From 53fbc47636fc92952a12b6da8b81504a8f306700 Mon Sep 17 00:00:00 2001
From: Edwin <edwin@rndr.studio>
Date: Fri, 15 Apr 2022 12:58:19 +0200
Subject: [PATCH] [orx-fx] Add super sampling to Contour filter

---
 orx-fx/src/commonMain/kotlin/edges/Contour.kt |  5 ++++
 orx-fx/src/shaders/glsl/edges/contour.frag    | 27 ++++++++++++-------
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/orx-fx/src/commonMain/kotlin/edges/Contour.kt b/orx-fx/src/commonMain/kotlin/edges/Contour.kt
index a0ef1491..c332af1e 100644
--- a/orx-fx/src/commonMain/kotlin/edges/Contour.kt
+++ b/orx-fx/src/commonMain/kotlin/edges/Contour.kt
@@ -7,6 +7,7 @@ import org.openrndr.extra.fx.mppFilterShader
 import org.openrndr.extra.parameters.ColorParameter
 import org.openrndr.extra.parameters.Description
 import org.openrndr.extra.parameters.DoubleParameter
+import org.openrndr.extra.parameters.IntParameter
 
 @Description("Contour")
 class Contour : Filter(mppFilterShader(fx_contour, "contour")) {
@@ -25,11 +26,15 @@ class Contour : Filter(mppFilterShader(fx_contour, "contour")) {
     @ColorParameter("contour color")
     var contourColor: ColorRGBa by parameters
 
+    @IntParameter("window", 0, 10)
+    var window: Int by parameters
+
     init {
         levels = 6.0
         contourWidth = 0.4
         contourColor = ColorRGBa.BLACK
         backgroundOpacity = 1.0
         contourOpacity = 1.0
+        window = 1
     }
 }
diff --git a/orx-fx/src/shaders/glsl/edges/contour.frag b/orx-fx/src/shaders/glsl/edges/contour.frag
index 0d00c4a0..3d82721d 100644
--- a/orx-fx/src/shaders/glsl/edges/contour.frag
+++ b/orx-fx/src/shaders/glsl/edges/contour.frag
@@ -6,21 +6,28 @@ uniform float contourWidth;
 uniform float contourOpacity;
 uniform vec4 contourColor;
 uniform float backgroundOpacity;
+uniform int window;
+
+float calc_contour(vec2 uv) {
+    vec4 box = texture(tex0, uv);
+    float v = sin(3.1415926535 * levels * dot(vec3(1.0/3.0),box.xyz));
+    float level = floor(dot(vec3(1.0/3.0),box.xyz) * levels) / levels;
+    float contour = 1.0 - smoothstep(0., contourWidth, 0.5 * abs(v) / fwidth(v));
+    return contour;
+}
 
 void main() {
     vec2 step = 1.0 / textureSize(tex0, 0);
-    vec4 box = vec4(0.0);
-    for (int j = -1; j <=1; ++j) {
-        for (int i = -1; i <= 1; ++i) {
-            box += texture(tex0, v_texCoord0 + step * vec2(i, j));
+    float contour = 0.0;
+    float weight = 0.0;
+
+     for (int i = -window; i <= window; ++i) {
+        for (int j = -window; j <= window; ++j) {
+            contour += calc_contour(v_texCoord0 + step/(window+1.0) * vec2(i, j));
+            weight += 1.0;
         }
     }
-    box /= 9.0;
-    float v = sin(3.1415926535 * levels * dot(vec3(1.0/3.0),box.xyz));
-    float level = floor(dot(vec3(1.0/3.0),box.xyz) * levels) / levels;
-    //int plateauIndex = min(levels-1, int(level * levels));
-    float contour = 1.0 - smoothstep(0., contourWidth, 0.5 * abs(v) / fwidth(v));
-
+    contour /= weight;
     vec4 t = texture(tex0, v_texCoord0);
     o_output = t * backgroundOpacity * (1.0-contour) + contour * contourColor * contourOpacity * t.a;
 }
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