glitchy code

#define FASTLED_ESP8266_RAW_PIN_ORDER
#define FASTLED_ESP8266_NODEMCU_PIN_ORDER
#define FASTLED_ESP8266_D1_PIN_ORDER

#include "FastLED.h"

FASTLED_USING_NAMESPACE
#define LED_LEAD D1
#define LED_TYPE WS2812B
#define COLOR_ORDER GRB
#define NUM_LEDS 175
CRGB leds[NUM_LEDS];


int BOTTOM_INDEX = 0;
int TOP_INDEX = int(NUM_LEDS/2);
int EVENODD = NUM_LEDS%2;
int ledsX[NUM_LEDS][3];       //ARRAY FOR COPYING WHATS IN THE LED STRIP CURRENTLY (FOR CELL-AUTOMATA, MARCH, ECT)
int thisdelay = 20;


#define BRIGHTNESS 255
#define FRAMES_PER_SECOND 120

const int interval = 25;

unsigned long previousMillis = millis();

const int PIXEL_FLASH_INTERVAL = 25;

//unsigned long previousMillis = millis();


//FX LOOPS DELAY VAR
int thisstep = 20;
int thishue = 0;
int thissat = 255;

//LED FX VARS
int idex = 0;               //LED INDEX (0 TO NUM_LEDS-1)
int ihue = 0;               //HUE (0-255)
int ibright = 0;            //BRIGHTNESS (0-255)
int isat = 0;               //SATURATION (0-255);
int bouncedirection = 0;    //SWITCH FOR COLOR BOUNCE (0-1)
float tcount = 0.0;         //INC VAR FOR SIN LOOPS
int lcount = 0;             //ANOTHER COUNTING VAR



/*
//monitor button press
bool buttonListener() {
  bool modeChanged = false;
  buttonState = digitalRead(BUTTON_LEAD);

  if (buttonState != lastButtonState) {
    if (buttonState == LOW) {
      mode++;
      modeChanged = true;
      delay(250);  //Debounce delay
    }
  }
  lastButtonState = buttonState;

  return modeChanged;
}
*/

//---SET THE COLOR OF A SINGLE RGB LED
void set_color_led(int adex, int cred, int cgrn, int cblu) {
  leds[adex].setRGB( cred, cgrn, cblu);
}

//---FIND INDEX OF HORIZONAL OPPOSITE LED
int horizontal_index(int i) {
  //-ONLY WORKS WITH INDEX < TOPINDEX
  if (i == BOTTOM_INDEX) {return BOTTOM_INDEX;}
  if (i == TOP_INDEX && EVENODD == 1) {return TOP_INDEX + 1;}
  if (i == TOP_INDEX && EVENODD == 0) {return TOP_INDEX;}
  return NUM_LEDS - i;
}

//---FIND INDEX OF ANTIPODAL OPPOSITE LED
int antipodal_index(int i) {
  int iN = i + TOP_INDEX;
  if (i >= TOP_INDEX) {iN = ( i + TOP_INDEX ) % NUM_LEDS; }
  return iN;
}

void copy_led_array(){
  for(int i = 0; i < NUM_LEDS; i++ ) {
    ledsX[i][0] = leds[i].r;
    ledsX[i][1] = leds[i].g;
    ledsX[i][2] = leds[i].b;
  }
}


void one_color_all(int cred, int cgrn, int cblu) {       //-SET ALL LEDS TO ONE COLOR
    for(int i = 0 ; i < NUM_LEDS; i++ ) {
      leds[i].setRGB( cred, cgrn, cblu);
    }
}

/*
void one_color_allHSV(int ahue) {    //-SET ALL LEDS TO ONE COLOR (HSV)
    for(int i = 0 ; i < NUM_LEDS; i++ ) {
      leds[i] = CHSV(ahue, thissat, 255);
    }
}
*/

void rainbow_loop() {                        //-m3-LOOP HSV RAINBOW
  idex++;
  ihue = ihue + thisstep;
  if (idex >= NUM_LEDS) {idex = 0;}
  if (ihue > 255) {ihue = 0;}
  leds[idex] = CHSV(ihue, thissat, 255);
  LEDS.show();
  delay(thisdelay);
}

void random_burst() {                         //-m4-RANDOM INDEX/COLOR
  idex = random(0, NUM_LEDS);
  ihue = random(0, 255);
  leds[idex] = CHSV(ihue, thissat, 255);
  LEDS.show();
  delay(thisdelay);
}


void fade_vertical() {                    //-m12-FADE 'UP' THE LOOP

  idex++;
  if (idex > TOP_INDEX) {idex = 0;}
  int idexA = idex;
  int idexB = horizontal_index(idexA);
  ibright = ibright + 10;
  if (ibright > 255) {ibright = 0;}
  leds[idexA] = CHSV(thishue, thissat, ibright);
  leds[idexB] = CHSV(thishue, thissat, ibright);
  LEDS.show();
  delay(thisdelay);
}

void color_loop_vardelay() {                    //-m17-COLOR LOOP (SINGLE LED) w/ VARIABLE DELAY
  int di = abs(TOP_INDEX - idex);
  int t = constrain((10/di)*10, 10, 500);
  idex++;
  if (idex > NUM_LEDS) {idex = 0;}
  for(int i = 0; i < NUM_LEDS; i++ ) {
    if (i == idex) {
      leds[i] = CHSV(0, thissat, 255);
    }
    else {
      leds[i].r = 0; leds[i].g = 0; leds[i].b = 0;
    }
  }
  LEDS.show();
  delay(t);
}

void sin_bright_wave() {        //-m19-BRIGHTNESS SINE WAVE
  for(int i = 0; i < NUM_LEDS; i++ ) {
    tcount = tcount + .1;
    if (tcount > 3.14) {tcount = 0.0;}
    ibright = int(sin(tcount)*255);
    leds[i] = CHSV(thishue, thissat, ibright);
    LEDS.show();
    delay(thisdelay);
  }
}

void pop_horizontal() {        //-m20-POP FROM LEFT TO RIGHT UP THE RING
  int ix;
  if (bouncedirection == 0) {
    bouncedirection = 1;
    ix = idex;
  }
  else if (bouncedirection == 1) {
    bouncedirection = 0;
    ix = horizontal_index(idex);
    idex++;
    if (idex > TOP_INDEX) {idex = 0;}
  }
  for(int i = 0; i < NUM_LEDS; i++ ) {
    if (i == ix) {
      leds[i] = CHSV(thishue, thissat, 255);
    }
    else {
      leds[i].r = 0; leds[i].g = 0; leds[i].b = 0;
    }
  }
  LEDS.show();
  delay(thisdelay);
}

void rainbow_vertical() {                        //-m23-RAINBOW 'UP' THE LOOP
   idex++;
  if (idex > TOP_INDEX) {idex = 0;}
  ihue = ihue + thisstep;
  if (ihue > 255) {ihue = 0;}
  int idexA = idex;
  int idexB = horizontal_index(idexA);
  leds[idexA] = CHSV(ihue, thissat, 255);
  leds[idexB] = CHSV(ihue, thissat, 255);
  LEDS.show();
  delay(thisdelay);
}

void random_color_pop() {                         //-m25-RANDOM COLOR POP
  idex = random(0, NUM_LEDS);
  ihue = random(0, 255);
  one_color_all(0, 0, 0);
  leds[idex] = CHSV(ihue, thissat, 255);
  LEDS.show();
  delay(thisdelay);
}

void kitt() {                                     //-m28-KNIGHT INDUSTIES 2000
  int rand = random(0, TOP_INDEX);
  for(int i = 0; i < rand; i++ ) {
    leds[TOP_INDEX+i] = CHSV(thishue, thissat, 255);
    leds[TOP_INDEX-i] = CHSV(thishue, thissat, 255);
    LEDS.show();
    //delay(thisdelay/rand);
  }
  for(int i = rand; i > 0; i-- ) {
    leds[TOP_INDEX+i] = CHSV(thishue, thissat, 0);
    leds[TOP_INDEX-i] = CHSV(thishue, thissat, 0);
    LEDS.show();
    delay(thisdelay/rand);
  }
}

void matrix() {                                   //-m29-ONE LINE MATRIX
  int rand = random(0, 100);
  if (rand > 90) {
    leds[0] = CHSV(thishue, thissat, 255);
  }
  else {leds[0] = CHSV(thishue, thissat, 0);}
  copy_led_array();
    for(int i = 1; i < NUM_LEDS; i++ ) {
    leds[i].r = ledsX[i-1][0];
    leds[i].g = ledsX[i-1][1];
    leds[i].b = ledsX[i-1][2];
  }
  LEDS.show();
  delay(thisdelay);
}

void new_rainbow_loop(){                       //-m88-RAINBOW FADE FROM FAST_SPI2
  ihue -= 1;
  fill_rainbow( leds, NUM_LEDS, ihue );
  LEDS.show();
  delay(thisdelay);
}


//----------------------------------------SETUP AND LOOP---------------------------------------------


void setup() {
  FastLED.addLeds<LED_TYPE,LED_LEAD,COLOR_ORDER>(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);

  FastLED.setBrightness(BRIGHTNESS);
}

void loop() {
  int r = 10;


  thisdelay = 20; thisstep = 10; thishue = 0; thissat = 255;
  //one_color_all(255,255,255); LEDS.show(); delay(200);

  for(int i=0; i<r*20; i++) {rainbow_loop();}

  for(int i=0; i<r*20; i++) {random_burst();}

  thisdelay = 60; thishue = 180;
  for(int i = 0; i<r*5; i++) {fade_vertical();}

  thisdelay = 60; thishue = 95;
  for(int i=0; i<r*15; i++) {color_loop_vardelay();}

  thisdelay = 35; thishue = 180;
  for(int i=0; i<r; i++) {sin_bright_wave();}

  thisdelay = 100; thishue = 0;
  for(int i=0; i<r*5; i++) {pop_horizontal();}

  thisdelay = 50; thisstep = 15;
  for(int i=0; i<r*12; i++) {rainbow_vertical();}

  thisdelay = 35;
  for(int i=0; i<r*10; i++) {random_color_pop();}

  thisdelay = 100; thishue = 95;
  for(int i=0; i<r*10; i++) {kitt();}

  thisdelay = 30; thishue = 95;
  for(int i=0; i<r*25; i++) {matrix();}



}