metro

This patch does some of the same things as the "GlobalTransport" patch in the Extras menu, and shows what is likely going on behind the scenes in that patch. The toggle labeled "Start/Stop" starts the transport and immediately turns on the metro to begin triggering time reports. The button labeled "Rewind" sends a time position of bar 1, beat 1, 0 ticks to the transport to reset its time.

Timing objects such as metro normally operate with their time interval specified in milliseconds, and they are controlled by the Max scheduler, which is always running.

This patch allows you to try out various filter settings of the biquad~ object, via the filtergraph~ object. For adjusting the parameters you can drag on filtergraph~ with the mouse, or you can send values in its three rightmost inlets for frequency, gain, and Q. The spectroscope~ object tries to draw the spectrum of the signal.

The up-down arrow keys seem like reasonable keys to use for incrementing or decrementing a number box or a slider. But rather than require a new key press for each step up or down, you can use a fast metro to trigger messages continuously as long as the key is pressed. There are several ways one could implement this in Max; here's one example.

For linear interpolation of a MSP signal, the line~ object sends out a signal that progress to some new value over a certain amount of time interpolating sample-by-sample along the way. The input to line~ is a pair of numbers representing a destination value (where it should eventually arrive) and a transition time (how long it should take to get there). It can receive multiple pairs of numbers in a single message, and it will use the pairs in order, starting each new pair when the previous transition has finished.

The upper example shows how to count from 1 to 10 at a specific rate (e.g., one count every 500 ms) and stop when you reach 10. The metro object sends out a bang message when it is turned on (when it receives a nonzero number in its left inlet), and continues to send out bang every x milliseconds (specified by the typed-in argument or by a number received in its right inlet). You can type in minimum and maximum values as arguments in the counter object.

The jit.qt.movie object can open (read) a .mov file (or really any media file that QuickTime is capable of dealing with) and start playing it, loading its visual content into its internal Jitter matrix. But that matrix is only made visible when you send it a bang, which causes it to send out a jit_matrix message to jit.window telling it where in memory to look to get the data to be displayed.