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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.48 by root, Sun Jun 10 15:01:14 2012 UTC vs.
Revision 1.71 by root, Mon Jul 2 01:40:41 2012 UTC

…		…
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		6
7	#TODO: once, rootalign
8
9	=head1 NAME	7	=head1 NAME
10		8
11	background - manage terminal background	9	background - manage terminal background
12		10
13	=head1 SYNOPSIS	11	=head1 SYNOPSIS
…		…
28	to be as simple as possible.	26	to be as simple as possible.
29		27
30	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
31	use:	29	use:
32		30
33	urxvt --background-expr 'scale load "/path/to/mybg.png"'	31	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
34		32
35	Or specified as a X resource:	33	Or specified as a X resource:
36		34
37	URxvt.background-expr: scale load "/path/to/mybg.png"	35	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }
38		36
39	=head1 THEORY OF OPERATION	37	=head1 THEORY OF OPERATION
40		38
41	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
42	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
…		…
55	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
56	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
57	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
58	timer elapses), then the expression will be evaluated again.	56	timer elapses), then the expression will be evaluated again.
59		57
60	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"
61	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
62	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
63	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
64	after it's size changes.	62	after its size changes.
65		63
66	=head2 EXPRESSIONS	64	=head2 EXPRESSIONS
67		65
68	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
69	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
70		68
		69	scale keep {
71	again 3600;	70	again 3600;
72	if (localtime now)[6]) {	71	if (localtime now)[6]) {
73	return scale load "$HOME/weekday.png";	72	return load "$HOME/weekday.png";
74	} else {	73	} else {
75	return scale load "$HOME/sunday.png";	74	return load "$HOME/sunday.png";
		75	}
76	}	76	}
77		77
78	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
79	background on Sundays, and F<weekday.png> on all other days.	80	Sundays, and F<weekday.png> on all other days.
80		81
81	Fortunately, we expect that most expressions will be much simpler, with	82	Fortunately, we expect that most expressions will be much simpler, with
82	little Perl knowledge needed.	83	little Perl knowledge needed.
83		84
84	Basically, you always start with a function that "generates" an image	85	Basically, you always start with a function that "generates" an image
…		…
117	horizontal and vertical dimensions. For example, this halves the image	118	horizontal and vertical dimensions. For example, this halves the image
118	width and doubles the image height:	119	width and doubles the image height:
119		120
120	scale 0.5, 2, load "$HOME/mypic.png"	121	scale 0.5, 2, load "$HOME/mypic.png"
121		122
122	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,
123	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:
124		127
		128	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		129
		130	The C<keep> operator executes all the statements inside the braces only
		131	once, or when it thinks the outcome might change. In other cases it
		132	returns the last value computed by the brace block.
		133
		134	This means that the C<load> is only executed once, which makes it much
		135	faster, but also means that more memory is being used, because the loaded
		136	image must be kept in memory at all times. In this expression, the
		137	trade-off is likely worth it.
		138
		139	But back to effects: Other effects than scaling are also readily
		140	available, for example, you can tile the image to fill the whole window,
		141	instead of resizing it:
		142
125	tile load "$HOME/mypic.png"	143	tile keep { load "$HOME/mypic.png" }
126		144
127	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	145	In fact, images returned by C<load> are in C<tile> mode by default, so the
128	is kind of superfluous.	146	C<tile> operator is kind of superfluous.
129		147
130	Another common effect is to mirror the image, so that the same edges touch:	148	Another common effect is to mirror the image, so that the same edges
		149	touch:
131		150
132	mirror load "$HOME/mypic.png"	151	mirror keep { load "$HOME/mypic.png" }
133		152
134	This is also a typical background expression:	153	Another common background expression is:
135		154
136	rootalign root	155	rootalign root
137		156
138	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
139	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
140	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:
141	moved around.	160	the image seems to be static while the window is moved around.
142		161
143	=head2 CYCLES AND CACHING	162	=head2 COLOUR SPECIFICATIONS
144		163
145	As has been mentioned before, the expression might be evaluated multiple	164	Whenever an oprator expects a "colour", then this can be specified in one
146	times. Each time the expression is reevaluated, a new cycle is said to	165	of two ways: Either as string with an X11 colour specification, such as:
147	have begun. Many operators cache their results till the next cycle.
148		166
149	For example, the C<load> operator keeps a copy of the image. If it is	167	"red" # named colour
150	asked to load the same image on the next cycle it will not load it again,	168	"#f00" # simple rgb
151	but return the cached copy.	169	"[50]red" # red with 50% alpha
		170	"TekHVC:300/50/50" # anything goes
152		171
153	This only works for one cycle though, so as long as you load the same	172	OR as an array reference with one, three or four components:
154	image every time, it will always be cached, but when you load a different
155	image, it will forget about the first one.
156		173
157	This allows you to either speed things up by keeping multiple images in	174	[0.5] # 50% gray, 100% alpha
158	memory, or comserve memory by loading images more often.	175	[0.5, 0, 0] # dark red, no green or blur, 100% alpha
		176	[0.5, 0, 0, 0.7] # same with explicit 70% alpha
159		177
160	For example, you can keep two images in memory and use a random one like	178	=head2 CACHING AND SENSITIVITY
161	this:
162		179
163	my $img1 = load "img1.png";	180	Since some operations (such as C<load> and C<blur>) can take a long time,
164	my $img2 = load "img2.png";	181	caching results can be very important for a smooth operation. Caching can
165	(0.5 > rand) ? $img1 : $img2	182	also be useful to reduce memory usage, though, for example, when an image
		183	is cached by C<load>, it could be shared by multiple terminal windows
		184	running inside urxvtd.
166		185
167	Since both images are "loaded" every time the expression is evaluated,	186	=head3 C<keep { ... }> caching
168	they are always kept in memory. Contrast this version:
169		187
170	my $path1 = "img1.png";	188	The most important way to cache expensive operations is to use C<keep {
171	my $path2 = "img2.png";	189	... }>. The C<keep> operator takes a block of multiple statements enclosed
172	load ((0.5 > rand) ? $path1 : $path2)	190	by C<{}> and keeps the return value in memory.
173		191
174	Here, a path is selected randomly, and load is only called for one image,	192	An expression can be "sensitive" to various external events, such as
175	so keeps only one image in memory. If, on the next evaluation, luck	193	scaling or moving the window, root background changes and timers. Simply
176	decides to use the other path, then it will have to load that image again.	194	using an expression (such as C<scale> without parameters) that depends on
		195	certain changing values (called "variables"), or using those variables
		196	directly, will make an expression sensitive to these events - for example,
		197	using C<scale> or C<TW> will make the expression sensitive to the terminal
		198	size, and thus to resizing events.
		199
		200	When such an event happens, C<keep> will automatically trigger a
		201	reevaluation of the whole expression with the new value of the expression.
		202
		203	C<keep> is most useful for expensive operations, such as C<blur>:
		204
		205	rootalign keep { blur 20, root }
		206
		207	This makes a blurred copy of the root background once, and on subsequent
		208	calls, just root-aligns it. Since C<blur> is usually quite slow and
		209	C<rootalign> is quite fast, this trades extra memory (for the cached
		210	blurred pixmap) with speed (blur only needs to be redone when root
		211	changes).
		212
		213	=head3 C<load> caching
		214
		215	The C<load> operator itself does not keep images in memory, but as long as
		216	the image is still in memory, C<load> will use the in-memory image instead
		217	of loading it freshly from disk.
		218
		219	That means that this expression:
		220
		221	keep { load "$HOME/path..." }
		222
		223	Not only caches the image in memory, other terminal instances that try to
		224	C<load> it can reuse that in-memory copy.
177		225
178	=head1 REFERENCE	226	=head1 REFERENCE
179		227
180	=head2 COMMAND LINE SWITCHES	228	=head2 COMMAND LINE SWITCHES
181		229
…		…
193	Specifying this flag changes the behaviour, so that the image only	241	Specifying this flag changes the behaviour, so that the image only
194	replaces the background of the character area.	242	replaces the background of the character area.
195		243
196	=item --background-interval seconds	244	=item --background-interval seconds
197		245
198	Since some operations in the underlying XRender extension can effetively	246	Since some operations in the underlying XRender extension can effectively
199	freeze your X-server for prolonged time, this extension enforces a minimum	247	freeze your X-server for prolonged time, this extension enforces a minimum
200	time between updates, which is normally about 0.1 seconds.	248	time between updates, which is normally about 0.1 seconds.
201		249
202	If you want to do updates more often, you can decrease this safety	250	If you want to do updates more often, you can decrease this safety
203	interval with this switch.	251	interval with this switch.
204		252
205	=back	253	=back
206		254
207	=cut	255	=cut
208		256
		257	our %_IMG_CACHE;
209	our $HOME;	258	our $HOME;
210	our ($self, $old, $new);	259	our ($self, $frame);
211	our ($x, $y, $w, $h);	260	our ($x, $y, $w, $h);
212		261
213	# enforce at least this interval between updates	262	# enforce at least this interval between updates
214	our $MIN_INTERVAL = 6/59.951;	263	our $MIN_INTERVAL = 6/59.951;
215		264
216	{	265	{
217	package urxvt::bgdsl; # background language	266	package urxvt::bgdsl; # background language
		267
		268	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		269	sub FR_CACHE () { 1 } # cached values
		270	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		271	sub FR_STATE () { 3 } # watchers etc.
218		272
219	use List::Util qw(min max sum shuffle);	273	use List::Util qw(min max sum shuffle);
220		274
221	=head2 PROVIDERS/GENERATORS	275	=head2 PROVIDERS/GENERATORS
222		276
…		…
229	=item load $path	283	=item load $path
230		284
231	Loads the image at the given C<$path>. The image is set to plane tiling	285	Loads the image at the given C<$path>. The image is set to plane tiling
232	mode.	286	mode.
233		287
234	Loaded images will be cached for one cycle.	288	If the image is already in memory (e.g. because another terminal instance
		289	uses it), then the in-memory copy us returned instead.
		290
		291	=item load_uc $path
		292
		293	Load uncached - same as load, but does not cache the image, which means it
		294	is I<always> loaded from the filesystem again.
235		295
236	=cut	296	=cut
237		297
238	sub load($) {	298	sub load($) {
239	my ($path) = @_;	299	my ($path) = @_;
240		300
241	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	301	$_IMG_CACHE{$path} \|\| do {
		302	my $img = $self->new_img_from_file ($path);
		303	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		304	$img
		305	}
242	}	306	}
243		307
244	=item root	308	=item root
245		309
246	Returns the root window pixmap, that is, hopefully, the background image	310	Returns the root window pixmap, that is, hopefully, the background image
247	of your screen. The image is set to extend mode.	311	of your screen.
248		312
249	This function makes your expression root sensitive, that means it will be	313	This function makes your expression root sensitive, that means it will be
250	reevaluated when the bg image changes.	314	reevaluated when the bg image changes.
251		315
252	=cut	316	=cut
253		317
254	sub root() {	318	sub root() {
255	$new->{rootpmap_sensitive} = 1;	319	$frame->[FR_AGAIN]{rootpmap} = 1;
256	die "root op not supported, exg, we need you";	320	$self->new_img_from_root
257	}	321	}
258		322
259	=item solid $colour	323	=item solid $colour
260		324
261	=item solid $width, $height, $colour	325	=item solid $width, $height, $colour
…		…
269	=cut	333	=cut
270		334
271	sub solid($;$$) {	335	sub solid($;$$) {
272	my $colour = pop;	336	my $colour = pop;
273		337
274	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	338	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
275	$img->fill ($colour);	339	$img->fill ($colour);
276	$img	340	$img
277	}	341	}
278		342
279	=item clone $img	343	=item clone $img
…		…
285		349
286	sub clone($) {	350	sub clone($) {
287	$_[0]->clone	351	$_[0]->clone
288	}	352	}
289		353
290	=back	354	=item merge $img ...
		355
		356	Takes any number of images and merges them together, creating a single
		357	image containing them all. The tiling mode of the first image is used as
		358	the tiling mode of the resulting image.
		359
		360	This function is called automatically when an expression returns multiple
		361	images.
		362
		363	=cut
		364
		365	sub merge(@) {
		366	return $_[0] unless $#_;
		367
		368	# rather annoyingly clumsy, but optimisation is for another time
		369
		370	my $x0 = +1e9;
		371	my $y0 = +1e9;
		372	my $x1 = -1e9;
		373	my $y1 = -1e9;
		374
		375	for (@_) {
		376	my ($x, $y, $w, $h) = $_->geometry;
		377
		378	$x0 = $x if $x0 > $x;
		379	$y0 = $y if $y0 > $y;
		380
		381	$x += $w;
		382	$y += $h;
		383
		384	$x1 = $x if $x1 < $x;
		385	$y1 = $y if $y1 < $y;
		386	}
		387
		388	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		389	$base->repeat_mode ($_[0]->repeat_mode);
		390	$base->fill ([0, 0, 0, 0]);
		391
		392	$base->draw ($_)
		393	for @_;
		394
		395	$base
		396	}
291		397
292	=head2 TILING MODES	398	=head2 TILING MODES
293		399
294	The following operators modify the tiling mode of an image, that is, the	400	The following operators modify the tiling mode of an image, that is, the
295	way that pixels outside the image area are painted when the image is used.	401	way that pixels outside the image area are painted when the image is used.
…		…
325	become transparent. This mode is most useful when you want to place an	431	become transparent. This mode is most useful when you want to place an
326	image over another image or the background colour while leaving all	432	image over another image or the background colour while leaving all
327	background pixels outside the image unchanged.	433	background pixels outside the image unchanged.
328		434
329	Example: load an image and display it in the upper left corner. The rest	435	Example: load an image and display it in the upper left corner. The rest
330	of the space is left "empty" (transparent or wahtever your compisotr does	436	of the space is left "empty" (transparent or whatever your compositor does
331	in alpha mode, else background colour).	437	in alpha mode, else background colour).
332		438
333	pad load "mybg.png"	439	pad load "mybg.png"
334		440
335	=item extend $img	441	=item extend $img
336		442
337	Extends the image over the whole plane, using the closest pixel in the	443	Extends the image over the whole plane, using the closest pixel in the
338	area outside the image. This mode is mostly useful when you more complex	444	area outside the image. This mode is mostly useful when you use more complex
339	filtering operations and want the pixels outside the image to have the	445	filtering operations and want the pixels outside the image to have the
340	same values as the pixels near the edge.	446	same values as the pixels near the edge.
341		447
342	Example: just for curiosity, how does this pixel extension stuff work?	448	Example: just for curiosity, how does this pixel extension stuff work?
343		449
…		…
392	Using these functions make your expression sensitive to window moves.	498	Using these functions make your expression sensitive to window moves.
393		499
394	These functions are mainly useful to align images to the root window.	500	These functions are mainly useful to align images to the root window.
395		501
396	Example: load an image and align it so it looks as if anchored to the	502	Example: load an image and align it so it looks as if anchored to the
397	background.	503	background (that's exactly what C<rootalign> does btw.):
398		504
399	move -TX, -TY, load "mybg.png"	505	move -TX, -TY, keep { load "mybg.png" }
400		506
401	=item TW	507	=item TW
402		508
403	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	509	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
404	terminal window is the full window by default, and the character area only	510	terminal window is the full window by default, and the character area only
…		…
410	the window size to conserve memory.	516	the window size to conserve memory.
411		517
412	Example: take the screen background, clip it to the window size, blur it a	518	Example: take the screen background, clip it to the window size, blur it a
413	bit, align it to the window position and use it as background.	519	bit, align it to the window position and use it as background.
414		520
415	clip move -TX, -TY, blur 5, root	521	clip move -TX, -TY, keep { blur 5, root }
416		522
417	=cut	523	=cut
418		524
419	sub TX() { $new->{position_sensitive} = 1; $x }	525	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
420	sub TY() { $new->{position_sensitive} = 1; $y }	526	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
421	sub TW() { $new->{size_sensitive} = 1; $w }	527	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
422	sub TH() { $new->{size_sensitive} = 1; $h }	528	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
423		529
424	=item now	530	=item now
425		531
426	Returns the current time as (fractional) seconds since the epoch.	532	Returns the current time as (fractional) seconds since the epoch.
427		533
…		…
434	C<$seconds> seconds.	540	C<$seconds> seconds.
435		541
436	Example: load some image and rotate it according to the time of day (as if it were	542	Example: load some image and rotate it according to the time of day (as if it were
437	the hour pointer of a clock). Update this image every minute.	543	the hour pointer of a clock). Update this image every minute.
438		544
		545	again 60;
439	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	546	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
440		547
441	=item counter $seconds	548	=item counter $seconds
442		549
443	Like C<again>, but also returns an increasing counter value, starting at	550	Like C<again>, but also returns an increasing counter value, starting at
444	0, which might be useful for some simple animation effects.	551	0, which might be useful for some simple animation effects.
…		…
446	=cut	553	=cut
447		554
448	sub now() { urxvt::NOW }	555	sub now() { urxvt::NOW }
449		556
450	sub again($) {	557	sub again($) {
451	$new->{again} = $_[0];	558	$frame->[FR_AGAIN]{time} = $_[0];
452	}	559	}
453		560
454	sub counter($) {	561	sub counter($) {
455	$new->{again} = $_[0];	562	$frame->[FR_AGAIN]{time} = $_[0];
456	$self->{counter} + 0	563	$frame->[FR_STATE]{counter} + 0
457	}	564	}
458		565
459	=back	566	=back
460		567
461	=head2 SHAPE CHANGING OPERATORS	568	=head2 SHAPE CHANGING OPERATORS
…		…
481	assumed.	588	assumed.
482		589
483	Example: load an image, blur it, and clip it to the window size to save	590	Example: load an image, blur it, and clip it to the window size to save
484	memory.	591	memory.
485		592
486	clip blur 10, load "mybg.png"	593	clip keep { blur 10, load "mybg.png" }
487		594
488	=cut	595	=cut
489		596
490	sub clip($;$$;$$) {	597	sub clip($;$$;$$) {
491	my $img = pop;	598	my $img = pop;
…		…
585	the terminal window (or the box specified by C<$width> and C<$height> if	692	the terminal window (or the box specified by C<$width> and C<$height> if
586	given).	693	given).
587		694
588	Example: load an image and center it.	695	Example: load an image and center it.
589		696
590	center pad load "mybg.png"	697	center keep { pad load "mybg.png" }
591		698
592	=item rootalign $img	699	=item rootalign $img
593		700
594	Moves the image so that it appears glued to the screen as opposed to the	701	Moves the image so that it appears glued to the screen as opposed to the
595	window. This gives the illusion of a larger area behind the window. It is	702	window. This gives the illusion of a larger area behind the window. It is
596	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	703	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
597	top left of the screen.	704	top left of the screen.
598		705
599	Example: load a background image, put it in mirror mode and root align it.	706	Example: load a background image, put it in mirror mode and root align it.
600		707
601	rootalign mirror load "mybg.png"	708	rootalign keep { mirror load "mybg.png" }
602		709
603	Example: take the screen background and align it, giving the illusion of	710	Example: take the screen background and align it, giving the illusion of
604	transparency as long as the window isn't in front of other windows.	711	transparency as long as the window isn't in front of other windows.
605		712
606	rootalign root	713	rootalign root
…		…
631		738
632	sub rootalign($) {	739	sub rootalign($) {
633	move -TX, -TY, $_[0]	740	move -TX, -TY, $_[0]
634	}	741	}
635		742
		743	=item rotate $center_x, $center_y, $degrees, $img
		744
		745	Rotates the image clockwise by C<$degrees> degrees, around the point at
		746	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		747
		748	Example: rotate the image by 90 degrees around it's center.
		749
		750	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		751
		752	=cut
		753
		754	sub rotate($$$$) {
		755	my $img = pop;
		756	$img->rotate (
		757	$_[0] * ($img->w + $img->x),
		758	$_[1] * ($img->h + $img->y),
		759	$_[2] * (3.14159265 / 180),
		760	)
		761	}
		762
636	=back	763	=back
637		764
638	=head2 COLOUR MODIFICATIONS	765	=head2 COLOUR MODIFICATIONS
639		766
640	The following operators change the pixels of the image.	767	The following operators change the pixels of the image.
641		768
642	=over 4	769	=over 4
		770
		771	=item tint $color, $img
		772
		773	Tints the image in the given colour.
		774
		775	Example: tint the image red.
		776
		777	tint "red", load "rgb.png"
		778
		779	Example: the same, but specify the colour by component.
		780
		781	tint [1, 0, 0], load "rgb.png"
		782
		783	=cut
		784
		785	sub tint($$) {
		786	$_[1]->tint ($_[0])
		787	}
643		788
644	=item contrast $factor, $img	789	=item contrast $factor, $img
645		790
646	=item contrast $r, $g, $b, $img	791	=item contrast $r, $g, $b, $img
647		792
…		…
674		819
675	Values less than 0 reduce brightness, while values larger than 0 increase	820	Values less than 0 reduce brightness, while values larger than 0 increase
676	it. Useful range is from -1 to 1 - the former results in a black, the	821	it. Useful range is from -1 to 1 - the former results in a black, the
677	latter in a white picture.	822	latter in a white picture.
678		823
679	Due to idiosynchrasies in the underlying XRender extension, biases less	824	Due to idiosyncrasies in the underlying XRender extension, biases less
680	than zero can be I<very> slow.	825	than zero can be I<very> slow.
681		826
682	=cut	827	=cut
683		828
684	sub contrast($$;$$;$) {	829	sub contrast($$;$$;$) {
685	my $img = pop;	830	my $img = pop;
686	my ($r, $g, $b, $a) = @_;	831	my ($r, $g, $b, $a) = @_;
687		832
688	($g, $b) = ($r, $r) if @_ < 4;	833	($g, $b) = ($r, $r) if @_ < 3;
689	$a = 1 if @_ < 5;	834	$a = 1 if @_ < 4;
690		835
691	$img = $img->clone;	836	$img = $img->clone;
692	$img->contrast ($r, $g, $b, $a);	837	$img->contrast ($r, $g, $b, $a);
693	$img	838	$img
694	}	839	}
695		840
696	sub brightness($$;$$;$) {	841	sub brightness($$;$$;$) {
697	my $img = pop;	842	my $img = pop;
698	my ($r, $g, $b, $a) = @_;	843	my ($r, $g, $b, $a) = @_;
699		844
700	($g, $b) = ($r, $r) if @_ < 4;	845	($g, $b) = ($r, $r) if @_ < 3;
701	$a = 1 if @_ < 5;	846	$a = 1 if @_ < 4;
702		847
703	$img = $img->clone;	848	$img = $img->clone;
704	$img->brightness ($r, $g, $b, $a);	849	$img->brightness ($r, $g, $b, $a);
705	$img	850	$img
706	}	851	}
…		…
722	sub blur($$;$) {	867	sub blur($$;$) {
723	my $img = pop;	868	my $img = pop;
724	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	869	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
725	}	870	}
726		871
727	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
728
729	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
730	pointer at C<$center_x> and C<$center_y> (specified as factor of image
731	width/height), generating a new image with width C<$new_width> and height
732	C<$new_height>.
733
734	#TODO# new width, height, maybe more operators?
735
736	Example: rotate the image by 90 degrees
737
738	=cut
739
740	sub rotate($$$$$$) {
741	my $img = pop;
742	$img->rotate (
743	$_[0],
744	$_[1],
745	$_[2] * $img->w,
746	$_[3] * $img->h,
747	$_[4] * (3.14159265 / 180),
748	)
749	}
750
751	=back	872	=back
752		873
		874	=head2 OTHER STUFF
		875
		876	Anything that didn't fit any of the other categories, even after applying
		877	force and closing our eyes.
		878
		879	=over 4
		880
		881	=item keep { ... }
		882
		883	This operator takes a code block as argument, that is, one or more
		884	statements enclosed by braces.
		885
		886	The trick is that this code block is only evaluated when the outcome
		887	changes - on other calls the C<keep> simply returns the image it computed
		888	previously (yes, it should only be used with images). Or in other words,
		889	C<keep> I<caches> the result of the code block so it doesn't need to be
		890	computed again.
		891
		892	This can be extremely useful to avoid redoing slow operations - for
		893	example, if your background expression takes the root background, blurs it
		894	and then root-aligns it it would have to blur the root background on every
		895	window move or resize.
		896
		897	Another example is C<load>, which can be quite slow.
		898
		899	In fact, urxvt itself encloses the whole expression in some kind of
		900	C<keep> block so it only is reevaluated as required.
		901
		902	Putting the blur into a C<keep> block will make sure the blur is only done
		903	once, while the C<rootalign> is still done each time the window moves.
		904
		905	rootlign keep { blur 10, root }
		906
		907	This leaves the question of how to force reevaluation of the block,
		908	in case the root background changes: If expression inside the block
		909	is sensitive to some event (root background changes, window geometry
		910	changes), then it will be reevaluated automatically as needed.
		911
		912	=cut
		913
		914	sub keep(&) {
		915	my $id = $_[0]+0;
		916
		917	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		918
		919	unless ($frame->[FR_CACHE]) {
		920	$frame->[FR_CACHE] = [ $_[0]() ];
		921
		922	my $self = $self;
		923	my $frame = $frame;
		924	Scalar::Util::weaken $frame;
		925	$self->compile_frame ($frame, sub {
		926	# clear this frame cache, also for all parents
		927	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		928	undef $frame->[FR_CACHE];
		929	}
		930
		931	$self->recalculate;
		932	});
		933	};
		934
		935	# in scalar context we always return the first original result, which
		936	# is not quite how perl works.
		937	wantarray
		938	? @{ $frame->[FR_CACHE] }
		939	: $frame->[FR_CACHE][0]
		940	}
		941
		942	# sub keep_clear() {
		943	# delete $self->{frame_cache};
		944	# }
		945
		946	=back
		947
753	=cut	948	=cut
754		949
755	}	950	}
756		951
757	sub parse_expr {	952	sub parse_expr {
758	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	953	my $expr = eval
		954	"sub {\n"
		955	. "package urxvt::bgdsl;\n"
		956	. "#line 0 'background expression'\n"
		957	. "$_[0]\n"
		958	. "}";
759	die if $@;	959	die if $@;
760	$expr	960	$expr
761	}	961	}
762		962
763	# compiles a parsed expression	963	# compiles a parsed expression
764	sub set_expr {	964	sub set_expr {
765	my ($self, $expr) = @_;	965	my ($self, $expr) = @_;
766		966
		967	$self->{root} = [];
767	$self->{expr} = $expr;	968	$self->{expr} = $expr;
768	$self->recalculate;	969	$self->recalculate;
		970	}
		971
		972	# takes a hash of sensitivity indicators and installs watchers
		973	sub compile_frame {
		974	my ($self, $frame, $cb) = @_;
		975
		976	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		977	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		978
		979	# don't keep stuff alive
		980	Scalar::Util::weaken $state;
		981
		982	if ($again->{nested}) {
		983	$state->{nested} = 1;
		984	} else {
		985	delete $state->{nested};
		986	}
		987
		988	if (my $interval = $again->{time}) {
		989	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		990	if $state->{time}[0] != $interval;
		991
		992	# callback might have changed, although we could just rule that out
		993	$state->{time}[1]->cb (sub {
		994	++$state->{counter};
		995	$cb->();
		996	});
		997	} else {
		998	delete $state->{time};
		999	}
		1000
		1001	if ($again->{position}) {
		1002	$state->{position} = $self->on (position_change => $cb);
		1003	} else {
		1004	delete $state->{position};
		1005	}
		1006
		1007	if ($again->{size}) {
		1008	$state->{size} = $self->on (size_change => $cb);
		1009	} else {
		1010	delete $state->{size};
		1011	}
		1012
		1013	if ($again->{rootpmap}) {
		1014	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		1015	} else {
		1016	delete $state->{rootpmap};
		1017	}
769	}	1018	}
770		1019
771	# evaluate the current bg expression	1020	# evaluate the current bg expression
772	sub recalculate {	1021	sub recalculate {
773	my ($arg_self) = @_;	1022	my ($arg_self) = @_;
…		…
783		1032
784	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1033	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
785		1034
786	# set environment to evaluate user expression	1035	# set environment to evaluate user expression
787		1036
788	local $self = $arg_self;	1037	local $self = $arg_self;
789
790	local $HOME = $ENV{HOME};	1038	local $HOME = $ENV{HOME};
791	local $old = $self->{state};	1039	local $frame = [];
792	local $new = my $state = $self->{state} = {};
793		1040
794	($x, $y, $w, $h) =
795	$self->background_geometry ($self->{border});	1041	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
796		1042
797	# evaluate user expression	1043	# evaluate user expression
798		1044
799	my $img = eval { $self->{expr}->() };	1045	my @img = eval { $self->{expr}->() };
800	warn $@ if $@;#d#	1046	die $@ if $@;
801	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";	1047	die "background-expr did not return anything.\n" unless @img;
		1048	die "background-expr: expected image(s), got something else.\n"
		1049	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
802		1050
803	$state->{size_sensitive} = 1	1051	my $img = urxvt::bgdsl::merge @img;
		1052
		1053	$frame->[FR_AGAIN]{size} = 1
804	if $img->repeat_mode != urxvt::RepeatNormal;	1054	if $img->repeat_mode != urxvt::RepeatNormal;
805		1055
806	# if the expression is sensitive to external events, prepare reevaluation then	1056	# if the expression is sensitive to external events, prepare reevaluation then
807		1057	$self->compile_frame ($frame, sub { $arg_self->recalculate });
808	my $repeat;
809
810	if (my $again = $state->{again}) {
811	$repeat = 1;
812	my $self = $self;
813	$state->{timer} = $again == $old->{again}
814	? $old->{timer}
815	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
816	++$self->{counter};
817	$self->recalculate
818	});
819	}
820
821	if (delete $state->{position_sensitive}) {
822	$repeat = 1;
823	$self->enable (position_change => sub { $_[0]->recalculate });
824	} else {
825	$self->disable ("position_change");
826	}
827
828	if (delete $state->{size_sensitive}) {
829	$repeat = 1;
830	$self->enable (size_change => sub { $_[0]->recalculate });
831	} else {
832	$self->disable ("size_change");
833	}
834
835	if (delete $state->{rootpmap_sensitive}) {
836	$repeat = 1;
837	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
838	} else {
839	$self->disable ("rootpmap_change");
840	}
841		1058
842	# clear stuff we no longer need	1059	# clear stuff we no longer need
843		1060
844	%$old = ();	1061	# unless (%{ $frame->[FR_STATE] }) {
845
846	unless ($repeat) {
847	delete $self->{state};	1062	# delete $self->{state};
848	delete $self->{expr};	1063	# delete $self->{expr};
849	}	1064	# }
850		1065
851	# set background pixmap	1066	# set background pixmap
852		1067
853	$self->set_background ($img, $self->{border});	1068	$self->set_background ($img, $self->{border});
854	$self->scr_recolour (0);	1069	$self->scr_recolour (0);

Diff Legend

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

Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.48 by root, Sun Jun 10 15:01:14 2012 UTC vs. Revision 1.71 by root, Mon Jul 2 01:40:41 2012 UTC

Diff Legend

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.48 by root, Sun Jun 10 15:01:14 2012 UTC vs.
Revision 1.71 by root, Mon Jul 2 01:40:41 2012 UTC