Hi bejoshaclone,

thank you for your response. Your idea sounds good, although I haven't had any experience with the graphic buffer yet. Do you probably have a chance to post your old sketch code or a link to the custom-buttons thing?

Here's the link to a example using the intersect() method:
http://www.learningprocessing.com/examples/chapter-10/example-10-3/

Chris

Edit: Perhaps I could do it by using a mask, setting the Color I finally want as BG color of an PImage, Loading the Shape above it and the other Shape convertet to an alpha image. Unfortunately, this won't be a very efficient approach if it works at all, I guess..

Hi again,
here is my first (working) attempt on solving the problem, still static. I wonder if this will work with about 10 interactions and 30 fps..

1. import processing.core.*;
   public class MaskTest extends PApplet{
   
       private PGraphics buf;
      
       public void setup(){
           size(500,500,JAVA2D);
           smooth();
          
           this.setBuf(createGraphics(500, 500,P2D));
           buf.background(255);
          
           //Draw the overlay shape
           PGraphics overlay = createGraphics(500,500,P2D);
           overlay.beginDraw();
           overlay.noStroke();
           overlay.fill(255,0,0);
           overlay.ellipse(200,200, 250, 250);
           overlay.endDraw();
          
           //Draw the intersect shape
           PGraphics intersect = createGraphics(500,500,P2D);
           intersect.beginDraw();
           intersect.noStroke();
           intersect.background(255);
           intersect.fill(0);
           intersect.ellipse(100, 100, 200, 200);
           intersect.endDraw();
          
           //masking
           overlay.mask(intersect);
          
           //Draw the background shape and add the masked shape, so the background is shown where both shapes overlap
           buf.beginDraw();
           buf.noStroke();
           buf.fill(0,255,0);
           buf.ellipse(200,200, 250, 250);
           buf.image(overlay,0,0);
           buf.endDraw();
          
       }
      
       public void draw(){
          
           this.image(this.getBuf(), 0, 0);
          
       }
   
       public PGraphics getBuf() {
           return buf;
       }
   
       public void setBuf(PGraphics buf) {
           this.buf = buf;
       }
      
   }
   
   

Although this seems to solve my problem, it made me discover a new one: the mask() method only works with the p2d/p3d renderer. Unfortunetely, I need the Java2D renderer for the breakShape()-Method in another part of my program. Has anyone a good idea how-to merge both?

Chris

Just pushing the thread again with another problem: "How-to combine 2 different Renderer-Methods" or "Is there any other possibility to highlight intersections between shapes"?

what about something like this .
works just fine.

1. PGraphics pg;
   
   void setup() {
     size(600,400);
     smooth();
     background(255);
     pg = createGraphics(width, height, P3D);
   }
   
   void draw() {
     background(255);
   
     noStroke();
     fill(255,0,255 );
     ellipse(mouseX,mouseY,250,250);
     fill(255,255,0 );
     ellipse(300,200,250,250);
     pg.beginDraw();
     pg.background(255);
     pg.fill(0,130);
     pg.noStroke();
     pg.ellipse(mouseX,mouseY,250,250);
     pg.ellipse(300,200,250,250);
     pg.endDraw();
   
    
     loadPixels();
     for(int i = 0; i<pg.pixels.length;i++){
       if(red(pg.pixels[i]) < 80)pixels[i] = color(0,255,0);
   
     }
   
     updatePixels();
   }
   
   
   
   
   

Oh well, this just works great. Thank you!

Btw, I also found another solution: Check in a loop for two pixels-Arrays from different PGraphics, if the pixels on the same spot are different from their background, so they must overlap. Color them.

Unfortunately, smoothing does yet not work with that method, although it would fit better to my purpose than the other one above. See other thread for that.

Thank you very much, guys!