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Revision 1.46 by root, Sun Jun 10 13:32:55 2012 UTC vs.
Revision 1.57 by root, Thu Jun 14 18:06:15 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#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
6
7#TODO: once, rootalign
8 6
9=head1 NAME 7=head1 NAME
10 8
11 background - manage terminal background 9 background - manage terminal background
12 10
59 57
60For example, an expression such as C<scale load "$HOME/mybg.png"> scales the 58For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
61image to the window size, so it relies on the window size and will 59image to the window size, so it relies on the window size and will
62be reevaluated each time it is changed, but not when it moves for 60be reevaluated each time it is changed, but not when it moves for
63example. That ensures that the picture always fills the terminal, even 61example. That ensures that the picture always fills the terminal, even
64after it's size changes. 62after its size changes.
65 63
66=head2 EXPRESSIONS 64=head2 EXPRESSIONS
67 65
68Expressions are normal Perl expressions, in fact, they are Perl blocks - 66Expressions are normal Perl expressions, in fact, they are Perl blocks -
69which means you could use multiple lines and statements: 67which means you could use multiple lines and statements:
73 return scale load "$HOME/weekday.png"; 71 return scale load "$HOME/weekday.png";
74 } else { 72 } else {
75 return scale load "$HOME/sunday.png"; 73 return scale load "$HOME/sunday.png";
76 } 74 }
77 75
78This expression gets evaluated once per hour. It will set F<sunday.png> as 76This expression is evaluated once per hour. It will set F<sunday.png> as
79background on Sundays, and F<weekday.png> on all other days. 77background on Sundays, and F<weekday.png> on all other days.
80 78
81Fortunately, we expect that most expressions will be much simpler, with 79Fortunately, we expect that most expressions will be much simpler, with
82little Perl knowledge needed. 80little Perl knowledge needed.
83 81
117horizontal and vertical dimensions. For example, this halves the image 115horizontal and vertical dimensions. For example, this halves the image
118width and doubles the image height: 116width and doubles the image height:
119 117
120 scale 0.5, 2, load "$HOME/mypic.png" 118 scale 0.5, 2, load "$HOME/mypic.png"
121 119
122Other effects than scalign are also readily available, for exmaple, you can 120Other effects than scaling are also readily available, for example, you can
123tile the image to fill the whole window, instead of resizing it: 121tile the image to fill the whole window, instead of resizing it:
124 122
125 tile load "$HOME/mypic.png" 123 tile load "$HOME/mypic.png"
126 124
127In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator 125In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator
153This only works for one cycle though, so as long as you load the same 151This only works for one cycle though, so as long as you load the same
154image every time, it will always be cached, but when you load a different 152image every time, it will always be cached, but when you load a different
155image, it will forget about the first one. 153image, it will forget about the first one.
156 154
157This allows you to either speed things up by keeping multiple images in 155This allows you to either speed things up by keeping multiple images in
158memory, or comserve memory by loading images more often. 156memory, or conserve memory by loading images more often.
159 157
160For example, you can keep two images in memory and use a random one like 158For example, you can keep two images in memory and use a random one like
161this: 159this:
162 160
163 my $img1 = load "img1.png"; 161 my $img1 = load "img1.png";
193Specifying this flag changes the behaviour, so that the image only 191Specifying this flag changes the behaviour, so that the image only
194replaces the background of the character area. 192replaces the background of the character area.
195 193
196=item --background-interval seconds 194=item --background-interval seconds
197 195
198Since some operations in the underlying XRender extension can effetively 196Since some operations in the underlying XRender extension can effectively
199freeze your X-server for prolonged time, this extension enforces a minimum 197freeze your X-server for prolonged time, this extension enforces a minimum
200time between updates, which is normally about 0.1 seconds. 198time between updates, which is normally about 0.1 seconds.
201 199
202If you want to do updates more often, you can decrease this safety 200If you want to do updates more often, you can decrease this safety
203interval with this switch. 201interval with this switch.
204 202
205=back 203=back
206 204
207=cut 205=cut
208 206
207our %_IMG_CACHE;
209our $HOME; 208our $HOME;
210our ($self, $old, $new); 209our ($self, $old, $new);
211our ($x, $y, $w, $h); 210our ($x, $y, $w, $h);
212 211
213# enforce at least this interval between updates 212# enforce at least this interval between updates
229=item load $path 228=item load $path
230 229
231Loads the image at the given C<$path>. The image is set to plane tiling 230Loads the image at the given C<$path>. The image is set to plane tiling
232mode. 231mode.
233 232
234Loaded images will be cached for one cycle. 233Loaded images will be cached for one cycle, and shared between temrinals
234running in the same process (e.g. in C<urxvtd>).
235 235
236=item load_uc $path
237
238Load uncached - same as load, but does not cache the image. This function
239is most useufl if you want to optimise a background expression in some
240way.
241
236=cut 242=cut
243
244 sub load_uc($) {
245 my ($path) = @_;
246
247 $_IMG_CACHE{$path} || do {
248 my $img = $self->new_img_from_file ($path);
249 Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
250 $img
251 }
252 }
237 253
238 sub load($) { 254 sub load($) {
239 my ($path) = @_; 255 my ($path) = @_;
240 256
241 $new->{load}{$path} = $old->{load}{$path} || $self->new_img_from_file ($path); 257 $new->{load}{$path} = $old->{load}{$path} || load_uc $path;
242 } 258 }
243 259
244=item root 260=item root
245 261
246Returns the root window pixmap, that is, hopefully, the background image 262Returns the root window pixmap, that is, hopefully, the background image
250reevaluated when the bg image changes. 266reevaluated when the bg image changes.
251 267
252=cut 268=cut
253 269
254 sub root() { 270 sub root() {
255 $new->{rootpmap_sensitive} = 1; 271 $new->{again}{rootpmap} = 1;
256 die "root op not supported, exg, we need you"; 272 $self->new_img_from_root
257 } 273 }
258 274
259=item solid $colour 275=item solid $colour
260 276
261=item solid $width, $height, $colour 277=item solid $width, $height, $colour
285 301
286 sub clone($) { 302 sub clone($) {
287 $_[0]->clone 303 $_[0]->clone
288 } 304 }
289 305
290=back 306=item merge $img ...
307
308Takes any number of images and merges them together, creating a single
309image containing them all.
310
311=cut
312
313 sub merge(@) {
314 #TODO
315 }
291 316
292=head2 TILING MODES 317=head2 TILING MODES
293 318
294The following operators modify the tiling mode of an image, that is, the 319The 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. 320way that pixels outside the image area are painted when the image is used.
325become transparent. This mode is most useful when you want to place an 350become transparent. This mode is most useful when you want to place an
326image over another image or the background colour while leaving all 351image over another image or the background colour while leaving all
327background pixels outside the image unchanged. 352background pixels outside the image unchanged.
328 353
329Example: load an image and display it in the upper left corner. The rest 354Example: 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 355of the space is left "empty" (transparent or whatever your compositor does
331in alpha mode, else background colour). 356in alpha mode, else background colour).
332 357
333 pad load "mybg.png" 358 pad load "mybg.png"
334 359
335=item extend $img 360=item extend $img
336 361
337Extends the image over the whole plane, using the closest pixel in the 362Extends 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 363area outside the image. This mode is mostly useful when you use more complex
339filtering operations and want the pixels outside the image to have the 364filtering operations and want the pixels outside the image to have the
340same values as the pixels near the edge. 365same values as the pixels near the edge.
341 366
342Example: just for curiosity, how does this pixel extension stuff work? 367Example: just for curiosity, how does this pixel extension stuff work?
343 368
410the window size to conserve memory. 435the window size to conserve memory.
411 436
412Example: take the screen background, clip it to the window size, blur it a 437Example: take the screen background, clip it to the window size, blur it a
413bit, align it to the window position and use it as background. 438bit, align it to the window position and use it as background.
414 439
415 clip move -TX, -TY, blur 5, root 440 clip move -TX, -TY, once { blur 5, root }
416 441
417=cut 442=cut
418 443
419 sub TX() { $new->{position_sensitive} = 1; $x } 444 sub TX() { $new->{again}{position} = 1; $x }
420 sub TY() { $new->{position_sensitive} = 1; $y } 445 sub TY() { $new->{again}{position} = 1; $y }
421 sub TW() { $new->{size_sensitive} = 1; $w } 446 sub TW() { $new->{again}{size} = 1; $w }
422 sub TH() { $new->{size_sensitive} = 1; $h } 447 sub TH() { $new->{again}{size} = 1; $h }
423 448
424=item now 449=item now
425 450
426Returns the current time as (fractional) seconds since the epoch. 451Returns the current time as (fractional) seconds since the epoch.
427 452
434C<$seconds> seconds. 459C<$seconds> seconds.
435 460
436Example: load some image and rotate it according to the time of day (as if it were 461Example: load some image and rotate it according to the time of day (as if it were
437the hour pointer of a clock). Update this image every minute. 462the hour pointer of a clock). Update this image every minute.
438 463
439 again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png" 464 again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
440 465
441=item counter $seconds 466=item counter $seconds
442 467
443Like C<again>, but also returns an increasing counter value, starting at 468Like C<again>, but also returns an increasing counter value, starting at
4440, which might be useful for some simple animation effects. 4690, which might be useful for some simple animation effects.
446=cut 471=cut
447 472
448 sub now() { urxvt::NOW } 473 sub now() { urxvt::NOW }
449 474
450 sub again($) { 475 sub again($) {
451 $new->{again} = $_[0]; 476 $new->{again}{time} = $_[0];
452 } 477 }
453 478
454 sub counter($) { 479 sub counter($) {
455 $new->{again} = $_[0]; 480 $new->{again}{time} = $_[0];
456 $self->{counter} + 0 481 $self->{counter} + 0
457 } 482 }
458 483
459=back 484=back
460 485
631 656
632 sub rootalign($) { 657 sub rootalign($) {
633 move -TX, -TY, $_[0] 658 move -TX, -TY, $_[0]
634 } 659 }
635 660
661=item rotate $center_x, $center_y, $degrees
662
663Rotates the image by C<$degrees> degrees, counter-clockwise, around the
664pointer at C<$center_x> and C<$center_y> (specified as factor of image
665width/height).
666
667#TODO# new width, height, maybe more operators?
668
669Example: rotate the image by 90 degrees
670
671=cut
672
673 sub rotate($$$$) {
674 my $img = pop;
675 $img->rotate (
676 $_[0] * $img->w,
677 $_[1] * $img->h,
678 $_[2] * (3.14159265 / 180),
679 )
680 }
681
636=back 682=back
637 683
638=head2 COLOUR MODIFICATIONS 684=head2 COLOUR MODIFICATIONS
639 685
640The following operators change the pixels of the image. 686The following operators change the pixels of the image.
674 720
675Values less than 0 reduce brightness, while values larger than 0 increase 721Values less than 0 reduce brightness, while values larger than 0 increase
676it. Useful range is from -1 to 1 - the former results in a black, the 722it. Useful range is from -1 to 1 - the former results in a black, the
677latter in a white picture. 723latter in a white picture.
678 724
679Due to idiosynchrasies in the underlying XRender extension, biases less 725Due to idiosyncrasies in the underlying XRender extension, biases less
680than zero can be I<very> slow. 726than zero can be I<very> slow.
681 727
682=cut 728=cut
683 729
684 sub contrast($$;$$;$) { 730 sub contrast($$;$$;$) {
685 my $img = pop; 731 my $img = pop;
686 my ($r, $g, $b, $a) = @_; 732 my ($r, $g, $b, $a) = @_;
687 733
688 ($g, $b) = ($r, $r) if @_ < 4; 734 ($g, $b) = ($r, $r) if @_ < 3;
689 $a = 1 if @_ < 5; 735 $a = 1 if @_ < 4;
690 736
691 $img = $img->clone; 737 $img = $img->clone;
692 $img->contrast ($r, $g, $b, $a); 738 $img->contrast ($r, $g, $b, $a);
693 $img 739 $img
694 } 740 }
695 741
696 sub brightness($$;$$;$) { 742 sub brightness($$;$$;$) {
697 my $img = pop; 743 my $img = pop;
698 my ($r, $g, $b, $a) = @_; 744 my ($r, $g, $b, $a) = @_;
699 745
700 ($g, $b) = ($r, $r) if @_ < 4; 746 ($g, $b) = ($r, $r) if @_ < 3;
701 $a = 1 if @_ < 5; 747 $a = 1 if @_ < 4;
702 748
703 $img = $img->clone; 749 $img = $img->clone;
704 $img->brightness ($r, $g, $b, $a); 750 $img->brightness ($r, $g, $b, $a);
705 $img 751 $img
706 } 752 }
722 sub blur($$;$) { 768 sub blur($$;$) {
723 my $img = pop; 769 my $img = pop;
724 $img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0]) 770 $img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
725 } 771 }
726 772
727=item rotate $new_width, $new_height, $center_x, $center_y, $degrees 773=back
728 774
729Rotates the image by C<$degrees> degrees, counter-clockwise, around the 775=head2 OTHER STUFF
730pointer at C<$center_x> and C<$center_y> (specified as factor of image
731width/height), generating a new image with width C<$new_width> and height
732C<$new_height>.
733 776
734#TODO# new width, height, maybe more operators? 777Anything that didn't fit any of the other categories, even after applying
778force and closing our eyes.
735 779
736Example: rotate the image by 90 degrees 780=over 4
737 781
738=cut 782=item once { ... }
739 783
740 sub rotate($$$$$$) { 784This function takes a code block as argument, that is, one or more
741 my $img = pop; 785statements enclosed by braces.
742 $img->rotate ( 786
743 $_[0], 787The trick is that this code block is only evaluated once - future calls
744 $_[1], 788will simply return the original image (yes, it should only be used with
745 $_[2] * $img->w, 789images).
746 $_[3] * $img->h, 790
747 $_[4] * (3.14159265 / 180), 791This can be extremely useful to avoid redoign the same slow operations
792again and again- for example, if your background expression takes the root
793background, blurs it and then root-aligns it it would have to blur the
794root background on every window move or resize.
795
796Putting the blur into a C<once> block will make sure the blur is only done
797once:
798
799 rootlign once { blur 10, root }
800
801This leaves the question of how to force reevaluation of the block, in
802case the root background changes: Right now, all once blocks forget that
803they ahve been executed before each time the root background changes (if
804the expression is sensitive to that) or when C<once_again> is called.
805
806=item once_again
807
808Resets all C<once> block as if they had never been called, i.e. on the
809next call they will be reevaluated again.
810
811=cut
812
813 sub once(&) {
814 my $once = $self->{once_cache}{$_[0]+0} ||= do {
815 local $new->{again};
816 my @res = $_[0]();
817 [$new->{again}, \@res]
748 ) 818 };
819
820 $new->{again} = {
821 %{ $new->{again} },
822 %{ $once->[0] }
823 };
824
825 # in scalar context we always return the first original result, which
826 # is not quite how perl works.
827 wantarray
828 ? @{ $once->[1] }
829 : $once->[1][0]
830 }
831
832 sub once_again() {
833 delete $self->{once_cache};
749 } 834 }
750 835
751=back 836=back
752 837
753=cut 838=cut
796 881
797 # evaluate user expression 882 # evaluate user expression
798 883
799 my $img = eval { $self->{expr}->() }; 884 my $img = eval { $self->{expr}->() };
800 warn $@ if $@;#d# 885 warn $@ if $@;#d#
801 die if !UNIVERSAL::isa $img, "urxvt::img"; 886 die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
802 887
803 $state->{size_sensitive} = 1 888 # if the expression is sensitive to external events, prepare reevaluation then
889
890 my $again = delete $state->{again};
891
892 $again->{size} = 1
804 if $img->repeat_mode != urxvt::RepeatNormal; 893 if $img->repeat_mode != urxvt::RepeatNormal;
805 894
806 # if the expression is sensitive to external events, prepare reevaluation then
807
808 my $repeat;
809
810 if (my $again = $state->{again}) { 895 if (my $again = $again->{time}) {
811 $repeat = 1;
812 my $self = $self; 896 my $self = $self;
813 $state->{timer} = $again == $old->{again} 897 $state->{timer} = $again == $old->{again}
814 ? $old->{timer} 898 ? $old->{timer}
815 : urxvt::timer->new->after ($again)->interval ($again)->cb (sub { 899 : urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
816 ++$self->{counter}; 900 ++$self->{counter};
817 $self->recalculate 901 $self->recalculate
818 }); 902 });
819 } 903 }
820 904
821 if (delete $state->{position_sensitive}) { 905 if ($again->{position}) {
822 $repeat = 1;
823 $self->enable (position_change => sub { $_[0]->recalculate }); 906 $self->enable (position_change => sub { $_[0]->recalculate });
824 } else { 907 } else {
825 $self->disable ("position_change"); 908 $self->disable ("position_change");
826 } 909 }
827 910
828 if (delete $state->{size_sensitive}) { 911 if ($again->{size}) {
829 $repeat = 1;
830 $self->enable (size_change => sub { $_[0]->recalculate }); 912 $self->enable (size_change => sub { $_[0]->recalculate });
831 } else { 913 } else {
832 $self->disable ("size_change"); 914 $self->disable ("size_change");
833 } 915 }
834 916
835 if (delete $state->{rootpmap_sensitive}) { 917 if ($again->{rootpmap}) {
836 $repeat = 1;
837 $self->enable (rootpmap_change => sub { $_[0]->recalculate }); 918 $self->enable (rootpmap_change => sub {
919 delete $_[0]{once_cache}; # this will override once-block values from
920 $_[0]->recalculate;
921 });
838 } else { 922 } else {
839 $self->disable ("rootpmap_change"); 923 $self->disable ("rootpmap_change");
840 } 924 }
841 925
842 # clear stuff we no longer need 926 # clear stuff we no longer need
843 927
844 %$old = (); 928 %$old = ();
845 929
846 unless ($repeat) { 930 unless (%$again) {
847 delete $self->{state}; 931 delete $self->{state};
848 delete $self->{expr}; 932 delete $self->{expr};
849 } 933 }
850 934
851 # set background pixmap 935 # set background pixmap
856} 940}
857 941
858sub on_start { 942sub on_start {
859 my ($self) = @_; 943 my ($self) = @_;
860 944
861 my $expr = $self->x_resource ("background.expr") 945 my $expr = $self->x_resource ("%.expr")
862 or return; 946 or return;
863 947
948 $self->has_render
949 or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
950
864 $self->set_expr (parse_expr $expr); 951 $self->set_expr (parse_expr $expr);
865 $self->{border} = $self->x_resource_boolean ("background.border"); 952 $self->{border} = $self->x_resource_boolean ("%.border");
866 953
867 $MIN_INTERVAL = $self->x_resource ("background.interval"); 954 $MIN_INTERVAL = $self->x_resource ("%.interval");
868 955
869 () 956 ()
870} 957}
871 958

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