vec3 modulus error

[LinusNeuman]

Hello!

I tried converting this shader I found to love2d, but I can't get it right.
This statement is the one in error:

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vec3 grain = vec3(((mod(mod(int(x), 13) + 1)* (mod(int(x), 123) + 1), 0.01) - 0.005) * noiseStrength); // 0.01 and - 0.005

Unable to find compatible overloaded function "mod(float)". I get the error because mod is supposed to get 2 values, 2 floats, but it gets one. And I don't know how the dude that made this wants it to be.

Shader:

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//layout(location = 0) out vec3 out_color;

//uniform sampler2D colorMap; // This is the original image without noise
uniform float time; // Time since the start of the frame

const float noiseStrength = 30.0; // The strength of the noise effect -- default 30.0

vec4 effect(vec4 col, Image texture, vec2 texturePos, vec2 screenPos)
{
    vec3 color = texture2D(texture, texturePos).xyz;
    float x = (texturePos.x + 4) * (texturePos.y + 4) * (time * 10);

    int a = 13;
    int b = 123;

    vec3 grain = vec3(((mod(mod(int(x), 13) + 1)* (mod(int(x), 123) + 1), 0.01) - 0.005) * noiseStrength); // 0.01 and - 0.005

    // This one is optional, it makes a small "tear" every now and then
    //if(mod(time, 100) > 98 && mod(texcoord.y, 10) > 7) grain = vec3(-3.0, -3.0, -3.0);
    //vec3 grain = vec3(0,0,0);
    color += grain;
    vec4 finalColor = vec4(color, 1.0);
    return finalColor;
}

Link to reddit forum that made this originally:
https://m.reddit.com/r/opengl/comments/ ... ain_noise/

[LinusNeuman]

Turns out that time was 0 all the time, so now I send time every frame.
I also deleted the error statement and replaced with this:

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float noise(vec2 seed)
{
  float x = (seed.x / 3.14159 + 4) * (seed.y / 13 + 4) * ((fract(time) + 1) * 10);
  return mod((mod(x, 13) + 1) * (mod(x, 123) + 1), 0.01) - 0.005;
}

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vec3 out_color = texture2D(texture, texturePos).xyz;

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vec2 seed = vec2(0.9,0.9);
    out_color += noise(seed);
    vec4 finalColor = vec4(out_color, 1.0);
    return finalColor;

Problem is.. Either the seed is so low that almost nothing happens, or it is so high that the screen flickers like crazy.