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Index › Programming Questions & Help › Syntax Questions › using custom methods inside PGraphics beginDraw();
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using custom methods inside PGraphics beginDraw(); (Read 864 times)
designeranton
using custom methods inside PGraphics beginDraw();
Mar 13th, 2010, 3:52pm  
I'd like to invoke a drawing method in an offscreen buffer, but I cant get it to work:

    buffer.beginDraw();
    buffer.background(255,0);
   buffer.myBlobs[i].update(inc);
   buffer.endDraw();

doesnt work: myBlobs is an array of objects from my blob class. They have a method called update to draw them. Inc is used to influence the noise().

How do I draw to an offscreen buffer with a local method?

i tried:
class blob extends PGraphics

to no avail...
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Giles
Re: using custom methods inside PGraphics beginDraw();
Reply #1 - Mar 13th, 2010, 6:04pm  
Coincidentally, just tonight I am trying to do something very similar (and also having problems).

Is buffer global? The update method needs to draw on buffer, within the class...rather than trying to do buffer.myBlobs[i].update(inc); This won't work as buffer doesn't have a myBlobs[i].update(inc) method.
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TfGuy44
Re: using custom methods inside PGraphics beginDraw();
Reply #2 - Mar 13th, 2010, 7:41pm  
You can always pass the PGraphics object that you want them to draw on to the class's drawing function.

myBlobs[i].update( inc, buffer );

class Blob {
//...
void update( int _inc ){
update( _inc, g );
}
void update( int _inc, PGraphics buf ){
buf.line(
//... etc.
}
}
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designeranton
Re: using custom methods inside PGraphics beginDraw();
Reply #3 - Mar 14th, 2010, 11:37am  
Tx Tfguy. What a great idea to insert make two update methods!

I have a question about this line:
Code:
update( _inc, g );


i suppose  the idea is to make the update method run on the normal canvas if I don't pass it a buffer. But how do I define g to be this normal screen?
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TfGuy44
Re: using custom methods inside PGraphics beginDraw();
Reply #4 - Mar 14th, 2010, 11:20pm  
g is already defined to be the normal screen. It's Processing magic.
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