GlShader 
  Creates a GskGLShader that will render pixels using the specified code.
Return
A new GskGLShader
Parameters
sourcecode
GLSL sourcecode for the shader, as a GBytes
Creates a GskGLShader that will render pixels using the specified code.
Return
A new GskGLShader
Parameters
resourcePath 
path to a resource that contains the GLSL sourcecode for the shader