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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.41 by root, Fri Jun 8 22:21:48 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
…		…
99	its result becomes the argument to the C<scale> function.	102	its result becomes the argument to the C<scale> function.
100		103
101	Many operators also allow some parameters preceding the input image	104	Many operators also allow some parameters preceding the input image
102	that modify its behaviour. For example, C<scale> without any additional	105	that modify its behaviour. For example, C<scale> without any additional
103	arguments scales the image to size of the terminal window. If you specify	106	arguments scales the image to size of the terminal window. If you specify
104	an additional argument, it uses it as a percentage:	107	an additional argument, it uses it as a scale factor (multiply by 100 to
		108	get a percentage):
105		109
106	scale 200, load "$HOME/mypic.png"	110	scale 2, load "$HOME/mypic.png"
107		111
108	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>	112	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
109	has now two arguments, the C<200> and the C<load> expression, while	113	has now two arguments, the C<200> and the C<load> expression, while
110	C<load> only has one argument. Arguments are separated from each other by	114	C<load> only has one argument. Arguments are separated from each other by
111	commas.	115	commas.
112		116
113	Scale also accepts two arguments, which are then separate factors for both	117	Scale also accepts two arguments, which are then separate factors for both
114	horizontal and vertical dimensions. For example, this halves the image	118	horizontal and vertical dimensions. For example, this halves the image
115	width and doubles the image height:	119	width and doubles the image height:
116		120
117	scale 50, 200, load "$HOME/mypic.png"	121	scale 0.5, 2, load "$HOME/mypic.png"
118		122
119	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,
120	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:
121		127
		128	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		129
		130	The C<keep> operator executes all the statements inside the braces only
		131	once, or when it thinks the outcome might change. In other cases it
		132	returns the last value computed by the brace block.
		133
		134	This means that the C<load> is only executed once, which makes it much
		135	faster, but also means that more memory is being used, because the loaded
		136	image must be kept in memory at all times. In this expression, the
		137	trade-off is likely worth it.
		138
		139	But back to effects: Other effects than scaling are also readily
		140	available, for example, you can tile the image to fill the whole window,
		141	instead of resizing it:
		142
122	tile load "$HOME/mypic.png"	143	tile keep { load "$HOME/mypic.png" }
123		144
124	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	145	In fact, images returned by C<load> are in C<tile> mode by default, so the
125	is kind of superfluous.	146	C<tile> operator is kind of superfluous.
126		147
127	Another common effect is to mirror the image, so that the same edges touch:	148	Another common effect is to mirror the image, so that the same edges
		149	touch:
128		150
129	mirror load "$HOME/mypic.png"	151	mirror keep { load "$HOME/mypic.png" }
130		152
131	This is also a typical background expression:	153	Another common background expression is:
132		154
133	rootalign root	155	rootalign root
134		156
135	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
136	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
137	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:
138	moved around.	160	the image seems to be static while the window is moved around.
139		161
140	=head2 CYCLES AND CACHING	162	=head2 CACHING AND SENSITIVITY
141		163
142	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,
143	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
144	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.
145		169
146	For example, the C<load> operator keeps a copy of the image. If it is	170	=head3 C<keep { ... }> caching
147	asked to load the same image on the next cycle it will not load it again,
148	but return the cached copy.
149		171
150	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 {
151	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
152	image, it will forget about the first one.	174	by C<{}> and keeps the return value in memory.
153		175
154	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
155	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.
156		183
157	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
158	this:	185	reevaluation of the whole expression with the new value of the expression.
159		186
160	my $img1 = load "img1.png";	187	C<keep> is most useful for expensive operations, such as C<blur>:
161	my $img2 = load "img2.png";
162	(0.5 > rand) ? $img1 : $img2
163		188
164	Since both images are "loaded" every time the expression is evaluated,	189	rootalign keep { blur 20, root }
165	they are always kept in memory. Contrast this version:
166		190
167	my $path1 = "img1.png";	191	This makes a blurred copy of the root background once, and on subsequent
168	my $path2 = "img2.png";	192	calls, just root-aligns it. Since C<blur> is usually quite slow and
169	load ((0.5 > rand) ? $path1 : $path2)	193	C<rootalign> is quite fast, this trades extra memory (for the cached
		194	blurred pixmap) with speed (blur only needs to be redone when root
		195	changes).
170		196
171	Here, a path is selected randomly, and load is only called for one image,	197	=head3 C<load> caching
172	so keeps only one image in memory. If, on the next evaluation, luck	198
173	decides to use the other path, then it will have to load that image again.	199	The C<load> operator itself does not keep images in memory, but as long as
		200	the image is still in memory, C<load> will use the in-memory image instead
		201	of loading it freshly from disk.
		202
		203	That means that this expression:
		204
		205	keep { load "$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.
174		209
175	=head1 REFERENCE	210	=head1 REFERENCE
176		211
177	=head2 COMMAND LINE SWITCHES	212	=head2 COMMAND LINE SWITCHES
178		213
…		…
188	overwriting borders and any other areas, such as the scrollbar.	223	overwriting borders and any other areas, such as the scrollbar.
189		224
190	Specifying this flag changes the behaviour, so that the image only	225	Specifying this flag changes the behaviour, so that the image only
191	replaces the background of the character area.	226	replaces the background of the character area.
192		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
193	=back	237	=back
194		238
195	=cut	239	=cut
196		240
		241	our %_IMG_CACHE;
197	our $HOME;	242	our $HOME;
198	our ($self, $old, $new);	243	our ($self, $frame);
199	our ($x, $y, $w, $h);	244	our ($x, $y, $w, $h);
200		245
201	# enforce at least this interval between updates	246	# enforce at least this interval between updates
202	our $MIN_INTERVAL = 1/100;	247	our $MIN_INTERVAL = 6/59.951;
203		248
204	{	249	{
205	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.
		256
		257	use List::Util qw(min max sum shuffle);
206		258
207	=head2 PROVIDERS/GENERATORS	259	=head2 PROVIDERS/GENERATORS
208		260
209	These functions provide an image, by loading it from disk, grabbing it	261	These functions provide an image, by loading it from disk, grabbing it
210	from the root screen or by simply generating it. They are used as starting	262	from the root screen or by simply generating it. They are used as starting
…		…
215	=item load $path	267	=item load $path
216		268
217	Loads the image at the given C<$path>. The image is set to plane tiling	269	Loads the image at the given C<$path>. The image is set to plane tiling
218	mode.	270	mode.
219		271
220	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.
221		274
		275	=item load_uc $path
		276
		277	Load uncached - same as load, but does not cache the image, which means it
		278	is I<always> loaded from the filesystem again.
		279
222	=cut	280	=cut
		281
		282	sub load_uc($) {
		283	$self->new_img_from_file ($path)
		284	}
223		285
224	sub load($) {	286	sub load($) {
225	my ($path) = @_;	287	my ($path) = @_;
226		288
227	$new->{load}{$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	}
228	}	294	}
229		295
230	=item root	296	=item root
231		297
232	Returns the root window pixmap, that is, hopefully, the background image	298	Returns the root window pixmap, that is, hopefully, the background image
233	of your screen. The image is set to extend mode.	299	of your screen.
234		300
235	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
236	reevaluated when the bg image changes.	302	reevaluated when the bg image changes.
237		303
238	=cut	304	=cut
239		305
240	sub root() {	306	sub root() {
241	$new->{rootpmap_sensitive} = 1;	307	$frame->[FR_AGAIN]{rootpmap} = 1;
242	die "root op not supported, exg, we need you";	308	$self->new_img_from_root
243	}	309	}
244		310
245	=item solid $colour	311	=item solid $colour
246		312
247	=item solid $width, $height, $colour	313	=item solid $width, $height, $colour
…		…
252	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is	318	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
253	useful for solid backgrounds or for use in filtering effects.	319	useful for solid backgrounds or for use in filtering effects.
254		320
255	=cut	321	=cut
256		322
257	sub solid($$;$) {	323	sub solid($;$$) {
258	my $colour = pop;	324	my $colour = pop;
259		325
260	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);
261	$img->fill ($colour);	327	$img->fill ($colour);
262	$img	328	$img
263	}	329	}
264		330
265	=back	331	=item clone $img
266		332
267	=head2 VARIABLES	333	Returns an exact copy of the image. This is useful if you want to have
		334	multiple copies of the same image to apply different effects to.
268		335
269	The following functions provide variable data such as the terminal window
270	dimensions. They are not (Perl-) variables, they jsut return stuff that
271	varies. Most of them make your expression sensitive to some events, for
272	example using C<TW> (terminal width) means your expression is evaluated
273	again when the terminal is resized.
274
275	=over 4
276
277	=item TX
278
279	=item TY
280
281	Return the X and Y coordinates of the terminal window (the terminal
282	window is the full window by default, and the character area only when in
283	border-respect mode).
284
285	Using these functions make your expression sensitive to window moves.
286
287	These functions are mainly useful to align images to the root window.
288
289	Example: load an image and align it so it looks as if anchored to the
290	background.
291
292	move -TX, -TY, load "mybg.png"
293
294	=item TW
295
296	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
297	terminal window is the full window by default, and the character area only
298	when in border-respect mode).
299
300	Using these functions make your expression sensitive to window resizes.
301
302	These functions are mainly useful to scale images, or to clip images to
303	the window size to conserve memory.
304
305	Example: take the screen background, clip it to the window size, blur it a
306	bit, align it to the window position and use it as background.
307
308	clip move -TX, -TY, blur 5, root
309
310	=cut	336	=cut
311		337
312	sub TX() { $new->{position_sensitive} = 1; $x }
313	sub TY() { $new->{position_sensitive} = 1; $y }
314	sub TW() { $new->{size_sensitive} = 1; $w }
315	sub TH() { $new->{size_sensitive} = 1; $h }
316
317	=item now
318
319	Returns the current time as (fractional) seconds since the epoch.
320
321	Using this expression does I<not> make your expression sensitive to time,
322	but the next two functions do.
323
324	=item again $seconds
325
326	When this function is used the expression will be reevaluated again in
327	C<$seconds> seconds.
328
329	Example: load some image and rotate it according to the time of day (as if it were
330	the hour pointer of a clock). Update this image every minute.
331
332	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
333
334	=item counter $seconds
335
336	Like C<again>, but also returns an increasing counter value, starting at
337	0, which might be useful for some simple animation effects.
338
339	=cut
340
341	sub now() { urxvt::NOW }
342
343	sub again($) {
344	$new->{again} = $_[0];
345	}
346
347	sub counter($) {	338	sub clone($) {
348	$new->{again} = $_[0];	339	$_[0]->clone
349	$self->{counter} + 0
350	}	340	}
351		341
352	=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	}
353		385
354	=head2 TILING MODES	386	=head2 TILING MODES
355		387
356	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
357	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.
…		…
387	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
388	image over another image or the background colour while leaving all	420	image over another image or the background colour while leaving all
389	background pixels outside the image unchanged.	421	background pixels outside the image unchanged.
390		422
391	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
392	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
393	in alpha mode, else background colour).	425	in alpha mode, else background colour).
394		426
395	pad load "mybg.png"	427	pad load "mybg.png"
396		428
397	=item extend $img	429	=item extend $img
398		430
399	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
400	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
401	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
402	same values as the pixels near the edge.	434	same values as the pixels near the edge.
403		435
404	Example: just for curiosity, how does this pixel extension stuff work?	436	Example: just for curiosity, how does this pixel extension stuff work?
405		437
…		…
431	$img	463	$img
432	}	464	}
433		465
434	=back	466	=back
435		467
436	=head2 PIXEL OPERATORS	468	=head2 VARIABLE VALUES
437		469
438	The following operators modify the image pixels in various ways.	470	The following functions provide variable data such as the terminal window
		471	dimensions. They are not (Perl-) variables, they just return stuff that
		472	varies. Most of them make your expression sensitive to some events, for
		473	example using C<TW> (terminal width) means your expression is evaluated
		474	again when the terminal is resized.
439		475
440	=over 4	476	=over 4
441		477
442	=item clone $img	478	=item TX
443		479
444	Returns an exact copy of the image.	480	=item TY
445		481
446	=cut	482	Return the X and Y coordinates of the terminal window (the terminal
		483	window is the full window by default, and the character area only when in
		484	border-respect mode).
447		485
		486	Using these functions make your expression sensitive to window moves.
		487
		488	These functions are mainly useful to align images to the root window.
		489
		490	Example: load an image and align it so it looks as if anchored to the
		491	background (that's exactly what C<rootalign> does btw.):
		492
		493	move -TX, -TY, keep { load "mybg.png" }
		494
		495	=item TW
		496
		497	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		498	terminal window is the full window by default, and the character area only
		499	when in border-respect mode).
		500
		501	Using these functions make your expression sensitive to window resizes.
		502
		503	These functions are mainly useful to scale images, or to clip images to
		504	the window size to conserve memory.
		505
		506	Example: take the screen background, clip it to the window size, blur it a
		507	bit, align it to the window position and use it as background.
		508
		509	clip move -TX, -TY, keep { blur 5, root }
		510
		511	=cut
		512
		513	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
		514	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
		515	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
		516	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
		517
		518	=item now
		519
		520	Returns the current time as (fractional) seconds since the epoch.
		521
		522	Using this expression does I<not> make your expression sensitive to time,
		523	but the next two functions do.
		524
		525	=item again $seconds
		526
		527	When this function is used the expression will be reevaluated again in
		528	C<$seconds> seconds.
		529
		530	Example: load some image and rotate it according to the time of day (as if it were
		531	the hour pointer of a clock). Update this image every minute.
		532
		533	again 60;
		534	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
		535
		536	=item counter $seconds
		537
		538	Like C<again>, but also returns an increasing counter value, starting at
		539	0, which might be useful for some simple animation effects.
		540
		541	=cut
		542
		543	sub now() { urxvt::NOW }
		544
		545	sub again($) {
		546	$frame->[FR_AGAIN]{time} = $_[0];
		547	}
		548
448	sub clone($) {	549	sub counter($) {
449	$_[0]->clone	550	$frame->[FR_AGAIN]{time} = $_[0];
		551	$frame->[FR_STATE]{counter} + 0
450	}	552	}
		553
		554	=back
		555
		556	=head2 SHAPE CHANGING OPERATORS
		557
		558	The following operators modify the shape, size or position of the image.
		559
		560	=over 4
451		561
452	=item clip $img	562	=item clip $img
453		563
454	=item clip $width, $height, $img	564	=item clip $width, $height, $img
455		565
…		…
466	assumed.	576	assumed.
467		577
468	Example: load an image, blur it, and clip it to the window size to save	578	Example: load an image, blur it, and clip it to the window size to save
469	memory.	579	memory.
470		580
471	clip blur 10, load "mybg.png"	581	clip keep { blur 10, load "mybg.png" }
472		582
473	=cut	583	=cut
474		584
475	sub clip($;$$;$$) {	585	sub clip($;$$;$$) {
476	my $img = pop;	586	my $img = pop;
…		…
479	$img->sub_rect ($_[0], $_[1], $w, $h)	589	$img->sub_rect ($_[0], $_[1], $w, $h)
480	}	590	}
481		591
482	=item scale $img	592	=item scale $img
483		593
484	=item scale $size_percent, $img	594	=item scale $size_factor, $img
485		595
486	=item scale $width_percent, $height_percent, $img	596	=item scale $width_factor, $height_factor, $img
487		597
488	Scales the image by the given percentages in horizontal	598	Scales the image by the given factors in horizontal
489	(C<$width_percent>) and vertical (C<$height_percent>) direction.	599	(C<$width>) and vertical (C<$height>) direction.
490		600
491	If only one percentage is give, it is used for both directions.	601	If only one factor is give, it is used for both directions.
492		602
493	If no percentages are given, scales the image to the window size without	603	If no factors are given, scales the image to the window size without
494	keeping aspect.	604	keeping aspect.
495		605
496	=item resize $width, $height, $img	606	=item resize $width, $height, $img
497		607
498	Resizes the image to exactly C<$width> times C<$height> pixels.	608	Resizes the image to exactly C<$width> times C<$height> pixels.
499		609
500	=cut	610	=item fit $img
501		611
502	#TODO: maximise, maximise_fill?	612	=item fit $width, $height, $img
		613
		614	Fits the image into the given C<$width> and C<$height> without changing
		615	aspect, or the terminal size. That means it will be shrunk or grown until
		616	the whole image fits into the given area, possibly leaving borders.
		617
		618	=item cover $img
		619
		620	=item cover $width, $height, $img
		621
		622	Similar to C<fit>, but shrinks or grows until all of the area is covered
		623	by the image, so instead of potentially leaving borders, it will cut off
		624	image data that doesn't fit.
		625
		626	=cut
503		627
504	sub scale($;$;$) {	628	sub scale($;$;$) {
505	my $img = pop;	629	my $img = pop;
506		630
507	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	631	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
508	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	632	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
509	: $img->scale (TW, TH)	633	: $img->scale (TW, TH)
510	}	634	}
511		635
512	sub resize($$$) {	636	sub resize($$$) {
513	my $img = pop;	637	my $img = pop;
514	$img->scale ($_[0], $_[1])	638	$img->scale ($_[0], $_[1])
515	}	639	}
516		640
		641	sub fit($;$$) {
		642	my $img = pop;
		643	my $w = ($_[0] \|\| TW) / $img->w;
		644	my $h = ($_[1] \|\| TH) / $img->h;
		645	scale +(min $w, $h), $img
		646	}
		647
		648	sub cover($;$$) {
		649	my $img = pop;
		650	my $w = ($_[0] \|\| TW) / $img->w;
		651	my $h = ($_[1] \|\| TH) / $img->h;
		652	scale +(max $w, $h), $img
		653	}
		654
517	=item move $dx, $dy, $img	655	=item move $dx, $dy, $img
518		656
519	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	657	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
520	the vertical.	658	the vertical.
521		659
522	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.
523		661
524	move 20, 30, ...	662	move 20, 30, ...
		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
		675	=item center $img
		676
		677	=item center $width, $height, $img
		678
		679	Centers the image, i.e. the center of the image is moved to the center of
		680	the terminal window (or the box specified by C<$width> and C<$height> if
		681	given).
		682
		683	Example: load an image and center it.
		684
		685	center keep { pad load "mybg.png" }
525		686
526	=item rootalign $img	687	=item rootalign $img
527		688
528	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
529	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
530	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
531	top left of the screen.	692	top left of the screen.
532		693
533	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.
534		695
535	rootalign mirror load "mybg.png"	696	rootalign keep { mirror load "mybg.png" }
536		697
537	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
538	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.
539		700
540	rootalign root	701	rootalign root
541		702
542	=cut	703	=cut
543		704
544	sub move($$;$) {	705	sub move($$;$) {
545	my $img = pop->clone;	706	my $img = pop->clone;
546	$img->move ($_[0], $_[1]);	707	$img->move ($_[0], $_[1]);
547	$img	708	$img
548	}	709	}
549		710
		711	sub align($;$$) {
		712	my $img = pop;
		713
		714	move $_[0] * (TW - $img->w),
		715	$_[1] * (TH - $img->h),
		716	$img
		717	}
		718
		719	sub center($;$$) {
		720	my $img = pop;
		721	my $w = $_[0] \|\| TW;
		722	my $h = $_[1] \|\| TH;
		723
		724	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		725	}
		726
550	sub rootalign($) {	727	sub rootalign($) {
551	move -TX, -TY, $_[0]	728	move -TX, -TY, $_[0]
552	}	729	}
553		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	)
		749	}
		750
		751	=back
		752
		753	=head2 COLOUR MODIFICATIONS
		754
		755	The following operators change the pixels of the image.
		756
		757	=over 4
		758
554	=item contrast $factor, $img	759	=item contrast $factor, $img
555		760
556	=item contrast $r, $g, $b, $img	761	=item contrast $r, $g, $b, $img
557		762
558	=item contrast $r, $g, $b, $a, $img	763	=item contrast $r, $g, $b, $a, $img
559		764
560	Adjusts the I<contrast> of an image.	765	Adjusts the I<contrast> of an image.
561		766
562	#TODO#	767	The first form applies a single C<$factor> to red, green and blue, the
		768	second form applies separate factors to each colour channel, and the last
		769	form includes the alpha channel.
563		770
		771	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		772	contrast.
		773
		774	Due to limitations in the underlying XRender extension, lowering contrast
		775	also reduces brightness, while increasing contrast currently also
		776	increases brightness.
		777
564	=item brightness $factor, $img	778	=item brightness $bias, $img
565		779
566	=item brightness $r, $g, $b, $img	780	=item brightness $r, $g, $b, $img
567		781
568	=item brightness $r, $g, $b, $a, $img	782	=item brightness $r, $g, $b, $a, $img
569		783
570	Adjusts the brightness of an image.	784	Adjusts the brightness of an image.
		785
		786	The first form applies a single C<$bias> to red, green and blue, the
		787	second form applies separate biases to each colour channel, and the last
		788	form includes the alpha channel.
		789
		790	Values less than 0 reduce brightness, while values larger than 0 increase
		791	it. Useful range is from -1 to 1 - the former results in a black, the
		792	latter in a white picture.
		793
		794	Due to idiosyncrasies in the underlying XRender extension, biases less
		795	than zero can be I<very> slow.
571		796
572	=cut	797	=cut
573		798
574	sub contrast($$;$$;$) {	799	sub contrast($$;$$;$) {
575	my $img = pop;	800	my $img = pop;
576	my ($r, $g, $b, $a) = @_;	801	my ($r, $g, $b, $a) = @_;
577		802
578	($g, $b) = ($r, $r) if @_ < 4;	803	($g, $b) = ($r, $r) if @_ < 3;
579	$a = 1 if @_ < 5;	804	$a = 1 if @_ < 4;
580		805
581	$img = $img->clone;	806	$img = $img->clone;
582	$img->contrast ($r, $g, $b, $a);	807	$img->contrast ($r, $g, $b, $a);
583	$img	808	$img
584	}	809	}
585		810
586	sub brightness($$;$$;$) {	811	sub brightness($$;$$;$) {
587	my $img = pop;	812	my $img = pop;
588	my ($r, $g, $b, $a) = @_;	813	my ($r, $g, $b, $a) = @_;
589		814
590	($g, $b) = ($r, $r) if @_ < 4;	815	($g, $b) = ($r, $r) if @_ < 3;
591	$a = 1 if @_ < 5;	816	$a = 1 if @_ < 4;
592		817
593	$img = $img->clone;	818	$img = $img->clone;
594	$img->brightness ($r, $g, $b, $a);	819	$img->brightness ($r, $g, $b, $a);
595	$img	820	$img
596	}	821	}
…		…
612	sub blur($$;$) {	837	sub blur($$;$) {
613	my $img = pop;	838	my $img = pop;
614	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	839	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
615	}	840	}
616		841
617	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
618
619	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
620	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
621	width/height), generating a new image with width C<$new_width> and height
622	C<$new_height>.
623
624	#TODO# new width, height, maybe more operators?
625
626	Example: rotate the image by 90 degrees
627
628	=cut
629
630	sub rotate($$$$$$) {
631	my $img = pop;
632	$img->rotate (
633	$_[0],
634	$_[1],
635	$_[2] * $img->w * .01,
636	$_[3] * $img->h * .01,
637	$_[4] * (3.14159265 / 180),
638	)
639	}
640
641	=back	842	=back
642		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
643	=cut	918	=cut
644		919
645	}	920	}
646		921
647	sub parse_expr {	922	sub parse_expr {
648	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	. "}";
649	die if $@;	929	die if $@;
650	$expr	930	$expr
651	}	931	}
652		932
653	# compiles a parsed expression	933	# compiles a parsed expression
654	sub set_expr {	934	sub set_expr {
655	my ($self, $expr) = @_;	935	my ($self, $expr) = @_;
656		936
		937	$self->{root} = [];
657	$self->{expr} = $expr;	938	$self->{expr} = $expr;
658	$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 $state->{rootpmap};
		987	}
659	}	988	}
660		989
661	# evaluate the current bg expression	990	# evaluate the current bg expression
662	sub recalculate {	991	sub recalculate {
663	my ($arg_self) = @_;	992	my ($arg_self) = @_;
…		…
673		1002
674	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1003	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
675		1004
676	# set environment to evaluate user expression	1005	# set environment to evaluate user expression
677		1006
678	local $self = $arg_self;	1007	local $self = $arg_self;
679
680	local $HOME = $ENV{HOME};	1008	local $HOME = $ENV{HOME};
681	local $old = $self->{state};	1009	local $frame = [];
682	local $new = my $state = $self->{state} = {};
683		1010
684	($x, $y, $w, $h) =
685	$self->background_geometry ($self->{border});	1011	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
686		1012
687	# evaluate user expression	1013	# evaluate user expression
688		1014
689	my $img = eval { $self->{expr}->() };	1015	my @img = eval { $self->{expr}->() };
690	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"
691	die if !UNIVERSAL::isa $img, "urxvt::img";	1019	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
692		1020
693	$state->{size_sensitive} = 1	1021	my $img = urxvt::bgdsl::merge @img;
		1022
		1023	$frame->[FR_AGAIN]{size} = 1
694	if $img->repeat_mode != urxvt::RepeatNormal;	1024	if $img->repeat_mode != urxvt::RepeatNormal;
695		1025
696	# if the expression is sensitive to external events, prepare reevaluation then	1026	# if the expression is sensitive to external events, prepare reevaluation then
697		1027	$self->compile_frame ($frame, sub { $arg_self->recalculate });
698	my $repeat;
699
700	if (my $again = $state->{again}) {
701	$repeat = 1;
702	my $self = $self;
703	$state->{timer} = $again == $old->{again}
704	? $old->{timer}
705	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
706	++$self->{counter};
707	$self->recalculate
708	});
709	}
710
711	if (delete $state->{position_sensitive}) {
712	$repeat = 1;
713	$self->enable (position_change => sub { $_[0]->recalculate });
714	} else {
715	$self->disable ("position_change");
716	}
717
718	if (delete $state->{size_sensitive}) {
719	$repeat = 1;
720	$self->enable (size_change => sub { $_[0]->recalculate });
721	} else {
722	$self->disable ("size_change");
723	}
724
725	if (delete $state->{rootpmap_sensitive}) {
726	$repeat = 1;
727	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
728	} else {
729	$self->disable ("rootpmap_change");
730	}
731		1028
732	# clear stuff we no longer need	1029	# clear stuff we no longer need
733		1030
734	%$old = ();	1031	# unless (%{ $frame->[FR_STATE] }) {
735
736	unless ($repeat) {
737	delete $self->{state};	1032	# delete $self->{state};
738	delete $self->{expr};	1033	# delete $self->{expr};
739	}	1034	# }
740		1035
741	# set background pixmap	1036	# set background pixmap
742		1037
743	$self->set_background ($img, $self->{border});	1038	$self->set_background ($img, $self->{border});
744	$self->scr_recolour (0);	1039	$self->scr_recolour (0);
…		…
746	}	1041	}
747		1042
748	sub on_start {	1043	sub on_start {
749	my ($self) = @_;	1044	my ($self) = @_;
750		1045
751	my $expr = $self->x_resource ("background.expr")	1046	my $expr = $self->x_resource ("%.expr")
752	or return;	1047	or return;
753		1048
		1049	$self->has_render
		1050	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		1051
754	$self->set_expr (parse_expr $expr);	1052	$self->set_expr (parse_expr $expr);
755	$self->{border} = $self->x_resource_boolean ("background.border");	1053	$self->{border} = $self->x_resource_boolean ("%.border");
		1054
		1055	$MIN_INTERVAL = $self->x_resource ("%.interval");
756		1056
757	()	1057	()
758	}	1058	}
759		1059

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.41 by root, Fri Jun 8 22:21:48 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 1.41 by root, Fri Jun 8 22:21:48 2012 UTC vs.
Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC