uniform samplerCube skyDome;
uniform sampler2D water;

uniform vec4 waterColour;

varying mat3 tanSpace;

void main(void)
{
   vec3 ref = ((gl_TexCoord[1] + texture2D(water, gl_TexCoord[0].xy)) * 0.5).xyz;
   ref *= 2.0;
   ref -= vec3(1.0, 1.0, 1.0);
   
   ref = tanSpace * ref;
  
   vec4 sample = waterColour
                   + ( (textureCube(skyDome, ref) - waterColour) 
                   * (dot(ref,vec3(0.0,0.0,1.0)) * waterColour.w));
   
   
   
   gl_FragColor = vec4( sample.xyz, 0.825);
}