How to clear the screen on KeyPress?

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litos92

How to clear the screen on KeyPress?

in General Discussion • Other • 4 months ago

I'm working in a sketch that draws lines over a real time video, captured for my WebCam ...
How can I erase the lines when I press a key??

(I already know about Call Background, but it doesn't work with video)

Replies(4)

benj.n.su..

Re: How to clear the screen on KeyPress?

4 months ago

Point of clarification: do want to clear the whole screen, lines, video, everything? Or just the lines but keep the video?

If it's the former, you could simply draw a big 'ol rectangle with a fill of your choosing. If the latter, I'll need to see some code. At least the order of events in your draw loop, and anything pertaining to the drawing of the lines.

litos92

Re: Re: How to clear the screen on KeyPress?

4 months ago

I want to erase just the lines, and keep the video for then draw more lines...
I also would like create a eraser tool or something like that.

either of the previous two would be nice.

Here a part of the code:

void draw() {

if (video.available()) {
    video.read();
}
video.loadPixels();
image(video, 0, 0);

float worldRecord = 500;

int closestX = 0;
int closestY = 0;

for (int x = 0; x < video.width; x ++ ) {
    for (int y = 0; y < video.height; y ++ ) {
      int loc = x + y*video.width;

      color currentColor = video.pixels[loc];
      float r1 = red(currentColor);
      float g1 = green(currentColor);
      float b1 = blue(currentColor);
      float r2 = red(trackColor);
      float g2 = green(trackColor);
      float b2 = blue(trackColor);

      // Using euclidean distance to compare colors
      float d = dist(r1, g1, b1, r2, g2, b2);// We are using the dist( ) function to compare the current color with the color we are tracking.

      // If current color is more similar to tracked color than closest color, save current location and current difference
      if (d < worldRecord) {
        worldRecord = d;
        closestX = x;
        closestY = y;
      }
    }
}
topLayer.beginDraw();
topLayer.stroke(trackColor);

// We only consider the color found if its color distance is less than 10. This threshold of 10 is arbitrary and you can adjust this number depending on how accurate you require the tracking to be.
if (worldRecord < 10) {
   topLayer.strokeWeight(6);
    topLayer.line(xprev,yprev,closestX, closestY);
    xprev = closestX;
    yprev = closestY;
}
topLayer.endDraw();
image(topLayer,0,0);
}

PhiLho

Re: How to clear the screen on KeyPress?

4 months ago

Showing some code clarifies a lot your request!

Just call topLayer.background(0, 0); to erase it while keeping its background transparent.

litos92

Re: Re: How to clear the screen on KeyPress?

4 months ago

oohh it works !! thanks !!

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