--- rxvt-unicode/src/perl/background 2012/06/05 19:32:29 1.13 +++ rxvt-unicode/src/perl/background 2012/06/08 22:19:21 1.40 @@ -1,51 +1,509 @@ #! perl -#:META:RESOURCE:$$:string:background expression +#:META:X_RESOURCE:%.expr:string:background expression +#:META:X_RESOURCE:%.border.:boolean:respect the terminal border -our $EXPR = 'move load "/root/pix/das_fette_schwein.jpg", repeat_wrap, X, Y'; -$EXPR = ' - rotate W, H, 50, 50, counter 1/59.95, repeat_mirror, - clip X, Y, W, H, repeat_mirror, - load "/root/pix/das_fette_schwein.jpg" -'; -#$EXPR = 'blur root, 10, 10' -#$EXPR = 'blur move (root, -x, -y), 5, 5' -#resize load "/root/pix/das_fette_schwein.jpg", w, h +#TODO: once, rootalign -use Safe; +=head1 background - manage terminal background -our ($bgdsl_self, $old, $new); -our ($l, $t, $w, $h); +=head2 SYNOPSIS -# enforce at leats this time between updates + urxvt --background-expr 'background expression' + --background-border + +=head2 DESCRIPTION + +This extension manages the terminal background by creating a picture that +is behind the text, replacing the normal background colour. + +It does so by evaluating a Perl expression that I the image on +the fly, for example, by grabbing the root background or loading a file. + +While the full power of Perl is available, the operators have been design +to be as simple as possible. + +For example, to load an image and scale it to the window size, you would +use: + + urxvt --background-expr 'scale load "/path/to/mybg.png"' + +Or specified as a X resource: + + URxvt.background-expr: scale load "/path/to/mybg.png" + +=head2 THEORY OF OPERATION + +At startup, just before the window is mapped for the first time, the +expression is evaluated and must yield an image. The image is then +extended as necessary to cover the whole terminal window, and is set as a +background pixmap. + +If the image contains an alpha channel, then it will be used as-is in +visuals that support alpha channels (for example, for a compositing +manager). In other visuals, the terminal background colour will be used to +replace any transparency. + +When the expression relies, directly or indirectly, on the window size, +position, the root pixmap, or a timer, then it will be remembered. If not, +then it will be removed. + +If any of the parameters that the expression relies on changes (when the +window is moved or resized, its position or size changes; when the root +pixmap is replaced by another one the root background changes; or when the +timer elapses), then the expression will be evaluated again. + +For example, an expression such as C scales the +image to the window size, so it relies on the window size and will +be reevaluated each time it is changed, but not when it moves for +example. That ensures that the picture always fills the terminal, even +after it's size changes. + +=head3 EXPRESSIONS + +Expressions are normal Perl expressions, in fact, they are Perl blocks - +which means you could use multiple lines and statements: + + again 3600; + if (localtime now)[6]) { + return scale load "$HOME/weekday.png"; + } else { + return scale load "$HOME/sunday.png"; + } + +This expression gets evaluated once per hour. It will set F as +background on Sundays, and F on all other days. + +Fortunately, we expect that most expressions will be much simpler, with +little Perl knowledge needed. + +Basically, you always start with a function that "generates" an image +object, such as C, which loads an image from disk, or C, which +returns the root window background image: + + load "$HOME/mypic.png" + +The path is usually specified as a quoted string (the exact rules can be +found in the L manpage). The F<$HOME> at the beginning of the +string is expanded to the home directory. + +Then you prepend one or more modifiers or filtering expressions, such as +C: + + scale load "$HOME/mypic.png" + +Just like a mathematical expression with functions, you should read these +expressions from right to left, as the C is evaluated first, and +its result becomes the argument to the C function. + +Many operators also allow some parameters preceding the input image +that modify its behaviour. For example, C without any additional +arguments scales the image to size of the terminal window. If you specify +an additional argument, it uses it as a percentage: + + scale 200, load "$HOME/mypic.png" + +This enlarges the image by a factor of 2 (200%). As you can see, C +has now two arguments, the C<200> and the C expression, while +C only has one argument. Arguments are separated from each other by +commas. + +Scale also accepts two arguments, which are then separate factors for both +horizontal and vertical dimensions. For example, this halves the image +width and doubles the image height: + + scale 50, 200, load "$HOME/mypic.png" + +Other effects than scalign are also readily available, for exmaple, you can +tile the image to fill the whole window, instead of resizing it: + + tile load "$HOME/mypic.png" + +In fact, images returned by C are in C mode by default, so the C operator +is kind of superfluous. + +Another common effect is to mirror the image, so that the same edges touch: + + mirror load "$HOME/mypic.png" + +This is also a typical background expression: + + rootalign root + +It first takes a snapshot of the screen background image, and then +moves it to the upper left corner of the screen - the result is +pseudo-transparency, as the image seems to be static while the window is +moved around. + +=head3 CYCLES AND CACHING + +As has been mentioned before, the expression might be evaluated multiple +times. Each time the expression is reevaluated, a new cycle is said to +have begun. Many operators cache their results till the next cycle. + +For example, the C operator keeps a copy of the image. If it is +asked to load the same image on the next cycle it will not load it again, +but return the cached copy. + +This only works for one cycle though, so as long as you load the same +image every time, it will always be cached, but when you load a different +image, it will forget about the first one. + +This allows you to either speed things up by keeping multiple images in +memory, or comserve memory by loading images more often. + +For example, you can keep two images in memory and use a random one like +this: + + my $img1 = load "img1.png"; + my $img2 = load "img2.png"; + (0.5 > rand) ? $img1 : $img2 + +Since both images are "loaded" every time the expression is evaluated, +they are always kept in memory. Contrast this version: + + my $path1 = "img1.png"; + my $path2 = "img2.png"; + load ((0.5 > rand) ? $path1 : $path2) + +Here, a path is selected randomly, and load is only called for one image, +so keeps only one image in memory. If, on the next evaluation, luck +decides to use the other path, then it will have to load that image again. + +=head2 REFERENCE + +=head3 COMMAND LINE SWITCHES + +=over 4 + +=item --background-expr perl-expression + +Specifies the Perl expression to evaluate. + +=item --background-border + +By default, the expression creates an image that fills the full window, +overwriting borders and any other areas, such as the scrollbar. + +Specifying this flag changes the behaviour, so that the image only +replaces the background of the character area. + +=back + +=cut + +our $HOME; +our ($self, $old, $new); +our ($x, $y, $w, $h); + +# enforce at least this interval between updates our $MIN_INTERVAL = 1/100; { package urxvt::bgdsl; # background language - *repeat_black = \&urxvt::RepeatNone; #TODO wtf - *repeat_wrap = \&urxvt::RepeatNormal; - *repeat_pad = \&urxvt::RepeatPad; - *repeat_mirror = \&urxvt::RepeatReflect; +=head2 PROVIDERS/GENERATORS + +These functions provide an image, by loading it from disk, grabbing it +from the root screen or by simply generating it. They are used as starting +points to get an image you can play with. + +=over 4 + +=item load $path + +Loads the image at the given C<$path>. The image is set to plane tiling +mode. + +Loaded images will be cached for one cycle. + +=cut sub load($) { my ($path) = @_; - $new->{load}{$path} = $old->{load}{$path} || $bgdsl_self->new_img_from_file ($path); + $new->{load}{$path} = $old->{load}{$path} || $self->new_img_from_file ($path); } +=item root + +Returns the root window pixmap, that is, hopefully, the background image +of your screen. The image is set to extend mode. + +This function makes your expression root sensitive, that means it will be +reevaluated when the bg image changes. + +=cut + sub root() { $new->{rootpmap_sensitive} = 1; die "root op not supported, exg, we need you"; } -# sub clone($) { -# $_[0]->clone -# } +=item solid $colour + +=item solid $width, $height, $colour + +Creates a new image and completely fills it with the given colour. The +image is set to tiling mode. + +If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is +useful for solid backgrounds or for use in filtering effects. + +=cut + + sub solid($$;$) { + my $colour = pop; + + my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] || 1, $_[1] || 1); + $img->fill ($colour); + $img + } + +=back + +=head2 VARIABLES + +The following functions provide variable data such as the terminal +window dimensions. Most of them make your expression sensitive to some +events, for example using C (terminal width) means your expression is +evaluated again when the terminal is resized. + +=over 4 + +=item TX + +=item TY + +Return the X and Y coordinates of the terminal window (the terminal +window is the full window by default, and the character area only when in +border-respect mode). + +Using these functions make your expression sensitive to window moves. + +These functions are mainly useful to align images to the root window. + +Example: load an image and align it so it looks as if anchored to the +background. + + move -TX, -TY, load "mybg.png" + +=item TW + +Return the width (C) and height (C) of the terminal window (the +terminal window is the full window by default, and the character area only +when in border-respect mode). + +Using these functions make your expression sensitive to window resizes. + +These functions are mainly useful to scale images, or to clip images to +the window size to conserve memory. + +Example: take the screen background, clip it to the window size, blur it a +bit, align it to the window position and use it as background. + + clip move -TX, -TY, blur 5, root + +=cut + + sub TX() { $new->{position_sensitive} = 1; $x } + sub TY() { $new->{position_sensitive} = 1; $y } + sub TW() { $new->{size_sensitive} = 1; $w } + sub TH() { $new->{size_sensitive} = 1; $h } + +=item now + +Returns the current time as (fractional) seconds since the epoch. + +Using this expression does I make your expression sensitive to time, +but the next two functions do. + +=item again $seconds + +When this function is used the expression will be reevaluated again in +C<$seconds> seconds. + +Example: load some image and rotate it according to the time of day (as if it were +the hour pointer of a clock). Update this image every minute. + + again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png" + +=item counter $seconds + +Like C, but also returns an increasing counter value, starting at +0, which might be useful for some simple animation effects. + +=cut + + sub now() { urxvt::NOW } + + sub again($) { + $new->{again} = $_[0]; + } + + sub counter($) { + $new->{again} = $_[0]; + $self->{counter} + 0 + } + +=back + +=head2 TILING MODES + +The following operators modify the tiling mode of an image, that is, the +way that pixels outside the image area are painted when the image is used. + +=over 4 + +=item tile $img + +Tiles the whole plane with the image and returns this new image - or in +other words, it returns a copy of the image in plane tiling mode. + +Example: load an image and tile it over the background, without +resizing. The C call is superfluous because C already defaults +to tiling mode. + + tile load "mybg.png" + +=item mirror $img + +Similar to tile, but reflects the image each time it uses a new copy, so +that top edges always touch top edges, right edges always touch right +edges and so on (with normal tiling, left edges always touch right edges +and top always touch bottom edges). + +Example: load an image and mirror it over the background, avoiding sharp +edges at the image borders at the expense of mirroring the image itself + + mirror load "mybg.png" + +=item pad $img + +Takes an image and modifies it so that all pixels outside the image area +become transparent. This mode is most useful when you want to place an +image over another image or the background colour while leaving all +background pixels outside the image unchanged. + +Example: load an image and display it in the upper left corner. The rest +of the space is left "empty" (transparent or wahtever your compisotr does +in alpha mode, else background colour). + + pad load "mybg.png" + +=item extend $img + +Extends the image over the whole plane, using the closest pixel in the +area outside the image. This mode is mostly useful when you more complex +filtering operations and want the pixels outside the image to have the +same values as the pixels near the edge. + +Example: just for curiosity, how does this pixel extension stuff work? + + extend move 50, 50, load "mybg.png" + +=cut + + sub pad($) { + my $img = $_[0]->clone; + $img->repeat_mode (urxvt::RepeatNone); + $img + } + + sub tile($) { + my $img = $_[0]->clone; + $img->repeat_mode (urxvt::RepeatNormal); + $img + } + + sub mirror($) { + my $img = $_[0]->clone; + $img->repeat_mode (urxvt::RepeatReflect); + $img + } + + sub extend($) { + my $img = $_[0]->clone; + $img->repeat_mode (urxvt::RepeatPad); + $img + } + +=back + +=head2 PIXEL OPERATORS + +The following operators modify the image pixels in various ways. + +=over 4 + +=item clone $img + +Returns an exact copy of the image. + +=cut + + sub clone($) { + $_[0]->clone + } + +=item clip $img + +=item clip $width, $height, $img + +=item clip $x, $y, $width, $height, $img + +Clips an image to the given rectangle. If the rectangle is outside the +image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is +larger than the image, then the tiling mode defines how the extra pixels +will be filled. + +If C<$x> an C<$y> are missing, then C<0> is assumed for both. + +If C<$width> and C<$height> are missing, then the window size will be +assumed. + +Example: load an image, blur it, and clip it to the window size to save +memory. + + clip blur 10, load "mybg.png" + +=cut + + sub clip($;$$;$$) { + my $img = pop; + my $h = pop || TH; + my $w = pop || TW; + $img->sub_rect ($_[0], $_[1], $w, $h) + } + +=item scale $img + +=item scale $size_percent, $img + +=item scale $width_percent, $height_percent, $img + +Scales the image by the given percentages in horizontal +(C<$width_percent>) and vertical (C<$height_percent>) direction. + +If only one percentage is give, it is used for both directions. + +If no percentages are given, scales the image to the window size without +keeping aspect. + +=item resize $width, $height, $img + +Resizes the image to exactly C<$width> times C<$height> pixels. + +=cut + +#TODO: maximise, maximise_fill? - sub clip($$$$$;$) { + sub scale($;$;$) { my $img = pop; - $img->sub_rect ($_[0], $_[1], $_[2], $_[3], $_[4]) + + @_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01) + : @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01) + : $img->scale (TW, TH) } sub resize($$$) { @@ -53,33 +511,62 @@ $img->scale ($_[0], $_[1]) } - # TODO: ugly +=item move $dx, $dy, $img + +Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in +the vertical. + +Example: move the image right by 20 pixels and down by 30. + + move 20, 30, ... + +=item rootalign $img + +Moves the image so that it appears glued to the screen as opposed to the +window. This gives the illusion of a larger area behind the window. It is +exactly equivalent to C, that is, it moves the image to the +top left of the screen. + +Example: load a background image, put it in mirror mode and root align it. + + rootalign mirror load "mybg.png" + +Example: take the screen background and align it, giving the illusion of +transparency as long as the window isn't in front of other windows. + + rootalign root + +=cut + sub move($$;$) { - my $img = pop; - $img->sub_rect ( - $_[0], $_[1], - $img->w, $img->h, - $_[2], - ) + my $img = pop->clone; + $img->move ($_[0], $_[1]); + $img } - sub rotate($$$$$$;$) { - my $img = pop; - $img->rotate ( - $_[0], - $_[1], - $_[2] * $img->w * .01, - $_[3] * $img->h * .01, - $_[4] * (3.14159265 / 180), - $_[5], - ) + sub rootalign($) { + move -TX, -TY, $_[0] } - sub blur($$$) { - my ($rh, $rv, $img) = @_; +=item contrast $factor, $img - $img->blur ($rh, $rv); - } +=item contrast $r, $g, $b, $img + +=item contrast $r, $g, $b, $a, $img + +Adjusts the I of an image. + +#TODO# + +=item brightness $factor, $img + +=item brightness $r, $g, $b, $img + +=item brightness $r, $g, $b, $a, $img + +Adjusts the brightness of an image. + +=cut sub contrast($$;$$;$) { my $img = pop; @@ -105,21 +592,53 @@ $img } - sub X() { $new->{position_sensitive} = 1; $l } - sub Y() { $new->{position_sensitive} = 1; $t } - sub W() { $new->{size_sensitive} = 1; $w } - sub H() { $new->{size_sensitive} = 1; $h } +=item blur $radius, $img - sub now() { urxvt::NOW } +=item blur $radius_horz, $radius_vert, $img - sub again($) { - $new->{again} = $_[0]; +Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii +can also be specified separately. + +Blurring is often I slow, at least compared or other +operators. Larger blur radii are slower than smaller ones, too, so if you +don't want to freeze your screen for long times, start experimenting with +low values for radius (<5). + +=cut + + sub blur($$;$) { + my $img = pop; + $img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0]) } - sub counter($) { - $new->{again} = $_[0]; - $bgdsl_self->{counter} + 0 +=item rotate $new_width, $new_height, $center_x, $center_y, $degrees + +Rotates the image by C<$degrees> degrees, counter-clockwise, around the +pointer at C<$center_x> and C<$center_y> (specified as percentage of image +width/height), generating a new image with width C<$new_width> and height +C<$new_height>. + +#TODO# new width, height, maybe more operators? + +Example: rotate the image by 90 degrees + +=cut + + sub rotate($$$$$$) { + my $img = pop; + $img->rotate ( + $_[0], + $_[1], + $_[2] * $img->w * .01, + $_[3] * $img->h * .01, + $_[4] * (3.14159265 / 180), + ) } + +=back + +=cut + } sub parse_expr { @@ -138,33 +657,38 @@ # evaluate the current bg expression sub recalculate { - my ($self) = @_; + my ($arg_self) = @_; # rate limit evaluation - if ($self->{next_refresh} > urxvt::NOW) { - $self->{next_refresh_timer} = urxvt::timer->new->after ($self->{next_refresh} - urxvt::NOW)->cb (sub { - $self->recalculate; + if ($arg_self->{next_refresh} > urxvt::NOW) { + $arg_self->{next_refresh_timer} = urxvt::timer->new->after ($arg_self->{next_refresh} - urxvt::NOW)->cb (sub { + $arg_self->recalculate; }); return; } - $self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL; + $arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL; # set environment to evaluate user expression - local $bgdsl_self = $self; + local $self = $arg_self; + local $HOME = $ENV{HOME}; local $old = $self->{state}; local $new = my $state = $self->{state} = {}; - ($l, $t, $w, $h) = - $self->get_geometry; + ($x, $y, $w, $h) = + $self->background_geometry ($self->{border}); # evaluate user expression my $img = eval { $self->{expr}->() }; warn $@ if $@;#d# + die if !UNIVERSAL::isa $img, "urxvt::img"; + + $state->{size_sensitive} = 1 + if $img->repeat_mode != urxvt::RepeatNormal; # if the expression is sensitive to external events, prepare reevaluation then @@ -172,6 +696,7 @@ if (my $again = $state->{again}) { $repeat = 1; + my $self = $self; $state->{timer} = $again == $old->{again} ? $old->{timer} : urxvt::timer->new->after ($again)->interval ($again)->cb (sub { @@ -210,12 +735,9 @@ delete $self->{expr}; } - # prepare and set background pixmap - - $img = $img->sub_rect (0, 0, $w, $h) - if $img->w != $w || $img->h != $h; + # set background pixmap - $self->set_background ($img); + $self->set_background ($img, $self->{border}); $self->scr_recolour (0); $self->want_refresh; } @@ -223,7 +745,11 @@ sub on_start { my ($self) = @_; - $self->set_expr (parse_expr $EXPR); + my $expr = $self->x_resource ("background.expr") + or return; + + $self->set_expr (parse_expr $expr); + $self->{border} = $self->x_resource_boolean ("background.border"); () }