vert1.glsl

#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

#define PROCESSING_TEXTURE_SHADER

uniform sampler2D texture;
uniform vec2 resolution;
uniform float time;
uniform vec4 m;

void main(void) {
  	vec2 p = gl_FragCoord.xy / resolution.xy;
	
	p.x -= mod(p.x, m.x);
	p.y -= mod(p.y, m.y);	
	p.y = mod(p.y + m.z*sin(m.a * time * p.x + p.x), 1.0);
	p.y = 1.0-p.y;

	float r = texture2D(texture, p).r;
	float g = texture2D(texture, p).g;
	float b = texture2D(texture, p).b;
	
  	gl_FragColor = vec4(r, g, b, 1.0);
}

vert2.glsl

#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

#define PROCESSING_TEXTURE_SHADER

uniform sampler2D texture;
uniform vec2 resolution;
uniform float time;
uniform vec3 m;

void main(void) {
  	vec2 p = gl_FragCoord.xy / resolution.xy;
	
	vec2 p1 = vec2(p.x, mod(time*m.x, 1.0));
	vec2 p2 = vec2(mod(time*m.y, 1.0), p.y);
	
	float mode = floor(m.z);
	
	float rx = texture2D(texture, p1).r;
	float ry = texture2D(texture, p2).r;
	float gx = texture2D(texture, p1).g;
	float gy = texture2D(texture, p2).g;
	float bx = texture2D(texture, p1).b;
	float by = texture2D(texture, p2).b;
	float r, g, b;
	if (mode==0.0) {
		r = rx * ry;
		g = gx * gy;
		b = bx * by;
	} else if (mode==1.0) {
		r = rx * ry;
		g = gx * by;
		b = bx * gy;
	} else if (mode==2.0) {
		r = rx * gy;
		g = gx * ry;
		b = bx * by;
	} else if (mode==3.0) {
		r = rx * gy;
		g = gx * by;
		b = bx * ry;
	} else if (mode==4.0) {
		r = rx * by;
		g = gx * ry;
		b = bx * gy;
	} else if (mode==5.0) {
		r = rx * by;
		g = gx * gy;
		b = bx * ry;
	} else if (mode==6.0) {
		r = 0.3333333 * (rx*ry + gx*gy + bx*by);
		g = r;
		b = r;
	}	
  	gl_FragColor = vec4(r, g, b, 1.0);
}

WekinatorShaderToggler.pde

// you need to put the glsl files into the sketch's data folder

String[] shaders = new String[] {
  "vert1.glsl", "vert2.glsl", "wrap.glsl" };
PGraphics pg;
PImage img;
PShader myShader;
int idx, nextIdx;
boolean isImage = true;

import oscP5.*;
import netP5.*;

OscP5 oscP5;


void setup() {
  size(828, 648, P2D);
  textureWrap(REPEAT);
  
  oscP5 = new OscP5(this,12000);
  
  idx = 0;
  nextIdx = 0;
  setupShader(idx);

  // load image  
  img = loadImage("/Users/gene/Desktop/discoball/DSC_0228.JPG");
  
  // create pgraphics
  pg = createGraphics(width, height, P2D);
  pg.beginDraw();
  pg.background(0, 255, 0);
  for (int i=0; i<100; i++) {
    pg.fill(random(255), random(255), random(255));
    pg.ellipse(random(pg.width), random(pg.height), 100, 100);
  }
  pg.endDraw();
}

void draw() {
  if (nextIdx != idx) {
    idx = nextIdx;
    setupShader(idx);
  }
  
  setShaderParameters();
  if (isImage) image(img, 0, 0, width, height);
  else         image(pg, 0, 0, width, height);
}

void setupShader(int idx) {
  myShader = loadShader(shaders[idx]);
  myShader.set("resolution", float(width), float(height));
  shader(myShader);   
}

void setShaderParameters() {
  myShader.set("time", millis()/1000.0);
  
  // vert1
  if (idx==0) {
    myShader.set("m", 0.2, 0.1, 0.3, 0.2);
  }

  // vert2
  else if (idx==1) {
    myShader.set("m", 0.2, 0.1, 0.3);
  }
  
  // wrap
  else if (idx==2) {
    myShader.set("mouse", float(mouseX), float(mouseY));
  }
}

void keyPressed() {
  if      (keyCode==LEFT)   idx = (shaders.length + idx - 1) % shaders.length;
  else if (keyCode==RIGHT)  idx = (idx + 1) % shaders.length;
  setupShader(idx);
}

void oscEvent(OscMessage theOscMessage) {
  String address = theOscMessage.addrPattern();
  if (address.equals("/wek/outputs")) {
    float myClass = theOscMessage.get(0).floatValue();
    if (myClass == 1.0) {
      nextIdx = 0;
    }
    else if (myClass == 2.0) {
      nextIdx = 1;
    }
    else if (myClass == 3.0) {
      nextIdx = 2;
    }
  }
}

wrap.glsl

#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

#define PROCESSING_TEXTURE_SHADER

uniform vec2 resolution;
uniform sampler2D texture;

void main(void) {
    vec2 p = -1.0 + 2.0 * gl_FragCoord.xy / resolution.xy;
    float a = atan(p.y,p.x);
    float r = sqrt(dot(p,p));
    vec2 uv;
	uv.x = (a + 3.14159265359)/6.28318530718;
	uv.y = r / sqrt(2.0);
    vec3 col = texture2D(texture, uv).rgb;
    gl_FragColor = vec4(col, 1.0);
}