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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.37 by root, Fri Jun 8 20:35:43 2012 UTC vs.
Revision 1.67 by sf-exg, Fri Jun 29 18:12:25 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	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
5		6
6	#TODO: once, rootalign	7	=head1 NAME
7		8
8	=head1 background - manage terminal background	9	background - manage terminal background
9		10
10	=head2 SYNOPSIS	11	=head1 SYNOPSIS
11		12
12	urxvt --background-expr 'background expression'	13	urxvt --background-expr 'background expression'
13	--background-border	14	--background-border
		15	--background-interval seconds
14		16
15	=head2 DESCRIPTION	17	=head1 DESCRIPTION
16		18
17	This extension manages the terminal background by creating a picture that	19	This extension manages the terminal background by creating a picture that
18	is behind the text, replacing the normal background colour.	20	is behind the text, replacing the normal background colour.
19		21
20	It does so by evaluating a Perl expression that I<calculates> the image on	22	It does so by evaluating a Perl expression that I<calculates> the image on
24	to be as simple as possible.	26	to be as simple as possible.
25		27
26	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
27	use:	29	use:
28		30
29	urxvt --background-expr 'scale load "/path/to/mybg.png"'	31	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
30		32
31	Or specified as a X resource:	33	Or specified as a X resource:
32		34
33	URxvt.background-expr: scale load "/path/to/mybg.png"	35	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }
34		36
35	=head2 THEORY OF OPERATION	37	=head1 THEORY OF OPERATION
36		38
37	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
38	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
39	extended as necessary to cover the whole terminal window, and is set as a	41	extended as necessary to cover the whole terminal window, and is set as a
40	background pixmap.	42	background pixmap.
…		…
51	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
52	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
53	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
54	timer elapses), then the expression will be evaluated again.	56	timer elapses), then the expression will be evaluated again.
55		57
56	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"
57	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
58	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
59	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
60	after it's size changes.	62	after its size changes.
61		63
62	=head3 EXPRESSIONS	64	=head2 EXPRESSIONS
63		65
64	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
65	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
66		68
		69	scale keep {
67	again 3600;	70	again 3600;
68	if (localtime now)[6]) {	71	if (localtime now)[6]) {
69	return scale load "$HOME/weekday.png";	72	return load "$HOME/weekday.png";
70	} else {	73	} else {
71	return scale load "$HOME/sunday.png";	74	return load "$HOME/sunday.png";
		75	}
72	}	76	}
73		77
74	This expression gets evaluated once per hour. It will set F<sunday.png> as	78	This expression is evaluated once per hour. It will set F<sunday.png> as
75	background on sundays, and F<weekday.png> on all other days.	79	background on Sundays, and F<weekday.png> on all other days.
76		80
77	Fortunately, we expect that most expressions will be much simpler, with	81	Fortunately, we expect that most expressions will be much simpler, with
78	little Perl knowledge needed.	82	little Perl knowledge needed.
79		83
80	Basically, you always start with a function that "generates" an image	84	Basically, you always start with a function that "generates" an image
…		…
97	its result becomes the argument to the C<scale> function.	101	its result becomes the argument to the C<scale> function.
98		102
99	Many operators also allow some parameters preceding the input image	103	Many operators also allow some parameters preceding the input image
100	that modify its behaviour. For example, C<scale> without any additional	104	that modify its behaviour. For example, C<scale> without any additional
101	arguments scales the image to size of the terminal window. If you specify	105	arguments scales the image to size of the terminal window. If you specify
102	an additional argument, it uses it as a percentage:	106	an additional argument, it uses it as a scale factor (multiply by 100 to
		107	get a percentage):
103		108
104	scale 200, load "$HOME/mypic.png"	109	scale 2, load "$HOME/mypic.png"
105		110
106	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>	111	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
107	has now two arguments, the C<200> and the C<load> expression, while	112	has now two arguments, the C<200> and the C<load> expression, while
108	C<load> only has one argument. Arguments are separated from each other by	113	C<load> only has one argument. Arguments are separated from each other by
109	commas.	114	commas.
110		115
111	Scale also accepts two arguments, which are then separate factors for both	116	Scale also accepts two arguments, which are then separate factors for both
112	horizontal and vertical dimensions. For example, this halves the image	117	horizontal and vertical dimensions. For example, this halves the image
113	width and doubles the image height:	118	width and doubles the image height:
114		119
115	scale 50, 200, load "$HOME/mypic.png"	120	scale 0.5, 2, load "$HOME/mypic.png"
116		121
117	TODO	122	IF you try out these expressions, you might suffer from sluggishness,
		123	because each time the terminal is resized, it again loads the PNG image
		124	and scales it. Scaling is usually fast, but loading the image can be quite
		125	time consuming. This is where C<keep> comes in handy:
118		126
119	=head3 CYCLES AND CACHING	127	scale 0.5, 2, keep { load "$HOME/mypic.png" }
120		128
121	TODO	129	The C<keep> operator executes all the statements inside the braces only
		130	once, or when it thinks the outcome might change. In other cases it
		131	returns the last value computed by the brace block.
122		132
123	Each time the expression is reevaluated, a new cycle is said to have begun. Many operators	133	This means that the C<load> is only executed once, which makes it much
124	cache their results till the next cycle. For example	134	faster, but also means that more memory is being used, because the loaded
		135	image must be kept in memory at all times. In this expression, the
		136	trade-off is likely worth it.
125		137
		138	But back to effects: Other effects than scaling are also readily
		139	available, for example, you can tile the image to fill the whole window,
		140	instead of resizing it:
		141
		142	tile keep { load "$HOME/mypic.png" }
		143
		144	In fact, images returned by C<load> are in C<tile> mode by default, so the
		145	C<tile> operator is kind of superfluous.
		146
		147	Another common effect is to mirror the image, so that the same edges
		148	touch:
		149
		150	mirror keep { load "$HOME/mypic.png" }
		151
		152	Another common background expression is:
		153
		154	rootalign root
		155
		156	This one first takes a snapshot of the screen background image, and then
		157	moves it to the upper left corner of the screen (as opposed to the upper
		158	left corner of the terminal window)- the result is pseudo-transparency:
		159	the image seems to be static while the window is moved around.
		160
		161	=head2 CACHING AND SENSITIVITY
		162
		163	Since some operations (such as C<load> and C<blur>) can take a long time,
		164	caching results can be very important for a smooth operation. Caching can
		165	also be useful to reduce memory usage, though, for example, when an image
		166	is cached by C<load>, it could be shared by multiple terminal windows
		167	running inside urxvtd.
		168
		169	=head3 C<keep { ... }> caching
		170
		171	The most important way to cache expensive operations is to use C<keep {
		172	... }>. The C<keep> operator takes a block of multiple statements enclosed
		173	by C<{}> and keeps the return value in memory.
		174
		175	An expression can be "sensitive" to various external events, such as
		176	scaling or moving the window, root background changes and timers. Simply
		177	using an expression (such as C<scale> without parameters) that depends on
		178	certain changing values (called "variables"), or using those variables
		179	directly, will make an expression sensitive to these events - for example,
		180	using C<scale> or C<TW> will make the expression sensitive to the terminal
		181	size, and thus to resizing events.
		182
		183	When such an event happens, C<keep> will automatically trigger a
		184	reevaluation of the whole expression with the new value of the expression.
		185
		186	C<keep> is most useful for expensive operations, such as C<blur>:
		187
		188	rootalign once { blur 20, root }
		189
		190	This makes a blurred copy of the root background once, and on subsequent
		191	calls, just root-aligns it. Since C<blur> is usually quite slow and
		192	C<rootalign> is quite fast, this trades extra memory (for the cached
		193	blurred pixmap) with speed (blur only needs to be redone when root
		194	changes).
		195
		196	=head3 C<load> caching
		197
		198	The C<load> operator itself does not keep images in memory, but as long as
		199	the image is still in memory, C<load> will use the in-memory image instead
		200	of loading it freshly from disk.
		201
		202	That means that this expression:
		203
		204	keep { load "$HOME/path..." }
		205
		206	Not only caches the image in memory, other terminal instances that try to
		207	C<load> it can reuse that in-memory copy.
		208
126	=head2 REFERENCE	209	=head1 REFERENCE
127		210
128	=head3 COMMAND LINE SWITCHES	211	=head2 COMMAND LINE SWITCHES
129		212
130	=over 4	213	=over 4
131		214
132	=item --background-expr perl-expression	215	=item --background-expr perl-expression
133		216
…		…
139	overwriting borders and any other areas, such as the scrollbar.	222	overwriting borders and any other areas, such as the scrollbar.
140		223
141	Specifying this flag changes the behaviour, so that the image only	224	Specifying this flag changes the behaviour, so that the image only
142	replaces the background of the character area.	225	replaces the background of the character area.
143		226
		227	=item --background-interval seconds
		228
		229	Since some operations in the underlying XRender extension can effectively
		230	freeze your X-server for prolonged time, this extension enforces a minimum
		231	time between updates, which is normally about 0.1 seconds.
		232
		233	If you want to do updates more often, you can decrease this safety
		234	interval with this switch.
		235
144	=back	236	=back
145		237
146	=cut	238	=cut
147		239
148	our $EXPR;#d#	240	our %_IMG_CACHE;
149	#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';
150	$EXPR = 'move -TX, -TY, load "argb.png"';
151	#$EXPR = '
152	# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,
153	# clip X, Y, W, H, repeat_mirror,
154	# load "/root/pix/das_fette_schwein.jpg"
155	#';
156	#$EXPR = 'solid "red"';
157	#$EXPR = 'blur root, 10, 10'
158	#$EXPR = 'blur move (root, -x, -y), 5, 5'
159	#resize load "/root/pix/das_fette_schwein.jpg", w, h
160
161	our $HOME;	241	our $HOME;
162	our ($self, $old, $new);	242	our ($self, $frame);
163	our ($x, $y, $w, $h);	243	our ($x, $y, $w, $h);
164		244
165	# enforce at least this interval between updates	245	# enforce at least this interval between updates
166	our $MIN_INTERVAL = 1/100;	246	our $MIN_INTERVAL = 6/59.951;
167		247
168	{	248	{
169	package urxvt::bgdsl; # background language	249	package urxvt::bgdsl; # background language
		250
		251	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		252	sub FR_CACHE () { 1 } # cached values
		253	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		254	sub FR_STATE () { 3 } # watchers etc.
		255
		256	use List::Util qw(min max sum shuffle);
170		257
171	=head2 PROVIDERS/GENERATORS	258	=head2 PROVIDERS/GENERATORS
172		259
173	These functions provide an image, by loading it from disk, grabbing it	260	These functions provide an image, by loading it from disk, grabbing it
174	from the root screen or by simply generating it. They are used as starting	261	from the root screen or by simply generating it. They are used as starting
…		…
179	=item load $path	266	=item load $path
180		267
181	Loads the image at the given C<$path>. The image is set to plane tiling	268	Loads the image at the given C<$path>. The image is set to plane tiling
182	mode.	269	mode.
183		270
184	Loaded images will be cached for one cycle.	271	If the image is already in memory (e.g. because another terminal instance
		272	uses it), then the in-memory copy us returned instead.
185		273
		274	=item load_uc $path
		275
		276	Load uncached - same as load, but does not cache the image, which means it
		277	is I<always> loaded from the filesystem again.
		278
186	=cut	279	=cut
		280
		281	sub load_uc($) {
		282	$self->new_img_from_file ($path)
		283	}
187		284
188	sub load($) {	285	sub load($) {
189	my ($path) = @_;	286	my ($path) = @_;
190		287
191	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	288	$_IMG_CACHE{$path} \|\| do {
		289	my $img = load_uc $path;
		290	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		291	$img
		292	}
192	}	293	}
193		294
194	=item root	295	=item root
195		296
196	Returns the root window pixmap, that is, hopefully, the background image	297	Returns the root window pixmap, that is, hopefully, the background image
197	of your screen. The image is set to extend mode.	298	of your screen.
198		299
199	This function makes your expression root sensitive, that means it will be	300	This function makes your expression root sensitive, that means it will be
200	reevaluated when the bg image changes.	301	reevaluated when the bg image changes.
201		302
202	=cut	303	=cut
203		304
204	sub root() {	305	sub root() {
205	$new->{rootpmap_sensitive} = 1;	306	$frame->[FR_AGAIN]{rootpmap} = 1;
206	die "root op not supported, exg, we need you";	307	$self->new_img_from_root
207	}	308	}
208		309
209	=item solid $colour	310	=item solid $colour
210		311
211	=item solid $width, $height, $colour	312	=item solid $width, $height, $colour
212		313
213	Creates a new image and completely fills it with the given colour. The	314	Creates a new image and completely fills it with the given colour. The
214	image is set to tiling mode.	315	image is set to tiling mode.
215		316
216	If <$width> and C<$height> are omitted, it creates a 1x1 image, which is	317	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
217	useful for solid backgrounds or for use in filtering effects.	318	useful for solid backgrounds or for use in filtering effects.
218		319
219	=cut	320	=cut
220		321
221	sub solid($$;$) {	322	sub solid($;$$) {
222	my $colour = pop;	323	my $colour = pop;
223		324
224	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	325	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
225	$img->fill ($colour);	326	$img->fill ($colour);
226	$img	327	$img
227	}	328	}
228		329
229	=back	330	=item clone $img
230		331
231	=head2 VARIABLES	332	Returns an exact copy of the image. This is useful if you want to have
		333	multiple copies of the same image to apply different effects to.
232		334
233	The following functions provide variable data such as the terminal
234	window dimensions. Most of them make your expression sensitive to some
235	events, for example using C<TW> (terminal width) means your expression is
236	evaluated again when the terminal is resized.
237
238	=over 4
239
240	=item TX
241
242	=item TY
243
244	Return the X and Y coordinates of the terminal window (the terminal
245	window is the full window by default, and the character area only when in
246	border-respect mode).
247
248	Using these functions make your expression sensitive to window moves.
249
250	These functions are mainly useful to align images to the root window.
251
252	Example: load an image and align it so it looks as if anchored to the
253	background.
254
255	move -TX, -TY, load "mybg.png"
256
257	=item TW
258
259	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
260	terminal window is the full window by default, and the character area only
261	when in border-respect mode).
262
263	Using these functions make your expression sensitive to window resizes.
264
265	These functions are mainly useful to scale images, or to clip images to
266	the window size to conserve memory.
267
268	Example: take the screen background, clip it to the window size, blur it a
269	bit, align it to the window position and use it as background.
270
271	clip move -TX, -TY, blur 5, root
272
273	=cut	335	=cut
274		336
275	sub TX() { $new->{position_sensitive} = 1; $x }
276	sub TY() { $new->{position_sensitive} = 1; $y }
277	sub TW() { $new->{size_sensitive} = 1; $w }
278	sub TH() { $new->{size_sensitive} = 1; $h }
279
280	=item now
281
282	Returns the current time as (fractional) seconds since the epoch.
283
284	Using this expression does I<not> make your expression sensitive to time,
285	but the next two functions do.
286
287	=item again $seconds
288
289	When this function is used the expression will be reevaluated again in
290	C<$seconds> seconds.
291
292	Example: load some image and rotate it according to the time of day (as if it were
293	the hour pointer of a clock). Update this image every minute.
294
295	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
296
297	=item counter $seconds
298
299	Like C<again>, but also returns an increasing counter value, starting at
300	0, which might be useful for some simple animation effects.
301
302	=cut
303
304	sub now() { urxvt::NOW }
305
306	sub again($) {
307	$new->{again} = $_[0];
308	}
309
310	sub counter($) {	337	sub clone($) {
311	$new->{again} = $_[0];	338	$_[0]->clone
312	$self->{counter} + 0
313	}	339	}
314		340
315	=back	341	=item merge $img ...
		342
		343	Takes any number of images and merges them together, creating a single
		344	image containing them all. The tiling mode of the first image is used as
		345	the tiling mode of the resulting image.
		346
		347	This function is called automatically when an expression returns multiple
		348	images.
		349
		350	=cut
		351
		352	sub merge(@) {
		353	return $_[0] unless $#_;
		354
		355	# rather annoyingly clumsy, but optimisation is for another time
		356
		357	my $x0 = +1e9;
		358	my $y0 = +1e9;
		359	my $x1 = -1e9;
		360	my $y1 = -1e9;
		361
		362	for (@_) {
		363	my ($x, $y, $w, $h) = $_->geometry;
		364
		365	$x0 = $x if $x0 > $x;
		366	$y0 = $y if $y0 > $y;
		367
		368	$x += $w;
		369	$y += $h;
		370
		371	$x1 = $x if $x1 < $x;
		372	$y1 = $y if $y1 < $y;
		373	}
		374
		375	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		376	$base->repeat_mode ($_[0]->repeat_mode);
		377	$base->fill ([0, 0, 0, 0]);
		378
		379	$base->draw ($_)
		380	for @_;
		381
		382	$base
		383	}
316		384
317	=head2 TILING MODES	385	=head2 TILING MODES
318		386
319	The following operators modify the tiling mode of an image, that is, the	387	The following operators modify the tiling mode of an image, that is, the
320	way that pixels outside the image area are painted when the image is used.	388	way that pixels outside the image area are painted when the image is used.
…		…
350	become transparent. This mode is most useful when you want to place an	418	become transparent. This mode is most useful when you want to place an
351	image over another image or the background colour while leaving all	419	image over another image or the background colour while leaving all
352	background pixels outside the image unchanged.	420	background pixels outside the image unchanged.
353		421
354	Example: load an image and display it in the upper left corner. The rest	422	Example: load an image and display it in the upper left corner. The rest
355	of the space is left "empty" (transparent or wahtever your compisotr does	423	of the space is left "empty" (transparent or whatever your compositor does
356	in alpha mode, else background colour).	424	in alpha mode, else background colour).
357		425
358	pad load "mybg.png"	426	pad load "mybg.png"
359		427
360	=item extend $img	428	=item extend $img
361		429
362	Extends the image over the whole plane, using the closest pixel in the	430	Extends the image over the whole plane, using the closest pixel in the
363	area outside the image. This mode is mostly useful when you more complex	431	area outside the image. This mode is mostly useful when you use more complex
364	filtering operations and want the pixels outside the image to have the	432	filtering operations and want the pixels outside the image to have the
365	same values as the pixels near the edge.	433	same values as the pixels near the edge.
366		434
367	Example: just for curiosity, how does this pixel extension stuff work?	435	Example: just for curiosity, how does this pixel extension stuff work?
368		436
…		…
394	$img	462	$img
395	}	463	}
396		464
397	=back	465	=back
398		466
399	=head2 PIXEL OPERATORS	467	=head2 VARIABLE VALUES
400		468
401	The following operators modify the image pixels in various ways.	469	The following functions provide variable data such as the terminal window
		470	dimensions. They are not (Perl-) variables, they just return stuff that
		471	varies. Most of them make your expression sensitive to some events, for
		472	example using C<TW> (terminal width) means your expression is evaluated
		473	again when the terminal is resized.
402		474
403	=over 4	475	=over 4
404		476
405	=item clone $img	477	=item TX
406		478
407	Returns an exact copy of the image.	479	=item TY
408		480
409	=cut	481	Return the X and Y coordinates of the terminal window (the terminal
		482	window is the full window by default, and the character area only when in
		483	border-respect mode).
410		484
		485	Using these functions make your expression sensitive to window moves.
		486
		487	These functions are mainly useful to align images to the root window.
		488
		489	Example: load an image and align it so it looks as if anchored to the
		490	background (that's exactly what C<rootalign> does btw.):
		491
		492	move -TX, -TY, keep { load "mybg.png" }
		493
		494	=item TW
		495
		496	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		497	terminal window is the full window by default, and the character area only
		498	when in border-respect mode).
		499
		500	Using these functions make your expression sensitive to window resizes.
		501
		502	These functions are mainly useful to scale images, or to clip images to
		503	the window size to conserve memory.
		504
		505	Example: take the screen background, clip it to the window size, blur it a
		506	bit, align it to the window position and use it as background.
		507
		508	clip move -TX, -TY, keep { blur 5, root }
		509
		510	=cut
		511
		512	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
		513	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
		514	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
		515	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
		516
		517	=item now
		518
		519	Returns the current time as (fractional) seconds since the epoch.
		520
		521	Using this expression does I<not> make your expression sensitive to time,
		522	but the next two functions do.
		523
		524	=item again $seconds
		525
		526	When this function is used the expression will be reevaluated again in
		527	C<$seconds> seconds.
		528
		529	Example: load some image and rotate it according to the time of day (as if it were
		530	the hour pointer of a clock). Update this image every minute.
		531
		532	again 60;
		533	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
		534
		535	=item counter $seconds
		536
		537	Like C<again>, but also returns an increasing counter value, starting at
		538	0, which might be useful for some simple animation effects.
		539
		540	=cut
		541
		542	sub now() { urxvt::NOW }
		543
		544	sub again($) {
		545	$frame->[FR_AGAIN]{time} = $_[0];
		546	}
		547
411	sub clone($) {	548	sub counter($) {
412	$_[0]->clone	549	$frame->[FR_AGAIN]{time} = $_[0];
		550	$frame->[FR_STATE]{counter} + 0
413	}	551	}
		552
		553	=back
		554
		555	=head2 SHAPE CHANGING OPERATORS
		556
		557	The following operators modify the shape, size or position of the image.
		558
		559	=over 4
414		560
415	=item clip $img	561	=item clip $img
416		562
417	=item clip $width, $height, $img	563	=item clip $width, $height, $img
418		564
…		…
429	assumed.	575	assumed.
430		576
431	Example: load an image, blur it, and clip it to the window size to save	577	Example: load an image, blur it, and clip it to the window size to save
432	memory.	578	memory.
433		579
434	clip blur 10, load "mybg.png"	580	clip keep { blur 10, load "mybg.png" }
435		581
436	=cut	582	=cut
437		583
438	sub clip($;$$;$$) {	584	sub clip($;$$;$$) {
439	my $img = pop;	585	my $img = pop;
…		…
442	$img->sub_rect ($_[0], $_[1], $w, $h)	588	$img->sub_rect ($_[0], $_[1], $w, $h)
443	}	589	}
444		590
445	=item scale $img	591	=item scale $img
446		592
447	=item scale $size_percent, $img	593	=item scale $size_factor, $img
448		594
449	=item scale $width_percent, $height_percent, $img	595	=item scale $width_factor, $height_factor, $img
450		596
451	Scales the image by the given percentages in horizontal	597	Scales the image by the given factors in horizontal
452	(C<$width_percent>) and vertical (C<$height_percent>) direction.	598	(C<$width>) and vertical (C<$height>) direction.
453		599
454	If only one percentage is give, it is used for both directions.	600	If only one factor is give, it is used for both directions.
455		601
456	If no percentages are given, scales the image to the window size without	602	If no factors are given, scales the image to the window size without
457	keeping aspect.	603	keeping aspect.
458		604
459	=item resize $width, $height, $img	605	=item resize $width, $height, $img
460		606
461	Resizes the image to exactly C<$width> times C<$height> pixels.	607	Resizes the image to exactly C<$width> times C<$height> pixels.
462		608
463	=cut	609	=item fit $img
464		610
465	#TODO: maximise, maximise_fill?	611	=item fit $width, $height, $img
		612
		613	Fits the image into the given C<$width> and C<$height> without changing
		614	aspect, or the terminal size. That means it will be shrunk or grown until
		615	the whole image fits into the given area, possibly leaving borders.
		616
		617	=item cover $img
		618
		619	=item cover $width, $height, $img
		620
		621	Similar to C<fit>, but shrinks or grows until all of the area is covered
		622	by the image, so instead of potentially leaving borders, it will cut off
		623	image data that doesn't fit.
		624
		625	=cut
466		626
467	sub scale($;$;$) {	627	sub scale($;$;$) {
468	my $img = pop;	628	my $img = pop;
469		629
470	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	630	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
471	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	631	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
472	: $img->scale (TW, TH)	632	: $img->scale (TW, TH)
473	}	633	}
474		634
475	sub resize($$$) {	635	sub resize($$$) {
476	my $img = pop;	636	my $img = pop;
477	$img->scale ($_[0], $_[1])	637	$img->scale ($_[0], $_[1])
478	}	638	}
479		639
		640	sub fit($;$$) {
		641	my $img = pop;
		642	my $w = ($_[0] \|\| TW) / $img->w;
		643	my $h = ($_[1] \|\| TH) / $img->h;
		644	scale +(min $w, $h), $img
		645	}
		646
		647	sub cover($;$$) {
		648	my $img = pop;
		649	my $w = ($_[0] \|\| TW) / $img->w;
		650	my $h = ($_[1] \|\| TH) / $img->h;
		651	scale +(max $w, $h), $img
		652	}
		653
480	=item move $dx, $dy, $img	654	=item move $dx, $dy, $img
481		655
482	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	656	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
483	the vertical.	657	the vertical.
484		658
485	Example: move the image right by 20 pixels and down by 30.	659	Example: move the image right by 20 pixels and down by 30.
486		660
487	move 20, 30, ...	661	move 20, 30, ...
		662
		663	=item align $xalign, $yalign, $img
		664
		665	Aligns the image according to a factor - C<0> means the image is moved to
		666	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		667	exactly centered and C<1> means it touches the right or bottom edge.
		668
		669	Example: remove any visible border around an image, center it vertically but move
		670	it to the right hand side.
		671
		672	align 1, 0.5, pad $img
		673
		674	=item center $img
		675
		676	=item center $width, $height, $img
		677
		678	Centers the image, i.e. the center of the image is moved to the center of
		679	the terminal window (or the box specified by C<$width> and C<$height> if
		680	given).
		681
		682	Example: load an image and center it.
		683
		684	center keep { pad load "mybg.png" }
488		685
489	=item rootalign $img	686	=item rootalign $img
490		687
491	Moves the image so that it appears glued to the screen as opposed to the	688	Moves the image so that it appears glued to the screen as opposed to the
492	window. This gives the illusion of a larger area behind the window. It is	689	window. This gives the illusion of a larger area behind the window. It is
493	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	690	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
494	top left of the screen.	691	top left of the screen.
495		692
496	Example: load a background image, put it in mirror mode and root align it.	693	Example: load a background image, put it in mirror mode and root align it.
497		694
498	rootalign mirror load "mybg.png"	695	rootalign keep { mirror load "mybg.png" }
499		696
500	Example: take the screen background and align it, giving the illusion of	697	Example: take the screen background and align it, giving the illusion of
501	transparency as long as the window isn't in front of other windows.	698	transparency as long as the window isn't in front of other windows.
502		699
503	rootalign root	700	rootalign root
504		701
505	=cut	702	=cut
506		703
507	sub move($$;$) {	704	sub move($$;$) {
508	my $img = pop->clone;	705	my $img = pop->clone;
509	$img->move ($_[0], $_[1]);	706	$img->move ($_[0], $_[1]);
510	$img	707	$img
511	}	708	}
512		709
		710	sub align($;$$) {
		711	my $img = pop;
		712
		713	move $_[0] * (TW - $img->w),
		714	$_[1] * (TH - $img->h),
		715	$img
		716	}
		717
		718	sub center($;$$) {
		719	my $img = pop;
		720	my $w = $_[0] \|\| TW;
		721	my $h = $_[1] \|\| TH;
		722
		723	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		724	}
		725
513	sub rootalign($) {	726	sub rootalign($) {
514	move -TX, -TY, $_[0]	727	move -TX, -TY, $_[0]
515	}	728	}
516		729
		730	=item rotate $center_x, $center_y, $degrees, $img
		731
		732	Rotates the image clockwise by C<$degrees> degrees, around the point at
		733	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		734
		735	Example: rotate the image by 90 degrees around it's center.
		736
		737	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		738
		739	=cut
		740
		741	sub rotate($$$$) {
		742	my $img = pop;
		743	$img->rotate (
		744	$_[0] * ($img->w + $img->x),
		745	$_[1] * ($img->h + $img->y),
		746	$_[2] * (3.14159265 / 180),
		747	)
		748	}
		749
		750	=back
		751
		752	=head2 COLOUR MODIFICATIONS
		753
		754	The following operators change the pixels of the image.
		755
		756	=over 4
		757
517	=item contrast $factor, $img	758	=item contrast $factor, $img
518		759
519	=item contrast $r, $g, $b, $img	760	=item contrast $r, $g, $b, $img
520		761
521	=item contrast $r, $g, $b, $a, $img	762	=item contrast $r, $g, $b, $a, $img
522		763
523	Adjusts the I<contrast> of an image.	764	Adjusts the I<contrast> of an image.
524		765
		766	The first form applies a single C<$factor> to red, green and blue, the
		767	second form applies separate factors to each colour channel, and the last
		768	form includes the alpha channel.
		769
		770	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		771	contrast.
		772
		773	Due to limitations in the underlying XRender extension, lowering contrast
		774	also reduces brightness, while increasing contrast currently also
		775	increases brightness.
		776
525	=item brightness $factor, $img	777	=item brightness $bias, $img
526		778
527	=item brightness $r, $g, $b, $img	779	=item brightness $r, $g, $b, $img
528		780
529	=item brightness $r, $g, $b, $a, $img	781	=item brightness $r, $g, $b, $a, $img
		782
		783	Adjusts the brightness of an image.
		784
		785	The first form applies a single C<$bias> to red, green and blue, the
		786	second form applies separate biases to each colour channel, and the last
		787	form includes the alpha channel.
		788
		789	Values less than 0 reduce brightness, while values larger than 0 increase
		790	it. Useful range is from -1 to 1 - the former results in a black, the
		791	latter in a white picture.
		792
		793	Due to idiosyncrasies in the underlying XRender extension, biases less
		794	than zero can be I<very> slow.
530		795
531	=cut	796	=cut
532		797
533	sub contrast($$;$$;$) {	798	sub contrast($$;$$;$) {
534	my $img = pop;	799	my $img = pop;
535	my ($r, $g, $b, $a) = @_;	800	my ($r, $g, $b, $a) = @_;
536		801
537	($g, $b) = ($r, $r) if @_ < 4;	802	($g, $b) = ($r, $r) if @_ < 3;
538	$a = 1 if @_ < 5;	803	$a = 1 if @_ < 4;
539		804
540	$img = $img->clone;	805	$img = $img->clone;
541	$img->contrast ($r, $g, $b, $a);	806	$img->contrast ($r, $g, $b, $a);
542	$img	807	$img
543	}	808	}
544		809
545	sub brightness($$;$$;$) {	810	sub brightness($$;$$;$) {
546	my $img = pop;	811	my $img = pop;
547	my ($r, $g, $b, $a) = @_;	812	my ($r, $g, $b, $a) = @_;
548		813
549	($g, $b) = ($r, $r) if @_ < 4;	814	($g, $b) = ($r, $r) if @_ < 3;
550	$a = 1 if @_ < 5;	815	$a = 1 if @_ < 4;
551		816
552	$img = $img->clone;	817	$img = $img->clone;
553	$img->brightness ($r, $g, $b, $a);	818	$img->brightness ($r, $g, $b, $a);
554	$img	819	$img
555	}	820	}
556		821
		822	=item blur $radius, $img
		823
		824	=item blur $radius_horz, $radius_vert, $img
		825
		826	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		827	can also be specified separately.
		828
		829	Blurring is often I<very> slow, at least compared or other
		830	operators. Larger blur radii are slower than smaller ones, too, so if you
		831	don't want to freeze your screen for long times, start experimenting with
		832	low values for radius (<5).
		833
		834	=cut
		835
557	sub blur($$;$) {	836	sub blur($$;$) {
558	my $img = pop;	837	my $img = pop;
559	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	838	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
560	}	839	}
561		840
562	sub rotate($$$$$$) {
563	my $img = pop;
564	$img->rotate (
565	$_[0],
566	$_[1],
567	$_[2] * $img->w * .01,
568	$_[3] * $img->h * .01,
569	$_[4] * (3.14159265 / 180),
570	)
571	}
572
573	=back	841	=back
574		842
		843	=head2 OTHER STUFF
		844
		845	Anything that didn't fit any of the other categories, even after applying
		846	force and closing our eyes.
		847
		848	=over 4
		849
		850	=item keep { ... }
		851
		852	#TODO#
		853
		854	This operator takes a code block as argument, that is, one or more
		855	statements enclosed by braces.
		856
		857	The trick is that this code block is only evaluated once - future calls
		858	will simply return the original image (yes, it should only be used with
		859	images).
		860
		861	This can be extremely useful to avoid redoing the same slow operations
		862	again and again- for example, if your background expression takes the root
		863	background, blurs it and then root-aligns it it would have to blur the
		864	root background on every window move or resize.
		865
		866	In fact, urxvt itself encloses the whole expression in some kind of
		867	C<once> block so it only is reevaluated as required.
		868
		869	Putting the blur into a C<once> block will make sure the blur is only done
		870	once:
		871
		872	rootlign keep { blur 10, root }
		873
		874	This leaves the question of how to force reevaluation of the block,
		875	in case the root background changes: If expression inside the block
		876	is sensitive to some event (root background changes, window geometry
		877	changes), then it will be reevaluated automatically as needed.
		878
		879	=item once_again
		880
		881	Resets all C<once> block as if they had never been called, i.e. on the
		882	next call they will be reevaluated again.
		883
		884	=cut
		885
		886	sub once(&) {
		887	my $id = $_[0]+0;
		888
		889	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		890
		891	unless ($frame->[FR_CACHE]) {
		892	$frame->[FR_CACHE] = [ $_[0]() ];
		893
		894	my $self = $self;
		895	my $frame = $frame;
		896	Scalar::Util::weaken $frame;
		897	$self->compile_frame ($frame, sub {
		898	# clear this frame cache, also for all parents
		899	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		900	undef $frame->[FR_CACHE];
		901	}
		902
		903	$self->recalculate;
		904	});
		905	};
		906
		907	# in scalar context we always return the first original result, which
		908	# is not quite how perl works.
		909	wantarray
		910	? @{ $frame->[FR_CACHE] }
		911	: $frame->[FR_CACHE][0]
		912	}
		913
		914	sub once_again() {
		915	delete $self->{frame_cache};
		916	}
		917
		918	=back
		919
575	=cut	920	=cut
576		921
577	}	922	}
578		923
579	sub parse_expr {	924	sub parse_expr {
580	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	925	my $expr = eval
		926	"sub {\n"
		927	. "package urxvt::bgdsl;\n"
		928	. "#line 0 'background expression'\n"
		929	. "$_[0]\n"
		930	. "}";
581	die if $@;	931	die if $@;
582	$expr	932	$expr
583	}	933	}
584		934
585	# compiles a parsed expression	935	# compiles a parsed expression
586	sub set_expr {	936	sub set_expr {
587	my ($self, $expr) = @_;	937	my ($self, $expr) = @_;
588		938
		939	$self->{root} = [];
589	$self->{expr} = $expr;	940	$self->{expr} = $expr;
590	$self->recalculate;	941	$self->recalculate;
		942	}
		943
		944	# takes a hash of sensitivity indicators and installs watchers
		945	sub compile_frame {
		946	my ($self, $frame, $cb) = @_;
		947
		948	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		949	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		950
		951	# don't keep stuff alive
		952	Scalar::Util::weaken $state;
		953
		954	if ($again->{nested}) {
		955	$state->{nested} = 1;
		956	} else {
		957	delete $state->{nested};
		958	}
		959
		960	if (my $interval = $again->{time}) {
		961	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		962	if $state->{time}[0] != $interval;
		963
		964	# callback might have changed, although we could just rule that out
		965	$state->{time}[1]->cb (sub {
		966	++$state->{counter};
		967	$cb->();
		968	});
		969	} else {
		970	delete $state->{time};
		971	}
		972
		973	if ($again->{position}) {
		974	$state->{position} = $self->on (position_change => $cb);
		975	} else {
		976	delete $state->{position};
		977	}
		978
		979	if ($again->{size}) {
		980	$state->{size} = $self->on (size_change => $cb);
		981	} else {
		982	delete $state->{size};
		983	}
		984
		985	if ($again->{rootpmap}) {
		986	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		987	} else {
		988	delete $state->{rootpmap};
		989	}
591	}	990	}
592		991
593	# evaluate the current bg expression	992	# evaluate the current bg expression
594	sub recalculate {	993	sub recalculate {
595	my ($arg_self) = @_;	994	my ($arg_self) = @_;
…		…
605		1004
606	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1005	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
607		1006
608	# set environment to evaluate user expression	1007	# set environment to evaluate user expression
609		1008
610	local $self = $arg_self;	1009	local $self = $arg_self;
611
612	local $HOME = $ENV{HOME};	1010	local $HOME = $ENV{HOME};
613	local $old = $self->{state};	1011	local $frame = [];
614	local $new = my $state = $self->{state} = {};
615		1012
616	($x, $y, $w, $h) =
617	$self->background_geometry ($self->{border});	1013	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
618		1014
619	# evaluate user expression	1015	# evaluate user expression
620		1016
621	my $img = eval { $self->{expr}->() };	1017	my @img = eval { $self->{expr}->() };
622	warn $@ if $@;#d#	1018	die $@ if $@;
		1019	die "background-expr did not return anything.\n" unless @img;
		1020	die "background-expr: expected image(s), got something else.\n"
623	die if !UNIVERSAL::isa $img, "urxvt::img";	1021	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
624		1022
625	$state->{size_sensitive} = 1	1023	my $img = urxvt::bgdsl::merge @img;
		1024
		1025	$frame->[FR_AGAIN]{size} = 1
626	if $img->repeat_mode != urxvt::RepeatNormal;	1026	if $img->repeat_mode != urxvt::RepeatNormal;
627		1027
628	# if the expression is sensitive to external events, prepare reevaluation then	1028	# if the expression is sensitive to external events, prepare reevaluation then
629		1029	$self->compile_frame ($frame, sub { $arg_self->recalculate });
630	my $repeat;
631
632	if (my $again = $state->{again}) {
633	$repeat = 1;
634	my $self = $self;
635	$state->{timer} = $again == $old->{again}
636	? $old->{timer}
637	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
638	++$self->{counter};
639	$self->recalculate
640	});
641	}
642
643	if (delete $state->{position_sensitive}) {
644	$repeat = 1;
645	$self->enable (position_change => sub { $_[0]->recalculate });
646	} else {
647	$self->disable ("position_change");
648	}
649
650	if (delete $state->{size_sensitive}) {
651	$repeat = 1;
652	$self->enable (size_change => sub { $_[0]->recalculate });
653	} else {
654	$self->disable ("size_change");
655	}
656
657	if (delete $state->{rootpmap_sensitive}) {
658	$repeat = 1;
659	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
660	} else {
661	$self->disable ("rootpmap_change");
662	}
663		1030
664	# clear stuff we no longer need	1031	# clear stuff we no longer need
665		1032
666	%$old = ();	1033	# unless (%{ $frame->[FR_STATE] }) {
667
668	unless ($repeat) {
669	delete $self->{state};	1034	# delete $self->{state};
670	delete $self->{expr};	1035	# delete $self->{expr};
671	}	1036	# }
672		1037
673	# set background pixmap	1038	# set background pixmap
674		1039
675	$self->set_background ($img, $self->{border});	1040	$self->set_background ($img, $self->{border});
676	$self->scr_recolour (0);	1041	$self->scr_recolour (0);
…		…
678	}	1043	}
679		1044
680	sub on_start {	1045	sub on_start {
681	my ($self) = @_;	1046	my ($self) = @_;
682		1047
683	my $expr = $self->x_resource ("background.expr")	1048	my $expr = $self->x_resource ("%.expr")
684	or return;	1049	or return;
685		1050
		1051	$self->has_render
		1052	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		1053
686	$self->set_expr (parse_expr $expr);	1054	$self->set_expr (parse_expr $expr);
687	$self->{border} = $self->x_resource_boolean ("background.border");	1055	$self->{border} = $self->x_resource_boolean ("%.border");
		1056
		1057	$MIN_INTERVAL = $self->x_resource ("%.interval");
688		1058
689	()	1059	()
690	}	1060	}
691		1061

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.37 by root, Fri Jun 8 20:35:43 2012 UTC vs. Revision 1.67 by sf-exg, Fri Jun 29 18:12:25 2012 UTC

Diff Legend

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.37 by root, Fri Jun 8 20:35:43 2012 UTC vs.
Revision 1.67 by sf-exg, Fri Jun 29 18:12:25 2012 UTC