#version 100
precision mediump int;
precision mediump float;

uniform float alpha_value;
uniform float time;

void main(void)
{ 
    vec4 color;
    color.x = 1.0;
    color.y = 1.0;
    color.z = 0.0;
    color.w = alpha_value * ((sin(time * 5.0) + 1.0) / 2.0);
    gl_FragColor = color;
}