Add orx-poisson-fill

orx-poisson-fill/src/main/kotlin/PoissonBlender.kt

@@ -0,0 +1,55 @@
+package org.openrndr.poissonfill
+
+import org.openrndr.draw.*
+import org.openrndr.filter.blend.subtract
+import org.openrndr.resourceUrl
+
+internal class BlendBoundary : Filter(filterShaderFromUrl(resourceUrl("/shaders/gl3/poisson/blend-boundary.frag")))
+class AlphaToBitmap : Filter(filterShaderFromUrl(resourceUrl("/shaders/gl3/poisson/alpha-to-bitmap.frag")))
+
+internal class BlendCombine : Filter(filterShaderFromUrl(resourceUrl("/shaders/gl3/poisson/blend-combine.frag"))) {
+    var softMaskGain: Double by parameters
+    init {
+        softMaskGain = 1.0
+    }
+}
+
+internal class Clamp : Filter(filterShaderFromUrl(resourceUrl("/shaders/gl3/poisson/clamp.frag"))) {
+    var minValue: Double by parameters
+    var maxValue: Double by parameters
+}
+
+class PoissonBlender(width: Int, height: Int, type: ColorType = ColorType.FLOAT32) {
+    private val pyramid = ConvolutionPyramid(width, height, 0, type = type)
+    private val preprocess = colorBuffer(width, height, type = type)
+    private val combined = colorBuffer(width, height, type = type)
+
+    private val fillBoundary = BlendBoundary()
+    private val fillCombine = BlendCombine()
+
+    private val difference = colorBuffer(width, height, type = type)
+
+    private val h1 = floatArrayOf(0.1507146f, 0.6835785f, 1.0334191f, 0.6836f, 0.1507f)
+    private val h2 = 0.0269546f
+    private val g = floatArrayOf(0.0311849f, 0.7752854f, 0.0311849f)
+
+    private val clamp = Clamp()
+
+    init {
+        pyramid.h1 = h1
+        pyramid.g = g
+        pyramid.h2 = h2
+    }
+
+    fun process(target: ColorBuffer, source: ColorBuffer, mask: ColorBuffer,
+                softMask: ColorBuffer = mask, softMaskGain: Double = 1.0): ColorBuffer {
+        subtract.apply(arrayOf(target, source), difference)
+        clamp.minValue = -0.50
+        clamp.maxValue = 0.50
+        fillBoundary.apply(arrayOf(difference, mask), preprocess)
+        val result = pyramid.process(preprocess)
+        fillCombine.softMaskGain = softMaskGain
+        fillCombine.apply(arrayOf(result, target, source, mask, softMask), arrayOf(combined))
+        return combined
+    }
+}