create and call methods from processing

clankill3r

I'm stilly reading the shader tutorial but it's so long that i already try out some stuff.

I'm wondering is something like this possible in the shader file:

uniform float fuzziness;

float minR, maxR, minG, maxG, minB, maxB;

void fuzziness(float v) {
  fuzziness = v;
  calcMinAndMax();
}

void calcMinAndMax() {
  minR = color.r-fuzziness;
  maxR = color.r+fuzziness;
  minG = color.g-fuzziness;
  maxG = color.g+fuzziness;
  minB = color.b-fuzziness;
  maxB = color.b+fuzziness;
}

And then call the fuzziness method from processing. Right now i get "The function targetColor(float, float, float) does not exist."

velvetkevorkian

I'm pretty sure you can't — you can only pass values into the shader using set() then tell the shader to run. Processing can't access shader methods, nor can the shader access Processing methods, AFAIK.

clankill3r

Yeah i think the same :) I'm only not sure how main is running. Like if i drop this in main:

minR = color.r-fuzziness;
  maxR = color.r+fuzziness;
  minG = color.g-fuzziness;
  maxG = color.g+fuzziness;
  minB = color.b-fuzziness;
  maxB = color.b+fuzziness;

will those values be recalculated for every pixel?

velvetkevorkian

That's my understanding, although I'm far from an expert. The fragment shader runs once for each fragment/pixel.