// Read depth from texture
float depth = texture(depthTex, fTexcoord).x;

// Since texture coords go from [0,1]
texcoords_in_ndc = fTexcoord.xy*2.0f - vec2(1.0f);

vec4 fragment_in_eye = invProjection * (texcoords_in_ndc,depth,1.0);

Line 2: error: 'depthTex' undeclared here (not in a function)
Line 2: error: 'fTexcoord' undeclared here (not in a function)
Line 2: error: request for member 'x' in something not a structure or union
Line 5: warning: data definition has no type or storage class
Line 7: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'fragment_in_eye'