attribute vec4 a_Position;
attribute vec2 a_TexCoord;
varying vec2 v_TexCoord;
void main(){
  gl_Position = a_Position;
  v_TexCoord = a_TexCoord;
}

precision mediump float;
uniform sampler2D u_Sampler;
varying vec2 v_TexCoord;
void main(){
  gl_FragColor = texture2D(u_Sampler, v_TexCoord);
}