zigzag~

Linked list function editor

Description

The zigzag~ object is similar to line~. While the line~ object's stack-based implementation does not retain information after it has been output, zigzag~ uses a linked list implementation. In addition to simply remembering the current "line", the zigzag~ object lets you modify the list by inserting, deleting, or appending points.

Each element in the zigzag~ object's linked list has a value (y), and a transition time value (delta-x), which specifies the amount of time over which the transition from one value to another will occur. When zigzag~ contains a list, this list can be triggered (the starting and ending points can be set and changed), traversed forwards or backwards at different speeds, and looped. The current position in the list can be jumped to, and also held.

Arguments

Name Type Opt Description
initial-target-value int or float opt Sets an initial target-value (y) for the zigzag~ object.

Messages

bang In left inlet: The zigzag~ object responds to a bang message according to its mode of behavior, which is set using the mode message.

If the zigzag~ object is set to mode 0 or mode 1, a bang message will cause the zigzag~ object to go to the start point (or end point if the direction is negative) and begin outputting values from there.

If the zigzag~ object is set to mode 2, a bang message will cause the zigzag~ object to jump to the next index in the list (or the previous index, if the current direction is negative) and begin outputting values from there.
int output-rate-coefficient [int]
In right inlet: Specifies the rate at which the value and time pairs will be output. A value of 1.0 traverses the list forward at normal speed. A playback rate of -1 traverses the list backwards (i.e. in reverse). A value of .5 traverses the linked list at half the normal speed (effectively doubling the delay time values).

(In left inlet: Converted to float.)
float output-rate-coefficient [float]
In left inlet: Each element in the zigzag~ object's linked list is a pair that consists of a target value (y), followed by a second number that specifies a total amount of time in milliseconds (delta-x). In that amount of time, numbers are output regularly in a line from the current index value to the target value. The list 0 0 3.5 500 10 1000 describes a line which begins with a value of 0 at time 0, rises to a value of 3.5 a half second later, and rises again to a value of 10 in 1 second.

In right inlet: Specifies the rate at which the value and time pairs will be output. A value of 1.0 traverses the list forward at normal speed. A playback rate of -1 traverses the list backwards (i.e. in reverse). A value of .5 traverses the linked list at half the normal speed (effectively doubling the delay time values).
list position-index and event-pair [list]
Performs the same function as append (without the word, "append").
append position-index and event-pair [list]
In left inlet: The word append, followed by an int which specifies a position (where 0 is the first element) and a list, will insert new event pair(s) after the index specified. The message append 0 5 500 will create a new second entry in the linked list (at the 0 index) with a value of 5 and a time of 500 milliseconds.
bangdelta transition-time [float]
In left inlet: The word bangdelta, followed by a float or int, specifies the time over which the transition between values occurs when the zigzag~ object receives a bang. The default is 0 (i.e., and immediate transition).
bound start-and-end-points [list]
In left inlet: The word bound, followed by two numbers which specify start and end indices (where 0 is the first element), sets the start and end points of the zigzag~ object's linked list.
delete position-index [list]
In left inlet: The word delete, followed by an int which specifies a position (where 0 is the first element), will delete the value and time pair associated with that index from the list. A list can follow the delete message if you want to remove multiple event pairs from the list. The message delete 0 will remove the current first value and time pair from the list; the second value and time pair (i.e. the value and time pair at index 1) will now become the first values in the list.
dump In left inlet: The word dump will cause a list consisting of all currently stored value and time pairs in the form

index target-value delta-x

to be sent out the zigzag~ object's 3rd outlet.
end ending-position-index [float]
In left inlet: The word end, followed by an int which specifies a position (where 0 is the first element), sets the point at which the zigzag~ object ceases its output when triggered by a bang.
insert position-index and event-pair [list]
In left inlet: The word insert, followed by an int which specifies a position (where 0 is the first element) and a list, will insert new event pair(s) before the index specified. The message insert 0 5 500 will create a new first entry in the linked list (at the 0 index) with a value of 5 and a time of 500 milliseconds.
jump position-index and transition-time [list]
In left inlet: The word jump, followed by an int which specifies a position (where 0 is the first element), skips to that point in the linked list and begins outputting value and time pairs from that point. An optional int can be used to specify the time, in milliseconds, over which the transition to the next value will occur (the default value is 0).
jumpend transition-time [float]
In left inlet: The word jumpend causes the zigzag~ object to immediately jump forward to the last value (y)on the linked list.
jumpstart transition-time [float]
In left inlet: The word jumpstart causes the zigzag~ object to immediately jump to the first value (y)on the linked list and then output the currently selected list or selected portion of the list.
mode object-response-mode (0 through 3) [int]
The word mode, followed by a number in the range 0-3, specifies the way that the zigzag~ object responds to messages and signal values. The modes of operation are:

mode 0 is the default mode of operation. When the zigzag~ object receives a bang, it will jump to the start point (or end point if our direction is negative) and begin outputting values from there. The time value associated with this jump has its length defined by the bangdelta message. The default value for bangdelta is 0. If a signal is connected to the left inlet of the zigzag~ object in this mode, the current index of the list is determined by the signal; any previously set speed, loopmode, start, and end messages are ignored.

mode 1 behavior for the zigzag~ object is exactly the same as in mode 0 in terms of the effect of a bang. In mode 1, signal inputs are handled differently. If a signal is connected to the left inlet of the zigzag~ object in mode 1, the input signal functions as a trigger signal; when the slope of the input signal changes from non-negative to negative, the object will be re-triggered as though a bang were received.

mode 2 sets the zigzag~ object to jump to the next index in the list (or the previous index, if the current direction is negative) and begin outputting values from there. The time value associated with this jump has its length defined by the bangdelta message. The default value for bangdelta is 0. If a signal is connected to the left inlet of the zigzag~ object in mode 2, the input signal functions as a trigger signal; when the slope of the input signal changes from non-negative to negative, the object will be re-triggered as though a bang were received.
loopmode looping-enable-flag (0 or 1) [int]
The word loopmode, followed by 1, turns on looping. loopmode 0 turns off looping. By default, looping is off. loopmode 2 turns on looping in "pendulum" mode, in which the value and time pairs are traversed in an alternating forward and reverse direction. By default, looping is off
next transition-time [float]
In left inlet: The word next skips to the next value and time pair in the linked list. An optional int can be used to specify the time over which the transition to the next value will occur (the default value is 0).
prev transition-time [float]
In left inlet: The word prev skips to the previous value and time pair in the linked list. An optional int can be used to specify the time over which the transition to the previous value will occur (the default value is 0).
print In left inlet: The word print causes the current status and contents of the zigzag~ object to be printed out in the Max window. The output consists of the current mode, loopmode, the start, end, and loop length of the current list, the pendulum state, and moving value of the object, followed by a listing of each index in the linked list, along with its y and delta-x values.
setindex position-index target-value and transition-time [list]
In left inlet: The word setindex, followed by an int which specifies a position (where 0 is the first element) and a pair of floats, sets the target value (y) and transition time amounts (delta-x) for the specified position in the list.
signal In left inlet: The zigzag~ object responds to signal values according to its mode of behavior, which is set using the mode message.
If the zigzag~ object is set to mode 0, the current index of the list is determined by the input signal value; any previously set speed, loopmode, start, and end messages will be ignored.
If a signal is connected to the left inlet of the zigzag~ object in mode 1, the input signal functions as a trigger signal; when the slope of the input signal changes from non-negative to negative, the object will be re-triggered as though a bang were received.
If a signal is connected to the left inlet of the zigzag~ object in mode 2, the input signal functions as a trigger signal; when the slope of the input signal changes from non-negative to negative, the object will be re-triggered as though a bang were received.

In right inlet: A signal value specifies the rate at which the value and time pairs will be output. A value of 1.0 traverses the list forward at normal speed. A playback rate of -1 traverses the list backwards (i.e. in reverse). A signal value of .5 traverses the linked list at half the normal speed (effectively doubling the delay time values). The value of the input signal is sampled once per input vector. Therefore, any periodic frequency modulation with a period which is greater than the current sample rate/(2*vector_size) will alias.
skip number-of-skipped-indices and transition-time [list]
In left inlet: The word skip, followed by a positive or negative number, will skip the specified number of indices in the zigzag~ object's linked list. Positive number values skip forward, and negative values skip backward. An optional integer can be used to specify the time over which the transition to the next or previous value will occur (the default value is 0).
speed output-rate-coefficient [float]
In left inlet: The word speed, followed by a positive or negative floating-point number, specifies the rate at which the value and time pairs will be output. The message speed 1.0 traverses the list forward at normal speed, speed -1 traverses the list backwards, speed .5 traverses the linked list at half the normal speed (effectively doubling the delay time values).
start starting-position-index [float]
In left inlet: The word start, followed by an int which specifies a position (where 0 is the first element), sets the point at which the zigzag~ object begins its output when triggered by a bang.
ramptime transition-time (milliseconds) [float]
In left inlet: The word ramptime, followed by a number, sets the ramp time, in milliseconds, at which the output signal will arrive at the target value.

Information for box attributes common to all objects

Output

bang: Out right outlet: When looping, a bang message is sent out when the loop (re-trigger) point is reached. A bang is also sent out when zigzag~ has finished generating all of its ramps.
list: Out 3rd outlet: In response to the dump message, a list consisting of all currently stored value and time pairs in the form

index target-value (y) delta-x

is output.
signal: Out 1st outlet: The current target value, or a ramp moving toward the target value according to the currently stored value and the target time.

Out 2nd outlet: The current delta-x value.

Examples

zigzag~ can be used as a multi-purpose editable ramp generator

See Also

Name Description
adsr~ ADSR envelope generator
curve~ Exponential ramp generator
kink~ Distort a sawtooth waveform
line~ Linear ramp generator