Wanted to know if anyone could point me in the right direction on techniques I could use to achieve this.

I want to create a Kaleidoscope application, idea being that I can take a triangle 'cutout' out of any source image and paste it over and over (mirrored over and over) and rotated around the center point.

I just don't know how to a) cut out a triangular shape out of another image and paste that and b) flip it

Any thoughts?

Cut out: Graphic as an image mask
Flip: Flip Image
Paste: image()

I added some comments to the cut-out code, so I re-paste it there:
Code:

PImage niceImage;
PImage maskedImage;
PGraphics graphicalMask;
int iw, ih;
int dw, dh;

void setup()
{
  size(500, 500);
  niceImage = loadImage("SomeImage.png");
  iw = niceImage.width;
  ih = niceImage.height;
  dw = width - iw;
  dh = height - ih;
  graphicalMask = createGraphics(iw, ih, JAVA2D);
}

void draw()
{
  background(200);

  graphicalMask.beginDraw();
  // Erase graphics with black background
  graphicalMask.background(0);
  // Draw the mask, depending on mouse position
  int x = mouseX - dw/2;
  int y = mouseY - dh/2;
  // Draw in white
  graphicalMask.fill(255);
  graphicalMask.noStroke();
  // An ellipse to see a good part of the image
  graphicalMask.ellipse(x, y, 100, 50);
  // Draw in gray, resulting in translucent mask
  graphicalMask.stroke(128);
  graphicalMask.strokeWeight(5);
  // Draw a thick cross-wire
  graphicalMask.line(0, y, iw, y);
  graphicalMask.line(x, 0, x, ih);
  graphicalMask.endDraw();

  // Copy the original image (kept as reference)
  maskedImage = niceImage.get();
  // Apply the mask
  maskedImage.mask(graphicalMask);
  // Display the result
  image(maskedImage, dw/2, dh/2);
}
 

In your case, you just have to draw a triangle().

I am working on a face tracking programming which distorts only certain regions of the face. I added the above masking into my code so it draws the ellipse mask around the area created by the face tracking but I have been unable to overlay only that "cropped" ellipse anywhere else for example back on the original video or what I'd even like to do is cut the face out with that ellipse then put it on another image source.

any ideas?

thanks.