"size cannot be used here" / loading images in settings()

pacoruiz

Hi, Im executing this code and find this error: "size cannot be used here"

PImage img;
PImage picture;
Integer[] palette;

void setup(){
  img = loadImage("palette.jpg");
  palette = getPalette(img);
  picture = loadImage("picture.jpg");
  size(picture.width,picture.height);
  background(255);
}

void draw(){
  colour(picture, palette);
  noLoop();
} 

koogs

size is first in setup and can't contain calculations (ie picture.width or height).

look into settings() in the reference.

jeremydouglass

To understand more, read both of these pages carefully:

• https://processing.org/reference/size_.html
• https://processing.org/reference/settings_.html

pacoruiz

Ive done this, and the message is the same

 PImage img;
PImage picture;
Integer[] palette;

void setup(){
  size(200,200);
  img = loadImage("palette.jpg");
  palette = getPalette(img);
  picture = loadImage("picture.jpg");
  //size(picture.width,picture.height);
  background(255);
}
void draw(){
  colour(picture, palette);
  noLoop();
} 

TfGuy44

You read up on using settings(), but still aren't using settings()? Are you sure you read about it?

pacoruiz

Ive tried this, but it displays a message saying that the size cannot be calculated in the code

 PImage img;
PImage picture;
Integer[] palette;
int a;
int b;
void settings(){
  img = loadImage("palette.jpg");
  palette = getPalette(img);
  picture = loadImage("picture.jpg");
   a = picture.width; 
   b = picture.height;
}
void setup(){  
  size(a,b);
  background(255);
}
void draw(){
  int a = picture.width;
  int b = picture.height;
  println (a);
  println (b);
  colour(picture, palette);
  noLoop();
} 

GoToLoop

https://Forum.Processing.org/two/discussion/16705/null-pointer-exception-when-loading-image-in-settings-p3-1-1#Item_1

quark

According to the PS3 documentation, the parameters for the size() method must only contain integer literals or integer constants. The parameters MUST not be variables or expressions (calculations).

The settings() method is provided when using other IDEs e.g. Eclipse and is not used in the Processing IDE.

You can use the surface.setSize() to do what you want like this

PImage img;

void setup() {
  size(100, 100);
  img = loadImage("shoot1.png");
  if (img != null) {
    surface.setSize(img.width, img.height);
  }
}

void draw() {
  if (img != null) {
    image(img, 0, 0);
  } else {
    background(200, 200, 255);
  }
}

pacoruiz

Thanks, Ill try

jeremydouglass

The settings() method is provided when using other IDEs e.g. Eclipse and is not used in the Processing IDE.

@quark -- that's not quite right. settings() is normally not needed in Processing 3 PDE, but it works just fine in PDE, and it allows variables in size() (as setup() does not.)

The example sketch from the settings documentation runs just fine in PDE with a dynamic size:

int w = 200;
int h = 200;
int x = 0;

void settings() {
  size(w, h);
}

void setup() {
  background(0);
  noStroke();
  fill(102);
}

void draw() {
  rect(x, 10, 1, 180); 
  x = x + 2;
}

quark

I am only quoting the PS3 documentation, so don't shoot the messenger :)