/* Serial call-and-response
by Tom Igoe (with adjustments by Dan)

Sends a byte out the serial port, and reads 3 bytes in.
sets background color, x location and rotation of a rect

Updated October 12, 2004
*/

int bkcolor;                         // background color
int[] serialStuff = new int[3];    // where we'll put what we receive
int serialCount = 0;                 // a count of how many bytes we receive
int xpos;                            // x location of rectangle
int rot;                             // rotation of rectangle
BFont font;
 
void setup() {
  //begin serial communication
  beginSerial();
  size(255, 200);
  font = loadFont("Garamond-Bold.vlw.gz");

  //start off our call and response by sending 65;
  serialWrite(65);
}

void loop() {
  
  //draw background with red value from sensor
  background(bkcolor,0,0);
  textFont(font, 44);
  fill(255);
  //display rotation value
  text(xpos, 5, 30);
  
  fill(0,0,255);
  rectMode(CENTER_DIAMETER);
  //draw rect at "xpos" and rotate with "rot"
  translate(xpos,100);
  rotate(radians(rot*2));
  rect(0,0, 50, 50);
  
}

void serialEvent() {
   // add the latest byte from the serial port to array:
  serialStuff[serialCount] = serial;
  serialCount++;

  // if we have 3 things set our variables:
  if (serialCount > 2 ) {
    bkcolor = serialStuff[0];
    xpos = serialStuff[1];
    rot = serialStuff[2];
    // clear the string when we're done, and ask for more:
    serialCount = 0;
    // send a capital A to request new sensor readings:
    serialWrite(65);
  }
}