Background() clear everything

Programming Questions

the.engin..

Background() clear everything

in Programming Questions • 10 months ago

Hi! My processing Sketch read from a log file and draw the datas in a koordinate sytem. I made a cursor with a vertical and a horizontal line, that cross each other, where the mouse is. But!

If I read a data, and draw it, then it will disappear, because of the background command, but if I do not use background() the program leave the previously cursor lines and it will be a mess.

How can I clear the cursor lines, without clear the data lines?

Replies(1)

tfguy44

Re: Background() clear everything

10 months ago

Quite simply, redraw everything!

void draw(){
background( bgcolor );
drawDataLines();
drawCursorLines();
}

Or draw your (static!) data, save it as an image, and then display that image.

PImage img;
void setup(){
size( wide, tall );
background( bgcolor );
loadData();
drawDataLines();
img = get();
}
void draw(){
image(img,0,0);
drawCursorLines();
}

You could also only save and restore the area under the custom cursor, but that's a lot harder and probably not worth the effort.