How to use glsl version 3.00

[smkplus]

I tried #version 300 es this but didn't work
http://www.shaderific.com/blog/2014/3/13/tutorial-how-to-update-a-shader-for-opengl-es-30

#ifdef GL_ES
precision mediump float;


#endif

uniform vec2 u_resolution;
uniform float u_time;

void main(){
    vec2 st = gl_FragCoord.xy/u_resolution.xy;
    gl_FragColor = vec4( 1 & 2);
}

[Larphoid]

You can include #version 300 es at the top of your shader. This means that you'll have to rewrite your shaders accordingly.
Moreover, if you don't provide your own vertex shader, then you would also need to edit dist/GlslCanvas.js.
Find this.vertexString = contextOptions.vertexString || and the string at the end should be replaced with something like:
'#version 300 es\n#ifdef GL_ES\nprecision mediump float;\n#endif\n\nin vec2 a_position;\nin vec2 a_texcoord;\n\nout vec2 v_texcoord;\n\nvoid main() {\n gl_Position = vec4(a_position, 0.0, 1.0);\n v_texcoord = a_texcoord;\n}\n'.
In your fragment shader you can still access gl_FragCoord as usual, but gl_FragColor should now be fragColor if you put out vec4 fragColor; after your # defines. This works for me !

Hope this helps.