Add a working X-Ray view

plugins/XRayView/xray.shader

@@ -0,0 +1,27 @@
+[shaders]
+vertex =
+    uniform highp mat4 u_modelViewProjectionMatrix;
+
+    attribute highp vec4 a_vertex;
+
+    void main()
+    {
+        gl_Position = u_modelViewProjectionMatrix * a_vertex;
+    }
+
+fragment =
+    uniform lowp vec4 u_color;
+
+    void main()
+    {
+        gl_FragColor = u_color;
+    }
+
+[defaults]
+u_color = [0.02, 0.02, 0.02, 1.0]
+
+[bindings]
+u_modelViewProjectionMatrix = model_view_projection_matrix
+
+[attributes]
+a_vertex = vertex