Is it possible to draw main graphics on a PGraphics?

Processing
1

Is it possible to draw g on a PGraphics?
It should be done in P3D and it should be done without using loadPixels();

So something like this:

PGraphics pg;

void setup() {
  size(512, 512, P3D);  
  
  pg = createGraphics(256, 256, P3D);
  
}

void draw() {
  background(0);
  fill(255,255,0);
  circle(width/2, height/2, 256);
  
  pg.beginDraw();
  pg.image(g, 0, 0, pg.width, pg.height);
  pg.endDraw(); 
}

I tried different things with pre and post and endDraw but so far no luck.

1 Like
2

I try understand what you want but is not clear, are you expected somethinf like that ?

PGraphics pg;
PImage  img;

void setup() {
  size(512, 512, P3D);  
  pg = createGraphics(256, 256, P3D);
  img = createImage(pg.width, pg.height, RGB);
}

void draw() {
  background(0);
  fill(255,255,0);
  circle(width/2, height/2, 256);
  
  g.loadPixels(); // need to load to don't have have null pixels
  img.copy(g,0,0,pg.width,pg.height, 0,0,pg.width,pg.height);
  
  fill(255,0,0);
  circle(width/2, height/2, 256);
  
  image(img,0,0);
  /*
  pg.beginDraw();
  pg.image(img, 0, 0, pg.width, pg.height);
  pg.endDraw();
  */
  pg.loadPixels();
  println("pg",pg.pixels); // return null
}

48
Capture dā€™eĢcran 2019-04-08 aĢ€ 10.48.48.jpg1148Ɨ1140 107 KB

1 Like
3

Can you explain why this is a requirement? This seems odd, since you want to access the pixels array of g ā€“ and that is what loadPixels is for.

You can try to skip this sometimes, but are explicitly warned against it in the reference:

Certain renderers may or may not seem to require loadPixels() or updatePixels() . However, the rule is that any time you want to manipulate the pixels[] array, you must have previously called loadPixels() , and after changes have been made, call updatePixels() . Even if the renderer may not seem to use this function in the current Processing release, this will always be subject to change.

4

Hi! What does no luck mean in this case?

I didnā€™t look at the source, but it could be that Processing automatically calls beginDraw and endDraw for the default g PGraphics at the begining and end of draw(). Maybe that means you canā€™t draw g onto something else because endDraw hasnā€™t been called yet?

Knowing why you want to do this may help suggest an alternative :slight_smile:

2 Likes
5

I made a renderer for the terminal:

fox.gif860Ɨ632

I donā€™t want to use loadPixels on the main graphics cause it can be really slow depending on itā€™s size.
So what I do now is make a smaller graphics, then I draw g on that smaller graphics and load the pixels from that instead. I can only get this working in post which is not safe to draw, but it worksā€¦

Here is the repository if anyone is interested. If you made something cool then please post a image.

4 Likes
6

I really like this kind of hacks that push whatā€™s possible or reasonable :slight_smile:

7

:clap: :clap: :clap:

Wild.

Does it also work as system shell output when called from processing-java?

8

I will check later, if it doesnā€™t I can probably make it work.
That will make it also more friendly for PDE users that donā€™t have additional IDEā€™s installed.

O yeah the thing is Max / Linux only, this has to do that I put the terminal in character mode. And Iā€™m tired of making things cross platform.

9

That is totally fair ā€“ I am too. Although a ā€œTerminal Modeā€ for PDE would be pretty cool.

10

Some people wanted to work on the console:

Not sure if they started yet, and if they will, not sure if they will follow specification to make a descent terminal (supporting ANSI escapes, single character mode etc.)

2 Likes
11

It might be worth having a look at the JLine library for this. Should enable it to be fully cross-platform too.

1 Like
12

I wasnā€™t familiar with JLine. Looks like it is here:

1 Like
13

Yes, sorry, should have added a link! Itā€™s also the library used by the Java shell in the JDK.

14

I updated the project, more here: