path: root/doc/pddp/help-trigger.pd

#N canvas 145 60 985 628 10;
#X obj 26 16 trigger;
#X text 24 230 As I see it \, the [trigger] object serves two great
purposes which aren't really related - but they might be on some level
that I don't fully understand yet.;
#X text 22 278 1 Sequence a series of bangs - or triggers for symbols
and/or other messages. In the example below \, you should see that
it is important that it is important that [metro] gets a tempo setting
before it is started - but let's assume for a moment that you wanted
to start the [metro] with only a single click.;
#X obj 26 481 metro;
#X msg 51 462 1000;
#X obj 26 501 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
-1;
#X obj 26 404 tgl 15 0 empty empty On/Off 0 -6 0 7 -262144 -1 -1 0
1;
#X text 24 104 The [trigger] object can be abbreviated as "t" and the
creation arguments can be abbreviated as follows:;
#X obj 114 150 trigger float bang symbol list pointer anything;
#X text 215 169 is the same as;
#X obj 218 189 t f b s l p a;
#X obj 26 422 t f b;
#X text 27 526 This example is simple \, and may not be very practicle
in most situations \, but it clearly shows how [trigger] can be used
to create a simple sequence of events. It is important to note however
that the messages sent from [trigger]'s outlets occur in ZERO time
with no delay between the events...more at the top right of the page...
;
#X obj 484 94 t b b;
#X msg 484 75 bang;
#X obj 484 124 timer;
#X floatatom 484 144 5 0 0 0 - - -;
#X obj 456 34 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
-1;
#X obj 456 600 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
-1;
#X text 518 75 Click here.;
#X text 524 141 Watch here.;
#X text 476 163 Now \, to prove that I'm not crazy...click here >;
#X obj 822 203 timer;
#X floatatom 822 222 5 0 0 0 - - -;
#X obj 847 182 delay 2000;
#X text 597 89 any delay between the first bang and the second bang
;
#X text 598 105 from the trigger.;
#X text 476 198 object to force a 2 second delay between the;
#X text 599 75 In this case \, the [timer] object does not perceive
;
#X text 471 290 2 Click this subpatch to read about [trigger]'s second
great purpose...;
#N canvas 148 22 927 612 trigger_can_convert_data_types 0;
#X msg 425 103 2.5;
#X msg 523 103 bang;
#X msg 465 103 23 64;
#X msg 569 103 symbol dog;
#X obj 425 228 trigger float bang symbol list anything;
#X text 24 24 All sophisticated programming environments provide tools
to convert data types. For instance \, Visual Basic has:;
#X text 24 55 - VarType: to check the data type.;
#X text 24 70 - CStr: to convert a variable to a string.;
#X text 23 84 - CDate: to convert a variable to a date.;
#X text 24 99 - isNumeric: to test whether the variable is a number.
;
#X text 22 113 - etc.;
#X text 19 137 [trigger] is one object in PD which can convert an incoming
atom to a different type of atom.;
#X text 422 30 In the example below \, you can see that this [trigger]
has creation arguments which specify what data type the object should
output through each outlet. Messages which are sent to the first outlet
will be floats \; the second outlet will send bangs \; the third \,
symbols \; etc.;
#X text 19 172 To prove this \, click on each of the messages below
and watch your terminal window for the output.;
#X obj 20 239 t b;
#X msg 20 210 bang;
#X msg 57 210 1;
#X floatatom 90 212 5 0 0 0 - - -;
#X msg 132 211 symbol cat;
#X msg 204 211 this is anything;
#X obj 20 259 print all_messages_are_converted_to_bangs;
#X text 20 292 Another example showing floats and symbols.;
#X msg 20 308 bang;
#X floatatom 90 310 5 0 0 0 - - -;
#X msg 132 309 symbol cat;
#X msg 206 319 this is anything;
#X obj 20 337 t f s;
#X msg 57 308 1 0;
#X obj 45 387 print converted_to_symbols;
#X obj 20 407 print converted_to_floats;
#X text 62 338 Note that "this is anything" causes an error. That is
because 'anythings' don't conform to floats \, symbols \, lists \,
pointers. They can only be converted to "bang".;
#X text 18 430 In the example above \, note that the trigger object
does not split a list among the outlets like [unpack] does. Instead
it sends all list elements through all outlets and converts them as
necessary.;
#X text 20 486 Also note that some messages don't convert as nicely
as others. Hence \, the symbol "cat" converts to a ZERO when [trigger]
converts that symbol into a float. Likewise \, all numbers will convert
to a symbol called "float" when sent through [trigger]'s right-most
outlet.;
#X floatatom 425 248 5 0 0 0 - - -;
#X obj 482 248 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
-1;
#X symbolatom 539 286 10 0 0 0 - - -;
#X floatatom 594 162 5 0 0 0 - - -;
#X obj 594 200 pack f s;
#X msg 637 161 symbol earth;
#X msg 652 181 symbol jupiter;
#X obj 596 267 print a_list;
#X floatatom 426 403 5 0 0 0 - - -;
#X symbolatom 470 403 10 0 0 0 - - -;
#X obj 514 421 print another_list;
#X text 630 131 Click on all these.;
#X obj 426 363 r anythings;
#X text 425 303 Note how each of the messages sent to this trigger
are converted appropriately for their receiving atoms boxes. Also note
that "anythings" are sent to the example below.;
#X text 430 447 I'e used the [route] object to show how "anythings"
are converted as they pass through the above [trigger]. Note that all
messages converted to floats are displayed here in the number box \,
all symbols are displayed in the symbol box \, and all lists are printed
to the terminal window.;
#X obj 654 247 s anythings;
#X obj 426 383 route float symbol list;
#X msg 642 103 symbol cat;
#X connect 0 0 4 0;
#X connect 1 0 4 0;
#X connect 2 0 4 0;
#X connect 3 0 4 0;
#X connect 4 0 33 0;
#X connect 4 1 34 0;
#X connect 4 2 35 0;
#X connect 4 3 40 0;
#X connect 4 4 48 0;
#X connect 14 0 20 0;
#X connect 15 0 14 0;
#X connect 16 0 14 0;
#X connect 17 0 14 0;
#X connect 18 0 14 0;
#X connect 19 0 14 0;
#X connect 22 0 26 0;
#X connect 23 0 26 0;
#X connect 24 0 26 0;
#X connect 25 0 26 0;
#X connect 26 0 29 0;
#X connect 26 1 28 0;
#X connect 27 0 26 0;
#X connect 36 0 37 0;
#X connect 37 0 4 0;
#X connect 38 0 37 1;
#X connect 39 0 37 1;
#X connect 45 0 49 0;
#X connect 49 0 41 0;
#X connect 49 1 42 0;
#X connect 49 2 43 0;
#X connect 50 0 4 0;
#X restore 475 325 pd trigger_can_convert_data_types;
#X obj 822 238 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
-1;
#X floatatom 902 164 5 0 0 0 - - -;
#X text 477 246 at the top-right to clearly see "logical time";
#X text 477 259 as measured by [timer].;
#X text 509 554 This document was updated for PD version 0.35 test
26 by Dave Sabine as part of a project called pddp proposed by Krzysztof
Czaja to build comprehensive documentation for PD.;
#X text 472 378 RELATED OBJECTS;
#X obj 557 404 route;
#X obj 477 404 unpack;
#X obj 523 404 pack;
#X obj 598 404 delay;
#X obj 640 404 pipe;
#X obj 675 404 float;
#X obj 715 404 int;
#X obj 744 404 symbol;
#N canvas 0 22 456 306 related_objects_from_other_libraries 0;
#X obj 31 36 exciter 200 200 8 0.1 1 1;
#X text 26 77 These objects are offered in PD only if you have downloaded
and properly installed the appropriate library. These objects may or
may not exist in a single library.;
#X text 25 126 The best places to find information about PD's libraries
is:;
#X text 22 148 www.pure-data.org and click on "Downloads" then "Software"
;
#X text 24 163 or;
#X text 24 178 iem.kug.ac.at/pdb/;
#X restore 477 435 pd related_objects_from_other_libraries;
#X obj 940 5 pddp;
#X text 472 463 MORE INFO;
#X obj 479 490 all_about_data_types;
#X obj 480 516 all_about_lists_vs_anythings;
#X obj 822 157 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
-1;
#X text 17 138 "float" = f;
#X text 17 150 "bang" = b;
#X text 16 162 "symbol" = s;
#X text 17 176 "list" = l;
#X text 17 204 "anything" = a;
#X text 17 190 "pointer" = p;
#X text 26 45 The [trigger] object outputs its input from right to
left \, converting to the types indicated by its creation arguments.
There is also a "pointer" argument type (see the [pointer] object.)
;
#X text 20 364 Click the toggle to set the tempo and start the [metro]
simultaneously.;
#X text 67 413 Triggers are sent from right to left...so our tempo
messages gets sent to [metro] immediately before the numbers from the
toggle to start and stop the [metro].;
#X text 482 40 Below is a simple structure which will measure the "logical
time" between "bangs" from the [trigger] object.;
#X text 477 184 In this case \, I've simply patched a [delay];
#X text 476 212 first and second "bangs" sent to the [timer].;
#X text 477 232 You can reset the [delay] with the number box;
#X text 86 15 - sequence messages in right-to-left order and convert
data;
#X text 503 15 types;
#X connect 3 0 5 0;
#X connect 4 0 3 1;
#X connect 6 0 11 0;
#X connect 11 0 3 0;
#X connect 11 1 4 0;
#X connect 13 0 15 1;
#X connect 13 1 15 0;
#X connect 14 0 13 0;
#X connect 15 0 16 0;
#X connect 17 0 18 0;
#X connect 22 0 23 0;
#X connect 23 0 31 0;
#X connect 24 0 22 1;
#X connect 32 0 24 1;
#X connect 50 0 24 0;
#X connect 50 0 22 0;