#version 300 es
precision highp float;

in vec3 vColor;
in float vAlpha;
in vec2 vQuadCoord;

out vec4 fragColor;

void main() {
    float dist = length(vQuadCoord);
    float falloff = smoothstep(1.0, 0.5, dist);
    fragColor = vec4(vColor, vAlpha * falloff);
}