Built-in functions | Mod - Shader Learning

Mod

Create a pattern of alternating black and red columns, with 9 columns of each color. Then, hide every third column that is colored red.

Requirements

The shader should avoid using branching or conditional statements in its code, and instead rely on the mod and step functions to determine the color of each pixel.

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fragment.glsl

uniform vec2 iResolution;

void main() {

// Normalized pixel coordinates (from 0 to 1)

vec2 uv = gl_FragCoord.xy / iResolution.xy;

uv *= 9.0;

float x = fract(uv.x);

x = step(0.5, x);

gl_FragColor = vec4(x, 0.0, 0.0, 1.0);

}

Expected

Output