[orx-fx] Add fade to Contour and CannyEdgeDetector

orx-fx/build.gradle.kts

@@ -34,6 +34,8 @@ kotlin {
                 implementation(project(":orx-color"))
                 implementation(project(":orx-fx"))
                 implementation(project(":orx-noise"))
+                implementation(project(":orx-shapes"))
+                implementation(project(":orx-image-fit"))
             }
         }
     }

orx-fx/src/commonMain/kotlin/edges/CannyEdgeDetector.kt

@@ -37,6 +37,9 @@ class CannyEdgeDetector : Filter1to1(
     var backgroundOpacity: Double by parameters
 
 
+    @DoubleParameter("fade", 0.0, 1.0, order = 7)
+    var fade: Double by parameters
+
     init {
         threshold0 = 2.0
         threshold1 = 0.0
@@ -45,6 +48,7 @@ class CannyEdgeDetector : Filter1to1(
         backgroundColor = ColorRGBa.BLACK
         backgroundOpacity = 1.0
         foregroundOpacity = 1.0
+        fade = 1.0
     }
 
 }

orx-fx/src/commonMain/kotlin/edges/Contour.kt

@@ -6,10 +6,7 @@ import org.openrndr.color.ColorRGBa
 import org.openrndr.draw.Filter1to1
 import org.openrndr.extra.fx.fx_contour
 import org.openrndr.extra.fx.mppFilterShader
-import org.openrndr.extra.parameters.ColorParameter
+import org.openrndr.extra.parameters.*
-import org.openrndr.extra.parameters.Description
-import org.openrndr.extra.parameters.DoubleParameter
-import org.openrndr.extra.parameters.IntParameter
 
 @Description("Contour")
 class Contour : Filter1to1(mppFilterShader(fx_contour, "contour")) {
@@ -28,13 +25,18 @@ class Contour : Filter1to1(mppFilterShader(fx_contour, "contour")) {
     @DoubleParameter("bias", -1.0, 1.0)
     var bias: Double by parameters
 
-
     @ColorParameter("contour color")
     var contourColor: ColorRGBa by parameters
 
     @IntParameter("window", 0, 10)
     var window: Int by parameters
 
+    @BooleanParameter("output bands", order = 100)
+    var outputBands: Boolean by parameters
+
+    @DoubleParameter("fade", 0.0, 1.0, order = 200)
+    var fade: Double by parameters
+
     init {
         levels = 6.0
         contourWidth = 0.4
@@ -43,5 +45,7 @@ class Contour : Filter1to1(mppFilterShader(fx_contour, "contour")) {
         contourOpacity = 1.0
         window = 1
         bias = 0.0
+        outputBands = false
+        fade = 1.0
     }
 }

orx-fx/src/jvmDemo/kotlin/DemoContour01.kt

@@ -0,0 +1,56 @@
+/**
+ * Demonstrate the Contour filter
+ * @author Edwin Jakobs
+ */
+
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.draw.createEquivalent
+import org.openrndr.draw.loadImage
+import org.openrndr.extra.fx.edges.Contour
+import org.openrndr.extra.imageFit.imageFit
+import org.openrndr.extra.shapes.primitives.grid
+
+fun main() = application {
+    configure {
+        width = 720
+        height = 720
+    }
+    program {
+        val image = loadImage("demo-data/images/image-001.png")
+        val contour = Contour()
+        contour.levels = 4.0
+        contour.window = 1
+        contour.outputBands = true
+        contour.contourColor = ColorRGBa.PINK
+        contour.backgroundOpacity = 0.0
+
+        val edges = image.createEquivalent()
+        extend {
+            val cells = drawer.bounds.grid(2, 2).flatten()
+            val actions = listOf(
+                {
+                    contour.outputBands = true
+                    contour.levels = 2.0
+                },
+                {
+                    contour.outputBands = false
+                    contour.levels = 2.0
+                },
+                {
+                    contour.outputBands = false
+                    contour.levels = 8.0
+                },
+                {
+                    contour.outputBands = true
+                    contour.levels = 8.0
+                },
+            )
+            for ((cell, action) in cells zip actions) {
+                action()
+                contour.apply(image, edges)
+                drawer.imageFit(edges, cell)
+            }
+        }
+    }
+}

orx-fx/src/shaders/glsl/edges/canny-edge-detector.frag

@@ -15,6 +15,8 @@ uniform vec4 foregroundColor;
 uniform float backgroundOpacity;
 uniform float foregroundOpacity;
 
+uniform float fade;
+
 vec2 iResolution;
 
 float getAve(vec2 uv) {
@@ -104,7 +106,11 @@ float cannyEdge(vec2 fragCoord, float mn, float mx){
 
 void main() {
     iResolution = vec2(textureSize(tex0, 0));
+    vec4 original = texture(tex0, v_texCoord0);
     vec2 fragCoord = v_texCoord0 * iResolution;
     float edge = cannyEdge(fragCoord, threshold0, threshold1);
-    o_output = mix(foregroundColor * foregroundOpacity, backgroundColor * backgroundOpacity, 1.-edge);
+    o_output = mix(original,
+                   mix(foregroundColor * foregroundOpacity,
+                       backgroundColor * backgroundOpacity, 1. - edge),
+                   fade);
 }

orx-fx/src/shaders/glsl/edges/contour.frag

@@ -8,27 +8,44 @@ uniform vec4 contourColor;
 uniform float backgroundOpacity;
 uniform int window;
 uniform float bias;
+uniform bool outputBands;
+uniform float fade;
 
-float calc_contour(vec2 uv) {
+vec2 calc_contour(vec2 uv) {
     vec4 box = texture(tex0, uv);
     float v = sin(3.1415926535 * levels * (dot(vec3(1.0 / 3.0), box.xyz) + bias));
-    float level = floor((dot(vec3(1.0 / 3.0), box.xyz) + bias) * levels) / levels;
+    float level = floor((dot(vec3(1.0 / 3.0), box.xyz) + bias) * levels);
     float contour = 1.0 - smoothstep(0., contourWidth, 0.5 * abs(v) / fwidth(v));
-    return contour;
+    return vec2(contour, level);
 }
 
 void main() {
     vec2 step = 1.0 / vec2(textureSize(tex0, 0));
     float contour = 0.0;
     float weight = 0.0;
+    float level = 0.0;
 
     for (int i = -window; i <= window; ++i) {
         for (int j = -window; j <= window; ++j) {
-            contour += calc_contour(v_texCoord0 + step / (float(window) + 1.0) * vec2(float(i), float(j)));
+            vec2 c = calc_contour(v_texCoord0 + step / (float(window) + 1.0) * vec2(float(i), float(j)));
+            contour += c.x;
+            level += c.y;
             weight += 1.0;
         }
     }
     contour /= weight;
+
     vec4 t = texture(tex0, v_texCoord0);
-    o_output = t * backgroundOpacity * (1.0 - contour) + contour * contourColor * contourOpacity * t.a;
+
+    if (outputBands) {
+        level /= weight;
+
+        level = 1.0 - max(0.0, fract(level / 2.0) * 2.0);
+        contour = level;
+    }
+
+    o_output = mix(t,
+                   t * backgroundOpacity * (1.0 - contour) + contour * contourColor * contourOpacity * clamp(t.a, 0.0, 1.0),
+                   fade);
+
 }