extern float t,w,h; vec4 effect(vec4 color,Image text,vec2 pos,vec2 scr_pos){ float x=scr_pos.x/w; float y=scr_pos.y/h; return vec4( .4-y*.3-.1*sin(t/6.26), .2+.1*sin(t), abs(.7-x*1.2+y*.5*sin(t/16.)), 1. ); }