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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.45 by root, Sun Jun 10 11:53:32 2012 UTC vs.
Revision 1.68 by root, Sun Jul 1 21:47:07 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	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
6	#TODO: once, rootalign
7		6
8	=head1 NAME	7	=head1 NAME
9		8
10	background - manage terminal background	9	background - manage terminal background
11		10
12	=head1 SYNOPSIS	11	=head1 SYNOPSIS
13		12
14	urxvt --background-expr 'background expression'	13	urxvt --background-expr 'background expression'
15	--background-border	14	--background-border
		15	--background-interval seconds
16		16
17	=head1 DESCRIPTION	17	=head1 DESCRIPTION
18		18
19	This extension manages the terminal background by creating a picture that	19	This extension manages the terminal background by creating a picture that
20	is behind the text, replacing the normal background colour.	20	is behind the text, replacing the normal background colour.
26	to be as simple as possible.	26	to be as simple as possible.
27		27
28	For example, to load an image and scale it to the window size, you would	28	For example, to load an image and scale it to the window size, you would
29	use:	29	use:
30		30
31	urxvt --background-expr 'scale load "/path/to/mybg.png"'	31	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
32		32
33	Or specified as a X resource:	33	Or specified as a X resource:
34		34
35	URxvt.background-expr: scale load "/path/to/mybg.png"	35	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }
36		36
37	=head1 THEORY OF OPERATION	37	=head1 THEORY OF OPERATION
38		38
39	At startup, just before the window is mapped for the first time, the	39	At startup, just before the window is mapped for the first time, the
40	expression is evaluated and must yield an image. The image is then	40	expression is evaluated and must yield an image. The image is then
…		…
53	If any of the parameters that the expression relies on changes (when the	53	If any of the parameters that the expression relies on changes (when the
54	window is moved or resized, its position or size changes; when the root	54	window is moved or resized, its position or size changes; when the root
55	pixmap is replaced by another one the root background changes; or when the	55	pixmap is replaced by another one the root background changes; or when the
56	timer elapses), then the expression will be evaluated again.	56	timer elapses), then the expression will be evaluated again.
57		57
58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	58	For example, an expression such as C<scale keep { load "$HOME/mybg.png"
59	image to the window size, so it relies on the window size and will	59	}> scales the image to the window size, so it relies on the window size
60	be reevaluated each time it is changed, but not when it moves for	60	and will be reevaluated each time it is changed, but not when it moves for
61	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
62	after it's size changes.	62	after its size changes.
63		63
64	=head2 EXPRESSIONS	64	=head2 EXPRESSIONS
65		65
66	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
67	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
68		68
		69	scale keep {
69	again 3600;	70	again 3600;
70	if (localtime now)[6]) {	71	if (localtime now)[6]) {
71	return scale load "$HOME/weekday.png";	72	return load "$HOME/weekday.png";
72	} else {	73	} else {
73	return scale load "$HOME/sunday.png";	74	return load "$HOME/sunday.png";
		75	}
74	}	76	}
75		77
76	This expression gets evaluated once per hour. It will set F<sunday.png> as	78	This inner expression is evaluated once per hour (and whenever the
		79	temrinal window is resized). It sets F<sunday.png> as background on
77	background on Sundays, and F<weekday.png> on all other days.	80	Sundays, and F<weekday.png> on all other days.
78		81
79	Fortunately, we expect that most expressions will be much simpler, with	82	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	83	little Perl knowledge needed.
81		84
82	Basically, you always start with a function that "generates" an image	85	Basically, you always start with a function that "generates" an image
…		…
115	horizontal and vertical dimensions. For example, this halves the image	118	horizontal and vertical dimensions. For example, this halves the image
116	width and doubles the image height:	119	width and doubles the image height:
117		120
118	scale 0.5, 2, load "$HOME/mypic.png"	121	scale 0.5, 2, load "$HOME/mypic.png"
119		122
120	Other effects than scalign are also readily available, for exmaple, you can	123	IF you try out these expressions, you might suffer from some sluggishness,
121	tile the image to fill the whole window, instead of resizing it:	124	because each time the terminal is resized, it loads the PNG image agin
		125	and scales it. Scaling is usually fast (and unavoidable), but loading the
		126	image can be quite time consuming. This is where C<keep> comes in handy:
122		127
		128	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		129
		130	The C<keep> operator executes all the statements inside the braces only
		131	once, or when it thinks the outcome might change. In other cases it
		132	returns the last value computed by the brace block.
		133
		134	This means that the C<load> is only executed once, which makes it much
		135	faster, but also means that more memory is being used, because the loaded
		136	image must be kept in memory at all times. In this expression, the
		137	trade-off is likely worth it.
		138
		139	But back to effects: Other effects than scaling are also readily
		140	available, for example, you can tile the image to fill the whole window,
		141	instead of resizing it:
		142
123	tile load "$HOME/mypic.png"	143	tile keep { load "$HOME/mypic.png" }
124		144
125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	145	In fact, images returned by C<load> are in C<tile> mode by default, so the
126	is kind of superfluous.	146	C<tile> operator is kind of superfluous.
127		147
128	Another common effect is to mirror the image, so that the same edges touch:	148	Another common effect is to mirror the image, so that the same edges
		149	touch:
129		150
130	mirror load "$HOME/mypic.png"	151	mirror keep { load "$HOME/mypic.png" }
131		152
132	This is also a typical background expression:	153	Another common background expression is:
133		154
134	rootalign root	155	rootalign root
135		156
136	It first takes a snapshot of the screen background image, and then	157	This one first takes a snapshot of the screen background image, and then
137	moves it to the upper left corner of the screen - the result is	158	moves it to the upper left corner of the screen (as opposed to the upper
138	pseudo-transparency, as the image seems to be static while the window is	159	left corner of the terminal window)- the result is pseudo-transparency:
139	moved around.	160	the image seems to be static while the window is moved around.
140		161
141	=head2 CYCLES AND CACHING	162	=head2 CACHING AND SENSITIVITY
142		163
143	As has been mentioned before, the expression might be evaluated multiple	164	Since some operations (such as C<load> and C<blur>) can take a long time,
144	times. Each time the expression is reevaluated, a new cycle is said to	165	caching results can be very important for a smooth operation. Caching can
145	have begun. Many operators cache their results till the next cycle.	166	also be useful to reduce memory usage, though, for example, when an image
		167	is cached by C<load>, it could be shared by multiple terminal windows
		168	running inside urxvtd.
146		169
147	For example, the C<load> operator keeps a copy of the image. If it is	170	=head3 C<keep { ... }> caching
148	asked to load the same image on the next cycle it will not load it again,
149	but return the cached copy.
150		171
151	This only works for one cycle though, so as long as you load the same	172	The most important way to cache expensive operations is to use C<keep {
152	image every time, it will always be cached, but when you load a different	173	... }>. The C<keep> operator takes a block of multiple statements enclosed
153	image, it will forget about the first one.	174	by C<{}> and keeps the return value in memory.
154		175
155	This allows you to either speed things up by keeping multiple images in	176	An expression can be "sensitive" to various external events, such as
156	memory, or comserve memory by loading images more often.	177	scaling or moving the window, root background changes and timers. Simply
		178	using an expression (such as C<scale> without parameters) that depends on
		179	certain changing values (called "variables"), or using those variables
		180	directly, will make an expression sensitive to these events - for example,
		181	using C<scale> or C<TW> will make the expression sensitive to the terminal
		182	size, and thus to resizing events.
157		183
158	For example, you can keep two images in memory and use a random one like	184	When such an event happens, C<keep> will automatically trigger a
159	this:	185	reevaluation of the whole expression with the new value of the expression.
160		186
161	my $img1 = load "img1.png";	187	C<keep> is most useful for expensive operations, such as C<blur>:
162	my $img2 = load "img2.png";
163	(0.5 > rand) ? $img1 : $img2
164		188
165	Since both images are "loaded" every time the expression is evaluated,	189	rootalign keep { blur 20, root }
166	they are always kept in memory. Contrast this version:
167		190
168	my $path1 = "img1.png";	191	This makes a blurred copy of the root background once, and on subsequent
169	my $path2 = "img2.png";	192	calls, just root-aligns it. Since C<blur> is usually quite slow and
170	load ((0.5 > rand) ? $path1 : $path2)	193	C<rootalign> is quite fast, this trades extra memory (for the cached
		194	blurred pixmap) with speed (blur only needs to be redone when root
		195	changes).
171		196
172	Here, a path is selected randomly, and load is only called for one image,	197	=head3 C<load> caching
173	so keeps only one image in memory. If, on the next evaluation, luck	198
174	decides to use the other path, then it will have to load that image again.	199	The C<load> operator itself does not keep images in memory, but as long as
		200	the image is still in memory, C<load> will use the in-memory image instead
		201	of loading it freshly from disk.
		202
		203	That means that this expression:
		204
		205	keep { load "$HOME/path..." }
		206
		207	Not only caches the image in memory, other terminal instances that try to
		208	C<load> it can reuse that in-memory copy.
175		209
176	=head1 REFERENCE	210	=head1 REFERENCE
177		211
178	=head2 COMMAND LINE SWITCHES	212	=head2 COMMAND LINE SWITCHES
179		213
…		…
189	overwriting borders and any other areas, such as the scrollbar.	223	overwriting borders and any other areas, such as the scrollbar.
190		224
191	Specifying this flag changes the behaviour, so that the image only	225	Specifying this flag changes the behaviour, so that the image only
192	replaces the background of the character area.	226	replaces the background of the character area.
193		227
		228	=item --background-interval seconds
		229
		230	Since some operations in the underlying XRender extension can effectively
		231	freeze your X-server for prolonged time, this extension enforces a minimum
		232	time between updates, which is normally about 0.1 seconds.
		233
		234	If you want to do updates more often, you can decrease this safety
		235	interval with this switch.
		236
194	=back	237	=back
195		238
196	=cut	239	=cut
197		240
		241	our %_IMG_CACHE;
198	our $HOME;	242	our $HOME;
199	our ($self, $old, $new);	243	our ($self, $frame);
200	our ($x, $y, $w, $h);	244	our ($x, $y, $w, $h);
201		245
202	# enforce at least this interval between updates	246	# enforce at least this interval between updates
203	our $MIN_INTERVAL = 1/100;	247	our $MIN_INTERVAL = 6/59.951;
204		248
205	{	249	{
206	package urxvt::bgdsl; # background language	250	package urxvt::bgdsl; # background language
		251
		252	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		253	sub FR_CACHE () { 1 } # cached values
		254	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		255	sub FR_STATE () { 3 } # watchers etc.
207		256
208	use List::Util qw(min max sum shuffle);	257	use List::Util qw(min max sum shuffle);
209		258
210	=head2 PROVIDERS/GENERATORS	259	=head2 PROVIDERS/GENERATORS
211		260
…		…
218	=item load $path	267	=item load $path
219		268
220	Loads the image at the given C<$path>. The image is set to plane tiling	269	Loads the image at the given C<$path>. The image is set to plane tiling
221	mode.	270	mode.
222		271
223	Loaded images will be cached for one cycle.	272	If the image is already in memory (e.g. because another terminal instance
		273	uses it), then the in-memory copy us returned instead.
224		274
		275	=item load_uc $path
		276
		277	Load uncached - same as load, but does not cache the image, which means it
		278	is I<always> loaded from the filesystem again.
		279
225	=cut	280	=cut
		281
		282	sub load_uc($) {
		283	$self->new_img_from_file ($path)
		284	}
226		285
227	sub load($) {	286	sub load($) {
228	my ($path) = @_;	287	my ($path) = @_;
229		288
230	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	289	$_IMG_CACHE{$path} \|\| do {
		290	my $img = load_uc $path;
		291	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		292	$img
		293	}
231	}	294	}
232		295
233	=item root	296	=item root
234		297
235	Returns the root window pixmap, that is, hopefully, the background image	298	Returns the root window pixmap, that is, hopefully, the background image
236	of your screen. The image is set to extend mode.	299	of your screen.
237		300
238	This function makes your expression root sensitive, that means it will be	301	This function makes your expression root sensitive, that means it will be
239	reevaluated when the bg image changes.	302	reevaluated when the bg image changes.
240		303
241	=cut	304	=cut
242		305
243	sub root() {	306	sub root() {
244	$new->{rootpmap_sensitive} = 1;	307	$frame->[FR_AGAIN]{rootpmap} = 1;
245	die "root op not supported, exg, we need you";	308	$self->new_img_from_root
246	}	309	}
247		310
248	=item solid $colour	311	=item solid $colour
249		312
250	=item solid $width, $height, $colour	313	=item solid $width, $height, $colour
…		…
258	=cut	321	=cut
259		322
260	sub solid($;$$) {	323	sub solid($;$$) {
261	my $colour = pop;	324	my $colour = pop;
262		325
263	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	326	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
264	$img->fill ($colour);	327	$img->fill ($colour);
265	$img	328	$img
266	}	329	}
267		330
268	=item clone $img	331	=item clone $img
…		…
274		337
275	sub clone($) {	338	sub clone($) {
276	$_[0]->clone	339	$_[0]->clone
277	}	340	}
278		341
279	=back	342	=item merge $img ...
		343
		344	Takes any number of images and merges them together, creating a single
		345	image containing them all. The tiling mode of the first image is used as
		346	the tiling mode of the resulting image.
		347
		348	This function is called automatically when an expression returns multiple
		349	images.
		350
		351	=cut
		352
		353	sub merge(@) {
		354	return $_[0] unless $#_;
		355
		356	# rather annoyingly clumsy, but optimisation is for another time
		357
		358	my $x0 = +1e9;
		359	my $y0 = +1e9;
		360	my $x1 = -1e9;
		361	my $y1 = -1e9;
		362
		363	for (@_) {
		364	my ($x, $y, $w, $h) = $_->geometry;
		365
		366	$x0 = $x if $x0 > $x;
		367	$y0 = $y if $y0 > $y;
		368
		369	$x += $w;
		370	$y += $h;
		371
		372	$x1 = $x if $x1 < $x;
		373	$y1 = $y if $y1 < $y;
		374	}
		375
		376	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		377	$base->repeat_mode ($_[0]->repeat_mode);
		378	$base->fill ([0, 0, 0, 0]);
		379
		380	$base->draw ($_)
		381	for @_;
		382
		383	$base
		384	}
280		385
281	=head2 TILING MODES	386	=head2 TILING MODES
282		387
283	The following operators modify the tiling mode of an image, that is, the	388	The following operators modify the tiling mode of an image, that is, the
284	way that pixels outside the image area are painted when the image is used.	389	way that pixels outside the image area are painted when the image is used.
…		…
314	become transparent. This mode is most useful when you want to place an	419	become transparent. This mode is most useful when you want to place an
315	image over another image or the background colour while leaving all	420	image over another image or the background colour while leaving all
316	background pixels outside the image unchanged.	421	background pixels outside the image unchanged.
317		422
318	Example: load an image and display it in the upper left corner. The rest	423	Example: load an image and display it in the upper left corner. The rest
319	of the space is left "empty" (transparent or wahtever your compisotr does	424	of the space is left "empty" (transparent or whatever your compositor does
320	in alpha mode, else background colour).	425	in alpha mode, else background colour).
321		426
322	pad load "mybg.png"	427	pad load "mybg.png"
323		428
324	=item extend $img	429	=item extend $img
325		430
326	Extends the image over the whole plane, using the closest pixel in the	431	Extends the image over the whole plane, using the closest pixel in the
327	area outside the image. This mode is mostly useful when you more complex	432	area outside the image. This mode is mostly useful when you use more complex
328	filtering operations and want the pixels outside the image to have the	433	filtering operations and want the pixels outside the image to have the
329	same values as the pixels near the edge.	434	same values as the pixels near the edge.
330		435
331	Example: just for curiosity, how does this pixel extension stuff work?	436	Example: just for curiosity, how does this pixel extension stuff work?
332		437
…		…
381	Using these functions make your expression sensitive to window moves.	486	Using these functions make your expression sensitive to window moves.
382		487
383	These functions are mainly useful to align images to the root window.	488	These functions are mainly useful to align images to the root window.
384		489
385	Example: load an image and align it so it looks as if anchored to the	490	Example: load an image and align it so it looks as if anchored to the
386	background.	491	background (that's exactly what C<rootalign> does btw.):
387		492
388	move -TX, -TY, load "mybg.png"	493	move -TX, -TY, keep { load "mybg.png" }
389		494
390	=item TW	495	=item TW
391		496
392	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	497	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
393	terminal window is the full window by default, and the character area only	498	terminal window is the full window by default, and the character area only
…		…
399	the window size to conserve memory.	504	the window size to conserve memory.
400		505
401	Example: take the screen background, clip it to the window size, blur it a	506	Example: take the screen background, clip it to the window size, blur it a
402	bit, align it to the window position and use it as background.	507	bit, align it to the window position and use it as background.
403		508
404	clip move -TX, -TY, blur 5, root	509	clip move -TX, -TY, keep { blur 5, root }
405		510
406	=cut	511	=cut
407		512
408	sub TX() { $new->{position_sensitive} = 1; $x }	513	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
409	sub TY() { $new->{position_sensitive} = 1; $y }	514	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
410	sub TW() { $new->{size_sensitive} = 1; $w }	515	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
411	sub TH() { $new->{size_sensitive} = 1; $h }	516	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
412		517
413	=item now	518	=item now
414		519
415	Returns the current time as (fractional) seconds since the epoch.	520	Returns the current time as (fractional) seconds since the epoch.
416		521
…		…
423	C<$seconds> seconds.	528	C<$seconds> seconds.
424		529
425	Example: load some image and rotate it according to the time of day (as if it were	530	Example: load some image and rotate it according to the time of day (as if it were
426	the hour pointer of a clock). Update this image every minute.	531	the hour pointer of a clock). Update this image every minute.
427		532
		533	again 60;
428	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	534	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
429		535
430	=item counter $seconds	536	=item counter $seconds
431		537
432	Like C<again>, but also returns an increasing counter value, starting at	538	Like C<again>, but also returns an increasing counter value, starting at
433	0, which might be useful for some simple animation effects.	539	0, which might be useful for some simple animation effects.
…		…
435	=cut	541	=cut
436		542
437	sub now() { urxvt::NOW }	543	sub now() { urxvt::NOW }
438		544
439	sub again($) {	545	sub again($) {
440	$new->{again} = $_[0];	546	$frame->[FR_AGAIN]{time} = $_[0];
441	}	547	}
442		548
443	sub counter($) {	549	sub counter($) {
444	$new->{again} = $_[0];	550	$frame->[FR_AGAIN]{time} = $_[0];
445	$self->{counter} + 0	551	$frame->[FR_STATE]{counter} + 0
446	}	552	}
447		553
448	=back	554	=back
449		555
450	=head2 SHAPE CHANGING OPERATORS	556	=head2 SHAPE CHANGING OPERATORS
…		…
470	assumed.	576	assumed.
471		577
472	Example: load an image, blur it, and clip it to the window size to save	578	Example: load an image, blur it, and clip it to the window size to save
473	memory.	579	memory.
474		580
475	clip blur 10, load "mybg.png"	581	clip keep { blur 10, load "mybg.png" }
476		582
477	=cut	583	=cut
478		584
479	sub clip($;$$;$$) {	585	sub clip($;$$;$$) {
480	my $img = pop;	586	my $img = pop;
…		…
553		659
554	Example: move the image right by 20 pixels and down by 30.	660	Example: move the image right by 20 pixels and down by 30.
555		661
556	move 20, 30, ...	662	move 20, 30, ...
557		663
		664	=item align $xalign, $yalign, $img
		665
		666	Aligns the image according to a factor - C<0> means the image is moved to
		667	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		668	exactly centered and C<1> means it touches the right or bottom edge.
		669
		670	Example: remove any visible border around an image, center it vertically but move
		671	it to the right hand side.
		672
		673	align 1, 0.5, pad $img
		674
558	=item center $img	675	=item center $img
559		676
560	=item center $width, $height, $img	677	=item center $width, $height, $img
561		678
562	Centers the image, i.e. the center of the image is moved to the center of	679	Centers the image, i.e. the center of the image is moved to the center of
563	the terminal window (or the box specified by C<$width> and C<$height> if	680	the terminal window (or the box specified by C<$width> and C<$height> if
564	given).	681	given).
		682
		683	Example: load an image and center it.
		684
		685	center keep { pad load "mybg.png" }
565		686
566	=item rootalign $img	687	=item rootalign $img
567		688
568	Moves the image so that it appears glued to the screen as opposed to the	689	Moves the image so that it appears glued to the screen as opposed to the
569	window. This gives the illusion of a larger area behind the window. It is	690	window. This gives the illusion of a larger area behind the window. It is
570	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	691	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
571	top left of the screen.	692	top left of the screen.
572		693
573	Example: load a background image, put it in mirror mode and root align it.	694	Example: load a background image, put it in mirror mode and root align it.
574		695
575	rootalign mirror load "mybg.png"	696	rootalign keep { mirror load "mybg.png" }
576		697
577	Example: take the screen background and align it, giving the illusion of	698	Example: take the screen background and align it, giving the illusion of
578	transparency as long as the window isn't in front of other windows.	699	transparency as long as the window isn't in front of other windows.
579		700
580	rootalign root	701	rootalign root
581		702
582	=cut	703	=cut
583		704
584	sub move($$;$) {	705	sub move($$;$) {
585	my $img = pop->clone;	706	my $img = pop->clone;
586	$img->move ($_[0], $_[1]);	707	$img->move ($_[0], $_[1]);
587	$img	708	$img
588	}	709	}
589		710
		711	sub align($;$$) {
		712	my $img = pop;
		713
		714	move $_[0] * (TW - $img->w),
		715	$_[1] * (TH - $img->h),
		716	$img
		717	}
		718
590	sub center($;$$) {	719	sub center($;$$) {
591	my $img = pop;	720	my $img = pop;
592	my $w = $_[0] \|\| TW;	721	my $w = $_[0] \|\| TW;
593	my $h = $_[0] \|\| TH;	722	my $h = $_[1] \|\| TH;
594		723
595	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img	724	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
596	}	725	}
597		726
598	sub rootalign($) {	727	sub rootalign($) {
599	move -TX, -TY, $_[0]	728	move -TX, -TY, $_[0]
		729	}
		730
		731	=item rotate $center_x, $center_y, $degrees, $img
		732
		733	Rotates the image clockwise by C<$degrees> degrees, around the point at
		734	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		735
		736	Example: rotate the image by 90 degrees around it's center.
		737
		738	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		739
		740	=cut
		741
		742	sub rotate($$$$) {
		743	my $img = pop;
		744	$img->rotate (
		745	$_[0] * ($img->w + $img->x),
		746	$_[1] * ($img->h + $img->y),
		747	$_[2] * (3.14159265 / 180),
		748	)
600	}	749	}
601		750
602	=back	751	=back
603		752
604	=head2 COLOUR MODIFICATIONS	753	=head2 COLOUR MODIFICATIONS
…		…
640		789
641	Values less than 0 reduce brightness, while values larger than 0 increase	790	Values less than 0 reduce brightness, while values larger than 0 increase
642	it. Useful range is from -1 to 1 - the former results in a black, the	791	it. Useful range is from -1 to 1 - the former results in a black, the
643	latter in a white picture.	792	latter in a white picture.
644		793
645	Due to idiosynchrasies in the underlying XRender extension, biases less	794	Due to idiosyncrasies in the underlying XRender extension, biases less
646	than zero can be I<very> slow.	795	than zero can be I<very> slow.
647		796
648	=cut	797	=cut
649		798
650	sub contrast($$;$$;$) {	799	sub contrast($$;$$;$) {
651	my $img = pop;	800	my $img = pop;
652	my ($r, $g, $b, $a) = @_;	801	my ($r, $g, $b, $a) = @_;
653		802
654	($g, $b) = ($r, $r) if @_ < 4;	803	($g, $b) = ($r, $r) if @_ < 3;
655	$a = 1 if @_ < 5;	804	$a = 1 if @_ < 4;
656		805
657	$img = $img->clone;	806	$img = $img->clone;
658	$img->contrast ($r, $g, $b, $a);	807	$img->contrast ($r, $g, $b, $a);
659	$img	808	$img
660	}	809	}
661		810
662	sub brightness($$;$$;$) {	811	sub brightness($$;$$;$) {
663	my $img = pop;	812	my $img = pop;
664	my ($r, $g, $b, $a) = @_;	813	my ($r, $g, $b, $a) = @_;
665		814
666	($g, $b) = ($r, $r) if @_ < 4;	815	($g, $b) = ($r, $r) if @_ < 3;
667	$a = 1 if @_ < 5;	816	$a = 1 if @_ < 4;
668		817
669	$img = $img->clone;	818	$img = $img->clone;
670	$img->brightness ($r, $g, $b, $a);	819	$img->brightness ($r, $g, $b, $a);
671	$img	820	$img
672	}	821	}
…		…
688	sub blur($$;$) {	837	sub blur($$;$) {
689	my $img = pop;	838	my $img = pop;
690	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	839	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
691	}	840	}
692		841
693	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
694
695	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
696	pointer at C<$center_x> and C<$center_y> (specified as factor of image
697	width/height), generating a new image with width C<$new_width> and height
698	C<$new_height>.
699
700	#TODO# new width, height, maybe more operators?
701
702	Example: rotate the image by 90 degrees
703
704	=cut
705
706	sub rotate($$$$$$) {
707	my $img = pop;
708	$img->rotate (
709	$_[0],
710	$_[1],
711	$_[2] * $img->w,
712	$_[3] * $img->h,
713	$_[4] * (3.14159265 / 180),
714	)
715	}
716
717	=back	842	=back
718		843
		844	=head2 OTHER STUFF
		845
		846	Anything that didn't fit any of the other categories, even after applying
		847	force and closing our eyes.
		848
		849	=over 4
		850
		851	=item keep { ... }
		852
		853	This operator takes a code block as argument, that is, one or more
		854	statements enclosed by braces.
		855
		856	The trick is that this code block is only evaluated when the outcome
		857	changes - on other calls the C<keep> simply returns the image it computed
		858	previously (yes, it should only be used with images). Or in other words,
		859	C<keep> I<caches> the result of the code block so it doesn't need to be
		860	computed again.
		861
		862	This can be extremely useful to avoid redoing slow operations - for
		863	example, if your background expression takes the root background, blurs it
		864	and then root-aligns it it would have to blur the root background on every
		865	window move or resize.
		866
		867	Another example is C<load>, which can be quite slow.
		868
		869	In fact, urxvt itself encloses the whole expression in some kind of
		870	C<keep> block so it only is reevaluated as required.
		871
		872	Putting the blur into a C<keep> block will make sure the blur is only done
		873	once, while the C<rootalign> is still done each time the window moves.
		874
		875	rootlign keep { blur 10, root }
		876
		877	This leaves the question of how to force reevaluation of the block,
		878	in case the root background changes: If expression inside the block
		879	is sensitive to some event (root background changes, window geometry
		880	changes), then it will be reevaluated automatically as needed.
		881
		882	=cut
		883
		884	sub keep(&) {
		885	my $id = $_[0]+0;
		886
		887	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		888
		889	unless ($frame->[FR_CACHE]) {
		890	$frame->[FR_CACHE] = [ $_[0]() ];
		891
		892	my $self = $self;
		893	my $frame = $frame;
		894	Scalar::Util::weaken $frame;
		895	$self->compile_frame ($frame, sub {
		896	# clear this frame cache, also for all parents
		897	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		898	undef $frame->[FR_CACHE];
		899	}
		900
		901	$self->recalculate;
		902	});
		903	};
		904
		905	# in scalar context we always return the first original result, which
		906	# is not quite how perl works.
		907	wantarray
		908	? @{ $frame->[FR_CACHE] }
		909	: $frame->[FR_CACHE][0]
		910	}
		911
		912	# sub keep_clear() {
		913	# delete $self->{frame_cache};
		914	# }
		915
		916	=back
		917
719	=cut	918	=cut
720		919
721	}	920	}
722		921
723	sub parse_expr {	922	sub parse_expr {
724	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	923	my $expr = eval
		924	"sub {\n"
		925	. "package urxvt::bgdsl;\n"
		926	. "#line 0 'background expression'\n"
		927	. "$_[0]\n"
		928	. "}";
725	die if $@;	929	die if $@;
726	$expr	930	$expr
727	}	931	}
728		932
729	# compiles a parsed expression	933	# compiles a parsed expression
730	sub set_expr {	934	sub set_expr {
731	my ($self, $expr) = @_;	935	my ($self, $expr) = @_;
732		936
		937	$self->{root} = [];
733	$self->{expr} = $expr;	938	$self->{expr} = $expr;
734	$self->recalculate;	939	$self->recalculate;
		940	}
		941
		942	# takes a hash of sensitivity indicators and installs watchers
		943	sub compile_frame {
		944	my ($self, $frame, $cb) = @_;
		945
		946	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		947	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		948
		949	# don't keep stuff alive
		950	Scalar::Util::weaken $state;
		951
		952	if ($again->{nested}) {
		953	$state->{nested} = 1;
		954	} else {
		955	delete $state->{nested};
		956	}
		957
		958	if (my $interval = $again->{time}) {
		959	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		960	if $state->{time}[0] != $interval;
		961
		962	# callback might have changed, although we could just rule that out
		963	$state->{time}[1]->cb (sub {
		964	++$state->{counter};
		965	$cb->();
		966	});
		967	} else {
		968	delete $state->{time};
		969	}
		970
		971	if ($again->{position}) {
		972	$state->{position} = $self->on (position_change => $cb);
		973	} else {
		974	delete $state->{position};
		975	}
		976
		977	if ($again->{size}) {
		978	$state->{size} = $self->on (size_change => $cb);
		979	} else {
		980	delete $state->{size};
		981	}
		982
		983	if ($again->{rootpmap}) {
		984	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		985	} else {
		986	delete $state->{rootpmap};
		987	}
735	}	988	}
736		989
737	# evaluate the current bg expression	990	# evaluate the current bg expression
738	sub recalculate {	991	sub recalculate {
739	my ($arg_self) = @_;	992	my ($arg_self) = @_;
…		…
749		1002
750	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1003	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
751		1004
752	# set environment to evaluate user expression	1005	# set environment to evaluate user expression
753		1006
754	local $self = $arg_self;	1007	local $self = $arg_self;
755
756	local $HOME = $ENV{HOME};	1008	local $HOME = $ENV{HOME};
757	local $old = $self->{state};	1009	local $frame = [];
758	local $new = my $state = $self->{state} = {};
759		1010
760	($x, $y, $w, $h) =
761	$self->background_geometry ($self->{border});	1011	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
762		1012
763	# evaluate user expression	1013	# evaluate user expression
764		1014
765	my $img = eval { $self->{expr}->() };	1015	my @img = eval { $self->{expr}->() };
766	warn $@ if $@;#d#	1016	die $@ if $@;
		1017	die "background-expr did not return anything.\n" unless @img;
		1018	die "background-expr: expected image(s), got something else.\n"
767	die if !UNIVERSAL::isa $img, "urxvt::img";	1019	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
768		1020
769	$state->{size_sensitive} = 1	1021	my $img = urxvt::bgdsl::merge @img;
		1022
		1023	$frame->[FR_AGAIN]{size} = 1
770	if $img->repeat_mode != urxvt::RepeatNormal;	1024	if $img->repeat_mode != urxvt::RepeatNormal;
771		1025
772	# if the expression is sensitive to external events, prepare reevaluation then	1026	# if the expression is sensitive to external events, prepare reevaluation then
773		1027	$self->compile_frame ($frame, sub { $arg_self->recalculate });
774	my $repeat;
775
776	if (my $again = $state->{again}) {
777	$repeat = 1;
778	my $self = $self;
779	$state->{timer} = $again == $old->{again}
780	? $old->{timer}
781	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
782	++$self->{counter};
783	$self->recalculate
784	});
785	}
786
787	if (delete $state->{position_sensitive}) {
788	$repeat = 1;
789	$self->enable (position_change => sub { $_[0]->recalculate });
790	} else {
791	$self->disable ("position_change");
792	}
793
794	if (delete $state->{size_sensitive}) {
795	$repeat = 1;
796	$self->enable (size_change => sub { $_[0]->recalculate });
797	} else {
798	$self->disable ("size_change");
799	}
800
801	if (delete $state->{rootpmap_sensitive}) {
802	$repeat = 1;
803	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
804	} else {
805	$self->disable ("rootpmap_change");
806	}
807		1028
808	# clear stuff we no longer need	1029	# clear stuff we no longer need
809		1030
810	%$old = ();	1031	# unless (%{ $frame->[FR_STATE] }) {
811
812	unless ($repeat) {
813	delete $self->{state};	1032	# delete $self->{state};
814	delete $self->{expr};	1033	# delete $self->{expr};
815	}	1034	# }
816		1035
817	# set background pixmap	1036	# set background pixmap
818		1037
819	$self->set_background ($img, $self->{border});	1038	$self->set_background ($img, $self->{border});
820	$self->scr_recolour (0);	1039	$self->scr_recolour (0);
…		…
822	}	1041	}
823		1042
824	sub on_start {	1043	sub on_start {
825	my ($self) = @_;	1044	my ($self) = @_;
826		1045
827	my $expr = $self->x_resource ("background.expr")	1046	my $expr = $self->x_resource ("%.expr")
828	or return;	1047	or return;
829		1048
		1049	$self->has_render
		1050	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		1051
830	$self->set_expr (parse_expr $expr);	1052	$self->set_expr (parse_expr $expr);
831	$self->{border} = $self->x_resource_boolean ("background.border");	1053	$self->{border} = $self->x_resource_boolean ("%.border");
		1054
		1055	$MIN_INTERVAL = $self->x_resource ("%.interval");
832		1056
833	()	1057	()
834	}	1058	}
835		1059

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.45 by root, Sun Jun 10 11:53:32 2012 UTC vs. Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC

Diff Legend

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.45 by root, Sun Jun 10 11:53:32 2012 UTC vs.
Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC