今日永杰开金

    float size = 100.;

    vec2 checkerboard = mod(floor(gl_FragCoord.xy / size), 2.);

    float c = mod(checkerboard.x + checkerboard.y, 2.);

    gl_FragColor = vec4(vec3(c), 1);

或

vec2 uv = floor(S * p.xy * vec2(iResolution.x / iResolution.y, 1) / iResolution.xy);
c = vec4(vec3(mod(uv.x + uv.y, 2.)), 1);

或

	float size = 100.;

    float oddX = mod(floor(gl_FragCoord.x / size), 2.);
    float oddY = mod(floor(gl_FragCoord.y / size), 2.);

    float c = 0.;

    if( oddX == oddY ){
        c = 1.;
    }

    gl_FragColor = vec4(vec3(c), 1);