Support float texture data on OpenGL ES 2.0

examples/models/resources/shaders/skybox.fs

@@ -9,7 +9,7 @@
 #version 330
 
 // Input vertex attributes (from vertex shader)
-in vec3 fragPos;
+in vec3 fragPosition;
 
 // Input uniform values
 uniform samplerCube environmentMap;
@@ -20,7 +20,7 @@ out vec4 finalColor;
 void main()
 {
     // Fetch color from texture map
-    vec3 color = texture(environmentMap, fragPos).rgb;
+    vec3 color = texture(environmentMap, fragPosition).rgb;
 
     // Apply gamma correction
     color = color/(color + vec3(1.0));