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

void main()
{
  vec4 col = texture2D(u_Tex0, v_TexCoord);

  // Shimmer effect
  float shimmer = sin(u_Time * 10.0) * 0.1;
  col.rgb += shimmer;

  // Twist effect
  float twist = sin(u_Time * 5.0) * 0.2;
  col.rgb += vec3(twist, twist, twist);

  // Glitch effect
  float glitchX = sin(u_Time * 20.0) * 0.01;
  float glitchY = cos(u_Time * 15.0) * 0.01;
  col.rgb += texture2D(u_Tex0, v_TexCoord + vec2(glitchX, glitchY)).rgb;

  // Fade effect
  float fade = smoothstep(0.0, 1.0, u_Time * 0.1);
  col.rgb *= fade;

  gl_FragColor = col;
}