uniform float u_Time;
uniform sampler2D u_Tex0;
varying vec2 v_TexCoord;

void main()
{
    vec4 col = texture2D(u_Tex0, v_TexCoord);
    float d = u_Time * 2;
    col.x += (1.0 + sin(d))*0.25;
    col.y += (1.0 + sin(d*2))*0.25;
    col.z += (1.0 + sin(d*4))*0.25;
    gl_FragColor = col;
}