Drawing a flower of life with 6 Vesica Piscis

Processing Coding Questions
7

As far as I know, scale within pushMatrix and popMatrix can inflate the stroke weight, exaggerating errors. I would try PVector methods to transform a shape instead. Single precision (32 bit) floating point error might be a contributing factor as well, but there’s little to be done about it with Processing’s methods.

screenCap
screenCap400×400 5.31 KB

void setup() {
  size(400, 400, JAVA2D);
  // size(400, 400, P2D);

  strokeJoin(MITER);
  // strokeJoin(BEVEL);
  // strokeJoin(ROUND);
}

void draw() {
  PVector coRight = new PVector(1.0, 0.0);
  PVector fhRight = new PVector(0.690599, 0.178633);
  PVector rhRight = new PVector(0.690599, -0.178633);

  PVector coLeft = new PVector(0.0, 0.0);
  PVector fhLeft = new PVector(0.309401, -0.178633);
  PVector rhLeft = new PVector(0.309401, 0.178633);

  // Rotate
  float theta = frameCount * TAU / 360.0;
  coRight.rotate(theta);
  fhRight.rotate(theta);
  rhRight.rotate(theta);

  coLeft.rotate(theta);
  fhLeft.rotate(theta);
  rhLeft.rotate(theta);

  // Scale
  float scale = min(width, height) * 0.5;
  coRight.mult(scale);
  fhRight.mult(scale);
  rhRight.mult(scale);

  coLeft.mult(scale);
  fhLeft.mult(scale);
  rhLeft.mult(scale);

  // Translate
  PVector origin = new PVector(width / 2.0, height / 2.0);
  coRight.add(origin);
  fhRight.add(origin);
  rhRight.add(origin);

  coLeft.add(origin);
  fhLeft.add(origin);
  rhLeft.add(origin);

  background(#fff7d5);
  stroke(#202020);
  strokeWeight(5.0);

  fill(#0080ff);

  beginShape();
  vertex(coRight.x, coRight.y);
  bezierVertex(
    fhRight.x, fhRight.y,
    rhLeft.x, rhLeft.y,
    coLeft.x, coLeft.y);
  bezierVertex(
    fhLeft.x, fhLeft.y,
    rhRight.x, rhRight.y,
    coRight.x, coRight.y);
  endShape(CLOSE);
}

I got flickering with the P2D renderer on version 4.4.1 .

Other than that, the default AWT renderer passes the strokeJoin constant on to BasicStroke. For an angle that sharp, BEVEL is what’s left when MITER raises problems.

If you had access to the AWT renderer directly, you might be able to fiddle with the miterLimit of the BasicStroke:

Never tried that myself.

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