虹色罫線のノートが作れるpdfを配布します！

↑イメージ画像
rainbow_note.pdf
↑★★★ダウンロード用URL★★★

↓Processing code.

import processing.pdf.*;

//A4 の大きさは　297mm x 210 mm
//72dpiの場合　842px X 595px
void setup() {
  size(595, 842, PDF, "filename.pdf");
  colorMode(HSB, 255,255,255);
  background(255);
  ellipseMode(CENTER);
  //smooth();
}

void line2(int x1, int y1, int x2, int y2){
  float h = random(255);
  for(int x=x1; x<x2; x++){
    float h_diff = random(3);
    h+=h_diff;
    if(h>360){ h-= 360; }
    float s=random(50,80);
    float b=random(240,255);
    color col=color(h,s,b);
    stroke(col);
    float y = y1 + random(0,0.2);
    point(x, y);
  }
}

//mainly red
void line3(int x1, int y1, int x2, int y2){
  float hW=10;
  float hyu=0;
  float h = random(hyu-hW, hyu+hW);
  for(int x=x1; x<x2; x++){
    float h_diff = random(-3,3);
    h+=h_diff;
    
    if(h < hyu-hW){ h = hyu-hW; }
    if(h > hyu+hW){ h = hyu+hW; }
    
    float s=random(150,180);
    float b=random(200,215);
    color col=color(h,s,b);
    stroke(col);
    float y = y1 + random(0,0.2);
    point(x, y);
  }
}

void draw() {
  int H=30;
  int W=30;
  for(int i=H*2; i<height-H*2; i+=H){
    int x1=0+W;
    int x2=width-W;
    
    int y1=i;
    int y2=i;
    line2(x1,y1,x2,y2);
  }
  
  line3(0+W, H, width-W, H);
  line3(0+W, height-H, width-W, height-H);
  
    // Exit the program 
  println("Finished.");
  exit();
}