop->clone; 611 my $img = pop->clone;
546 $img->move ($_[0], $_[1]); 612 $img->move ($_[0], $_[1]);
547 $img 613 $img
548 } 614 }
549 615
616 sub align($;$$) {
617 my $img = pop;
618
619 move $_[0] * (TW - $img->w),
620 $_[1] * (TH - $img->h),
621 $img
622 }
623
624 sub center($;$$) {
625 my $img = pop;
626 my $w = $_[0] || TW;
627 my $h = $_[1] || TH;
628
629 move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
630 }
631
550 sub rootalign($) { 632 sub rootalign($) {
551 move -TX, -TY, $_[0] 633 move -TX, -TY, $_[0]
552 } 634 }
553 635
636=back
637
638=head2 COLOUR MODIFICATIONS
639
640The following operators change the pixels of the image.
641
642=over 4
643
554=item contrast $factor, $img 644=item contrast $factor, $img
555 645
556=item contrast $r, $g, $b, $img 646=item contrast $r, $g, $b, $img
557 647
558=item contrast $r, $g, $b, $a, $img 648=item contrast $r, $g, $b, $a, $img
559 649
560Adjusts the I<contrast> of an image. 650Adjusts the I<contrast> of an image.
561 651
562#TODO# 652The first form applies a single C<$factor> to red, green and blue, the
653second form applies separate factors to each colour channel, and the last
654form includes the alpha channel.
563 655
656Values from 0 to 1 lower the contrast, values higher than 1 increase the
657contrast.
658
659Due to limitations in the underlying XRender extension, lowering contrast
660also reduces brightness, while increasing contrast currently also
661increases brightness.
662
564=item brightness $factor, $img 663=item brightness $bias, $img
565 664
566=item brightness $r, $g, $b, $img 665=item brightness $r, $g, $b, $img
567 666
568=item brightness $r, $g, $b, $a, $img 667=item brightness $r, $g, $b, $a, $img
569 668
570Adjusts the brightness of an image. 669Adjusts the brightness of an image.
670
671The first form applies a single C<$bias> to red, green and blue, the
672second form applies separate biases to each colour channel, and the last
673form includes the alpha channel.
674
675Values less than 0 reduce brightness, while values larger than 0 increase
676it. Useful range is from -1 to 1 - the former results in a black, the
677latter in a white picture.
678
679Due to idiosynchrasies in the underlying XRender extension, biases less
680than zero can be I<very> slow.
571 681
572=cut 682=cut
573 683
574 sub contrast($$;$$;$) { 684 sub contrast($$;$$;$) {
575 my $img = pop; 685 my $img = pop;
… …
615 } 725 }
616 726
617=item rotate $new_width, $new_height, $center_x, $center_y, $degrees 727=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
618 728
619Rotates the image by C<$degrees> degrees, counter-clockwise, around the 729Rotates the image by C<$degrees> degrees, counter-clockwise, around the
620pointer at C<$center_x> and C<$center_y> (specified as percentage of image 730pointer at C<$center_x> and C<$center_y> (specified as factor of image
621width/height), generating a new image with width C<$new_width> and height 731width/height), generating a new image with width C<$new_width> and height
622C<$new_height>. 732C<$new_height>.
623 733
624#TODO# new width, height, maybe more operators? 734#TODO# new width, height, maybe more operators?
625 735
… …
630 sub rotate($$$$$$) { 740 sub rotate($$$$$$) {
631 my $img = pop; 741 my $img = pop;
632 $img->rotate ( 742 $img->rotate (
633 $_[0], 743 $_[0],
634 $_[1], 744 $_[1],
635 $_[2] * $img->w * .01, 745 $_[2] * $img->w,
636 $_[3] * $img->h * .01, 746 $_[3] * $img->h,
637 $_[4] * (3.14159265 / 180), 747 $_[4] * (3.14159265 / 180),
638 ) 748 )
639 } 749 }
640 750
641=back 751=back
… …
686 796
687 # evaluate user expression 797 # evaluate user expression
688 798
689 my $img = eval { $self->{expr}->() }; 799 my $img = eval { $self->{expr}->() };
690 warn $@ if $@;#d# 800 warn $@ if $@;#d#
691 die if !UNIVERSAL::isa $img, "urxvt::img"; 801 die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
692 802
693 $state->{size_sensitive} = 1 803 $state->{size_sensitive} = 1
694 if $img->repeat_mode != urxvt::RepeatNormal; 804 if $img->repeat_mode != urxvt::RepeatNormal;
695 805
696 # if the expression is sensitive to external events, prepare reevaluation then 806 # if the expression is sensitive to external events, prepare reevaluation then
… …
746} 856}
747 857
748sub on_start { 858sub on_start {
749 my ($self) = @_; 859 my ($self) = @_;
750 860
751 my $expr = $self->x_resource ("background.expr") 861 my $expr = $self->x_resource ("%.expr")
752 or return; 862 or return;
753 863
864 $self->has_render
865 or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
866
754 $self->set_expr (parse_expr $expr); 867 $self->set_expr (parse_expr $expr);
755 $self->{border} = $self->x_resource_boolean ("background.border"); 868 $self->{border} = $self->x_resource_boolean ("%.border");
869
870 $MIN_INTERVAL = $self->x_resource ("%.interval");
756 871
757 () 872 ()
758} 873}
759 874

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