view fft/kissfft/FFT.js @ 21:a901eeeabf3b

Slice does not appear to be necessary for a typed array copy after all

"use strict";

var kissFFTModule = KissFFTModule({});

var kiss_fftr_alloc = kissFFTModule.cwrap(
    'kiss_fftr_alloc', 'number', ['number', 'number', 'number', 'number' ]
);

var kiss_fftr = kissFFTModule.cwrap(
    'kiss_fftr', 'void', ['number', 'number', 'number' ]
);

var kiss_fftri = kissFFTModule.cwrap(
    'kiss_fftri', 'void', ['number', 'number', 'number' ]
);

var kiss_fftr_free = kissFFTModule.cwrap(
    'kiss_fftr_free', 'void', ['number']
);

function KissFFT(size) {

    this.size = size;
    this.fcfg = kiss_fftr_alloc(size, false);
    this.icfg = kiss_fftr_alloc(size, true);
    
    this.rptr = kissFFTModule._malloc(size*4 + (size+2)*4);
    this.cptr = this.rptr + size*4;
    
    this.ri = new Float32Array(kissFFTModule.HEAPU8.buffer, this.rptr, size);
    this.ci = new Float32Array(kissFFTModule.HEAPU8.buffer, this.cptr, size+2);
    
    this.forward = function(real) {
	this.ri.set(real);
	kiss_fftr(this.fcfg, this.rptr, this.cptr);
	return new Float32Array(kissFFTModule.HEAPU8.buffer,
				this.cptr, this.size + 2);
    }
    
    this.inverse = function(cpx) {
	this.ci.set(cpx);
	kiss_fftri(this.icfg, this.cptr, this.rptr);
	return new Float32Array(kissFFTModule.HEAPU8.buffer,
				this.rptr, this.size);
    }
    
    this.dispose = function() {
	kissFFTModule._free(this.rptr);
	kiss_fftr_free(this.fcfg);
	kiss_fftr_free(this.icfg);
    }
}