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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.35 by root, Fri Jun 8 08:06:38 2012 UTC vs.
Revision 1.49 by root, Sun Jun 10 15:29:18 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	#TODO: once, rootalign
7		8
		9	=head1 NAME
		10
8	=head1 background - manage terminal background	11	background - manage terminal background
9		12
10	=head2 SYNOPSIS	13	=head1 SYNOPSIS
11		14
12	rxvt -background-expr 'background expression'	15	urxvt --background-expr 'background expression'
13	-background-border	16	--background-border
		17	--background-interval seconds
14		18
15	=head2 DESCRIPTION	19	=head1 DESCRIPTION
16		20
		21	This extension manages the terminal background by creating a picture that
		22	is behind the text, replacing the normal background colour.
		23
		24	It does so by evaluating a Perl expression that I<calculates> the image on
		25	the fly, for example, by grabbing the root background or loading a file.
		26
		27	While the full power of Perl is available, the operators have been design
		28	to be as simple as possible.
		29
		30	For example, to load an image and scale it to the window size, you would
		31	use:
		32
		33	urxvt --background-expr 'scale load "/path/to/mybg.png"'
		34
		35	Or specified as a X resource:
		36
		37	URxvt.background-expr: scale load "/path/to/mybg.png"
		38
		39	=head1 THEORY OF OPERATION
		40
		41	At startup, just before the window is mapped for the first time, the
		42	expression is evaluated and must yield an image. The image is then
		43	extended as necessary to cover the whole terminal window, and is set as a
		44	background pixmap.
		45
		46	If the image contains an alpha channel, then it will be used as-is in
		47	visuals that support alpha channels (for example, for a compositing
		48	manager). In other visuals, the terminal background colour will be used to
		49	replace any transparency.
		50
		51	When the expression relies, directly or indirectly, on the window size,
		52	position, the root pixmap, or a timer, then it will be remembered. If not,
		53	then it will be removed.
		54
		55	If any of the parameters that the expression relies on changes (when the
		56	window is moved or resized, its position or size changes; when the root
		57	pixmap is replaced by another one the root background changes; or when the
		58	timer elapses), then the expression will be evaluated again.
		59
		60	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
		61	image to the window size, so it relies on the window size and will
		62	be reevaluated each time it is changed, but not when it moves for
		63	example. That ensures that the picture always fills the terminal, even
		64	after it's size changes.
		65
		66	=head2 EXPRESSIONS
		67
		68	Expressions are normal Perl expressions, in fact, they are Perl blocks -
		69	which means you could use multiple lines and statements:
		70
		71	again 3600;
		72	if (localtime now)[6]) {
		73	return scale load "$HOME/weekday.png";
		74	} else {
		75	return scale load "$HOME/sunday.png";
		76	}
		77
		78	This expression gets evaluated once per hour. It will set F<sunday.png> as
		79	background on Sundays, and F<weekday.png> on all other days.
		80
		81	Fortunately, we expect that most expressions will be much simpler, with
		82	little Perl knowledge needed.
		83
		84	Basically, you always start with a function that "generates" an image
		85	object, such as C<load>, which loads an image from disk, or C<root>, which
		86	returns the root window background image:
		87
		88	load "$HOME/mypic.png"
		89
		90	The path is usually specified as a quoted string (the exact rules can be
		91	found in the L<perlop> manpage). The F<$HOME> at the beginning of the
		92	string is expanded to the home directory.
		93
		94	Then you prepend one or more modifiers or filtering expressions, such as
		95	C<scale>:
		96
		97	scale load "$HOME/mypic.png"
		98
		99	Just like a mathematical expression with functions, you should read these
		100	expressions from right to left, as the C<load> is evaluated first, and
		101	its result becomes the argument to the C<scale> function.
		102
		103	Many operators also allow some parameters preceding the input image
		104	that modify its behaviour. For example, C<scale> without any additional
		105	arguments scales the image to size of the terminal window. If you specify
		106	an additional argument, it uses it as a scale factor (multiply by 100 to
		107	get a percentage):
		108
		109	scale 2, load "$HOME/mypic.png"
		110
		111	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
		112	has now two arguments, the C<200> and the C<load> expression, while
		113	C<load> only has one argument. Arguments are separated from each other by
		114	commas.
		115
		116	Scale also accepts two arguments, which are then separate factors for both
		117	horizontal and vertical dimensions. For example, this halves the image
		118	width and doubles the image height:
		119
		120	scale 0.5, 2, load "$HOME/mypic.png"
		121
		122	Other effects than scalign are also readily available, for exmaple, you can
		123	tile the image to fill the whole window, instead of resizing it:
		124
		125	tile load "$HOME/mypic.png"
		126
		127	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator
		128	is kind of superfluous.
		129
		130	Another common effect is to mirror the image, so that the same edges touch:
		131
		132	mirror load "$HOME/mypic.png"
		133
		134	This is also a typical background expression:
		135
		136	rootalign root
		137
		138	It first takes a snapshot of the screen background image, and then
		139	moves it to the upper left corner of the screen - the result is
		140	pseudo-transparency, as the image seems to be static while the window is
		141	moved around.
		142
		143	=head2 CYCLES AND CACHING
		144
		145	As has been mentioned before, the expression might be evaluated multiple
		146	times. Each time the expression is reevaluated, a new cycle is said to
		147	have begun. Many operators cache their results till the next cycle.
		148
		149	For example, the C<load> operator keeps a copy of the image. If it is
		150	asked to load the same image on the next cycle it will not load it again,
		151	but return the cached copy.
		152
		153	This only works for one cycle though, so as long as you load the same
		154	image every time, it will always be cached, but when you load a different
		155	image, it will forget about the first one.
		156
		157	This allows you to either speed things up by keeping multiple images in
		158	memory, or comserve memory by loading images more often.
		159
		160	For example, you can keep two images in memory and use a random one like
		161	this:
		162
		163	my $img1 = load "img1.png";
		164	my $img2 = load "img2.png";
		165	(0.5 > rand) ? $img1 : $img2
		166
		167	Since both images are "loaded" every time the expression is evaluated,
		168	they are always kept in memory. Contrast this version:
		169
		170	my $path1 = "img1.png";
		171	my $path2 = "img2.png";
		172	load ((0.5 > rand) ? $path1 : $path2)
		173
		174	Here, a path is selected randomly, and load is only called for one image,
		175	so keeps only one image in memory. If, on the next evaluation, luck
		176	decides to use the other path, then it will have to load that image again.
		177
17	=head2 REFERENCE	178	=head1 REFERENCE
18		179
19	=cut	180	=head2 COMMAND LINE SWITCHES
20		181
21	our $EXPR;	182	=over 4
22	#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';
23	$EXPR = 'move -TX, -TY, load "argb.png"';
24	#$EXPR = '
25	# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,
26	# clip X, Y, W, H, repeat_mirror,
27	# load "/root/pix/das_fette_schwein.jpg"
28	#';
29	#$EXPR = 'solid "red"';
30	#$EXPR = 'blur root, 10, 10'
31	#$EXPR = 'blur move (root, -x, -y), 5, 5'
32	#resize load "/root/pix/das_fette_schwein.jpg", w, h
33		183
		184	=item --background-expr perl-expression
		185
		186	Specifies the Perl expression to evaluate.
		187
		188	=item --background-border
		189
		190	By default, the expression creates an image that fills the full window,
		191	overwriting borders and any other areas, such as the scrollbar.
		192
		193	Specifying this flag changes the behaviour, so that the image only
		194	replaces the background of the character area.
		195
		196	=item --background-interval seconds
		197
		198	Since some operations in the underlying XRender extension can effetively
		199	freeze your X-server for prolonged time, this extension enforces a minimum
		200	time between updates, which is normally about 0.1 seconds.
		201
		202	If you want to do updates more often, you can decrease this safety
		203	interval with this switch.
		204
		205	=back
		206
		207	=cut
		208
		209	our %_IMGCACHE;
		210	our $HOME;
34	our ($self, $old, $new);	211	our ($self, $old, $new);
35	our ($x, $y, $w, $h);	212	our ($x, $y, $w, $h);
36		213
37	# enforce at least this interval between updates	214	# enforce at least this interval between updates
38	our $MIN_INTERVAL = 1/100;	215	our $MIN_INTERVAL = 6/59.951;
39		216
40	{	217	{
41	package urxvt::bgdsl; # background language	218	package urxvt::bgdsl; # background language
		219
		220	use List::Util qw(min max sum shuffle);
42		221
43	=head2 PROVIDERS/GENERATORS	222	=head2 PROVIDERS/GENERATORS
44		223
45	These functions provide an image, by loading it from disk, grabbing it	224	These functions provide an image, by loading it from disk, grabbing it
46	from the root screen or by simply generating it. They are used as starting	225	from the root screen or by simply generating it. They are used as starting
83	=item solid $width, $height, $colour	262	=item solid $width, $height, $colour
84		263
85	Creates a new image and completely fills it with the given colour. The	264	Creates a new image and completely fills it with the given colour. The
86	image is set to tiling mode.	265	image is set to tiling mode.
87		266
88	If <$width> and C<$height> are omitted, it creates a 1x1 image, which is	267	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
89	useful for solid backgrounds or for use in filtering effects.	268	useful for solid backgrounds or for use in filtering effects.
90		269
91	=cut	270	=cut
92		271
93	sub solid($$;$) {	272	sub solid($;$$) {
94	my $colour = pop;	273	my $colour = pop;
95		274
96	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	275	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
97	$img->fill ($colour);	276	$img->fill ($colour);
98	$img	277	$img
99	}	278	}
100		279
		280	=item clone $img
		281
		282	Returns an exact copy of the image. This is useful if you want to have
		283	multiple copies of the same image to apply different effects to.
		284
		285	=cut
		286
		287	sub clone($) {
		288	$_[0]->clone
		289	}
		290
101	=back	291	=back
102		292
		293	=head2 TILING MODES
		294
		295	The following operators modify the tiling mode of an image, that is, the
		296	way that pixels outside the image area are painted when the image is used.
		297
		298	=over 4
		299
		300	=item tile $img
		301
		302	Tiles the whole plane with the image and returns this new image - or in
		303	other words, it returns a copy of the image in plane tiling mode.
		304
		305	Example: load an image and tile it over the background, without
		306	resizing. The C<tile> call is superfluous because C<load> already defaults
		307	to tiling mode.
		308
		309	tile load "mybg.png"
		310
		311	=item mirror $img
		312
		313	Similar to tile, but reflects the image each time it uses a new copy, so
		314	that top edges always touch top edges, right edges always touch right
		315	edges and so on (with normal tiling, left edges always touch right edges
		316	and top always touch bottom edges).
		317
		318	Example: load an image and mirror it over the background, avoiding sharp
		319	edges at the image borders at the expense of mirroring the image itself
		320
		321	mirror load "mybg.png"
		322
		323	=item pad $img
		324
		325	Takes an image and modifies it so that all pixels outside the image area
		326	become transparent. This mode is most useful when you want to place an
		327	image over another image or the background colour while leaving all
		328	background pixels outside the image unchanged.
		329
		330	Example: load an image and display it in the upper left corner. The rest
		331	of the space is left "empty" (transparent or wahtever your compisotr does
		332	in alpha mode, else background colour).
		333
		334	pad load "mybg.png"
		335
		336	=item extend $img
		337
		338	Extends the image over the whole plane, using the closest pixel in the
		339	area outside the image. This mode is mostly useful when you more complex
		340	filtering operations and want the pixels outside the image to have the
		341	same values as the pixels near the edge.
		342
		343	Example: just for curiosity, how does this pixel extension stuff work?
		344
		345	extend move 50, 50, load "mybg.png"
		346
		347	=cut
		348
		349	sub pad($) {
		350	my $img = $_[0]->clone;
		351	$img->repeat_mode (urxvt::RepeatNone);
		352	$img
		353	}
		354
		355	sub tile($) {
		356	my $img = $_[0]->clone;
		357	$img->repeat_mode (urxvt::RepeatNormal);
		358	$img
		359	}
		360
		361	sub mirror($) {
		362	my $img = $_[0]->clone;
		363	$img->repeat_mode (urxvt::RepeatReflect);
		364	$img
		365	}
		366
		367	sub extend($) {
		368	my $img = $_[0]->clone;
		369	$img->repeat_mode (urxvt::RepeatPad);
		370	$img
		371	}
		372
		373	=back
		374
103	=head2 VARIABLES	375	=head2 VARIABLE VALUES
104		376
105	The following functions provide variable data such as the terminal	377	The following functions provide variable data such as the terminal window
		378	dimensions. They are not (Perl-) variables, they just return stuff that
106	window dimensions. Most of them make your expression sensitive to some	379	varies. Most of them make your expression sensitive to some events, for
107	events, for example using C<TW> (terminal width) means your expression is	380	example using C<TW> (terminal width) means your expression is evaluated
108	evaluated again when the terminal is resized.	381	again when the terminal is resized.
109		382
110	=over 4	383	=over 4
111		384
112	=item TX	385	=item TX
113		386
…		…
160		433
161	When this function is used the expression will be reevaluated again in	434	When this function is used the expression will be reevaluated again in
162	C<$seconds> seconds.	435	C<$seconds> seconds.
163		436
164	Example: load some image and rotate it according to the time of day (as if it were	437	Example: load some image and rotate it according to the time of day (as if it were
165	the hour pointer of a clock). update this image every minute.	438	the hour pointer of a clock). Update this image every minute.
166		439
167	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	440	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
168		441
169	=item counter $seconds	442	=item counter $seconds
170		443
…		…
184	$self->{counter} + 0	457	$self->{counter} + 0
185	}	458	}
186		459
187	=back	460	=back
188		461
189	=head2 TILING MODES	462	=head2 SHAPE CHANGING OPERATORS
190		463
191	The following operators modify the tiling mode of an image, that is, the	464	The following operators modify the shape, size or position of the image.
192	way that pixels outside the image area are painted when the image is used.
193		465
194	=over 4	466	=over 4
195
196	=item tile $img
197
198	Tiles the whole plane with the image and returns this new image - or in
199	other words, it returns a copy of the image in plane tiling mode.
200
201	Example: load an image and tile it over the background, without
202	resizing. The C<tile> call is superfluous because C<load> already defaults
203	to tiling mode.
204
205	tile load "mybg.png"
206
207	=item mirror $img
208
209	Similar to tile, but reflects the image each time it uses a new copy, so
210	that top edges always touch top edges, right edges always touch right
211	edges and so on (with normal tiling, left edges always touch right edges
212	and top always touch bottom edges).
213
214	Exmaple: load an image and mirror it over the background, avoiding sharp
215	edges at the image borders at the expense of mirroring the image itself
216
217	mirror load "mybg.png"
218
219	=item pad $img
220
221	Takes an image and modifies it so that all pixels outside the image area
222	become transparent. This mode is most useful when you want to place an
223	image over another image or the background colour while leaving all
224	background pixels outside the image unchanged.
225
226	Example: load an image and display it in the upper left corner. The rets
227	of the space is left "empty" (transparent or wahtever your compisotr does
228	in alpha mode, else background colour).
229
230	pad load "mybg.png"
231
232	=item extend $img
233
234	Extends the image over the whole plane, using the closest pixel in the
235	area outside the image. This mode is mostly useful when you more complex
236	filtering operations and want the pixels outside the image to have the
237	same values as the pixels near the edge.
238
239	Example: just for curiosity, how does this pixel extension stuff work?
240
241	extend move 50, 50, load "mybg.png"
242
243	=cut
244
245	sub pad($) {
246	my $img = $_[0]->clone;
247	$img->repeat_mode (urxvt::RepeatNone);
248	$img
249	}
250
251	sub tile($) {
252	my $img = $_[0]->clone;
253	$img->repeat_mode (urxvt::RepeatNormal);
254	$img
255	}
256
257	sub mirror($) {
258	my $img = $_[0]->clone;
259	$img->repeat_mode (urxvt::RepeatReflect);
260	$img
261	}
262
263	sub extend($) {
264	my $img = $_[0]->clone;
265	$img->repeat_mode (urxvt::RepeatPad);
266	$img
267	}
268
269	=back
270
271	=head2 PIXEL OPERATORS
272
273	The following operators modify the image pixels in various ways.
274
275	=over 4
276
277	=item clone $img
278
279	Returns an exact copy of the image.
280
281	=cut
282
283	sub clone($) {
284	$_[0]->clone
285	}
286		467
287	=item clip $img	468	=item clip $img
288		469
289	=item clip $width, $height, $img	470	=item clip $width, $height, $img
290		471
…		…
314	$img->sub_rect ($_[0], $_[1], $w, $h)	495	$img->sub_rect ($_[0], $_[1], $w, $h)
315	}	496	}
316		497
317	=item scale $img	498	=item scale $img
318		499
319	=item scale $size_percent, $img	500	=item scale $size_factor, $img
320		501
321	=item scale $width_percent, $height_percent, $img	502	=item scale $width_factor, $height_factor, $img
322		503
323	Scales the image by the given percentages in horizontal	504	Scales the image by the given factors in horizontal
324	(C<$width_percent>) and vertical (C<$height_percent>) direction.	505	(C<$width>) and vertical (C<$height>) direction.
325		506
326	If only one percentage is give, it is used for both directions.	507	If only one factor is give, it is used for both directions.
327		508
328	If no percentages are given, scales the image to the window size without	509	If no factors are given, scales the image to the window size without
329	keeping aspect.	510	keeping aspect.
330		511
331	=item resize $width, $height, $img	512	=item resize $width, $height, $img
332		513
333	Resizes the image to exactly C<$width> times C<$height> pixels.	514	Resizes the image to exactly C<$width> times C<$height> pixels.
334		515
335	=cut	516	=item fit $img
336		517
337	#TODO: maximise, maximise_fill?	518	=item fit $width, $height, $img
		519
		520	Fits the image into the given C<$width> and C<$height> without changing
		521	aspect, or the terminal size. That means it will be shrunk or grown until
		522	the whole image fits into the given area, possibly leaving borders.
		523
		524	=item cover $img
		525
		526	=item cover $width, $height, $img
		527
		528	Similar to C<fit>, but shrinks or grows until all of the area is covered
		529	by the image, so instead of potentially leaving borders, it will cut off
		530	image data that doesn't fit.
		531
		532	=cut
338		533
339	sub scale($;$;$) {	534	sub scale($;$;$) {
340	my $img = pop;	535	my $img = pop;
341		536
342	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	537	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
343	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	538	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
344	: $img->scale (TW, TH)	539	: $img->scale (TW, TH)
345	}	540	}
346		541
347	sub resize($$$) {	542	sub resize($$$) {
348	my $img = pop;	543	my $img = pop;
349	$img->scale ($_[0], $_[1])	544	$img->scale ($_[0], $_[1])
350	}	545	}
		546
		547	sub fit($;$$) {
		548	my $img = pop;
		549	my $w = ($_[0] \|\| TW) / $img->w;
		550	my $h = ($_[1] \|\| TH) / $img->h;
		551	scale +(min $w, $h), $img
		552	}
		553
		554	sub cover($;$$) {
		555	my $img = pop;
		556	my $w = ($_[0] \|\| TW) / $img->w;
		557	my $h = ($_[1] \|\| TH) / $img->h;
		558	scale +(max $w, $h), $img
		559	}
		560
		561	=item move $dx, $dy, $img
		562
		563	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
		564	the vertical.
		565
		566	Example: move the image right by 20 pixels and down by 30.
		567
		568	move 20, 30, ...
		569
		570	=item align $xalign, $yalign, $img
		571
		572	Aligns the image according to a factor - C<0> means the image is moved to
		573	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		574	exactly centered and C<1> means it touches the right or bottom edge.
		575
		576	Example: remove any visible border around an image, center it vertically but move
		577	it to the right hand side.
		578
		579	align 1, 0.5, pad $img
		580
		581	=item center $img
		582
		583	=item center $width, $height, $img
		584
		585	Centers the image, i.e. the center of the image is moved to the center of
		586	the terminal window (or the box specified by C<$width> and C<$height> if
		587	given).
		588
		589	Example: load an image and center it.
		590
		591	center pad load "mybg.png"
		592
		593	=item rootalign $img
		594
		595	Moves the image so that it appears glued to the screen as opposed to the
		596	window. This gives the illusion of a larger area behind the window. It is
		597	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
		598	top left of the screen.
		599
		600	Example: load a background image, put it in mirror mode and root align it.
		601
		602	rootalign mirror load "mybg.png"
		603
		604	Example: take the screen background and align it, giving the illusion of
		605	transparency as long as the window isn't in front of other windows.
		606
		607	rootalign root
		608
		609	=cut
351		610
352	sub move($$;$) {	611	sub move($$;$) {
353	my $img = pop->clone;	612	my $img = pop->clone;
354	$img->move ($_[0], $_[1]);	613	$img->move ($_[0], $_[1]);
355	$img	614	$img
356	}	615	}
357		616
		617	sub align($;$$) {
		618	my $img = pop;
		619
		620	move $_[0] * (TW - $img->w),
		621	$_[1] * (TH - $img->h),
		622	$img
		623	}
		624
		625	sub center($;$$) {
		626	my $img = pop;
		627	my $w = $_[0] \|\| TW;
		628	my $h = $_[1] \|\| TH;
		629
		630	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		631	}
		632
		633	sub rootalign($) {
		634	move -TX, -TY, $_[0]
		635	}
		636
		637	=back
		638
		639	=head2 COLOUR MODIFICATIONS
		640
		641	The following operators change the pixels of the image.
		642
		643	=over 4
		644
		645	=item contrast $factor, $img
		646
		647	=item contrast $r, $g, $b, $img
		648
		649	=item contrast $r, $g, $b, $a, $img
		650
		651	Adjusts the I<contrast> of an image.
		652
		653	The first form applies a single C<$factor> to red, green and blue, the
		654	second form applies separate factors to each colour channel, and the last
		655	form includes the alpha channel.
		656
		657	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		658	contrast.
		659
		660	Due to limitations in the underlying XRender extension, lowering contrast
		661	also reduces brightness, while increasing contrast currently also
		662	increases brightness.
		663
		664	=item brightness $bias, $img
		665
		666	=item brightness $r, $g, $b, $img
		667
		668	=item brightness $r, $g, $b, $a, $img
		669
		670	Adjusts the brightness of an image.
		671
		672	The first form applies a single C<$bias> to red, green and blue, the
		673	second form applies separate biases to each colour channel, and the last
		674	form includes the alpha channel.
		675
		676	Values less than 0 reduce brightness, while values larger than 0 increase
		677	it. Useful range is from -1 to 1 - the former results in a black, the
		678	latter in a white picture.
		679
		680	Due to idiosynchrasies in the underlying XRender extension, biases less
		681	than zero can be I<very> slow.
		682
		683	=cut
		684
		685	sub contrast($$;$$;$) {
		686	my $img = pop;
		687	my ($r, $g, $b, $a) = @_;
		688
		689	($g, $b) = ($r, $r) if @_ < 3;
		690	$a = 1 if @_ < 4;
		691
		692	$img = $img->clone;
		693	$img->contrast ($r, $g, $b, $a);
		694	$img
		695	}
		696
		697	sub brightness($$;$$;$) {
		698	my $img = pop;
		699	my ($r, $g, $b, $a) = @_;
		700
		701	($g, $b) = ($r, $r) if @_ < 3;
		702	$a = 1 if @_ < 4;
		703
		704	$img = $img->clone;
		705	$img->brightness ($r, $g, $b, $a);
		706	$img
		707	}
		708
		709	=item blur $radius, $img
		710
		711	=item blur $radius_horz, $radius_vert, $img
		712
		713	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		714	can also be specified separately.
		715
		716	Blurring is often I<very> slow, at least compared or other
		717	operators. Larger blur radii are slower than smaller ones, too, so if you
		718	don't want to freeze your screen for long times, start experimenting with
		719	low values for radius (<5).
		720
		721	=cut
		722
		723	sub blur($$;$) {
		724	my $img = pop;
		725	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
		726	}
		727
		728	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
		729
		730	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		731	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		732	width/height), generating a new image with width C<$new_width> and height
		733	C<$new_height>.
		734
		735	#TODO# new width, height, maybe more operators?
		736
		737	Example: rotate the image by 90 degrees
		738
		739	=cut
		740
358	sub rotate($$$$$$) {	741	sub rotate($$$$$$) {
359	my $img = pop;	742	my $img = pop;
360	$img->rotate (	743	$img->rotate (
361	$_[0],	744	$_[0],
362	$_[1],	745	$_[1],
363	$_[2] * $img->w * .01,	746	$_[2] * $img->w,
364	$_[3] * $img->h * .01,	747	$_[3] * $img->h,
365	$_[4] * (3.14159265 / 180),	748	$_[4] * (3.14159265 / 180),
366	)	749	)
367	}
368
369	sub blur($$;$) {
370	my $img = pop;
371	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
372	}
373
374	sub contrast($$;$$;$) {
375	my $img = pop;
376	my ($r, $g, $b, $a) = @_;
377
378	($g, $b) = ($r, $r) if @_ < 4;
379	$a = 1 if @_ < 5;
380
381	$img = $img->clone;
382	$img->contrast ($r, $g, $b, $a);
383	$img
384	}
385
386	sub brightness($$;$$;$) {
387	my $img = pop;
388	my ($r, $g, $b, $a) = @_;
389
390	($g, $b) = ($r, $r) if @_ < 4;
391	$a = 1 if @_ < 5;
392
393	$img = $img->clone;
394	$img->brightness ($r, $g, $b, $a);
395	$img
396	}	750	}
397		751
398	=back	752	=back
399		753
400	=cut	754	=cut
…		…
432		786
433	# set environment to evaluate user expression	787	# set environment to evaluate user expression
434		788
435	local $self = $arg_self;	789	local $self = $arg_self;
436		790
		791	local $HOME = $ENV{HOME};
437	local $old = $self->{state};	792	local $old = $self->{state};
438	local $new = my $state = $self->{state} = {};	793	local $new = my $state = $self->{state} = {};
439		794
440	($x, $y, $w, $h) =	795	($x, $y, $w, $h) =
441	$self->background_geometry ($self->{border});	796	$self->background_geometry ($self->{border});
442		797
443	# evaluate user expression	798	# evaluate user expression
444		799
445	my $img = eval { $self->{expr}->() };	800	my $img = eval { $self->{expr}->() };
446	warn $@ if $@;#d#	801	warn $@ if $@;#d#
447	die if !UNIVERSAL::isa $img, "urxvt::img";	802	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
448		803
449	$state->{size_sensitive} = 1	804	$state->{size_sensitive} = 1
450	if $img->repeat_mode != urxvt::RepeatNormal;	805	if $img->repeat_mode != urxvt::RepeatNormal;
451		806
452	# if the expression is sensitive to external events, prepare reevaluation then	807	# if the expression is sensitive to external events, prepare reevaluation then
…		…
502	}	857	}
503		858
504	sub on_start {	859	sub on_start {
505	my ($self) = @_;	860	my ($self) = @_;
506		861
507	my $expr = $self->x_resource ("background.expr")	862	my $expr = $self->x_resource ("%.expr")
508	or return;	863	or return;
509		864
		865	$self->has_render
		866	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		867
510	$self->set_expr (parse_expr $expr);	868	$self->set_expr (parse_expr $expr);
511	$self->{border} = $self->x_resource_boolean ("background.border");	869	$self->{border} = $self->x_resource_boolean ("%.border");
		870
		871	$MIN_INTERVAL = $self->x_resource ("%.interval");
512		872
513	()	873	()
514	}	874	}
515		875

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.35 by root, Fri Jun 8 08:06:38 2012 UTC vs. Revision 1.49 by root, Sun Jun 10 15:29:18 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.35 by root, Fri Jun 8 08:06:38 2012 UTC vs.
Revision 1.49 by root, Sun Jun 10 15:29:18 2012 UTC