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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs.
Revision 1.74 by root, Sat Jul 14 08:42:54 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	terminal 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 again
		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 COLOUR SPECIFICATIONS
141		163
142	As has been mentioned before, the expression might be evaluated multiple	164	Whenever an operator expects a "colour", then this can be specified in one
143	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:
144	have begun. Many operators cache their results till the next cycle.
145		166
146	For example, the C<load> operator keeps a copy of the image. If it is	167	"red" # named colour
147	asked to load the same image on the next cycle it will not load it again,	168	"#f00" # simple rgb
148	but return the cached copy.	169	"[50]red" # red with 50% alpha
		170	"TekHVC:300/50/50" # anything goes
149		171
150	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:
151	image every time, it will always be cached, but when you load a different
152	image, it will forget about the first one.
153		173
154	This allows you to either speed things up by keeping multiple images in	174	[0.5] # 50% gray, 100% alpha
155	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
156		177
157	For example, you can keep two images in memory and use a random one like	178	=head2 CACHING AND SENSITIVITY
158	this:
159		179
160	my $img1 = load "img1.png";	180	Since some operations (such as C<load> and C<blur>) can take a long time,
161	my $img2 = load "img2.png";	181	caching results can be very important for a smooth operation. Caching can
162	(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.
163		185
164	Since both images are "loaded" every time the expression is evaluated,	186	=head3 C<keep { ... }> caching
165	they are always kept in memory. Contrast this version:
166		187
167	my $path1 = "img1.png";	188	The most important way to cache expensive operations is to use C<keep {
168	my $path2 = "img2.png";	189	... }>. The C<keep> operator takes a block of multiple statements enclosed
169	load ((0.5 > rand) ? $path1 : $path2)	190	by C<{}> and keeps the return value in memory.
170		191
171	Here, a path is selected randomly, and load is only called for one image,	192	An expression can be "sensitive" to various external events, such as
172	so keeps only one image in memory. If, on the next evaluation, luck	193	scaling or moving the window, root background changes and timers. Simply
173	decides to use the other path, then it will have to load that image again.	194	using an expression (such as C<scale> without parameters) that depends on
		195	certain changing values (called "variables"), or using those variables
		196	directly, will make an expression sensitive to these events - for example,
		197	using C<scale> or C<TW> will make the expression sensitive to the terminal
		198	size, and thus to resizing events.
		199
		200	When such an event happens, C<keep> will automatically trigger a
		201	reevaluation of the whole expression with the new value of the expression.
		202
		203	C<keep> is most useful for expensive operations, such as C<blur>:
		204
		205	rootalign keep { blur 20, root }
		206
		207	This makes a blurred copy of the root background once, and on subsequent
		208	calls, just root-aligns it. Since C<blur> is usually quite slow and
		209	C<rootalign> is quite fast, this trades extra memory (for the cached
		210	blurred pixmap) with speed (blur only needs to be redone when root
		211	changes).
		212
		213	=head3 C<load> caching
		214
		215	The C<load> operator itself does not keep images in memory, but as long as
		216	the image is still in memory, C<load> will use the in-memory image instead
		217	of loading it freshly from disk.
		218
		219	That means that this expression:
		220
		221	keep { load "$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.
174		225
175	=head1 REFERENCE	226	=head1 REFERENCE
176		227
177	=head2 COMMAND LINE SWITCHES	228	=head2 COMMAND LINE SWITCHES
178		229
…		…
188	overwriting borders and any other areas, such as the scrollbar.	239	overwriting borders and any other areas, such as the scrollbar.
189		240
190	Specifying this flag changes the behaviour, so that the image only	241	Specifying this flag changes the behaviour, so that the image only
191	replaces the background of the character area.	242	replaces the background of the character area.
192		243
		244	=item --background-interval seconds
		245
		246	Since some operations in the underlying XRender extension can effectively
		247	freeze your X-server for prolonged time, this extension enforces a minimum
		248	time between updates, which is normally about 0.1 seconds.
		249
		250	If you want to do updates more often, you can decrease this safety
		251	interval with this switch.
		252
193	=back	253	=back
194		254
195	=cut	255	=cut
196		256
		257	our %_IMG_CACHE;
197	our $HOME;	258	our $HOME;
198	our ($self, $old, $new);	259	our ($self, $frame);
199	our ($x, $y, $w, $h);	260	our ($x, $y, $w, $h);
200		261
201	# enforce at least this interval between updates	262	# enforce at least this interval between updates
202	our $MIN_INTERVAL = 1/100;	263	our $MIN_INTERVAL = 6/59.951;
203		264
204	{	265	{
205	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.
		272
		273	use List::Util qw(min max sum shuffle);
206		274
207	=head2 PROVIDERS/GENERATORS	275	=head2 PROVIDERS/GENERATORS
208		276
209	These functions provide an image, by loading it from disk, grabbing it	277	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	278	from the root screen or by simply generating it. They are used as starting
…		…
215	=item load $path	283	=item load $path
216		284
217	Loads the image at the given C<$path>. The image is set to plane tiling	285	Loads the image at the given C<$path>. The image is set to plane tiling
218	mode.	286	mode.
219		287
220	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.
221		290
		291	=item load_uc $path
		292
		293	Load uncached - same as load, but does not cache the image, which means it
		294	is I<always> loaded from the filesystem again, even if another copy of it
		295	is in memory at the time.
		296
222	=cut	297	=cut
		298
		299	sub load_uc($) {
		300	$self->new_img_from_file ($_[0])
		301	}
223		302
224	sub load($) {	303	sub load($) {
225	my ($path) = @_;	304	my ($path) = @_;
226		305
227	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	306	$_IMG_CACHE{$path} \|\| do {
		307	my $img = load_uc $path;
		308	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		309	$img
		310	}
228	}	311	}
229		312
230	=item root	313	=item root
231		314
232	Returns the root window pixmap, that is, hopefully, the background image	315	Returns the root window pixmap, that is, hopefully, the background image
233	of your screen. The image is set to extend mode.	316	of your screen.
234		317
235	This function makes your expression root sensitive, that means it will be	318	This function makes your expression root sensitive, that means it will be
236	reevaluated when the bg image changes.	319	reevaluated when the bg image changes.
237		320
238	=cut	321	=cut
239		322
240	sub root() {	323	sub root() {
241	$new->{rootpmap_sensitive} = 1;	324	$frame->[FR_AGAIN]{rootpmap} = 1;
242	die "root op not supported, exg, we need you";	325	$self->new_img_from_root
243	}	326	}
244		327
245	=item solid $colour	328	=item solid $colour
246		329
247	=item solid $width, $height, $colour	330	=item solid $width, $height, $colour
…		…
255	=cut	338	=cut
256		339
257	sub solid($;$$) {	340	sub solid($;$$) {
258	my $colour = pop;	341	my $colour = pop;
259		342
260	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	343	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
261	$img->fill ($colour);	344	$img->fill ($colour);
262	$img	345	$img
263	}	346	}
264		347
265	=back	348	=item clone $img
266		349
267	=head2 VARIABLES	350	Returns an exact copy of the image. This is useful if you want to have
		351	multiple copies of the same image to apply different effects to.
268		352
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	353	=cut
311		354
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} = $_[0];
345	}
346
347	sub counter($) {	355	sub clone($) {
348	$new->{again} = $_[0];	356	$_[0]->clone
349	$self->{counter} + 0
350	}	357	}
351		358
352	=back	359	=item merge $img ...
		360
		361	Takes any number of images and merges them together, creating a single
		362	image containing them all. The tiling mode of the first image is used as
		363	the tiling mode of the resulting image.
		364
		365	This function is called automatically when an expression returns multiple
		366	images.
		367
		368	=cut
		369
		370	sub merge(@) {
		371	return $_[0] unless $#_;
		372
		373	# rather annoyingly clumsy, but optimisation is for another time
		374
		375	my $x0 = +1e9;
		376	my $y0 = +1e9;
		377	my $x1 = -1e9;
		378	my $y1 = -1e9;
		379
		380	for (@_) {
		381	my ($x, $y, $w, $h) = $_->geometry;
		382
		383	$x0 = $x if $x0 > $x;
		384	$y0 = $y if $y0 > $y;
		385
		386	$x += $w;
		387	$y += $h;
		388
		389	$x1 = $x if $x1 < $x;
		390	$y1 = $y if $y1 < $y;
		391	}
		392
		393	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		394	$base->repeat_mode ($_[0]->repeat_mode);
		395	$base->fill ([0, 0, 0, 0]);
		396
		397	$base->draw ($_)
		398	for @_;
		399
		400	$base
		401	}
353		402
354	=head2 TILING MODES	403	=head2 TILING MODES
355		404
356	The following operators modify the tiling mode of an image, that is, the	405	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.	406	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	436	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	437	image over another image or the background colour while leaving all
389	background pixels outside the image unchanged.	438	background pixels outside the image unchanged.
390		439
391	Example: load an image and display it in the upper left corner. The rest	440	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	441	of the space is left "empty" (transparent or whatever your compositor does
393	in alpha mode, else background colour).	442	in alpha mode, else background colour).
394		443
395	pad load "mybg.png"	444	pad load "mybg.png"
396		445
397	=item extend $img	446	=item extend $img
398		447
399	Extends the image over the whole plane, using the closest pixel in the	448	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	449	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	450	filtering operations and want the pixels outside the image to have the
402	same values as the pixels near the edge.	451	same values as the pixels near the edge.
403		452
404	Example: just for curiosity, how does this pixel extension stuff work?	453	Example: just for curiosity, how does this pixel extension stuff work?
405		454
…		…
431	$img	480	$img
432	}	481	}
433		482
434	=back	483	=back
435		484
436	=head2 PIXEL OPERATORS	485	=head2 VARIABLE VALUES
437		486
438	The following operators modify the image pixels in various ways.	487	The following functions provide variable data such as the terminal window
		488	dimensions. They are not (Perl-) variables, they just return stuff that
		489	varies. Most of them make your expression sensitive to some events, for
		490	example using C<TW> (terminal width) means your expression is evaluated
		491	again when the terminal is resized.
439		492
440	=over 4	493	=over 4
441		494
442	=item clone $img	495	=item TX
443		496
444	Returns an exact copy of the image.	497	=item TY
445		498
446	=cut	499	Return the X and Y coordinates of the terminal window (the terminal
		500	window is the full window by default, and the character area only when in
		501	border-respect mode).
447		502
		503	Using these functions make your expression sensitive to window moves.
		504
		505	These functions are mainly useful to align images to the root window.
		506
		507	Example: load an image and align it so it looks as if anchored to the
		508	background (that's exactly what C<rootalign> does btw.):
		509
		510	move -TX, -TY, keep { load "mybg.png" }
		511
		512	=item TW
		513
		514	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		515	terminal window is the full window by default, and the character area only
		516	when in border-respect mode).
		517
		518	Using these functions make your expression sensitive to window resizes.
		519
		520	These functions are mainly useful to scale images, or to clip images to
		521	the window size to conserve memory.
		522
		523	Example: take the screen background, clip it to the window size, blur it a
		524	bit, align it to the window position and use it as background.
		525
		526	clip move -TX, -TY, keep { blur 5, root }
		527
		528	=cut
		529
		530	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
		531	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
		532	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
		533	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
		534
		535	=item now
		536
		537	Returns the current time as (fractional) seconds since the epoch.
		538
		539	Using this expression does I<not> make your expression sensitive to time,
		540	but the next two functions do.
		541
		542	=item again $seconds
		543
		544	When this function is used the expression will be reevaluated again in
		545	C<$seconds> seconds.
		546
		547	Example: load some image and rotate it according to the time of day (as if it were
		548	the hour pointer of a clock). Update this image every minute.
		549
		550	again 60;
		551	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
		552
		553	=item counter $seconds
		554
		555	Like C<again>, but also returns an increasing counter value, starting at
		556	0, which might be useful for some simple animation effects.
		557
		558	=cut
		559
		560	sub now() { urxvt::NOW }
		561
		562	sub again($) {
		563	$frame->[FR_AGAIN]{time} = $_[0];
		564	}
		565
448	sub clone($) {	566	sub counter($) {
449	$_[0]->clone	567	$frame->[FR_AGAIN]{time} = $_[0];
		568	$frame->[FR_STATE]{counter} + 0
450	}	569	}
		570
		571	=back
		572
		573	=head2 SHAPE CHANGING OPERATORS
		574
		575	The following operators modify the shape, size or position of the image.
		576
		577	=over 4
451		578
452	=item clip $img	579	=item clip $img
453		580
454	=item clip $width, $height, $img	581	=item clip $width, $height, $img
455		582
…		…
466	assumed.	593	assumed.
467		594
468	Example: load an image, blur it, and clip it to the window size to save	595	Example: load an image, blur it, and clip it to the window size to save
469	memory.	596	memory.
470		597
471	clip blur 10, load "mybg.png"	598	clip keep { blur 10, load "mybg.png" }
472		599
473	=cut	600	=cut
474		601
475	sub clip($;$$;$$) {	602	sub clip($;$$;$$) {
476	my $img = pop;	603	my $img = pop;
…		…
479	$img->sub_rect ($_[0], $_[1], $w, $h)	606	$img->sub_rect ($_[0], $_[1], $w, $h)
480	}	607	}
481		608
482	=item scale $img	609	=item scale $img
483		610
484	=item scale $size_percent, $img	611	=item scale $size_factor, $img
485		612
486	=item scale $width_percent, $height_percent, $img	613	=item scale $width_factor, $height_factor, $img
487		614
488	Scales the image by the given percentages in horizontal	615	Scales the image by the given factors in horizontal
489	(C<$width_percent>) and vertical (C<$height_percent>) direction.	616	(C<$width>) and vertical (C<$height>) direction.
490		617
491	If only one percentage is give, it is used for both directions.	618	If only one factor is give, it is used for both directions.
492		619
493	If no percentages are given, scales the image to the window size without	620	If no factors are given, scales the image to the window size without
494	keeping aspect.	621	keeping aspect.
495		622
496	=item resize $width, $height, $img	623	=item resize $width, $height, $img
497		624
498	Resizes the image to exactly C<$width> times C<$height> pixels.	625	Resizes the image to exactly C<$width> times C<$height> pixels.
499		626
500	=cut	627	=item fit $img
501		628
502	#TODO: maximise, maximise_fill?	629	=item fit $width, $height, $img
		630
		631	Fits the image into the given C<$width> and C<$height> without changing
		632	aspect, or the terminal size. That means it will be shrunk or grown until
		633	the whole image fits into the given area, possibly leaving borders.
		634
		635	=item cover $img
		636
		637	=item cover $width, $height, $img
		638
		639	Similar to C<fit>, but shrinks or grows until all of the area is covered
		640	by the image, so instead of potentially leaving borders, it will cut off
		641	image data that doesn't fit.
		642
		643	=cut
503		644
504	sub scale($;$;$) {	645	sub scale($;$;$) {
505	my $img = pop;	646	my $img = pop;
506		647
507	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	648	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
508	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	649	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
509	: $img->scale (TW, TH)	650	: $img->scale (TW, TH)
510	}	651	}
511		652
512	sub resize($$$) {	653	sub resize($$$) {
513	my $img = pop;	654	my $img = pop;
514	$img->scale ($_[0], $_[1])	655	$img->scale ($_[0], $_[1])
515	}	656	}
516		657
		658	sub fit($;$$) {
		659	my $img = pop;
		660	my $w = ($_[0] \|\| TW) / $img->w;
		661	my $h = ($_[1] \|\| TH) / $img->h;
		662	scale +(min $w, $h), $img
		663	}
		664
		665	sub cover($;$$) {
		666	my $img = pop;
		667	my $w = ($_[0] \|\| TW) / $img->w;
		668	my $h = ($_[1] \|\| TH) / $img->h;
		669	scale +(max $w, $h), $img
		670	}
		671
517	=item move $dx, $dy, $img	672	=item move $dx, $dy, $img
518		673
519	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	674	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
520	the vertical.	675	the vertical.
521		676
522	Example: move the image right by 20 pixels and down by 30.	677	Example: move the image right by 20 pixels and down by 30.
523		678
524	move 20, 30, ...	679	move 20, 30, ...
		680
		681	=item align $xalign, $yalign, $img
		682
		683	Aligns the image according to a factor - C<0> means the image is moved to
		684	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		685	exactly centered and C<1> means it touches the right or bottom edge.
		686
		687	Example: remove any visible border around an image, center it vertically but move
		688	it to the right hand side.
		689
		690	align 1, 0.5, pad $img
		691
		692	=item center $img
		693
		694	=item center $width, $height, $img
		695
		696	Centers the image, i.e. the center of the image is moved to the center of
		697	the terminal window (or the box specified by C<$width> and C<$height> if
		698	given).
		699
		700	Example: load an image and center it.
		701
		702	center keep { pad load "mybg.png" }
525		703
526	=item rootalign $img	704	=item rootalign $img
527		705
528	Moves the image so that it appears glued to the screen as opposed to the	706	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	707	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	708	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
531	top left of the screen.	709	top left of the screen.
532		710
533	Example: load a background image, put it in mirror mode and root align it.	711	Example: load a background image, put it in mirror mode and root align it.
534		712
535	rootalign mirror load "mybg.png"	713	rootalign keep { mirror load "mybg.png" }
536		714
537	Example: take the screen background and align it, giving the illusion of	715	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.	716	transparency as long as the window isn't in front of other windows.
539		717
540	rootalign root	718	rootalign root
541		719
542	=cut	720	=cut
543		721
544	sub move($$;$) {	722	sub move($$;$) {
545	my $img = pop->clone;	723	my $img = pop->clone;
546	$img->move ($_[0], $_[1]);	724	$img->move ($_[0], $_[1]);
547	$img	725	$img
548	}	726	}
549		727
		728	sub align($;$$) {
		729	my $img = pop;
		730
		731	move $_[0] * (TW - $img->w),
		732	$_[1] * (TH - $img->h),
		733	$img
		734	}
		735
		736	sub center($;$$) {
		737	my $img = pop;
		738	my $w = $_[0] \|\| TW;
		739	my $h = $_[1] \|\| TH;
		740
		741	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		742	}
		743
550	sub rootalign($) {	744	sub rootalign($) {
551	move -TX, -TY, $_[0]	745	move -TX, -TY, $_[0]
552	}	746	}
553		747
		748	=item rotate $center_x, $center_y, $degrees, $img
		749
		750	Rotates the image clockwise by C<$degrees> degrees, around the point at
		751	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		752
		753	Example: rotate the image by 90 degrees around it's center.
		754
		755	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		756
		757	=cut
		758
		759	sub rotate($$$$) {
		760	my $img = pop;
		761	$img->rotate (
		762	$_[0] * ($img->w + $img->x),
		763	$_[1] * ($img->h + $img->y),
		764	$_[2] * (3.14159265 / 180),
		765	)
		766	}
		767
		768	=back
		769
		770	=head2 COLOUR MODIFICATIONS
		771
		772	The following operators change the pixels of the image.
		773
		774	=over 4
		775
		776	=item tint $color, $img
		777
		778	Tints the image in the given colour.
		779
		780	Example: tint the image red.
		781
		782	tint "red", load "rgb.png"
		783
		784	Example: the same, but specify the colour by component.
		785
		786	tint [1, 0, 0], load "rgb.png"
		787
		788	=cut
		789
		790	sub tint($$) {
		791	$_[1]->tint ($_[0])
		792	}
		793
554	=item contrast $factor, $img	794	=item contrast $factor, $img
555		795
556	=item contrast $r, $g, $b, $img	796	=item contrast $r, $g, $b, $img
557		797
558	=item contrast $r, $g, $b, $a, $img	798	=item contrast $r, $g, $b, $a, $img
559		799
560	Adjusts the I<contrast> of an image.	800	Adjusts the I<contrast> of an image.
561		801
562	#TODO#	802	The first form applies a single C<$factor> to red, green and blue, the
		803	second form applies separate factors to each colour channel, and the last
		804	form includes the alpha channel.
563		805
		806	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		807	contrast.
		808
		809	Due to limitations in the underlying XRender extension, lowering contrast
		810	also reduces brightness, while increasing contrast currently also
		811	increases brightness.
		812
564	=item brightness $factor, $img	813	=item brightness $bias, $img
565		814
566	=item brightness $r, $g, $b, $img	815	=item brightness $r, $g, $b, $img
567		816
568	=item brightness $r, $g, $b, $a, $img	817	=item brightness $r, $g, $b, $a, $img
569		818
570	Adjusts the brightness of an image.	819	Adjusts the brightness of an image.
		820
		821	The first form applies a single C<$bias> to red, green and blue, the
		822	second form applies separate biases to each colour channel, and the last
		823	form includes the alpha channel.
		824
		825	Values less than 0 reduce brightness, while values larger than 0 increase
		826	it. Useful range is from -1 to 1 - the former results in a black, the
		827	latter in a white picture.
		828
		829	Due to idiosyncrasies in the underlying XRender extension, biases less
		830	than zero can be I<very> slow.
571		831
572	=cut	832	=cut
573		833
574	sub contrast($$;$$;$) {	834	sub contrast($$;$$;$) {
575	my $img = pop;	835	my $img = pop;
576	my ($r, $g, $b, $a) = @_;	836	my ($r, $g, $b, $a) = @_;
577		837
578	($g, $b) = ($r, $r) if @_ < 4;	838	($g, $b) = ($r, $r) if @_ < 3;
579	$a = 1 if @_ < 5;	839	$a = 1 if @_ < 4;
580		840
581	$img = $img->clone;	841	$img = $img->clone;
582	$img->contrast ($r, $g, $b, $a);	842	$img->contrast ($r, $g, $b, $a);
583	$img	843	$img
584	}	844	}
585		845
586	sub brightness($$;$$;$) {	846	sub brightness($$;$$;$) {
587	my $img = pop;	847	my $img = pop;
588	my ($r, $g, $b, $a) = @_;	848	my ($r, $g, $b, $a) = @_;
589		849
590	($g, $b) = ($r, $r) if @_ < 4;	850	($g, $b) = ($r, $r) if @_ < 3;
591	$a = 1 if @_ < 5;	851	$a = 1 if @_ < 4;
592		852
593	$img = $img->clone;	853	$img = $img->clone;
594	$img->brightness ($r, $g, $b, $a);	854	$img->brightness ($r, $g, $b, $a);
595	$img	855	$img
596	}	856	}
…		…
612	sub blur($$;$) {	872	sub blur($$;$) {
613	my $img = pop;	873	my $img = pop;
614	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	874	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
615	}	875	}
616		876
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	877	=back
642		878
		879	=head2 OTHER STUFF
		880
		881	Anything that didn't fit any of the other categories, even after applying
		882	force and closing our eyes.
		883
		884	=over 4
		885
		886	=item keep { ... }
		887
		888	This operator takes a code block as argument, that is, one or more
		889	statements enclosed by braces.
		890
		891	The trick is that this code block is only evaluated when the outcome
		892	changes - on other calls the C<keep> simply returns the image it computed
		893	previously (yes, it should only be used with images). Or in other words,
		894	C<keep> I<caches> the result of the code block so it doesn't need to be
		895	computed again.
		896
		897	This can be extremely useful to avoid redoing slow operations - for
		898	example, if your background expression takes the root background, blurs it
		899	and then root-aligns it it would have to blur the root background on every
		900	window move or resize.
		901
		902	Another example is C<load>, which can be quite slow.
		903
		904	In fact, urxvt itself encloses the whole expression in some kind of
		905	C<keep> block so it only is reevaluated as required.
		906
		907	Putting the blur into a C<keep> block will make sure the blur is only done
		908	once, while the C<rootalign> is still done each time the window moves.
		909
		910	rootalign keep { blur 10, root }
		911
		912	This leaves the question of how to force reevaluation of the block,
		913	in case the root background changes: If expression inside the block
		914	is sensitive to some event (root background changes, window geometry
		915	changes), then it will be reevaluated automatically as needed.
		916
		917	=cut
		918
		919	sub keep(&) {
		920	my $id = $_[0]+0;
		921
		922	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		923
		924	unless ($frame->[FR_CACHE]) {
		925	$frame->[FR_CACHE] = [ $_[0]() ];
		926
		927	my $self = $self;
		928	my $frame = $frame;
		929	Scalar::Util::weaken $frame;
		930	$self->compile_frame ($frame, sub {
		931	# clear this frame cache, also for all parents
		932	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		933	undef $frame->[FR_CACHE];
		934	}
		935
		936	$self->recalculate;
		937	});
		938	};
		939
		940	# in scalar context we always return the first original result, which
		941	# is not quite how perl works.
		942	wantarray
		943	? @{ $frame->[FR_CACHE] }
		944	: $frame->[FR_CACHE][0]
		945	}
		946
		947	# sub keep_clear() {
		948	# delete $self->{frame_cache};
		949	# }
		950
		951	=back
		952
643	=cut	953	=cut
644		954
645	}	955	}
646		956
647	sub parse_expr {	957	sub parse_expr {
648	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	958	my $expr = eval
		959	"sub {\n"
		960	. "package urxvt::bgdsl;\n"
		961	. "#line 0 'background expression'\n"
		962	. "$_[0]\n"
		963	. "}";
649	die if $@;	964	die if $@;
650	$expr	965	$expr
651	}	966	}
652		967
653	# compiles a parsed expression	968	# compiles a parsed expression
654	sub set_expr {	969	sub set_expr {
655	my ($self, $expr) = @_;	970	my ($self, $expr) = @_;
656		971
		972	$self->{root} = []; # the outermost frame
657	$self->{expr} = $expr;	973	$self->{expr} = $expr;
658	$self->recalculate;	974	$self->recalculate;
		975	}
		976
		977	# takes a hash of sensitivity indicators and installs watchers
		978	sub compile_frame {
		979	my ($self, $frame, $cb) = @_;
		980
		981	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		982	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		983
		984	# don't keep stuff alive
		985	Scalar::Util::weaken $state;
		986
		987	if ($again->{nested}) {
		988	$state->{nested} = 1;
		989	} else {
		990	delete $state->{nested};
		991	}
		992
		993	if (my $interval = $again->{time}) {
		994	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		995	if $state->{time}[0] != $interval;
		996
		997	# callback might have changed, although we could just rule that out
		998	$state->{time}[1]->cb (sub {
		999	++$state->{counter};
		1000	$cb->();
		1001	});
		1002	} else {
		1003	delete $state->{time};
		1004	}
		1005
		1006	if ($again->{position}) {
		1007	$state->{position} = $self->on (position_change => $cb);
		1008	} else {
		1009	delete $state->{position};
		1010	}
		1011
		1012	if ($again->{size}) {
		1013	$state->{size} = $self->on (size_change => $cb);
		1014	} else {
		1015	delete $state->{size};
		1016	}
		1017
		1018	if ($again->{rootpmap}) {
		1019	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		1020	} else {
		1021	delete $state->{rootpmap};
		1022	}
659	}	1023	}
660		1024
661	# evaluate the current bg expression	1025	# evaluate the current bg expression
662	sub recalculate {	1026	sub recalculate {
663	my ($arg_self) = @_;	1027	my ($arg_self) = @_;
…		…
673		1037
674	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1038	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
675		1039
676	# set environment to evaluate user expression	1040	# set environment to evaluate user expression
677		1041
678	local $self = $arg_self;	1042	local $self = $arg_self;
679
680	local $HOME = $ENV{HOME};	1043	local $HOME = $ENV{HOME};
681	local $old = $self->{state};	1044	local $frame = $self->{root};
682	local $new = my $state = $self->{state} = {};
683		1045
684	($x, $y, $w, $h) =
685	$self->background_geometry ($self->{border});	1046	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
686		1047
687	# evaluate user expression	1048	# evaluate user expression
688		1049
689	my $img = eval { $self->{expr}->() };	1050	my @img = eval { $self->{expr}->() };
690	warn $@ if $@;#d#	1051	die $@ if $@;
		1052	die "background-expr did not return anything.\n" unless @img;
		1053	die "background-expr: expected image(s), got something else.\n"
691	die if !UNIVERSAL::isa $img, "urxvt::img";	1054	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
692		1055
693	$state->{size_sensitive} = 1	1056	my $img = urxvt::bgdsl::merge @img;
		1057
		1058	$frame->[FR_AGAIN]{size} = 1
694	if $img->repeat_mode != urxvt::RepeatNormal;	1059	if $img->repeat_mode != urxvt::RepeatNormal;
695		1060
696	# if the expression is sensitive to external events, prepare reevaluation then	1061	# if the expression is sensitive to external events, prepare reevaluation then
697		1062	$self->compile_frame ($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	$self->disable ("rootpmap_change");
730	}
731		1063
732	# clear stuff we no longer need	1064	# clear stuff we no longer need
733		1065
734	%$old = ();	1066	# unless (%{ $frame->[FR_STATE] }) {
735
736	unless ($repeat) {
737	delete $self->{state};	1067	# delete $self->{state};
738	delete $self->{expr};	1068	# delete $self->{expr};
739	}	1069	# }
740		1070
741	# set background pixmap	1071	# set background pixmap
742		1072
743	$self->set_background ($img, $self->{border});	1073	$self->set_background ($img, $self->{border});
744	$self->scr_recolour (0);	1074	$self->scr_recolour (0);
…		…
746	}	1076	}
747		1077
748	sub on_start {	1078	sub on_start {
749	my ($self) = @_;	1079	my ($self) = @_;
750		1080
751	my $expr = $self->x_resource ("background.expr")	1081	my $expr = $self->x_resource ("%.expr")
752	or return;	1082	or return;
753		1083
		1084	$self->has_render
		1085	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		1086
754	$self->set_expr (parse_expr $expr);	1087	$self->set_expr (parse_expr $expr);
755	$self->{border} = $self->x_resource_boolean ("background.border");	1088	$self->{border} = $self->x_resource_boolean ("%.border");
		1089
		1090	$MIN_INTERVAL = $self->x_resource ("%.interval");
756		1091
757	()	1092	()
758	}	1093	}
759		1094

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs. Revision 1.74 by root, Sat Jul 14 08:42:54 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs.
Revision 1.74 by root, Sat Jul 14 08:42:54 2012 UTC