1 files changed, 24 insertions, 0 deletions
diff --git a/src/mbgl/shader/box.fragment.glsl b/src/mbgl/shader/box.fragment.glsl
new file mode 100644
index 0000000000..030f1219f8
--- /dev/null
+++ b/src/mbgl/shader/box.fragment.glsl
@@ -0,0 +1,24 @@
+uniform float u_zoom;
+uniform float u_maxzoom;
+
+varying float v_max_zoom;
+varying float v_placement_zoom;
+
+void main() {
+
+    float alpha = 0.5;
+
+    gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0) * alpha;
+
+    if (v_placement_zoom > u_zoom) {
+        gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0) * alpha;
+    }
+
+    if (u_zoom >= v_max_zoom) {
+        gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0) * alpha * 0.25;
+    }
+
+    if (v_placement_zoom >= u_maxzoom) {
+        gl_FragColor = vec4(0.0, 0.0, 1.0, 1.0) * alpha * 0.2;
+    }
+}