Swapped example code to my old project frame.

assets/shaders/skybox.fs

@@ -0,0 +1,30 @@
+#version 330
+
+// Input vertex attributes (from vertex shader)
+in vec3 fragPosition;
+
+// Input uniform values
+uniform samplerCube environmentMap;
+uniform bool vflipped;
+uniform bool doGamma;
+
+// Output fragment color
+out vec4 finalColor;
+
+void main()
+{
+    // Fetch color from texture map
+    vec3 color = vec3(0.0);
+
+    if (vflipped) color = texture(environmentMap, vec3(fragPosition.x, -fragPosition.y, fragPosition.z)).rgb;
+    else color = texture(environmentMap, fragPosition).rgb;
+
+    if (doGamma)// Apply gamma correction
+    {
+        color = color/(color + vec3(1.0));
+        color = pow(color, vec3(1.0/2.2));
+    }
+
+    // Calculate final fragment color
+    finalColor = vec4(color, 1.0);
+}