fix render advanced pipeline issues

res/shaders/entity.glslf

@@ -24,15 +24,19 @@ uniform vec3 u_sunDir;
 
 void main() {
     float shadow = calc_shadow(a_modelpos, a_realnormal, a_distance);
-    vec3 fogColor = texture(u_skybox, a_dir).rgb;
-    vec4 tex_color = texture(u_texture0, a_texCoord);
-    float alpha = a_color.a * tex_color.a;
+    vec4 texColor = texture(u_texture0, a_texCoord);
+    float alpha = a_color.a * texColor.a;
     // anyway it's any alpha-test alternative required
     if (alpha < (u_alphaClip ? 0.5f : 0.15f)) {
         discard;
     }
-    f_color = a_color * tex_color * shadow;
+    f_color = a_color * texColor * shadow;
+
+#ifndef ADVANCED_RENDER
+    vec3 fogColor = texture(u_skybox, a_dir).rgb;
     f_color = mix(f_color, vec4(fogColor, 1.0), a_fog);
+#endif
+
     f_color.a = alpha;
     f_position = vec4(a_position, 1.0);
     f_normal = vec4(a_normal, 1.0);