shader.lua

crtShader = lg.newShader([[
    extern float elapsed;
    extern float colorI;
    
    vec2 radialDistortion(vec2 coord, float dist) {
        vec2 cc = coord - 0.5;
        dist = dot(cc, cc) * dist + cos(elapsed * .3) * .01;
        return (coord + cc * (1.0 + dist) * dist);
    }
    
    vec4 effect(vec4 color, Image tex, vec2 tc, vec2 pc) {
        vec2 tcr = radialDistortion(tc, .24)  + vec2(.001, 0);
        vec2 tcg = radialDistortion(tc, .20);
        vec2 tcb = radialDistortion(tc, .18) - vec2(.001, 0);
        vec4 res = vec4(Texel(tex, tcr).r, Texel(tex, tcg).g, Texel(tex, tcb).b, 1)
        - cos(tcg.y * 128. * 3.142 * 2) * colorI
        - sin(tcg.x * 128. * 3.142 * 2) * colorI;
        return res * Texel(tex, tcg).a;
    }
]])