#include "U8glib.h"
// U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST );
U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK ); // Fast I2C / TWI
void setup() {
  u8g.setColorIndex(2); //White
} 

  int points[ 8 ][ 2 ]; //eight 2D points for the cube

  int orig_points [8][3] = { // eight 3D points - set values
  {-1, -1,	1},
  {1,	-1,	1},
  {1,	1,	1},
  {-1,	1,	1},
  {-1,	-1,	-1},
  {1,	-1,	-1},
  {1,	1,	-1},
  {-1,	1,	-1}

};

float rotated_3d_points [8][3]; // eight 3D points - rotated around Y axis
float angle_deg = 60.0;   // rotation around the Y axis
float z_offset = -4.0;    // offset on Z axis
float cube_size = 70.0;   // cube size (multiplier)
float time_frame;         // ever increasing time value


void loop() {

  time_frame++;
  cube_size = 50 + sin(time_frame * 0.2) * 20; // oscilate between values 30 - 70

  z_offset = -2.0;
  cube_size = 18.0;
  
  // increase the angle
  if (angle_deg < 90-5 ) {
    angle_deg = angle_deg + 5;
  } else {
    angle_deg = 0;
  }

  // calculate the points
  for (int i=0; i<8; i++) {
    // rotate 3d points
    rotated_3d_points [i][0] = orig_points [i][0] * cos(radians(angle_deg)) - orig_points [i][2] * sin(radians(angle_deg));
    rotated_3d_points [i][1] = orig_points [i][1];
    rotated_3d_points [i][2] = orig_points [i][0] * sin(radians(angle_deg)) + orig_points [i][2] * cos(radians(angle_deg)) + z_offset;

    // project 3d points into 2d space
    points[i][0] = round(64 + rotated_3d_points [i][0] / rotated_3d_points [i][2] * cube_size);
    points[i][1] = round(32 + rotated_3d_points [i][1] / rotated_3d_points [i][2] * cube_size);
  }

  u8g.firstPage();
  do { 
    u8g.drawLine(points[ 0 ][ 0 ], points[ 0 ][ 1 ], points[ 1 ][ 0 ], points[ 1 ][ 1 ] ); // connect points 0-1
    u8g.drawLine(points[ 1 ][ 0 ], points[ 1 ][ 1 ], points[ 2 ][ 0 ], points[ 2 ][ 1 ] ); // connect points 1-2
    u8g.drawLine(points[ 2 ][ 0 ], points[ 2 ][ 1 ], points[ 3 ][ 0 ], points[ 3 ][ 1 ] ); // connect points 2-3
    u8g.drawLine(points[ 3 ][ 0 ], points[ 3 ][ 1 ], points[ 0 ][ 0 ], points[ 0 ][ 1 ] ); // connect points 3-0 

    u8g.drawLine(points[ 4 ][ 0 ], points[ 4 ][ 1 ], points[ 5 ][ 0 ], points[ 5 ][ 1 ] ); // connect points 0-1
    u8g.drawLine(points[ 5 ][ 0 ], points[ 5 ][ 1 ], points[ 6 ][ 0 ], points[ 6 ][ 1 ] ); // connect points 1-2
    u8g.drawLine(points[ 6 ][ 0 ], points[ 6 ][ 1 ], points[ 7 ][ 0 ], points[ 7 ][ 1 ] ); // connect points 2-3
    u8g.drawLine(points[ 7 ][ 0 ], points[ 7 ][ 1 ], points[ 4 ][ 0 ], points[ 4 ][ 1 ] ); // connect points 3-0
    
    u8g.drawLine(points[ 0 ][ 0 ], points[ 0 ][ 1 ], points[ 4 ][ 0 ], points[ 4 ][ 1 ] ); // connect points 0-1
    u8g.drawLine(points[ 1 ][ 0 ], points[ 1 ][ 1 ], points[ 5 ][ 0 ], points[ 5 ][ 1 ] ); // connect points 1-2
    u8g.drawLine(points[ 2 ][ 0 ], points[ 2 ][ 1 ], points[ 6 ][ 0 ], points[ 6 ][ 1 ] ); // connect points 2-3
    u8g.drawLine(points[ 3 ][ 0 ], points[ 3 ][ 1 ], points[ 7 ][ 0 ], points[ 7 ][ 1 ] ); // connect points 3-0  
     // u8g.drawLine(7, 10, 40, 55);
  } while( u8g.nextPage() );
}