/** Demo of using gbuffer rendering pass. Fragment shader */

#version 110

uniform sampler2D normalMap;

varying vec3 vnormal;
varying vec3 vtangent;
varying vec3 vbinormal;

void main(){

    // look up the normal map
    vec3 normal = texture2D(normalMap, gl_TexCoord[0].xy).xyz;

    // transform the normal to view space
    normal -= 0.5;
    normal = normalize(normal.x * vtangent + 
                       normal.y * vbinormal +
               normal.z * vnormal);

    // Now back to colour space of [0, 1]
    normal = normal * 0.5 + 0.5;

    gl_FragData[0] = vec4(normal, 1.0);
    gl_FragData[1] = vec4(1.0, 0.0, 0.0, 1.0);
}