pixels[] and image.get

pixelorchestra

Hello list, i have this problem: i'd like to copy a portion of my screen into an image. both are different sizes. usually I use

    myImage = get(x, y, w, h).

now I'd like to use pixels[] array to speed up a little the program.

     loadPixels();   // load data from the screen
      for (int i = 0; i < grab.width; i++) {
        for (int j = 0; j < grab.height; j++) {
              grab.pixels[i + j*grab.width] = pixels[i + j*grab.width];
       }
      }
    grab.updatePixels(); // push data into grab image
    image(grab, 500, 500);

What's wrong with this code?

thank you, Bruno

GoToLoop

http://forum.Processing.org/two/discussion/8045/how-to-format-code-and-text
https://Processing.org/reference/copy_.html

PhiLho

"What's wrong with this code?"
Well, you should tell us... :-)

One missing thing is the coordinates of the grabbing, the x and y of the get() call. Something like pixels[x + i + (y + j)*grab.width]

pixelorchestra

philho thanks for the hint.

i figure out with this:

PImage bkg, grab; 

int startXClone; // were the cloning starts
int startYClone;


void setup() {
  size(1080, 720);
  bkg = loadImage("bkg.jpg");
  grab = createImage(320, 240, RGB);
  startXClone=100;
  startYClone=100;
  // noLoop();
}



void draw() {
  image(bkg, 0, 0);
  ellipse(mouseX, mouseY, 40, 40);
  grab.loadPixels();
  loadPixels(); 
  for (int y = startYClone; y < grab.height+startYClone; y++)
  {
    println(y);
    for (int x = startXClone; x < grab.width+startXClone; x++)
    {
      // Faster array access, but still involves math to find index
      grab.pixels[x-startXClone+((y-startYClone) * grab.width)]=pixels[x + (y * width)];
    }   
  } 
  grab.updatePixels();
  image(grab, 300, 500);
}

still doubt to clean the code to make it more readable and put it in a class