I made this filter a while ago and forget about it. I dunno. maybe someone will find it useful.
The object that has the filter must also have a timer property called “timer”
uniform sampler2D bgl_RenderedTexture;
uniform float timer;
void main()
{
float amp = 0.08;
float turb = 20.0;
vec2 texCoo = gl_TexCoord[0].st;
float X = gl_TexCoord[0].s-0.5;
float Y = gl_TexCoord[0].t-0.5;
vec2 warp = vec2(X*(sin(timer+X*turb)*amp+0.9)+0.5,
Y*(cos(timer+Y*turb)*amp+0.9)+0.5);
vec4 warped = texture2D(bgl_RenderedTexture, warp);
//****************************************************//
const float contrast = 1.5; //1 is no contrast.
const float brightness = 1.3; //1 is no brightness
vec4 color = texture2D(bgl_RenderedTexture, gl_TexCoord[0].st);
color = ((color-1.0)*max(contrast,0.0));
color = color+brightness;
color.r += 0.05*sin(timer);
color.g += 0.25*cos(timer);
color.b += 0.05*cos(sin(timer));
gl_FragColor = warped+color;
}
