#include <TinyWireM.h>

// Pins
int const sda = 0;
int const scl = 2;

// Constants
int const address = 60;
int const commands = 0x00;
int const onecommand = 0x80;
int const data = 0x40;
int const onedata = 0xC0;

#define ADDRESS 0x3C

// OLED display **********************************************

// Write a single command
void Single (uint8_t x) {
  TinyWireM.write(onecommand);
  TinyWireM.write(x);
}

void InitDisplay () {
  TinyWireM.beginTransmission(address);
  TinyWireM.write(commands);
  TinyWireM.write(0xA1);  // Flip horizontal
  TinyWireM.write(0xAF);  // Display on
  TinyWireM.endTransmission();
}

void ClearDisplay () {
  for (int p = 0 ; p < 8; p++) {
    TinyWireM.beginTransmission(address);
    Single(0xB0 + p);
    TinyWireM.endTransmission();
    for (int q = 0 ; q < 8; q++) {
      TinyWireM.beginTransmission(address);
      TinyWireM.write(data);
      for (int i = 0 ; i < 20; i++) TinyWireM.write(0);
      TinyWireM.endTransmission();
    }
  }
}

// Plot point x,y into buffer if in current slice 
void PlotPoint (int x, int y, int mode) {
  TinyWireM.beginTransmission(address);
  Single(0x00 + ((x + 2) & 0x0F));        // Column low nibble
  Single(0x10 + ((x + 2)>>4));            // Column high nibble
  Single(0xB0 + (y >> 3));                // Page
  Single(0xE0);                           // Read modify write
  TinyWireM.write(onedata);
  TinyWireM.endTransmission();
  TinyWireM.requestFrom(address, 2);
  TinyWireM.read();                            // Dummy read
  int j = TinyWireM.read();
  TinyWireM.beginTransmission(address);
  TinyWireM.write(onedata);
 //  TinyWireM.write((1<<(y & 0x07)) | j);   // full block 4x4 pixels  ----------------------------
  Single(0xEE);                           // Cancel read modify write
  TinyWireM.endTransmission();       
}   

/*       
// Plot point (SSD1306): x (0 to 127), y (0 to 63), mode (0 = point, 1 = histogram)
void PlotPoint (int x, int y, int mode) {
  TinyWireM.beginTransmission(address);
  TinyWireM.write(commands);
  TinyWireM.write(0x21); TinyWireM.write(x); TinyWireM.write(x);  // Column range
  TinyWireM.write(0x22); TinyWireM.write(0); TinyWireM.write(7);  // Page range
  TinyWireM.endTransmission();
  TinyWireM.beginTransmission(address);
  TinyWireM.write(data);
  for (int i=0; i<8; i++) {
    if (y > 7) TinyWireM.write(- mode);
    else if (y < 0) TinyWireM.write(0);
    else TinyWireM.write((1<<y) - mode);
    y = y - 8;
  }
  TinyWireM.endTransmission();   
}  */


// Draw crossTinyWireMs
void Cross () {
  for (int x=0; x<126; x++) PlotPoint(x, 32, 0);
  delay(500); 
  ClearDisplay();
  for (int y=0; y<63; y++) PlotPoint(8, y, 0);
  delay(1000); 
  ClearDisplay();
}

const uint8_t BALL[8][8] = {
  {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
  {0x00, 0x18, 0x3F, 0x66, 0x66, 0x3F, 0x18, 0x00},
  {0x00, 0x3F, 0x66, 0xFF, 0xFF, 0x66, 0x3F, 0x00},
  {0x00, 0x66, 0xFF, 0xFF, 0xFF, 0xFF, 0x66, 0x00},
  {0x00, 0x66, 0xFF, 0xFF, 0xFF, 0xFF, 0x66, 0x00},
  {0x00, 0x3F, 0x66, 0xFF, 0xFF, 0x66, 0x3F, 0x00},
  {0x00, 0x18, 0x3F, 0x66, 0x66, 0x3F, 0x18, 0x00},
  {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
};

int x = 0;
int y = 0;
int dx = 1;
int dy = 1;


void setup() {
  TinyWireM.begin();
  InitDisplay();
  Cross();
  delay(1000); 
  ClearDisplay();
}

void loop() {
 ClearDisplay();

  // Draw image
  for (int p = 0; p < 8; p++) {
    TinyWireM.beginTransmission(ADDRESS);
    TinyWireM.write(0xB0 + p + y); // Page address
    TinyWireM.write(0x00); // Column address
    TinyWireM.write(0x10); // Column address
    for (int q = 0; q < 4; q++) { 
      TinyWireM.write(BALL[p][q]);
    }
    TinyWireM.endTransmission();
  }

  // Update position
  x += dx;
  y += dy;
  
  // Bounce off edges
  if (x < 0 || x > 3) dx = -dx;
  if (y < 0 || y > 3) dy = -dy;
  
  delay(50);


}

/*
#include <TinyWireM.h>

// Constants
#define ADDRESS 0x3C

const uint8_t LETTER_A[4][4] = {
  0x0E, 0x0A, 0x0A, 0x0E,
  0x11, 0x11, 0x11, 0x11,
  0x11, 0x11, 0x11, 0x11,
  0x0E, 0x0A, 0x0A, 0x0E
};

int x = 0;
int y = 0;
int dx = 1;
int dy = 1;

void setup() {
  TinyWireM.begin();
  delay(100);
  
  // Initialize OLED display
  TinyWireM.beginTransmission(ADDRESS);
  TinyWireM.write(0x00); // Command mode
  TinyWireM.write(0xAE); // Display off
  TinyWireM.write(0xD5); // Clock divide ratio
  TinyWireM.write(0x80); // Clock divide ratio
  TinyWireM.write(0xA8); // Multiplex ratio
  TinyWireM.write(0x3F); // Multiplex ratio
  TinyWireM.write(0xD3); // Display offset
  TinyWireM.write(0x00); // Display offset
  TinyWireM.write(0x40); // Display start line
  TinyWireM.write(0x8D); // Charge pump
  TinyWireM.write(0x14); // Charge pump
  TinyWireM.write(0xA1); // Segment remap
  TinyWireM.write(0xC8); // COM output scan direction
  TinyWireM.write(0xDA); // COM pins hardware configuration
  TinyWireM.write(0x12); // COM pins hardware configuration
  TinyWireM.write(0x81); // Contrast control
  TinyWireM.write(0xCF); // Contrast control
  TinyWireM.write(0xD9); // Pre-charge period
  TinyWireM.write(0xF1); // Pre-charge period
  TinyWireM.write(0xDB); // VCOMH deselect level
  TinyWireM.write(0x40); // VCOMH deselect level
  TinyWireM.write(0xA4); // Entire display on
  TinyWireM.write(0xA6); // Inverse display off
  TinyWireM.write(0xAF); // Display on
  TinyWireM.endTransmission();
  
  delay(100);
}

void loop() {
  // Clear display
  for (int p = 0 ; p < 4; p++) {
    TinyWireM.beginTransmission(ADDRESS);
    TinyWireM.write(0xB0 + p); // Page address
    TinyWireM.write(0x00); // Column address
    TinyWireM.write(0x10); // Column address
    for (int q = 0 ; q < 4; q++) {
      TinyWireM.write(0x00); // Data
    }
    TinyWireM.endTransmission();
  }
  
  // Draw image
  for (int p = 0; p < 4; p++) {
    TinyWireM.beginTransmission(ADDRESS);
    TinyWireM.write(0xB0 + p + y); // Page address
    TinyWireM.write(0x00); // Column address
    TinyWireM.write(0x10); // Column address
    for (int q = 0; q < 4; q++) { 
      TinyWireM.write(LETTER_A[p][q]);
    }
    TinyWireM.endTransmission();
  }
  
  // Update position
  x += dx;
  y += dy;
  
  // Bounce off edges
  if (x < 0 || x > 3) dx = -dx;
  if (y < 0 || y > 3) dy = -dy;
  
  delay(50);
}

*/