We closed this forum 18 June 2010. It has served us well since 2005 as the ALPHA forum did before it from 2002 to 2005. New discussions are ongoing at the new URL http://forum.processing.org. You'll need to sign up and get a new user account. We're sorry about that inconvenience, but we think it's better in the long run. The content on this forum will remain online.

Index › Programming Questions & Help › Syntax Questions › pixel color offscreen with shape functions

Rick Junior Member Offline Posts: 78

pixel color offscreen with shape functions Jun 8th, 2008, 6:24pm   I might be missing something obvious, but I'm having trouble getting pixel colors out of the pixel array of an offscreen instance. Quote: PGraphics b; color[]cols; void setup() {  size(400,400);  loadPixels();  b = createGraphics(400,400,P3D);  b.loadPixels();  b.fill(255, 0, 0);  b.rect(0,0,400,400);  b.updatePixels(); } void draw() {  /*  for(int x=0; x<width; x++) {    for(int y=0; y<height; y++) {      b.pixels[y*width+x] = color((int)random(255),(int)random(255),(int)random(255));    }  }  */  arraycopy(b.pixels, pixels);  updatePixels();  int ran = (int)random(b.pixels.length);  println(red(b.pixels[ran]) + " : " + green(b.pixels[ran]) + " : " + green(b.pixels[ran])); } Shouldn't it give me a red pixel? It works if you set the pixels directly (the commented section).

http://r6753.com/ I need a job.

antiplastik YaBB Moderator Offline Posts: 699 France	Re: pixel color offscreen with shape functions Reply #1 - Jun 8th, 2008, 8:13pm   Instead of calling b.loadPixels() and b.updatePixels() in your setup, you have to call b.beginDraw() and b.endDraw().

Rick Junior Member Offline Posts: 78	Re: pixel color offscreen with shape functions Reply #2 - Jun 9th, 2008, 3:43am   Right, I forgot about that. Thanks. I feel pretty stupid.
	http://r6753.com/ I need a job.