fixture ghost test

assets/shaders/ghastlywhite.frag

@@ -0,0 +1,13 @@
+varying vec4 v_color;
+varying vec2 v_texCoords;
+uniform sampler2D u_texture;
+
+vec2 boolean = vec2(0.0, 1.0);
+vec4 desaturate = vec4(0.2126, 0.7152, 0.0722, 0.0);
+
+void main(void) {
+    vec4 incolour = texture2D(u_texture, v_texCoords);
+    float lum = dot(incolour * desaturate, boolean.yyyx) * 0.5 + 0.5;
+
+    gl_FragColor = v_color * (vec4(lum) * boolean.yyyx + incolour * boolean.xxxy);
+}