[orx-fx] convert to MPP

orx-fx/src/commonMain/kotlin/blur/ZoomBlur.kt

@@ -0,0 +1,44 @@
+package org.openrndr.extra.fx.blur
+
+import org.openrndr.draw.*
+import org.openrndr.extra.fx.fx_zoom_blur
+import org.openrndr.extra.fx.mppFilterShader
+import org.openrndr.extra.parameters.Description
+import org.openrndr.extra.parameters.DoubleParameter
+import org.openrndr.math.Vector2
+
+@Description("Zoom Blur")
+class ZoomBlur : Filter(mppFilterShader(fx_zoom_blur, "zoom-blur")) {
+    var center: Vector2 by parameters
+
+    @DoubleParameter("strength", 0.0, 1.0)
+    var strength: Double by parameters
+
+    init {
+        center = Vector2.ONE / 2.0
+        strength = 0.2
+    }
+
+    private var intermediate: ColorBuffer? = null
+
+    override fun apply(source: Array<ColorBuffer>, target: Array<ColorBuffer>) {
+        intermediate?.let {
+            if (it.width != target[0].width || it.height != target[0].height) {
+                intermediate = null
+            }
+        }
+
+        if (intermediate == null) {
+            intermediate =
+                colorBuffer(target[0].width, target[0].height, target[0].contentScale, target[0].format, target[0].type)
+        }
+
+        intermediate?.let {
+            parameters["dimensions"] = Vector2(it.effectiveWidth.toDouble(), it.effectiveHeight.toDouble())
+
+            super.apply(source, arrayOf(it))
+
+            it.copyTo(target[0])
+        }
+    }
+}