From 6e6f095439f292bbbfcfb872b69dd35f5c309108 Mon Sep 17 00:00:00 2001
From: Ricardo Matias <ricardo.matias0@gmail.com>
Date: Tue, 7 Jan 2020 14:53:48 +0100
Subject: [PATCH] Add Chromatic Aberration effect

---
 .../main/kotlin/color/ChromaticAberration.kt  | 40 +++++++++++++++++++
 .../fx/gl3/color/chromatic-aberration.frag    | 23 +++++++++++
 2 files changed, 63 insertions(+)
 create mode 100644 orx-fx/src/main/kotlin/color/ChromaticAberration.kt
 create mode 100644 orx-fx/src/main/resources/org/openrndr/extra/fx/gl3/color/chromatic-aberration.frag

diff --git a/orx-fx/src/main/kotlin/color/ChromaticAberration.kt b/orx-fx/src/main/kotlin/color/ChromaticAberration.kt
new file mode 100644
index 00000000..d6544020
--- /dev/null
+++ b/orx-fx/src/main/kotlin/color/ChromaticAberration.kt
@@ -0,0 +1,40 @@
+package org.openrndr.extra.fx.color
+
+import org.openrndr.draw.*
+import org.openrndr.extra.fx.filterFragmentCode
+import org.openrndr.math.Vector2
+import org.openrndr.resourceUrl
+
+class ChromaticAberration : Filter(Shader.createFromCode(Filter.filterVertexCode, filterFragmentCode("color/chromatic-aberration.frag"))){
+    /**
+     * aberration factor, default value is 1.0
+     */
+    var aberrationFactor: Double by parameters
+
+
+    init {
+        aberrationFactor = 8.0
+    }
+
+    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])
+        }
+    }
+}
diff --git a/orx-fx/src/main/resources/org/openrndr/extra/fx/gl3/color/chromatic-aberration.frag b/orx-fx/src/main/resources/org/openrndr/extra/fx/gl3/color/chromatic-aberration.frag
new file mode 100644
index 00000000..f74a633b
--- /dev/null
+++ b/orx-fx/src/main/resources/org/openrndr/extra/fx/gl3/color/chromatic-aberration.frag
@@ -0,0 +1,23 @@
+#version 330
+
+in vec2 v_texCoord0;
+
+uniform sampler2D tex0;
+
+uniform float aberrationFactor;
+uniform vec2 dimensions;
+
+out vec4 o_color;
+
+void main() {
+    vec2 uv = v_texCoord0;
+    float factor = (1.0 / dimensions.x) * aberrationFactor;
+
+    vec4 tex = texture(tex0, uv);
+
+    float r = texture(tex0, vec2(uv.x - factor, uv.y)).r;
+    float g = tex.g;
+    float b = texture(tex0, vec2(uv.x + factor, uv.y)).b;
+
+    o_color = vec4(vec3(r, g, b), tex.a);
+}
\ No newline at end of file