Does loadPixels() take "fill()" function into account ?

ToJah

Hi there, ready to look at a beginner's problem ?

I wrote (what i thought would be) a simple function : get (x, y)-point's color values :

function getPix(_x, _y) { loadPixels(); let off = (_x + _y * width) * pixelDensity() * 4; let result = [ pixels[off], pixels[off + 1], pixels[off + 2], pixels[off + 3] ]; return result; }

The function seems to work fine : console.log(off) sends back the right index, according to the "_x" & "_y" values, and i get the background's RGBA values.

Now, in Draw, i have an object displaying something. (say a blue square at 0, 0)

var col = color(0, 0, 255, 255); obj.show() { fill(col); rect(0, 0, 10, 10); }

But if i am to call getPix(0, 0); again, i still get my background's color as a result : how comes ? My guess is : loadPixels() loads before my object is shown, but since i'm using this function for the first time, i surely have some misconceptions about the way it works.

The original code is slightly more complex, and i may give it if needed, but this exemple is still pretty much alike.

Thanks for any answer to come :)

ToJah

Well, the problem came from a misconception indeed :

Since my sketch includes a camera object, i assumed loadPixels() took the translate informations into account, and started a (0, 0) (god knows why).

Adding my camera's X & Y displacement values to _x and _y solved it, obviously.

Hope this could help someone, some day, somehow

kfrajer

Thank you for sharing your solution.

loadPixels() took the translate informations into account

Notice your first post doesn't mention translate. When you have a problem like this, it is recommended to provide an MCVE so to get better feedback.

Kf

ToJah

No problem !

True for the lack of MCVE : I'll provide one next time :)