Noob needs brightness help

Programming Questions

flixc3

in Programming Questions • 1 year ago

Literally minutes new to processing and I have an error that i dont understand or know how to resolve, can someone help?

code:

PImage img;

void setup() {

size(200, 200);

frameRate(30);

img = loadImage("pip_boy_3000_wp.jpg");

img.loadPixels();

loadPixels();

}

void draw() { background(0);

image(img,0,0);

for (int x = 0; x < img.width; x++) {

for (int y = 0; y < img.height; y++ ) {

int loc = x + y*img.width;

float r,g,b;

r = red (img.pixels[loc]);

float maxdist = 50;

float d = dist(x,y,mouseX,mouseY);

float adjustbrightness = 255*(maxdist-d)/maxdist;

r += adjustbrightness;

r = constrain(r,0,255);

color c = color(r);

pixels[y*width + x] = c;

}

updatePixels();

}

error:

Aug 6 20:30:06 guy.local java[463] <Error>: CGContextGetCTM: invalid context 0x0

Aug 6 20:30:06 guy.local java[463] <Error>: CGContextSetBaseCTM: invalid context 0x0

Aug 6 20:30:06 guy.local java[463] <Error>: CGContextGetCTM: invalid context 0x0

Aug 6 20:30:06 guy.local java[463] <Error>: CGContextSetBaseCTM: invalid context 0x0

Exception in thread "Animation Thread" java.lang.ArrayIndexOutOfBoundsException: 40000

at Img_bright.draw(Img_bright.java:42)

at processing.core.PApplet.handleDraw(PApplet.java:1631)

at processing.core.PApplet.run(PApplet.java:1530)

at java.lang.Thread.run(Thread.java:680)

Replies(3)

amnon.owed

Re: Noob needs brightness help

1 year ago

Your sketch has only 40.000 pixels (200x200). Apparantly your image is larger.

Once you try setting a pixel in the sketch that is greater than 40.000 it will give an out-of-bounds exception.

You are doing exactly this with the line: pixels[y*width + x] = c;

There are many ways to solve this error depending on what you are trying to accomplish.

Also see: http://processing.org/learning/pixels/

flixc3

Re: Re: Noob needs brightness help

1 year ago

so what exactly do I do? My out of bounds exception is 1400000

benja

Re: Noob needs brightness help

1 year ago

You could try to resize your picture, to ensure, that it doesn't have more pixels than your pixels[]-array.

img.resize(width, height);

Or you loop through the pixels of you sketch instead of the pixels of your image.

for (int x = 0; x < width; x++) {

for (int y = 0; y < height; y++ ) {

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