Only part of the code has reset background

General Discussion Other

njitram

Only part of the code has reset background

in General Discussion • Other • 4 months ago

I'm making a drawing sketch but i want to draw some guidelines also, but they can't stay on the screen forever. Is there a way to program my sketch so that my actual drawing stays and the guidelines move around and update.

I'm generating my drawing with line() and i use 2 variables 'p' and 'pOld'. 'pOld' is the previous location of 'p'.

Cheers

Replies(2)

tfguy44

Re: Only part of the code has reset background

4 months ago

Yes, this is possible, but the trick to doing it is not obvious.

You have to do the drawing to a separate PGraphics objects.

Example:

final int w = 600;
final int h = 400;
PGraphics pg;
void setup(){
size(w,h,P2D);
pg = createGraphics(width,height,P2D);
pg.beginDraw();
pg.background(0);
pg.smooth();
pg.ellipseMode(CENTER);
pg.fill(255,0,0);
pg.noStroke();
pg.endDraw();
stroke(255);
}
void draw(){
image(pg,0,0);
if( !keyPressed ){
line( mouseX, 0, mouseX, height);
line( 0, mouseY, width, mouseY);
}
if( mousePressed ){
pg.beginDraw();
pg.ellipse(mouseX,mouseY,10,10);
pg.endDraw();
}
}

njitram

Re: Only part of the code has reset background

4 months ago

Wow! How cool!

Thanks for the help, this is a really cool technique.

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