OpenGL Shader Problem

Processing Coding Questions
2

Hi @svan,

in principle you don’t need the whole GL background and code, as processing gives you a PShader which handle this for you …

PShader shader;

String vshaderSource[] = {
  "#version 410", 
  "uniform mat4 transform;",
  "in vec4 vertex;",
  "void main(void) {", 
  "   gl_Position = transform * vertex;",
  "}"
};

String fshaderSource[] = {
  "#version 410", 
  "uniform float mytime;",
  "void main(void) {", 
  "   float t = sin(mytime)*0.5+0.5;",
  "   gl_FragColor = vec4(1.0-t,t,0.0,1.0);",
  "}", 
};

void setup() {
  size(640, 480, P2D);  
  rectMode(CENTER);
  shader = new PShader(g.parent, vshaderSource, fshaderSource);
}

void draw() {
  background(0);
  translate(width/2,height/2);
  shader.set("mytime",millis()/250.0);
  shader(shader);
  fill(255);
  rect(0,0,100,100);
}

ezgif.com-gif-maker (1)

Cheers
— mnse