[ViewVC] Diff of: cvs/rxvt-unicode/src/perl/background

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.33 by root, Thu Jun 7 16:30:58 2012 UTC vs.
Revision 1.38 by root, Fri Jun 8 21:48:07 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		5
		6	#TODO: once, rootalign
		7
6	=head1 background - manage terminal background	8	=head1 background - manage terminal background
7		9
8	=head2 SYNOPSIS	10	=head2 SYNOPSIS
9		11
10	rxvt -background-expr 'background expression'	12	urxvt --background-expr 'background expression'
11	-background-border	13	--background-border
12		14
13	=head2 DESCRIPTION	15	=head2 DESCRIPTION
14		16
		17	This extension manages the terminal background by creating a picture that
		18	is behind the text, replacing the normal background colour.
		19
		20	It does so by evaluating a Perl expression that I<calculates> the image on
		21	the fly, for example, by grabbing the root background or loading a file.
		22
		23	While the full power of Perl is available, the operators have been design
		24	to be as simple as possible.
		25
		26	For example, to load an image and scale it to the window size, you would
		27	use:
		28
		29	urxvt --background-expr 'scale load "/path/to/mybg.png"'
		30
		31	Or specified as a X resource:
		32
		33	URxvt.background-expr: scale load "/path/to/mybg.png"
		34
		35	=head2 THEORY OF OPERATION
		36
		37	At startup, just before the window is mapped for the first time, the
		38	expression is evaluated and must yield an image. The image is then
		39	extended as necessary to cover the whole terminal window, and is set as a
		40	background pixmap.
		41
		42	If the image contains an alpha channel, then it will be used as-is in
		43	visuals that support alpha channels (for example, for a compositing
		44	manager). In other visuals, the terminal background colour will be used to
		45	replace any transparency.
		46
		47	When the expression relies, directly or indirectly, on the window size,
		48	position, the root pixmap, or a timer, then it will be remembered. If not,
		49	then it will be removed.
		50
		51	If any of the parameters that the expression relies on changes (when the
		52	window is moved or resized, its position or size changes; when the root
		53	pixmap is replaced by another one the root background changes; or when the
		54	timer elapses), then the expression will be evaluated again.
		55
		56	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
		57	image to the window size, so it relies on the window size and will
		58	be reevaluated each time it is changed, but not when it moves for
		59	example. That ensures that the picture always fills the terminal, even
		60	after it's size changes.
		61
		62	=head3 EXPRESSIONS
		63
		64	Expressions are normal Perl expressions, in fact, they are Perl blocks -
		65	which means you could use multiple lines and statements:
		66
		67	again 3600;
		68	if (localtime now)[6]) {
		69	return scale load "$HOME/weekday.png";
		70	} else {
		71	return scale load "$HOME/sunday.png";
		72	}
		73
		74	This expression gets evaluated once per hour. It will set F<sunday.png> as
		75	background on sundays, and F<weekday.png> on all other days.
		76
		77	Fortunately, we expect that most expressions will be much simpler, with
		78	little Perl knowledge needed.
		79
		80	Basically, you always start with a function that "generates" an image
		81	object, such as C<load>, which loads an image from disk, or C<root>, which
		82	returns the root window background image:
		83
		84	load "$HOME/mypic.png"
		85
		86	The path is usually specified as a quoted string (the exact rules can be
		87	found in the L<perlop> manpage). The F<$HOME> at the beginning of the
		88	string is expanded to the home directory.
		89
		90	Then you prepend one or more modifiers or filtering expressions, such as
		91	C<scale>:
		92
		93	scale load "$HOME/mypic.png"
		94
		95	Just like a mathematical expression with functions, you should read these
		96	expressions from right to left, as the C<load> is evaluated first, and
		97	its result becomes the argument to the C<scale> function.
		98
		99	Many operators also allow some parameters preceding the input image
		100	that modify its behaviour. For example, C<scale> without any additional
		101	arguments scales the image to size of the terminal window. If you specify
		102	an additional argument, it uses it as a percentage:
		103
		104	scale 200, load "$HOME/mypic.png"
		105
		106	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
		107	has now two arguments, the C<200> and the C<load> expression, while
		108	C<load> only has one argument. Arguments are separated from each other by
		109	commas.
		110
		111	Scale also accepts two arguments, which are then separate factors for both
		112	horizontal and vertical dimensions. For example, this halves the image
		113	width and doubles the image height:
		114
		115	scale 50, 200, load "$HOME/mypic.png"
		116
		117	TODO
		118
		119	=head3 CYCLES AND CACHING
		120
		121	TODO
		122
		123	Each time the expression is reevaluated, a new cycle is said to have begun. Many operators
		124	cache their results till the next cycle. For example
		125
15	=head2 REFERENCE	126	=head2 REFERENCE
16		127
17	=cut	128	=head3 COMMAND LINE SWITCHES
18		129
		130	=over 4
		131
		132	=item --background-expr perl-expression
		133
		134	Specifies the Perl expression to evaluate.
		135
		136	=item --background-border
		137
		138	By default, the expression creates an image that fills the full window,
		139	overwriting borders and any other areas, such as the scrollbar.
		140
		141	Specifying this flag changes the behaviour, so that the image only
		142	replaces the background of the character area.
		143
		144	=back
		145
		146	=cut
		147
19	our $EXPR;	148	our $EXPR;#d#
20	#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';	149	#$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"';	150	$EXPR = 'move -TX, -TY, load "argb.png"';
22	#$EXPR = '	151	#$EXPR = '
23	# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,	152	# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,
24	# clip X, Y, W, H, repeat_mirror,	153	# clip X, Y, W, H, repeat_mirror,
27	#$EXPR = 'solid "red"';	156	#$EXPR = 'solid "red"';
28	#$EXPR = 'blur root, 10, 10'	157	#$EXPR = 'blur root, 10, 10'
29	#$EXPR = 'blur move (root, -x, -y), 5, 5'	158	#$EXPR = 'blur move (root, -x, -y), 5, 5'
30	#resize load "/root/pix/das_fette_schwein.jpg", w, h	159	#resize load "/root/pix/das_fette_schwein.jpg", w, h
31		160
		161	our $HOME;
32	our ($self, $old, $new);	162	our ($self, $old, $new);
33	our ($x, $y, $w, $h);	163	our ($x, $y, $w, $h);
34		164
35	# enforce at least this interval between updates	165	# enforce at least this interval between updates
36	our $MIN_INTERVAL = 1/100;	166	our $MIN_INTERVAL = 1/100;
…		…
158		288
159	When this function is used the expression will be reevaluated again in	289	When this function is used the expression will be reevaluated again in
160	C<$seconds> seconds.	290	C<$seconds> seconds.
161		291
162	Example: load some image and rotate it according to the time of day (as if it were	292	Example: load some image and rotate it according to the time of day (as if it were
163	the hour pointer of a clock). update this image every minute.	293	the hour pointer of a clock). Update this image every minute.
164		294
165	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	295	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
166		296
167	=item counter $seconds	297	=item counter $seconds
168		298
…		…
193		323
194	=item tile $img	324	=item tile $img
195		325
196	Tiles the whole plane with the image and returns this new image - or in	326	Tiles the whole plane with the image and returns this new image - or in
197	other words, it returns a copy of the image in plane tiling mode.	327	other words, it returns a copy of the image in plane tiling mode.
		328
		329	Example: load an image and tile it over the background, without
		330	resizing. The C<tile> call is superfluous because C<load> already defaults
		331	to tiling mode.
		332
		333	tile load "mybg.png"
198		334
199	=item mirror $img	335	=item mirror $img
200		336
201	Similar to tile, but reflects the image each time it uses a new copy, so	337	Similar to tile, but reflects the image each time it uses a new copy, so
202	that top edges always touch top edges, right edges always touch right	338	that top edges always touch top edges, right edges always touch right
203	edges and so on (with normal tiling, left edges always touch right edges	339	edges and so on (with normal tiling, left edges always touch right edges
204	and top always touch bottom edges).	340	and top always touch bottom edges).
205		341
		342	Example: load an image and mirror it over the background, avoiding sharp
		343	edges at the image borders at the expense of mirroring the image itself
		344
		345	mirror load "mybg.png"
		346
206	=item pad $img	347	=item pad $img
207		348
208	Takes an image and modifies it so that all pixels outside the image area	349	Takes an image and modifies it so that all pixels outside the image area
209	become transparent. This mode is most useful when you want to place an	350	become transparent. This mode is most useful when you want to place an
210	image over another image or the background colour while leaving all	351	image over another image or the background colour while leaving all
211	background pixels outside the image unchanged.	352	background pixels outside the image unchanged.
212		353
		354	Example: load an image and display it in the upper left corner. The rest
		355	of the space is left "empty" (transparent or wahtever your compisotr does
		356	in alpha mode, else background colour).
		357
		358	pad load "mybg.png"
		359
213	=item extend $img	360	=item extend $img
214		361
215	Extends the image over the whole plane, using the closest pixel in the	362	Extends the image over the whole plane, using the closest pixel in the
216	area outside the image. This mode is mostly useful when you more complex	363	area outside the image. This mode is mostly useful when you more complex
217	filtering operations and want the pixels outside the image to have the	364	filtering operations and want the pixels outside the image to have the
218	same values as the pixels near the edge.	365	same values as the pixels near the edge.
		366
		367	Example: just for curiosity, how does this pixel extension stuff work?
		368
		369	extend move 50, 50, load "mybg.png"
219		370
220	=cut	371	=cut
221		372
222	sub pad($) {	373	sub pad($) {
223	my $img = $_[0]->clone;	374	my $img = $_[0]->clone;
…		…
324	sub resize($$$) {	475	sub resize($$$) {
325	my $img = pop;	476	my $img = pop;
326	$img->scale ($_[0], $_[1])	477	$img->scale ($_[0], $_[1])
327	}	478	}
328		479
		480	=item move $dx, $dy, $img
		481
		482	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
		483	the vertical.
		484
		485	Example: move the image right by 20 pixels and down by 30.
		486
		487	move 20, 30, ...
		488
		489	=item rootalign $img
		490
		491	Moves the image so that it appears glued to the screen as opposed to the
		492	window. This gives the illusion of a larger area behind the window. It is
		493	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
		494	top left of the screen.
		495
		496	Example: load a background image, put it in mirror mode and root align it.
		497
		498	rootalign mirror load "mybg.png"
		499
		500	Example: take the screen background and align it, giving the illusion of
		501	transparency as long as the window isn't in front of other windows.
		502
		503	rootalign root
		504
		505	=cut
		506
329	sub move($$;$) {	507	sub move($$;$) {
330	my $img = pop->clone;	508	my $img = pop->clone;
331	$img->move ($_[0], $_[1]);	509	$img->move ($_[0], $_[1]);
332	$img	510	$img
333	}	511	}
		512
		513	sub rootalign($) {
		514	move -TX, -TY, $_[0]
		515	}
		516
		517	=item contrast $factor, $img
		518
		519	=item contrast $r, $g, $b, $img
		520
		521	=item contrast $r, $g, $b, $a, $img
		522
		523	Adjusts the I<contrast> of an image.
		524
		525	#TODO#
		526
		527	=item brightness $factor, $img
		528
		529	=item brightness $r, $g, $b, $img
		530
		531	=item brightness $r, $g, $b, $a, $img
		532
		533	Adjusts the brightness of an image.
		534
		535	=cut
		536
		537	sub contrast($$;$$;$) {
		538	my $img = pop;
		539	my ($r, $g, $b, $a) = @_;
		540
		541	($g, $b) = ($r, $r) if @_ < 4;
		542	$a = 1 if @_ < 5;
		543
		544	$img = $img->clone;
		545	$img->contrast ($r, $g, $b, $a);
		546	$img
		547	}
		548
		549	sub brightness($$;$$;$) {
		550	my $img = pop;
		551	my ($r, $g, $b, $a) = @_;
		552
		553	($g, $b) = ($r, $r) if @_ < 4;
		554	$a = 1 if @_ < 5;
		555
		556	$img = $img->clone;
		557	$img->brightness ($r, $g, $b, $a);
		558	$img
		559	}
		560
		561	=item blur $radius, $img
		562
		563	=item blur $radius_horz, $radius_vert, $img
		564
		565	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		566	can also be specified separately.
		567
		568	=cut
		569
		570	sub blur($$;$) {
		571	my $img = pop;
		572	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
		573	}
		574
		575	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
		576
		577	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		578	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
		579	width/height), generating a new image with width C<$new_width> and height
		580	C<$new_height>.
		581
		582	#TODO# new width, height, maybe more operators?
		583
		584	Example: rotate the image by 90 degrees
		585
		586	=cut
334		587
335	sub rotate($$$$$$) {	588	sub rotate($$$$$$) {
336	my $img = pop;	589	my $img = pop;
337	$img->rotate (	590	$img->rotate (
338	$_[0],	591	$_[0],
…		…
341	$_[3] * $img->h * .01,	594	$_[3] * $img->h * .01,
342	$_[4] * (3.14159265 / 180),	595	$_[4] * (3.14159265 / 180),
343	)	596	)
344	}	597	}
345		598
346	sub blur($$;$) {
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	}
374
375	=back	599	=back
376		600
377	=cut	601	=cut
378		602
379	}	603	}
…		…
409		633
410	# set environment to evaluate user expression	634	# set environment to evaluate user expression
411		635
412	local $self = $arg_self;	636	local $self = $arg_self;
413		637
		638	local $HOME = $ENV{HOME};
414	local $old = $self->{state};	639	local $old = $self->{state};
415	local $new = my $state = $self->{state} = {};	640	local $new = my $state = $self->{state} = {};
416		641
417	($x, $y, $w, $h) =	642	($x, $y, $w, $h) =
418	$self->background_geometry ($self->{border});	643	$self->background_geometry ($self->{border});
…		…
421		646
422	my $img = eval { $self->{expr}->() };	647	my $img = eval { $self->{expr}->() };
423	warn $@ if $@;#d#	648	warn $@ if $@;#d#
424	die if !UNIVERSAL::isa $img, "urxvt::img";	649	die if !UNIVERSAL::isa $img, "urxvt::img";
425		650
		651	$state->{size_sensitive} = 1
		652	if $img->repeat_mode != urxvt::RepeatNormal;
		653
426	# if the expression is sensitive to external events, prepare reevaluation then	654	# if the expression is sensitive to external events, prepare reevaluation then
427		655
428	my $repeat;	656	my $repeat;
429		657
430	if (my $again = $state->{again}) {	658	if (my $again = $state->{again}) {
431	$repeat = 1;	659	$repeat = 1;
		660	my $self = $self;
432	$state->{timer} = $again == $old->{again}	661	$state->{timer} = $again == $old->{again}
433	? $old->{timer}	662	? $old->{timer}
434	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	663	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
435	++$self->{counter};	664	++$self->{counter};
436	$self->recalculate	665	$self->recalculate
…		…
465	unless ($repeat) {	694	unless ($repeat) {
466	delete $self->{state};	695	delete $self->{state};
467	delete $self->{expr};	696	delete $self->{expr};
468	}	697	}
469		698
470	# prepare and set background pixmap	699	# set background pixmap
471
472	$img = $img->sub_rect (0, 0, $w, $h)
473	if $img->w != $w \|\| $img->h != $h;
474		700
475	$self->set_background ($img, $self->{border});	701	$self->set_background ($img, $self->{border});
476	$self->scr_recolour (0);	702	$self->scr_recolour (0);
477	$self->want_refresh;	703	$self->want_refresh;
478	}	704	}

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.33 by root, Thu Jun 7 16:30:58 2012 UTC vs. Revision 1.38 by root, Fri Jun 8 21:48:07 2012 UTC

Diff Legend

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.33 by root, Thu Jun 7 16:30:58 2012 UTC vs.
Revision 1.38 by root, Fri Jun 8 21:48:07 2012 UTC