`#version 300 es
//#version directive must occur on the first line of the shader

//Why it is necessary to set precission for the fragment shader? 
//Vertex shader works without this, but fragment shader 
//doesn't work without this code row (as I see). 
// Why the different behaviour exist?  
// fragment shaders don't have a default precision so we need
// to pick one. highp is a good default. It means "high precision"

precision highp float;


// we need to declare an output for the fragment shader
// WebGL2  no more gl_FragColor

out vec4 outColor;

// all shaders have a main function
  void main() {
    //WebGL1:  gl_FragColor = vec4(1, 0, 0.5, 1); 
      outColor = vec4(0.5, 0.5, 0.5, 1) ;
}`