From ff12413f1f46a2c30155004102e7de5c7a608acb Mon Sep 17 00:00:00 2001
From: Edwin Jakobs <edwin@rndr.studio>
Date: Sat, 3 Sep 2022 13:08:02 +0200
Subject: [PATCH] [orx-fx] Add DirectionalBlur

---
 .../commonMain/kotlin/blur/DirectionalBlur.kt | 53 +++++++++++++++
 .../src/demo/kotlin/DemoDirectionalBlur01.kt  | 38 +++++++++++
 .../shaders/glsl/blur/directional-blur.frag   | 67 +++++++++++++++++++
 3 files changed, 158 insertions(+)
 create mode 100644 orx-fx/src/commonMain/kotlin/blur/DirectionalBlur.kt
 create mode 100644 orx-fx/src/demo/kotlin/DemoDirectionalBlur01.kt
 create mode 100644 orx-fx/src/shaders/glsl/blur/directional-blur.frag

diff --git a/orx-fx/src/commonMain/kotlin/blur/DirectionalBlur.kt b/orx-fx/src/commonMain/kotlin/blur/DirectionalBlur.kt
new file mode 100644
index 00000000..591a6330
--- /dev/null
+++ b/orx-fx/src/commonMain/kotlin/blur/DirectionalBlur.kt
@@ -0,0 +1,53 @@
+package org.openrndr.extra.fx.blur
+
+import org.openrndr.draw.*
+import org.openrndr.extra.fx.fx_directional_blur
+import org.openrndr.extra.fx.mppFilterShader
+import org.openrndr.extra.parameters.BooleanParameter
+import org.openrndr.extra.parameters.Description
+import org.openrndr.extra.parameters.DoubleParameter
+import org.openrndr.extra.parameters.IntParameter
+
+/**
+ * Directional blur filter. Takes source image and direction buffer inputs
+ */
+@Description("Directional blur")
+class DirectionalBlur : Filter(mppFilterShader(fx_directional_blur, "directional-blur")) {
+
+    /**
+     * The sample window, default is 5
+     */
+    @IntParameter("window size", 1, 25)
+    var window: Int by parameters
+
+    /**
+     * Spread multiplier, default is 1.0
+     */
+    @DoubleParameter("kernel spread", 1.0, 4.0)
+    var spread: Double by parameters
+
+    /**
+     * Post-blur gain, default is 1.0
+     */
+    @DoubleParameter("gain", 0.0, 4.0)
+    var gain: Double by parameters
+
+    /**
+     * Should filter use directions perpendicular to those in the direction buffer?
+     */
+    @BooleanParameter("perpendicular")
+    var perpendicular: Boolean by parameters
+
+    init {
+        window = 5
+        spread = 1.0
+        gain = 1.0
+        perpendicular = false
+    }
+
+    override fun apply(source: Array<ColorBuffer>, target: Array<ColorBuffer>) {
+        parameters["wrapX"] = false
+        parameters["wrapY"] = false
+        super.apply(source, target)
+    }
+}
\ No newline at end of file
diff --git a/orx-fx/src/demo/kotlin/DemoDirectionalBlur01.kt b/orx-fx/src/demo/kotlin/DemoDirectionalBlur01.kt
new file mode 100644
index 00000000..1ff50916
--- /dev/null
+++ b/orx-fx/src/demo/kotlin/DemoDirectionalBlur01.kt
@@ -0,0 +1,38 @@
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.draw.*
+import org.openrndr.extra.fx.blur.DirectionalBlur
+import org.openrndr.math.smoothstep
+import kotlin.math.cos
+import kotlin.math.sin
+
+fun main() = application {
+    program {
+        val db = DirectionalBlur()
+        val rt = renderTarget(width, height) {
+            colorBuffer()
+        }
+
+        val blurred = colorBuffer(width, height)
+        val direction = colorBuffer(width, height, type = ColorType.FLOAT32)
+        val s = direction.shadow
+        for (y in 0 until height) {
+            for (x in 0 until width) {
+                val a = smoothstep(0.45, 0.55, cos((x + y) * 0.01) * 0.5 + 0.5)
+                s[x, y] = ColorRGBa(cos(y * .1) * a, sin(x * 0.1) * a, 0.0, 1.0)
+            }
+        }
+
+        s.upload()
+        val image = loadImage("demo-data/images/image-001.png")
+        extend {
+            drawer.isolatedWithTarget(rt) {
+                clear(ColorRGBa.BLACK)
+                drawer.image(image)
+            }
+            db.window = 10
+            db.apply(arrayOf(rt.colorBuffer(0), direction), blurred)
+            drawer.image(blurred)
+        }
+    }
+}
\ No newline at end of file
diff --git a/orx-fx/src/shaders/glsl/blur/directional-blur.frag b/orx-fx/src/shaders/glsl/blur/directional-blur.frag
new file mode 100644
index 00000000..3e0803e4
--- /dev/null
+++ b/orx-fx/src/shaders/glsl/blur/directional-blur.frag
@@ -0,0 +1,67 @@
+#ifdef OR_IN_OUT
+in vec2 v_texCoord0;
+#else
+varying vec2 v_texCoord0;
+#endif
+
+uniform sampler2D tex0; // image
+uniform sampler2D tex1; // blurDirection
+uniform vec2 textureSize0;
+
+uniform int window;
+uniform float sigma;
+uniform float gain;
+uniform vec4 subtract;
+uniform float spread;
+
+uniform bool wrapX;
+uniform bool wrapY;
+uniform bool perpendicular;
+
+
+#ifndef OR_GL_FRAGCOLOR
+out vec4 o_color;
+#endif
+
+vec2 wrap(vec2 uv) {
+    vec2 res = uv;
+    if (wrapX) {
+        res.x = mod(res.x, 1.0);
+    }
+    if (wrapY) {
+        res.y = mod(res.y, 1.0);
+    }
+    return res;
+
+}
+void main() {
+    vec2 s = textureSize0;
+    s = vec2(1.0 / s.x, 1.0 / s.y);
+
+
+    vec4 sum = vec4(0.0, 0.0, 0.0, 0.0);
+    #ifndef OR_GL_TEXTURE2D
+    vec2 blurDirection = texture(tex1, v_texCoord0).xy;
+    if (perpendicular) {
+        blurDirection = vec2(-blurDirection.y, blurDirection.x);
+    }
+    float weight = 0.0;
+    for (int x = 0; x < window; ++x) {
+        sum += texture(tex0, wrap(v_texCoord0 + float(x) * blurDirection * s * spread));
+        weight += 1.0;
+    }
+    #else
+    vec2 blurDirection = texture2D(tex1, v_texCoord0);
+    float weight = 0.0;
+        sum += texture2D(tex0, wrap(v_texCoord0 * blurDirection * s * spread));
+
+    #endif
+
+
+    vec4 result = (sum/weight) * gain;
+    #ifdef OR_GL_FRAGCOLOR
+    gl_FragColor = result;
+    #else
+    o_color = result;
+    #endif
+}
\ No newline at end of file