Eclipse

Updated now... looks more like an eclipse!

b e n

//
// Eclipse v1.1.
//

int kWidth = 480 ;
int kHeight = 480 ; // 320 ;

int kMoonRadius = kHeight / 3 ;
int kSpeed = 8 ;

//
// Dimensions of texture.
// For fast PCs reduce or remove the denominator.
//
int kTextureWidth = kWidth ;
int kTextureHeight = kHeight ;

//
// Define a history buffer.
//
PImage history = createImage( kTextureWidth, kTextureHeight, RGB ) ;


void setup()
{
  size( kWidth, kHeight ) ;
  colorMode( RGB, 1.0 ) ;

  smooth() ;
}

void draw()
{
  float t = frameCount * 0.01 ;

  //
  // Draw the radiation.
  //
  //  background( 0.0 ) ;


  image( history, -kSpeed*0.5, -kSpeed*0.5, kWidth + kSpeed, kHeight + kSpeed ) ;

  noStroke() ;
  fill( 0.0, 0.02 ) ;
  rect( 0, 0, kWidth, kHeight ) ;


  //
  // Draw the seed for the radiation.
  //.
  // This is just an outlined circle and the roughness in the circle
  // seeds the structure in the radiation.
  //
  // Colour and radius varied to add a bit of variation to the radiation.
  //
  // Also add some random spots to create flares in the radiation.
  //
  pushMatrix() ;

  translate( kWidth/2, kHeight/2 ) ;

  stroke( noise( t ) ) ;
  noFill() ;

  float radius = kMoonRadius * ( 0.9 + 0.1 * sin( t ) ) ;
  ellipse( 0.0, 0.0, radius, radius ) ;

  noStroke() ;
  fill( 1.0 ) ;

  //
  // Sources for flares.
  //
  for ( int i = 0 ; i < 8 ; ++ i )
    ellipse( ( 0.5 - noise(t, 0, i ) ) * kMoonRadius * 0.8, ( 0.5 - noise( t, 1, i ) ) * kMoonRadius * 0.8, 4, 4 ) ;

  //
  // Source for spikes.
  //
  stroke( 1.0 ) ;
  noFill() ;
  for ( int i = 0 ; i < 2 ; ++ i )
    ellipse( kMoonRadius * 0.3 * sin( 2.0 * PI * i / 2 ), kMoonRadius * 0.3 * cos( 2.0 * PI * i / 2 ), 8, 8 ) ;


  //
  // Draw a comet.
  //
  float r = 150 * cos( t * 0.1 ) ;
  noStroke() ;
  fill( 0.9, 1.0, 0.9 ) ;

  ellipse( r*sin(t), r*cos(t), 2, 2 ) ;

  popMatrix() ;

  //
  // Use the current frame as the texture for the
  // radiation in the next frame.
  //
  history.copy( get(), 0, 0, kWidth, kHeight, 0, 0, kTextureWidth, kTextureHeight ) ;

  //
  // Now draw the Moon.
  // The radius is enlarged to cover the outlined circle.
  //
  pushMatrix() ;

  translate( kWidth/2, kHeight/2 ) ;

  stroke( 0.0 ) ;
  fill( 0.0 ) ;
  ellipse( 0.0, 0.0, kMoonRadius+1.0, kMoonRadius+1.0 ) ;

  popMatrix() ;
}