Creating Rainbow Backgrounds With Processing

// 
// Code by Raymond Burkholder
//   ray@oneunified.net
//  copyright (c) 2014
//

import themidibus.*; //Import the library
import javax.sound.midi.MidiMessage; //Import the MidiMessage classes http://java.sun.com/j2se/1.5.0/docs/api/javax/sound/midi/MidiMessage.html
import javax.sound.midi.SysexMessage;
import javax.sound.midi.ShortMessage;

MidiBus myBus; // The MidiBus

PImage imgCue;
PImage imgBlack;

int nHues = 6 * 256;

color[] rHue = new color[ nHues ];

int valAlpha = 0xff;
int valRed = 255;
int valGrn = 0;
int valBlu = 0;

boolean bBlack = false;
boolean bUseImage = false;

String sCue = "c";
String sPath = "D:\\Data\\Projects\\Test\\Frames\\";

int widthHue = nHues;

color hue = color( 255, 0, 0 );  // to be deprecated
int ixHue = 0;  // red

float cycle( float f ) {
  return sin( TWO_PI * f ) * 255 + 127;
}

void setup() {
  int ixHues = 0;
  for ( int ix = 0; 255 >= ix; ix += 1 ) { rHue[ ixHues ] = color( 255,  ix,   0 ); ixHues += 1; };
  for ( int ix = 255; 0 <= ix; ix -= 1 ) { rHue[ ixHues ] = color(  ix, 255,   0 ); ixHues += 1; };
  for ( int ix = 0; 255 >= ix; ix += 1 ) { rHue[ ixHues ] = color(   0, 255,  ix ); ixHues += 1; };
  for ( int ix = 255; 0 <= ix; ix -= 1 ) { rHue[ ixHues ] = color(   0,  ix, 255 ); ixHues += 1; };
  for ( int ix = 0; 255 >= ix; ix += 1 ) { rHue[ ixHues ] = color(  ix,   0, 255 ); ixHues += 1; };
  for ( int ix = 255; 0 <= ix; ix -= 1 ) { rHue[ ixHues ] = color( 255,   0,  ix ); ixHues += 1; };
//  size( 800, 600 );
  //size(1280, 720);
  //size( 1920, 1280 );
  // https://sites.google.com/site/visualizationlaboratory/activity/runningprocessingsketchinfullscreen
  size(displayWidth,displayHeight,OPENGL);
  strokeWeight(1);
  if (null != frame ) {
    frame.setResizable( true );
  }
  
  myBus = new MidiBus( this, "processing", -1 );
  
  imgCue = loadImage( sPath + "\\c000.jpg" );
  imgBlack = loadImage( sPath + "\\c000.jpg" );
}

boolean sketchFullScreen() {
  return true;
}

void mouseClicked() {
  bUseImage = false;
  switch ( mouseButton ) {
    case LEFT:
      ixHue = floor( float( mouseX ) / float( width ) * nHues );
      hue = rHue[ ixHue ];
      widthHue = floor( float( mouseY ) / float( height ) * float( nHues ) );
      
      println( mouseX, mouseY, widthHue, red( hue ), green( hue ), blue( hue ) );  
    break;
    case RIGHT:
      //saveFrame("D:\\Data\\Projects\\Jackson 2014\\Frames\\cyc-#####.jpg");
      saveFrame(sPath + sCue + ".jpg");
      println( "saved", sCue );
    break;
  }
}

void keyPressed() {
  switch ( key ) {
    case 'c':
      sCue = "c";
      println( sCue );
      break;
    case 'b':
      bBlack = !bBlack;
      println( "Black: ", key, bBlack );
      break;
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
      sCue = sCue + key;
      println( sCue );
      break;
  }
  if ( 'b' == key ) {
  }
}

void mouseMoved() {
  //println( mouseX, mouseY, widthHue, red( hue ), green( hue ), blue( hue ) );  
}

void midiMessage(MidiMessage message) { // You can also use midiMessage(MidiMessage message, long timestamp, String bus_name)
  // Receive a MidiMessage
  // MidiMessage is an abstract class, the actual passed object will be either javax.sound.midi.MetaMessage, javax.sound.midi.ShortMessage, javax.sound.midi.SysexMessage.
  // Check it out here http://java.sun.com/j2se/1.5.0/docs/api/javax/sound/midi/package-summary.html
  println();
  println("MidiMessage Data:");
  //println("--------");
  int nCommand = (int)message.getStatus();
  int nParam2 = 0;
  int nParam3 = 0;
  println("Status Byte/MIDI Command:"+nCommand);
  for (int i = 1;i < message.getMessage().length;i++) {
    println("Param "+(i+1)+": "+(int)(message.getMessage()[i] & 0xFF));
    if ( 1 == i ) { nParam2 = (int)(message.getMessage()[i] & 0xFF); };
    if ( 2 == i ) { nParam3 = (int)(message.getMessage()[i] & 0xFF); };
  }
  if ( ( 176 == nCommand ) && ( 1 == nParam2 ) ) {
    println( "execute ", nCommand, nParam2, nParam3 );
    //PImage img = loadImage( sPath + "\\c000.jpg" );
    switch ( nParam3 ) {
      case 0:
        imgCue = loadImage( sPath + "\\c000.jpg" );
        break;
      case 1:
        imgCue = loadImage( sPath + "\\c160.jpg" );
        println( "loaded" );
        break;
      case 2:
        imgCue = loadImage( sPath + "\\c120.jpg" );
        println( "loaded" );
        break;
      }
    image( imgCue, 0, 0 );  
    bUseImage = true;
  }
}

void drawRegular() {
    int ixWidth = 0;
    int sweepIx = 0;
    int sweepDir = 0; // default to no sweep
    int ix;
    if ( 0 != widthHue ) { sweepDir = 1; } // start sweep in positive direction
    while ( ixWidth < width ) {
      switch ( sweepDir ) {
        case 0:
          break;
        case 1:
          ix = ixHue + sweepIx;
          if ( nHues <= ix ) { ix -= nHues; };
          hue = rHue[ ix ];
          if ( widthHue == sweepIx ) {
            sweepDir = -1;
            sweepIx -= 1;
            //sweepIx = 0; 
          }
          else {
            sweepIx += 1;
          }
          break;
        case -1:
          ix = ixHue + sweepIx;
          if ( nHues <= ix ) { ix -= nHues; };
          hue = rHue[ ix ];
          if ( 0 == sweepIx ) {
            sweepDir = 1;
            sweepIx += 1; 
          }
          else {
            sweepIx -= 1;
          }
          break;
      }
      stroke( red( hue ), green( hue ), blue( hue ) );
      line( ixWidth, 0, ixWidth, height - 1 );
      ixWidth += 1;
    }
}

void draw() {
  background(0);
  
  if ( bUseImage ) {
    image( imgCue, 0, 0 );  
    //bUseImage = false;
  }
  else {
    if ( !bBlack ) {
      drawRegular();
    }
  }
  
}

// r  g  b
// 255   0   0
// 255 255   0
//   0 255   0
//   0 255 255
//   0   0 255
// 255   0 255