J3698

const fs = require('fs');
const alph = 'abcdefghijklmnopqrstuvwxyz'

demo();
 
function demo() {
	try {
		var fileContents = fs.readFileSync('./dictionary.txt', 'utf8');
	} catch(err) {
		throw "Dictionary file does not exist";

J3698

function randomWord(chain, length) {
	// get initial prefix
	word = randomOccurance(chain, '');

	for (var i = 0; i < length - 2; i++) {
		lastTwoLetters = word.substr(-2);

		// restart if chain hits dead end
		if (chain[lastTwoLetters] == undefined) {
			return randomWord(chain, length);

J3698

function createChain(words) {
	chain = {};
	for (const word of words) {
		addWordToChain(chain, word);
	}
	return chain;
}

/*
 * Example: Adding "beat" to the chain will

J3698

{
	''  : ...,
	'he': ...,
	'th': {
		occurances: ['e', 'i', 'u', ...],
		e: 582,
		i: 226,
		u: 56,
		...
		total: 1692

J3698

# use gcc as the compiler
CC=gcc

visualizer: simple_visualizer.c libapa102.a moving_average.c
	$(CC) -I/usr/local/include -L/usr/local/lib -L./libapa102  -I./libapa102/lib -o visualizer simple_visualizer.c moving_average.c -lapa102 -lwiringPi -lpthread -ljack -lm

libapa102.a: ~/visualizer/libapa102/lib/build/apa102.o ~/visualizer/libapa102/lib/build/apa102_anim.o
	ar rcs $@ $^

~/visualizer/libapa102/lib/build/apa102.o:

J3698

#ifndef MV_AVG_H                                                                
#define MV_AVG_H                                                                
                                                                                
typedef struct {                                                                
        double average;                                                         
        size_t oldest_index;                                                    
        double *samples;                                                        
        size_t num_samples;                                                     
} movingAverage_t;                                                              
                                                                                

J3698

#include <stdlib.h>                                                             
#include "moving_average.h"                                                     
                                                                                
movingAverage_t* movingAverage_new(size_t num_samples) {                        
        movingAverage_t *ma = malloc(sizeof(movingAverage_t));                  
        ma->samples = malloc(num_samples * sizeof(double));                     
        ma->oldest_index = 0;                                                   
        ma->num_samples = num_samples;                                          
}                                                                               
                                                                                

J3698

typedef struct {
        double average;
        size_t oldest_index;
        double *samples;
        size_t num_samples;
} movingAverage_t;

void movingAverage_update(movingAverage_t *ma, double new_sample) {
        ma->average -= ma->samples[ma->oldest_index];
        ma->samples[ma->oldest_index] = new_sample;

J3698

bool has_beat(sample_t *audio_left, sample_t *audio_right, jack_nframes_t num_samples) {
        static movingAverage_t *moving_avg = NULL;
        if (moving_avg == NULL) {
                moving_avg = movingAverage_new(FILTER_SAMPLES);
        }

        // beat detected if volume much higher than moving avg
        double volume = calc_volume(audio_left, audio_right, num_samples);
        bool beat_detected =
                volume * FILTER_SAMPLES > BEAT_FACTOR * moving_avg->average;

J3698

void update_lights(bool beat_detected) {                                        
        static uint8_t blueness = 0;                                            
                                                                                
        if (beat_detected) {                                                    
                blueness = MAX_BRIGHTNESS;                                      
        } else if (blueness >= BRIGHTNESS_DECAY) {                              
                blueness = blueness - BRIGHTNESS_DECAY;                         
        } else {                                                                
                blueness = 0;                                                   
        }