// title: Re: [improved] Gradually change TempoClock tempo [ accelerando / decelerando ] [extension]
// author: tom.dugovic
// description:
// This gradually changes the tempo of a TempoClock, each beat of a specified number of beats, and starting at the next bar.
// 
// 
// Personally, I was not able to heavily distinguish between `.linlin` and `.linexp` for reasonable musical tempos.
// 
// 
// There may be a mathematically smoother way of handling this at the control rate.
// 
// 
// This function does not gracefully handle multiple simultaneous invocations.
// code:
// Put this in your extensions directory
+ TempoClock {
    gradualTempo_ {|newTempo, beats=4, quant=1|
        if(beats <=1, {
            this.tempo_(newTempo);
        },{
            var startTime = this.nextTimeOnGrid(quant);
            this.schedAbs(this.nextTimeOnGrid(quant), {
                this.prRecurseGradualTempo(newTempo, beats);
            });
        });
    }

    prRecurseGradualTempo {|finalTempo, beatsRemaining|
        if(beatsRemaining <= 0, {
            this.tempo_(finalTempo);
        }, {
            var stepTempo = 1.linexp(0, beatsRemaining, this.tempo, finalTempo);
            this.tempo_(stepTempo);
            this.sched(1, {
                this.prRecurseGradualTempo(finalTempo, beatsRemaining-1);
            });
        });
    }
}