4x4x4 cube driver

gistfile1.c

#include <avr/pgmspace.h> 

#define LAYER_TIME 3333
#define LAYER_BITS 16
#define FRAME_TIME 20

PROGMEM prog_uchar drip[] = 
  {
    /* snip */
  };

PROGMEM prog_uchar reverse_drip[] =
  {
    /* snip */
  };

PROGMEM prog_uchar diagonal[] = 
  {
    /* snip */
  };
  
PROGMEM prog_uchar spin[] = 
  {
    /* snip */
  };
  
PROGMEM prog_uchar on_and_off[] = 
  {
    /* snip */
  };
  
PROGMEM prog_uchar snake[] = 
  {    
    /* snip */
  };
  
PROGMEM prog_uchar wireframe[] = 
  {
    /* snip */
  };

prog_uchar* animation_order[] = 
  {
    wireframe,
    wireframe,
    wireframe,
    drip,
    diagonal, 
    spin, 
    on_and_off,
    reverse_drip,
    snake, 
    NULL
  };
    
                    
int leds[] = {15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14};
int layers[] = {16, 17, 18, 19};

void setup() {
  for(int i = 0; i < LAYER_BITS; i++) {
    pinMode(leds[i], OUTPUT);
  }
  
  for(int i = 0; i < 4; i++) {
    pinMode(layers[i], OUTPUT);
  }
}

void do_animation(prog_uchar* animation) {
  byte layer_buffer[LAYER_BITS];
  int  pointer = 0;
  unsigned long pattern_time, target_time;
  
  do {
    memcpy_P(layer_buffer, animation + pointer, LAYER_BITS);
    pointer += LAYER_BITS;
    
    pattern_time = pgm_read_byte_near(animation + pointer++);
    target_time  = millis() + pattern_time * FRAME_TIME;
    
    while(millis() < target_time) {
      int group = 0; 
      for(int p = 0; p < 4; p++) {
        int pin = 0;
        if(p == 0) 
          digitalWrite(layers[3], LOW);
        else
          digitalWrite(layers[p-1], LOW);
          
         for(int row = 0; row < 4; row++) {
           for(int col = 0; col < 4; col++) {
             digitalWrite(leds[pin++], layer_buffer[group] & (1 << col));
           }
         
           group++;
         }
         digitalWrite(layers[p], HIGH);
         
         delayMicroseconds(LAYER_TIME);
      }
    }       
  } while(pattern_time > 0); 
}

void loop() {
  int pointer = 0;
  do {
    do_animation(animation_order[pointer++]);
  } while(animation_order[pointer] != NULL);
}