The Rolling Hills of Cramlington

Another attempt at making use of the noise() function.

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/**
 * The Rolling Hills of Cramlington - v1.0.
 */

int kWidth = 800 ;
int kHeight = 400 ;

int kPlanes = 8 ;
int kHorizon = kHeight / 2 ;

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

void draw()
{
  background( 1.0 ) ;

  //
  // Animate using the current time.
  //
  float m = millis() * 0.01 ;

  //
  // Draw planes of hills/mountains.
  //
  for ( int i = 1 ; i <= kPlanes ; ++ i )
  {
    //
    // Front planes scroll faster than abck planes.
    //
    float t = m * 1.6 * i ;

    //
    // Work out the baseline for the mountian range.
    //
    float startY = kHorizon + kHeight * i / kPlanes ;

    //
    // Scale the noise according to the plane.
    // Front planes are stretched horizontally and .
    //
    float nx = i * 0.2 ;
    float hrzScale = (kPlanes - i + 1 ) * 0.001 ;
    float vrtScale = kHeight * (  i ) / kPlanes ;

    //
    // Fade planes from white to grey.
    //
    float whiteness =  0.95 - ( 0.95 - 0.2 ) * ( i - 1 ) / ( kPlanes - 1 ) ;

    stroke( whiteness ) ;

    //
    // Draw this plane of moutnians.
    //
    drawNoise( t, nx, hrzScale, vrtScale, startY ) ;
  }
}

//
// Draw a mountain range using th noise() function.
//
//   t controls the horizontal poisiotn of the mountian range
//   nx selects which mountian range
//   hrzScale controls how fast the mountains change height horizontally
//   vrtScale scales the height of the mountains
//
//
void drawNoise( float t, float nx, float hrzScale, float vrtScale, float startY )
{
  beginShape( LINES ) ;

  for ( int i = 0 ; i < kWidth ; ++ i )
  {
    float v = t + i ;

    float h = vrtScale * noise( v * hrzScale, nx ) ;

    vertex( i, startY ) ;
    vertex( i, h ) ; 
  }

  endShape() ;
}