Added Matt DesLauriers' crosshatch shader as a Filter...

It's also using Hugh Kennedy's glsl-luma, which is a dependency of glsl-crosshatch-filter.

orx-fx/src/main/kotlin/dither/Crosshatch.kt

@@ -0,0 +1,30 @@
+package org.openrndr.extra.fx.dither
+
+import org.openrndr.draw.Filter
+import org.openrndr.draw.Shader
+import org.openrndr.extra.fx.filterFragmentCode
+import org.openrndr.extra.parameters.Description
+import org.openrndr.extra.parameters.DoubleParameter
+
+
+@Description("Crosshatch")
+class Crosshatch: Filter(Shader.createFromCode(filterVertexCode, filterFragmentCode("dither/crosshatch.frag"))) {
+    @DoubleParameter("threshold 1", 0.0, 1.0)
+    var t1: Double by parameters
+
+    @DoubleParameter("threshold 2", 0.0, 1.0)
+    var t2: Double by parameters
+
+    @DoubleParameter("threshold 3", 0.0, 1.0)
+    var t3: Double by parameters
+
+    @DoubleParameter("threshold 4", 0.0, 1.0)
+    var t4: Double by parameters
+
+    init {
+        t1 = 1.0
+        t2 = 0.75
+        t3 = 0.5
+        t4 = 0.3
+    }
+}