[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 1.51 by sf-exg, Sun Jun 10 19:01:03 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	rxvt -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
		19	This extension manages the terminal background by creating a picture that
		20	is behind the text, replacing the normal background colour.
		21
		22	It does so by evaluating a Perl expression that I<calculates> the image on
		23	the fly, for example, by grabbing the root background or loading a file.
		24
		25	While the full power of Perl is available, the operators have been design
		26	to be as simple as possible.
		27
		28	For example, to load an image and scale it to the window size, you would
		29	use:
		30
		31	urxvt --background-expr 'scale load "/path/to/mybg.png"'
		32
		33	Or specified as a X resource:
		34
		35	URxvt.background-expr: scale load "/path/to/mybg.png"
		36
		37	=head1 THEORY OF OPERATION
		38
		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
		41	extended as necessary to cover the whole terminal window, and is set as a
		42	background pixmap.
		43
		44	If the image contains an alpha channel, then it will be used as-is in
		45	visuals that support alpha channels (for example, for a compositing
		46	manager). In other visuals, the terminal background colour will be used to
		47	replace any transparency.
		48
		49	When the expression relies, directly or indirectly, on the window size,
		50	position, the root pixmap, or a timer, then it will be remembered. If not,
		51	then it will be removed.
		52
		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
		55	pixmap is replaced by another one the root background changes; or when the
		56	timer elapses), then the expression will be evaluated again.
		57
		58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
		59	image to the window size, so it relies on the window size and will
		60	be reevaluated each time it is changed, but not when it moves for
		61	example. That ensures that the picture always fills the terminal, even
		62	after its size changes.
		63
		64	=head2 EXPRESSIONS
		65
		66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
		67	which means you could use multiple lines and statements:
		68
		69	again 3600;
		70	if (localtime now)[6]) {
		71	return scale load "$HOME/weekday.png";
		72	} else {
		73	return scale load "$HOME/sunday.png";
		74	}
		75
		76	This expression gets evaluated once per hour. It will set F<sunday.png> as
		77	background on Sundays, and F<weekday.png> on all other days.
		78
		79	Fortunately, we expect that most expressions will be much simpler, with
		80	little Perl knowledge needed.
		81
		82	Basically, you always start with a function that "generates" an image
		83	object, such as C<load>, which loads an image from disk, or C<root>, which
		84	returns the root window background image:
		85
		86	load "$HOME/mypic.png"
		87
		88	The path is usually specified as a quoted string (the exact rules can be
		89	found in the L<perlop> manpage). The F<$HOME> at the beginning of the
		90	string is expanded to the home directory.
		91
		92	Then you prepend one or more modifiers or filtering expressions, such as
		93	C<scale>:
		94
		95	scale load "$HOME/mypic.png"
		96
		97	Just like a mathematical expression with functions, you should read these
		98	expressions from right to left, as the C<load> is evaluated first, and
		99	its result becomes the argument to the C<scale> function.
		100
		101	Many operators also allow some parameters preceding the input image
		102	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
		104	an additional argument, it uses it as a scale factor (multiply by 100 to
		105	get a percentage):
		106
		107	scale 2, load "$HOME/mypic.png"
		108
		109	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
		110	has now two arguments, the C<200> and the C<load> expression, while
		111	C<load> only has one argument. Arguments are separated from each other by
		112	commas.
		113
		114	Scale also accepts two arguments, which are then separate factors for both
		115	horizontal and vertical dimensions. For example, this halves the image
		116	width and doubles the image height:
		117
		118	scale 0.5, 2, load "$HOME/mypic.png"
		119
		120	Other effects than scaling are also readily available, for example, you can
		121	tile the image to fill the whole window, instead of resizing it:
		122
		123	tile load "$HOME/mypic.png"
		124
		125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator
		126	is kind of superfluous.
		127
		128	Another common effect is to mirror the image, so that the same edges touch:
		129
		130	mirror load "$HOME/mypic.png"
		131
		132	This is also a typical background expression:
		133
		134	rootalign root
		135
		136	It first takes a snapshot of the screen background image, and then
		137	moves it to the upper left corner of the screen - the result is
		138	pseudo-transparency, as the image seems to be static while the window is
		139	moved around.
		140
		141	=head2 CYCLES AND CACHING
		142
		143	As has been mentioned before, the expression might be evaluated multiple
		144	times. Each time the expression is reevaluated, a new cycle is said to
		145	have begun. Many operators cache their results till the next cycle.
		146
		147	For example, the C<load> operator keeps a copy of the image. If it is
		148	asked to load the same image on the next cycle it will not load it again,
		149	but return the cached copy.
		150
		151	This only works for one cycle though, so as long as you load the same
		152	image every time, it will always be cached, but when you load a different
		153	image, it will forget about the first one.
		154
		155	This allows you to either speed things up by keeping multiple images in
		156	memory, or conserve memory by loading images more often.
		157
		158	For example, you can keep two images in memory and use a random one like
		159	this:
		160
		161	my $img1 = load "img1.png";
		162	my $img2 = load "img2.png";
		163	(0.5 > rand) ? $img1 : $img2
		164
		165	Since both images are "loaded" every time the expression is evaluated,
		166	they are always kept in memory. Contrast this version:
		167
		168	my $path1 = "img1.png";
		169	my $path2 = "img2.png";
		170	load ((0.5 > rand) ? $path1 : $path2)
		171
		172	Here, a path is selected randomly, and load is only called for one image,
		173	so keeps only one image in memory. If, on the next evaluation, luck
		174	decides to use the other path, then it will have to load that image again.
		175
17	=head2 REFERENCE	176	=head1 REFERENCE
18		177
19	=cut	178	=head2 COMMAND LINE SWITCHES
20		179
21	our $EXPR;	180	=over 4
22	#$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		181
		182	=item --background-expr perl-expression
		183
		184	Specifies the Perl expression to evaluate.
		185
		186	=item --background-border
		187
		188	By default, the expression creates an image that fills the full window,
		189	overwriting borders and any other areas, such as the scrollbar.
		190
		191	Specifying this flag changes the behaviour, so that the image only
		192	replaces the background of the character area.
		193
		194	=item --background-interval seconds
		195
		196	Since some operations in the underlying XRender extension can effectively
		197	freeze your X-server for prolonged time, this extension enforces a minimum
		198	time between updates, which is normally about 0.1 seconds.
		199
		200	If you want to do updates more often, you can decrease this safety
		201	interval with this switch.
		202
		203	=back
		204
		205	=cut
		206
		207	our %_IMGCACHE;
		208	our $HOME;
34	our ($self, $old, $new);	209	our ($self, $old, $new);
35	our ($x, $y, $w, $h);	210	our ($x, $y, $w, $h);
36		211
37	# enforce at least this interval between updates	212	# enforce at least this interval between updates
38	our $MIN_INTERVAL = 1/100;	213	our $MIN_INTERVAL = 6/59.951;
39		214
40	{	215	{
41	package urxvt::bgdsl; # background language	216	package urxvt::bgdsl; # background language
		217
		218	use List::Util qw(min max sum shuffle);
42		219
43	=head2 PROVIDERS/GENERATORS	220	=head2 PROVIDERS/GENERATORS
44		221
45	These functions provide an image, by loading it from disk, grabbing it	222	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	223	from the root screen or by simply generating it. They are used as starting
83	=item solid $width, $height, $colour	260	=item solid $width, $height, $colour
84		261
85	Creates a new image and completely fills it with the given colour. The	262	Creates a new image and completely fills it with the given colour. The
86	image is set to tiling mode.	263	image is set to tiling mode.
87		264
88	If <$width> and C<$height> are omitted, it creates a 1x1 image, which is	265	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
89	useful for solid backgrounds or for use in filtering effects.	266	useful for solid backgrounds or for use in filtering effects.
90		267
91	=cut	268	=cut
92		269
93	sub solid($$;$) {	270	sub solid($;$$) {
94	my $colour = pop;	271	my $colour = pop;
95		272
96	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	273	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
97	$img->fill ($colour);	274	$img->fill ($colour);
98	$img	275	$img
99	}	276	}
100		277
		278	=item clone $img
		279
		280	Returns an exact copy of the image. This is useful if you want to have
		281	multiple copies of the same image to apply different effects to.
		282
		283	=cut
		284
		285	sub clone($) {
		286	$_[0]->clone
		287	}
		288
101	=back	289	=back
102		290
		291	=head2 TILING MODES
		292
		293	The following operators modify the tiling mode of an image, that is, the
		294	way that pixels outside the image area are painted when the image is used.
		295
		296	=over 4
		297
		298	=item tile $img
		299
		300	Tiles the whole plane with the image and returns this new image - or in
		301	other words, it returns a copy of the image in plane tiling mode.
		302
		303	Example: load an image and tile it over the background, without
		304	resizing. The C<tile> call is superfluous because C<load> already defaults
		305	to tiling mode.
		306
		307	tile load "mybg.png"
		308
		309	=item mirror $img
		310
		311	Similar to tile, but reflects the image each time it uses a new copy, so
		312	that top edges always touch top edges, right edges always touch right
		313	edges and so on (with normal tiling, left edges always touch right edges
		314	and top always touch bottom edges).
		315
		316	Example: load an image and mirror it over the background, avoiding sharp
		317	edges at the image borders at the expense of mirroring the image itself
		318
		319	mirror load "mybg.png"
		320
		321	=item pad $img
		322
		323	Takes an image and modifies it so that all pixels outside the image area
		324	become transparent. This mode is most useful when you want to place an
		325	image over another image or the background colour while leaving all
		326	background pixels outside the image unchanged.
		327
		328	Example: load an image and display it in the upper left corner. The rest
		329	of the space is left "empty" (transparent or whatever your compositor does
		330	in alpha mode, else background colour).
		331
		332	pad load "mybg.png"
		333
		334	=item extend $img
		335
		336	Extends the image over the whole plane, using the closest pixel in the
		337	area outside the image. This mode is mostly useful when you use more complex
		338	filtering operations and want the pixels outside the image to have the
		339	same values as the pixels near the edge.
		340
		341	Example: just for curiosity, how does this pixel extension stuff work?
		342
		343	extend move 50, 50, load "mybg.png"
		344
		345	=cut
		346
		347	sub pad($) {
		348	my $img = $_[0]->clone;
		349	$img->repeat_mode (urxvt::RepeatNone);
		350	$img
		351	}
		352
		353	sub tile($) {
		354	my $img = $_[0]->clone;
		355	$img->repeat_mode (urxvt::RepeatNormal);
		356	$img
		357	}
		358
		359	sub mirror($) {
		360	my $img = $_[0]->clone;
		361	$img->repeat_mode (urxvt::RepeatReflect);
		362	$img
		363	}
		364
		365	sub extend($) {
		366	my $img = $_[0]->clone;
		367	$img->repeat_mode (urxvt::RepeatPad);
		368	$img
		369	}
		370
		371	=back
		372
103	=head2 VARIABLES	373	=head2 VARIABLE VALUES
104		374
105	The following functions provide variable data such as the terminal	375	The following functions provide variable data such as the terminal window
		376	dimensions. They are not (Perl-) variables, they just return stuff that
106	window dimensions. Most of them make your expression sensitive to some	377	varies. Most of them make your expression sensitive to some events, for
107	events, for example using C<TW> (terminal width) means your expression is	378	example using C<TW> (terminal width) means your expression is evaluated
108	evaluated again when the terminal is resized.	379	again when the terminal is resized.
109		380
110	=over 4	381	=over 4
111		382
112	=item TX	383	=item TX
113		384
…		…
160		431
161	When this function is used the expression will be reevaluated again in	432	When this function is used the expression will be reevaluated again in
162	C<$seconds> seconds.	433	C<$seconds> seconds.
163		434
164	Example: load some image and rotate it according to the time of day (as if it were	435	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.	436	the hour pointer of a clock). Update this image every minute.
166		437
167	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	438	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
168		439
169	=item counter $seconds	440	=item counter $seconds
170		441
…		…
184	$self->{counter} + 0	455	$self->{counter} + 0
185	}	456	}
186		457
187	=back	458	=back
188		459
189	=head2 TILING MODES	460	=head2 SHAPE CHANGING OPERATORS
190		461
191	The following operators modify the tiling mode of an image, that is, the	462	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		463
194	=over 4	464	=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		465
287	=item clip $img	466	=item clip $img
288		467
289	=item clip $width, $height, $img	468	=item clip $width, $height, $img
290		469
…		…
314	$img->sub_rect ($_[0], $_[1], $w, $h)	493	$img->sub_rect ($_[0], $_[1], $w, $h)
315	}	494	}
316		495
317	=item scale $img	496	=item scale $img
318		497
319	=item scale $size_percent, $img	498	=item scale $size_factor, $img
320		499
321	=item scale $width_percent, $height_percent, $img	500	=item scale $width_factor, $height_factor, $img
322		501
323	Scales the image by the given percentages in horizontal	502	Scales the image by the given factors in horizontal
324	(C<$width_percent>) and vertical (C<$height_percent>) direction.	503	(C<$width>) and vertical (C<$height>) direction.
325		504
326	If only one percentage is give, it is used for both directions.	505	If only one factor is give, it is used for both directions.
327		506
328	If no percentages are given, scales the image to the window size without	507	If no factors are given, scales the image to the window size without
329	keeping aspect.	508	keeping aspect.
330		509
331	=item resize $width, $height, $img	510	=item resize $width, $height, $img
332		511
333	Resizes the image to exactly C<$width> times C<$height> pixels.	512	Resizes the image to exactly C<$width> times C<$height> pixels.
334		513
335	=cut	514	=item fit $img
336		515
337	#TODO: maximise, maximise_fill?	516	=item fit $width, $height, $img
		517
		518	Fits the image into the given C<$width> and C<$height> without changing
		519	aspect, or the terminal size. That means it will be shrunk or grown until
		520	the whole image fits into the given area, possibly leaving borders.
		521
		522	=item cover $img
		523
		524	=item cover $width, $height, $img
		525
		526	Similar to C<fit>, but shrinks or grows until all of the area is covered
		527	by the image, so instead of potentially leaving borders, it will cut off
		528	image data that doesn't fit.
		529
		530	=cut
338		531
339	sub scale($;$;$) {	532	sub scale($;$;$) {
340	my $img = pop;	533	my $img = pop;
341		534
342	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	535	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
343	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	536	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
344	: $img->scale (TW, TH)	537	: $img->scale (TW, TH)
345	}	538	}
346		539
347	sub resize($$$) {	540	sub resize($$$) {
348	my $img = pop;	541	my $img = pop;
349	$img->scale ($_[0], $_[1])	542	$img->scale ($_[0], $_[1])
350	}	543	}
		544
		545	sub fit($;$$) {
		546	my $img = pop;
		547	my $w = ($_[0] \|\| TW) / $img->w;
		548	my $h = ($_[1] \|\| TH) / $img->h;
		549	scale +(min $w, $h), $img
		550	}
		551
		552	sub cover($;$$) {
		553	my $img = pop;
		554	my $w = ($_[0] \|\| TW) / $img->w;
		555	my $h = ($_[1] \|\| TH) / $img->h;
		556	scale +(max $w, $h), $img
		557	}
		558
		559	=item move $dx, $dy, $img
		560
		561	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
		562	the vertical.
		563
		564	Example: move the image right by 20 pixels and down by 30.
		565
		566	move 20, 30, ...
		567
		568	=item align $xalign, $yalign, $img
		569
		570	Aligns the image according to a factor - C<0> means the image is moved to
		571	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		572	exactly centered and C<1> means it touches the right or bottom edge.
		573
		574	Example: remove any visible border around an image, center it vertically but move
		575	it to the right hand side.
		576
		577	align 1, 0.5, pad $img
		578
		579	=item center $img
		580
		581	=item center $width, $height, $img
		582
		583	Centers the image, i.e. the center of the image is moved to the center of
		584	the terminal window (or the box specified by C<$width> and C<$height> if
		585	given).
		586
		587	Example: load an image and center it.
		588
		589	center pad load "mybg.png"
		590
		591	=item rootalign $img
		592
		593	Moves the image so that it appears glued to the screen as opposed to the
		594	window. This gives the illusion of a larger area behind the window. It is
		595	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
		596	top left of the screen.
		597
		598	Example: load a background image, put it in mirror mode and root align it.
		599
		600	rootalign mirror load "mybg.png"
		601
		602	Example: take the screen background and align it, giving the illusion of
		603	transparency as long as the window isn't in front of other windows.
		604
		605	rootalign root
		606
		607	=cut
351		608
352	sub move($$;$) {	609	sub move($$;$) {
353	my $img = pop->clone;	610	my $img = pop->clone;
354	$img->move ($_[0], $_[1]);	611	$img->move ($_[0], $_[1]);
355	$img	612	$img
356	}	613	}
357		614
		615	sub align($;$$) {
		616	my $img = pop;
		617
		618	move $_[0] * (TW - $img->w),
		619	$_[1] * (TH - $img->h),
		620	$img
		621	}
		622
		623	sub center($;$$) {
		624	my $img = pop;
		625	my $w = $_[0] \|\| TW;
		626	my $h = $_[1] \|\| TH;
		627
		628	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		629	}
		630
		631	sub rootalign($) {
		632	move -TX, -TY, $_[0]
		633	}
		634
		635	=back
		636
		637	=head2 COLOUR MODIFICATIONS
		638
		639	The following operators change the pixels of the image.
		640
		641	=over 4
		642
		643	=item contrast $factor, $img
		644
		645	=item contrast $r, $g, $b, $img
		646
		647	=item contrast $r, $g, $b, $a, $img
		648
		649	Adjusts the I<contrast> of an image.
		650
		651	The first form applies a single C<$factor> to red, green and blue, the
		652	second form applies separate factors to each colour channel, and the last
		653	form includes the alpha channel.
		654
		655	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		656	contrast.
		657
		658	Due to limitations in the underlying XRender extension, lowering contrast
		659	also reduces brightness, while increasing contrast currently also
		660	increases brightness.
		661
		662	=item brightness $bias, $img
		663
		664	=item brightness $r, $g, $b, $img
		665
		666	=item brightness $r, $g, $b, $a, $img
		667
		668	Adjusts the brightness of an image.
		669
		670	The first form applies a single C<$bias> to red, green and blue, the
		671	second form applies separate biases to each colour channel, and the last
		672	form includes the alpha channel.
		673
		674	Values less than 0 reduce brightness, while values larger than 0 increase
		675	it. Useful range is from -1 to 1 - the former results in a black, the
		676	latter in a white picture.
		677
		678	Due to idiosyncrasies in the underlying XRender extension, biases less
		679	than zero can be I<very> slow.
		680
		681	=cut
		682
		683	sub contrast($$;$$;$) {
		684	my $img = pop;
		685	my ($r, $g, $b, $a) = @_;
		686
		687	($g, $b) = ($r, $r) if @_ < 3;
		688	$a = 1 if @_ < 4;
		689
		690	$img = $img->clone;
		691	$img->contrast ($r, $g, $b, $a);
		692	$img
		693	}
		694
		695	sub brightness($$;$$;$) {
		696	my $img = pop;
		697	my ($r, $g, $b, $a) = @_;
		698
		699	($g, $b) = ($r, $r) if @_ < 3;
		700	$a = 1 if @_ < 4;
		701
		702	$img = $img->clone;
		703	$img->brightness ($r, $g, $b, $a);
		704	$img
		705	}
		706
		707	=item blur $radius, $img
		708
		709	=item blur $radius_horz, $radius_vert, $img
		710
		711	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		712	can also be specified separately.
		713
		714	Blurring is often I<very> slow, at least compared or other
		715	operators. Larger blur radii are slower than smaller ones, too, so if you
		716	don't want to freeze your screen for long times, start experimenting with
		717	low values for radius (<5).
		718
		719	=cut
		720
		721	sub blur($$;$) {
		722	my $img = pop;
		723	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
		724	}
		725
		726	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
		727
		728	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		729	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		730	width/height), generating a new image with width C<$new_width> and height
		731	C<$new_height>.
		732
		733	#TODO# new width, height, maybe more operators?
		734
		735	Example: rotate the image by 90 degrees
		736
		737	=cut
		738
358	sub rotate($$$$$$) {	739	sub rotate($$$$$$) {
359	my $img = pop;	740	my $img = pop;
360	$img->rotate (	741	$img->rotate (
361	$_[0],	742	$_[0],
362	$_[1],	743	$_[1],
363	$_[2] * $img->w * .01,	744	$_[2] * $img->w,
364	$_[3] * $img->h * .01,	745	$_[3] * $img->h,
365	$_[4] * (3.14159265 / 180),	746	$_[4] * (3.14159265 / 180),
366	)	747	)
367	}
368
369	sub blur($$;$) {
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	}	748	}
397		749
398	=back	750	=back
399		751
400	=cut	752	=cut
…		…
432		784
433	# set environment to evaluate user expression	785	# set environment to evaluate user expression
434		786
435	local $self = $arg_self;	787	local $self = $arg_self;
436		788
		789	local $HOME = $ENV{HOME};
437	local $old = $self->{state};	790	local $old = $self->{state};
438	local $new = my $state = $self->{state} = {};	791	local $new = my $state = $self->{state} = {};
439		792
440	($x, $y, $w, $h) =	793	($x, $y, $w, $h) =
441	$self->background_geometry ($self->{border});	794	$self->background_geometry ($self->{border});
442		795
443	# evaluate user expression	796	# evaluate user expression
444		797
445	my $img = eval { $self->{expr}->() };	798	my $img = eval { $self->{expr}->() };
446	warn $@ if $@;#d#	799	warn $@ if $@;#d#
447	die if !UNIVERSAL::isa $img, "urxvt::img";	800	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
448		801
449	$state->{size_sensitive} = 1	802	$state->{size_sensitive} = 1
450	if $img->repeat_mode != urxvt::RepeatNormal;	803	if $img->repeat_mode != urxvt::RepeatNormal;
451		804
452	# if the expression is sensitive to external events, prepare reevaluation then	805	# if the expression is sensitive to external events, prepare reevaluation then
…		…
502	}	855	}
503		856
504	sub on_start {	857	sub on_start {
505	my ($self) = @_;	858	my ($self) = @_;
506		859
507	my $expr = $self->x_resource ("background.expr")	860	my $expr = $self->x_resource ("%.expr")
508	or return;	861	or return;
509		862
		863	$self->has_render
		864	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		865
510	$self->set_expr (parse_expr $expr);	866	$self->set_expr (parse_expr $expr);
511	$self->{border} = $self->x_resource_boolean ("background.border");	867	$self->{border} = $self->x_resource_boolean ("%.border");
		868
		869	$MIN_INTERVAL = $self->x_resource ("%.interval");
512		870
513	()	871	()
514	}	872	}
515		873

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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 1.51 by sf-exg, Sun Jun 10 19:01:03 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 1.51 by sf-exg, Sun Jun 10 19:01:03 2012 UTC