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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.34 by root, Thu Jun 7 17:04:33 2012 UTC vs.
Revision 1.66 by root, Thu Jun 28 15:19:15 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
		7	=head1 NAME
		8
6	=head1 background - manage terminal background	9	background - manage terminal background
7		10
8	=head2 SYNOPSIS	11	=head1 SYNOPSIS
9		12
10	rxvt -background-expr 'background expression'	13	urxvt --background-expr 'background expression'
11	-background-border	14	--background-border
		15	--background-interval seconds
12		16
13	=head2 DESCRIPTION	17	=head1 DESCRIPTION
14		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 keep { load "/path/to/mybg.png" }'
		32
		33	Or specified as a X resource:
		34
		35	URxvt.background-expr: scale keep { 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 keep { load "$HOME/mybg.png"
		59	}> scales the image to the window size, so it relies on the window size
		60	and will be reevaluated each time it is changed, but not when it moves for
		61	example. That ensures that the picture always fills the terminal, even
		62	after its size changes.
		63
		64	=head2 EXPRESSIONS
		65
		66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
		67	which means you could use multiple lines and statements:
		68
		69	scale keep {
		70	again 3600;
		71	if (localtime now)[6]) {
		72	return load "$HOME/weekday.png";
		73	} else {
		74	return load "$HOME/sunday.png";
		75	}
		76	}
		77
		78	This expression is evaluated once per hour. It will set F<sunday.png> as
		79	background on Sundays, and F<weekday.png> on all other days.
		80
		81	Fortunately, we expect that most expressions will be much simpler, with
		82	little Perl knowledge needed.
		83
		84	Basically, you always start with a function that "generates" an image
		85	object, such as C<load>, which loads an image from disk, or C<root>, which
		86	returns the root window background image:
		87
		88	load "$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	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:
		126
		127	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		128
		129	The C<keep> operator executes all the statements inside the braces only
		130	once, or when it thinks the outcome might change. In other cases it
		131	returns the last value computed by the brace block.
		132
		133	This means that the C<load> is only executed once, which makes it much
		134	faster, but also means that more memory is being used, because the loaded
		135	image must be kept in memory at all times. In this expression, the
		136	trade-off is likely worth it.
		137
		138	But back to effects: Other effects than scaling are also readily
		139	available, for example, you can tile the image to fill the whole window,
		140	instead of resizing it:
		141
		142	tile keep { load "$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 depend 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
15	=head2 REFERENCE	209	=head1 REFERENCE
16		210
17	=cut	211	=head2 COMMAND LINE SWITCHES
18		212
19	our $EXPR;	213	=over 4
20	#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';
21	$EXPR = 'move -TX, -TY, load "argb.png"';
22	#$EXPR = '
23	# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,
24	# clip X, Y, W, H, repeat_mirror,
25	# load "/root/pix/das_fette_schwein.jpg"
26	#';
27	#$EXPR = 'solid "red"';
28	#$EXPR = 'blur root, 10, 10'
29	#$EXPR = 'blur move (root, -x, -y), 5, 5'
30	#resize load "/root/pix/das_fette_schwein.jpg", w, h
31		214
32	our ($self, $old, $new);	215	=item --background-expr perl-expression
		216
		217	Specifies the Perl expression to evaluate.
		218
		219	=item --background-border
		220
		221	By default, the expression creates an image that fills the full window,
		222	overwriting borders and any other areas, such as the scrollbar.
		223
		224	Specifying this flag changes the behaviour, so that the image only
		225	replaces the background of the character area.
		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
		236	=back
		237
		238	=cut
		239
		240	our %_IMG_CACHE;
		241	our $HOME;
		242	our ($self, $frame);
33	our ($x, $y, $w, $h);	243	our ($x, $y, $w, $h);
34		244
35	# enforce at least this interval between updates	245	# enforce at least this interval between updates
36	our $MIN_INTERVAL = 1/100;	246	our $MIN_INTERVAL = 6/59.951;
37		247
38	{	248	{
39	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);
40		257
41	=head2 PROVIDERS/GENERATORS	258	=head2 PROVIDERS/GENERATORS
42		259
43	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
44	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
49	=item load $path	266	=item load $path
50		267
51	Loads the image at the given C<$path>. The image is set to plane tiling	268	Loads the image at the given C<$path>. The image is set to plane tiling
52	mode.	269	mode.
53		270
54	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.
55		273
		274	=item load_uc $path
		275
		276	Load uncached - same as load, but does not cache the image, which means it
		277	is I<always> loaded from the filesystem again.
		278
56	=cut	279	=cut
		280
		281	sub load_uc($) {
		282	$self->new_img_from_file ($path)
		283	}
57		284
58	sub load($) {	285	sub load($) {
59	my ($path) = @_;	286	my ($path) = @_;
60		287
61	$new->{load}{$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	}
62	}	293	}
63		294
64	=item root	295	=item root
65		296
66	Returns the root window pixmap, that is, hopefully, the background image	297	Returns the root window pixmap, that is, hopefully, the background image
67	of your screen. The image is set to extend mode.	298	of your screen.
68		299
69	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
70	reevaluated when the bg image changes.	301	reevaluated when the bg image changes.
71		302
72	=cut	303	=cut
73		304
74	sub root() {	305	sub root() {
75	$new->{rootpmap_sensitive} = 1;	306	$frame->[FR_AGAIN]{rootpmap} = 1;
76	die "root op not supported, exg, we need you";	307	$self->new_img_from_root
77	}	308	}
78		309
79	=item solid $colour	310	=item solid $colour
80		311
81	=item solid $width, $height, $colour	312	=item solid $width, $height, $colour
82		313
83	Creates a new image and completely fills it with the given colour. The	314	Creates a new image and completely fills it with the given colour. The
84	image is set to tiling mode.	315	image is set to tiling mode.
85		316
86	If <$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
87	useful for solid backgrounds or for use in filtering effects.	318	useful for solid backgrounds or for use in filtering effects.
88		319
89	=cut	320	=cut
90		321
91	sub solid($$;$) {	322	sub solid($;$$) {
92	my $colour = pop;	323	my $colour = pop;
93		324
94	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);
95	$img->fill ($colour);	326	$img->fill ($colour);
96	$img	327	$img
97	}	328	}
98		329
99	=back	330	=item clone $img
100		331
101	=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.
102		334
103	The following functions provide variable data such as the terminal
104	window dimensions. Most of them make your expression sensitive to some
105	events, for example using C<TW> (terminal width) means your expression is
106	evaluated again when the terminal is resized.
107
108	=over 4
109
110	=item TX
111
112	=item TY
113
114	Return the X and Y coordinates of the terminal window (the terminal
115	window is the full window by default, and the character area only when in
116	border-respect mode).
117
118	Using these functions make your expression sensitive to window moves.
119
120	These functions are mainly useful to align images to the root window.
121
122	Example: load an image and align it so it looks as if anchored to the
123	background.
124
125	move -TX, -TY, load "mybg.png"
126
127	=item TW
128
129	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
130	terminal window is the full window by default, and the character area only
131	when in border-respect mode).
132
133	Using these functions make your expression sensitive to window resizes.
134
135	These functions are mainly useful to scale images, or to clip images to
136	the window size to conserve memory.
137
138	Example: take the screen background, clip it to the window size, blur it a
139	bit, align it to the window position and use it as background.
140
141	clip move -TX, -TY, blur 5, root
142
143	=cut	335	=cut
144		336
145	sub TX() { $new->{position_sensitive} = 1; $x }
146	sub TY() { $new->{position_sensitive} = 1; $y }
147	sub TW() { $new->{size_sensitive} = 1; $w }
148	sub TH() { $new->{size_sensitive} = 1; $h }
149
150	=item now
151
152	Returns the current time as (fractional) seconds since the epoch.
153
154	Using this expression does I<not> make your expression sensitive to time,
155	but the next two functions do.
156
157	=item again $seconds
158
159	When this function is used the expression will be reevaluated again in
160	C<$seconds> seconds.
161
162	Example: load some image and rotate it according to the time of day (as if it were
163	the hour pointer of a clock). update this image every minute.
164
165	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
166
167	=item counter $seconds
168
169	Like C<again>, but also returns an increasing counter value, starting at
170	0, which might be useful for some simple animation effects.
171
172	=cut
173
174	sub now() { urxvt::NOW }
175
176	sub again($) {
177	$new->{again} = $_[0];
178	}
179
180	sub counter($) {	337	sub clone($) {
181	$new->{again} = $_[0];	338	$_[0]->clone
182	$self->{counter} + 0
183	}	339	}
184		340
185	=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	}
186		384
187	=head2 TILING MODES	385	=head2 TILING MODES
188		386
189	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
190	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.
…		…
207	Similar to tile, but reflects the image each time it uses a new copy, so	405	Similar to tile, but reflects the image each time it uses a new copy, so
208	that top edges always touch top edges, right edges always touch right	406	that top edges always touch top edges, right edges always touch right
209	edges and so on (with normal tiling, left edges always touch right edges	407	edges and so on (with normal tiling, left edges always touch right edges
210	and top always touch bottom edges).	408	and top always touch bottom edges).
211		409
212	Exmaple: load an image and mirror it over the background, avoiding sharp	410	Example: load an image and mirror it over the background, avoiding sharp
213	edges at the image borders at the expense of mirroring the image itself	411	edges at the image borders at the expense of mirroring the image itself
214		412
215	mirror load "mybg.png"	413	mirror load "mybg.png"
216		414
217	=item pad $img	415	=item pad $img
…		…
219	Takes an image and modifies it so that all pixels outside the image area	417	Takes an image and modifies it so that all pixels outside the image area
220	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
221	image over another image or the background colour while leaving all	419	image over another image or the background colour while leaving all
222	background pixels outside the image unchanged.	420	background pixels outside the image unchanged.
223		421
224	Example: load an image and display it in the upper left corner. The rets	422	Example: load an image and display it in the upper left corner. The rest
225	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
226	in alpha mode, else background colour).	424	in alpha mode, else background colour).
227		425
228	pad load "mybg.png"	426	pad load "mybg.png"
229		427
230	=item extend $img	428	=item extend $img
231		429
232	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
233	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
234	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
235	same values as the pixels near the edge.	433	same values as the pixels near the edge.
236		434
237	Example: just for curiosity, how does this pixel extension stuff work?	435	Example: just for curiosity, how does this pixel extension stuff work?
238		436
…		…
264	$img	462	$img
265	}	463	}
266		464
267	=back	465	=back
268		466
269	=head2 PIXEL OPERATORS	467	=head2 VARIABLE VALUES
270		468
271	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.
272		474
273	=over 4	475	=over 4
274		476
275	=item clone $img	477	=item TX
276		478
277	Returns an exact copy of the image.	479	=item TY
278		480
279	=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).
280		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} = $_[0];
		546	}
		547
281	sub clone($) {	548	sub counter($) {
282	$_[0]->clone	549	$frame->[FR_AGAIN]{time} = $_[0];
		550	$frame->[FR_STATE]{counter} + 0
283	}	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
284		560
285	=item clip $img	561	=item clip $img
286		562
287	=item clip $width, $height, $img	563	=item clip $width, $height, $img
288		564
…		…
299	assumed.	575	assumed.
300		576
301	Example: load an image, blur it, and clip it to the window size to save	577	Example: load an image, blur it, and clip it to the window size to save
302	memory.	578	memory.
303		579
304	clip blur 10, load "mybg.png"	580	clip keep { blur 10, load "mybg.png" }
305		581
306	=cut	582	=cut
307		583
308	sub clip($;$$;$$) {	584	sub clip($;$$;$$) {
309	my $img = pop;	585	my $img = pop;
…		…
312	$img->sub_rect ($_[0], $_[1], $w, $h)	588	$img->sub_rect ($_[0], $_[1], $w, $h)
313	}	589	}
314		590
315	=item scale $img	591	=item scale $img
316		592
317	=item scale $size_percent, $img	593	=item scale $size_factor, $img
318		594
319	=item scale $width_percent, $height_percent, $img	595	=item scale $width_factor, $height_factor, $img
320		596
321	Scales the image by the given percentages in horizontal	597	Scales the image by the given factors in horizontal
322	(C<$width_percent>) and vertical (C<$height_percent>) direction.	598	(C<$width>) and vertical (C<$height>) direction.
323		599
324	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.
325		601
326	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
327	keeping aspect.	603	keeping aspect.
328		604
329	=item resize $width, $height, $img	605	=item resize $width, $height, $img
330		606
331	Resizes the image to exactly C<$width> times C<$height> pixels.	607	Resizes the image to exactly C<$width> times C<$height> pixels.
332		608
333	=cut	609	=item fit $img
334		610
335	#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, $img
		620
		621	Similar to C<fit>, but shrinks or grows until all of the area is covered
		622	by the image, so instead of potentially leaving borders, it will cut off
		623	image data that doesn't fit.
		624
		625	=cut
336		626
337	sub scale($;$;$) {	627	sub scale($;$;$) {
338	my $img = pop;	628	my $img = pop;
339		629
340	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	630	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
341	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	631	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
342	: $img->scale (TW, TH)	632	: $img->scale (TW, TH)
343	}	633	}
344		634
345	sub resize($$$) {	635	sub resize($$$) {
346	my $img = pop;	636	my $img = pop;
347	$img->scale ($_[0], $_[1])	637	$img->scale ($_[0], $_[1])
348	}	638	}
		639
		640	sub fit($;$$) {
		641	my $img = pop;
		642	my $w = ($_[0] \|\| TW) / $img->w;
		643	my $h = ($_[1] \|\| TH) / $img->h;
		644	scale +(min $w, $h), $img
		645	}
		646
		647	sub cover($;$$) {
		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
		654	=item move $dx, $dy, $img
		655
		656	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
		657	the vertical.
		658
		659	Example: move the image right by 20 pixels and down by 30.
		660
		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" }
		685
		686	=item rootalign $img
		687
		688	Moves the image so that it appears glued to the screen as opposed to the
		689	window. This gives the illusion of a larger area behind the window. It is
		690	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
		691	top left of the screen.
		692
		693	Example: load a background image, put it in mirror mode and root align it.
		694
		695	rootalign keep { mirror load "mybg.png" }
		696
		697	Example: take the screen background and align it, giving the illusion of
		698	transparency as long as the window isn't in front of other windows.
		699
		700	rootalign root
		701
		702	=cut
349		703
350	sub move($$;$) {	704	sub move($$;$) {
351	my $img = pop->clone;	705	my $img = pop->clone;
352	$img->move ($_[0], $_[1]);	706	$img->move ($_[0], $_[1]);
353	$img	707	$img
354	}	708	}
355		709
		710	sub align($;$$) {
		711	my $img = pop;
		712
		713	move $_[0] * (TW - $img->w),
		714	$_[1] * (TH - $img->h),
		715	$img
		716	}
		717
		718	sub center($;$$) {
		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), $img
		724	}
		725
		726	sub rootalign($) {
		727	move -TX, -TY, $_[0]
		728	}
		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
356	sub rotate($$$$$$) {	741	sub rotate($$$$) {
357	my $img = pop;	742	my $img = pop;
358	$img->rotate (	743	$img->rotate (
359	$_[0],	744	$_[0] * ($img->w + $img->x),
360	$_[1],	745	$_[1] * ($img->h + $img->y),
361	$_[2] * $img->w * .01,
362	$_[3] * $img->h * .01,
363	$_[4] * (3.14159265 / 180),	746	$_[2] * (3.14159265 / 180),
364	)	747	)
365	}	748	}
		749
		750	=back
		751
		752	=head2 COLOUR MODIFICATIONS
		753
		754	The following operators change the pixels of the image.
		755
		756	=over 4
		757
		758	=item contrast $factor, $img
		759
		760	=item contrast $r, $g, $b, $img
		761
		762	=item contrast $r, $g, $b, $a, $img
		763
		764	Adjusts the I<contrast> of an image.
		765
		766	The first form applies a single C<$factor> to red, green and blue, the
		767	second form applies separate factors to each colour channel, and the last
		768	form includes the alpha channel.
		769
		770	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		771	contrast.
		772
		773	Due to limitations in the underlying XRender extension, lowering contrast
		774	also reduces brightness, while increasing contrast currently also
		775	increases brightness.
		776
		777	=item brightness $bias, $img
		778
		779	=item brightness $r, $g, $b, $img
		780
		781	=item brightness $r, $g, $b, $a, $img
		782
		783	Adjusts the brightness of an image.
		784
		785	The first form applies a single C<$bias> to red, green and blue, the
		786	second form applies separate biases to each colour channel, and the last
		787	form includes the alpha channel.
		788
		789	Values less than 0 reduce brightness, while values larger than 0 increase
		790	it. Useful range is from -1 to 1 - the former results in a black, the
		791	latter in a white picture.
		792
		793	Due to idiosyncrasies in the underlying XRender extension, biases less
		794	than zero can be I<very> slow.
		795
		796	=cut
		797
		798	sub contrast($$;$$;$) {
		799	my $img = pop;
		800	my ($r, $g, $b, $a) = @_;
		801
		802	($g, $b) = ($r, $r) if @_ < 3;
		803	$a = 1 if @_ < 4;
		804
		805	$img = $img->clone;
		806	$img->contrast ($r, $g, $b, $a);
		807	$img
		808	}
		809
		810	sub brightness($$;$$;$) {
		811	my $img = pop;
		812	my ($r, $g, $b, $a) = @_;
		813
		814	($g, $b) = ($r, $r) if @_ < 3;
		815	$a = 1 if @_ < 4;
		816
		817	$img = $img->clone;
		818	$img->brightness ($r, $g, $b, $a);
		819	$img
		820	}
		821
		822	=item blur $radius, $img
		823
		824	=item blur $radius_horz, $radius_vert, $img
		825
		826	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		827	can also be specified separately.
		828
		829	Blurring is often I<very> slow, at least compared or other
		830	operators. Larger blur radii are slower than smaller ones, too, so if you
		831	don't want to freeze your screen for long times, start experimenting with
		832	low values for radius (<5).
		833
		834	=cut
366		835
367	sub blur($$;$) {	836	sub blur($$;$) {
368	my $img = pop;	837	my $img = pop;
369	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	838	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
370	}	839	}
371		840
372	sub contrast($$;$$;$) {
373	my $img = pop;
374	my ($r, $g, $b, $a) = @_;
375
376	($g, $b) = ($r, $r) if @_ < 4;
377	$a = 1 if @_ < 5;
378
379	$img = $img->clone;
380	$img->contrast ($r, $g, $b, $a);
381	$img
382	}
383
384	sub brightness($$;$$;$) {
385	my $img = pop;
386	my ($r, $g, $b, $a) = @_;
387
388	($g, $b) = ($r, $r) if @_ < 4;
389	$a = 1 if @_ < 5;
390
391	$img = $img->clone;
392	$img->brightness ($r, $g, $b, $a);
393	$img
394	}
395
396	=back	841	=back
397		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
398	=cut	920	=cut
399		921
400	}	922	}
401		923
402	sub parse_expr {	924	sub parse_expr {
403	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	. "}";
404	die if $@;	931	die if $@;
405	$expr	932	$expr
406	}	933	}
407		934
408	# compiles a parsed expression	935	# compiles a parsed expression
409	sub set_expr {	936	sub set_expr {
410	my ($self, $expr) = @_;	937	my ($self, $expr) = @_;
411		938
		939	$self->{root} = [];
412	$self->{expr} = $expr;	940	$self->{expr} = $expr;
413	$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 $state->{rootpmap};
		989	}
414	}	990	}
415		991
416	# evaluate the current bg expression	992	# evaluate the current bg expression
417	sub recalculate {	993	sub recalculate {
418	my ($arg_self) = @_;	994	my ($arg_self) = @_;
…		…
428		1004
429	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1005	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
430		1006
431	# set environment to evaluate user expression	1007	# set environment to evaluate user expression
432		1008
433	local $self = $arg_self;	1009	local $self = $arg_self;
		1010	local $HOME = $ENV{HOME};
		1011	local $frame = [];
434		1012
435	local $old = $self->{state};
436	local $new = my $state = $self->{state} = {};
437
438	($x, $y, $w, $h) =
439	$self->background_geometry ($self->{border});	1013	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
440		1014
441	# evaluate user expression	1015	# evaluate user expression
442		1016
443	my $img = eval { $self->{expr}->() };	1017	my @img = eval { $self->{expr}->() };
444	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"
445	die if !UNIVERSAL::isa $img, "urxvt::img";	1021	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
446		1022
447	$state->{size_sensitive} = 1	1023	my $img = urxvt::bgdsl::merge @img;
		1024
		1025	$frame->[FR_AGAIN]{size} = 1
448	if $img->repeat_mode != urxvt::RepeatNormal;	1026	if $img->repeat_mode != urxvt::RepeatNormal;
449		1027
450	# if the expression is sensitive to external events, prepare reevaluation then	1028	# if the expression is sensitive to external events, prepare reevaluation then
451		1029	$self->compile_frame ($frame, sub { $arg_self->recalculate });
452	my $repeat;
453
454	if (my $again = $state->{again}) {
455	$repeat = 1;
456	$state->{timer} = $again == $old->{again}
457	? $old->{timer}
458	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
459	++$self->{counter};
460	$self->recalculate
461	});
462	}
463
464	if (delete $state->{position_sensitive}) {
465	$repeat = 1;
466	$self->enable (position_change => sub { $_[0]->recalculate });
467	} else {
468	$self->disable ("position_change");
469	}
470
471	if (delete $state->{size_sensitive}) {
472	$repeat = 1;
473	$self->enable (size_change => sub { $_[0]->recalculate });
474	} else {
475	$self->disable ("size_change");
476	}
477
478	if (delete $state->{rootpmap_sensitive}) {
479	$repeat = 1;
480	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
481	} else {
482	$self->disable ("rootpmap_change");
483	}
484		1030
485	# clear stuff we no longer need	1031	# clear stuff we no longer need
486		1032
487	%$old = ();	1033	# unless (%{ $frame->[FR_STATE] }) {
488
489	unless ($repeat) {
490	delete $self->{state};	1034	# delete $self->{state};
491	delete $self->{expr};	1035	# delete $self->{expr};
492	}	1036	# }
493		1037
494	# set background pixmap	1038	# set background pixmap
495		1039
496	$self->set_background ($img, $self->{border});	1040	$self->set_background ($img, $self->{border});
497	$self->scr_recolour (0);	1041	$self->scr_recolour (0);
…		…
499	}	1043	}
500		1044
501	sub on_start {	1045	sub on_start {
502	my ($self) = @_;	1046	my ($self) = @_;
503		1047
504	my $expr = $self->x_resource ("background.expr")	1048	my $expr = $self->x_resource ("%.expr")
505	or return;	1049	or return;
506		1050
		1051	$self->has_render
		1052	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		1053
507	$self->set_expr (parse_expr $expr);	1054	$self->set_expr (parse_expr $expr);
508	$self->{border} = $self->x_resource_boolean ("background.border");	1055	$self->{border} = $self->x_resource_boolean ("%.border");
		1056
		1057	$MIN_INTERVAL = $self->x_resource ("%.interval");
509		1058
510	()	1059	()
511	}	1060	}
512		1061

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.34 by root, Thu Jun 7 17:04:33 2012 UTC vs. Revision 1.66 by root, Thu Jun 28 15:19:15 2012 UTC

Diff Legend

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.34 by root, Thu Jun 7 17:04:33 2012 UTC vs.
Revision 1.66 by root, Thu Jun 28 15:19:15 2012 UTC