[orx-fx] Add Lenses Filter

orx-fx/src/commonMain/kotlin/distort/BlockRepeat.kt

@@ -1,8 +1,12 @@
 package org.openrndr.extra.fx.distort
 
+import org.openrndr.draw.ColorBuffer
 import org.openrndr.draw.Filter
+import org.openrndr.draw.MagnifyingFilter
+import org.openrndr.draw.MinifyingFilter
 import org.openrndr.extra.fx.fx_block_repeat
 import org.openrndr.extra.fx.mppFilterShader
+import org.openrndr.extra.parameters.BooleanParameter
 import org.openrndr.extra.parameters.Description
 import org.openrndr.extra.parameters.DoubleParameter
 
@@ -32,6 +36,17 @@ class BlockRepeat : Filter(mppFilterShader(fx_block_repeat, "block-repeat")) {
     @DoubleParameter("source y-offset", -.5, .5, order = 6)
     var sourceOffsetY: Double by parameters
 
+    @BooleanParameter("bicubic filtering")
+    var bicubicFiltering: Boolean by parameters
+
+    override fun apply(source: Array<ColorBuffer>, target: Array<ColorBuffer>) {
+        if (bicubicFiltering && source.isNotEmpty()) {
+            source[0].generateMipmaps()
+            source[0].filter(MinifyingFilter.LINEAR_MIPMAP_LINEAR, MagnifyingFilter.LINEAR)
+        }
+        super.apply(source, target)
+    }
+
     init {
         blockWidth = 0.25
         blockHeight = 0.25
@@ -40,5 +55,6 @@ class BlockRepeat : Filter(mppFilterShader(fx_block_repeat, "block-repeat")) {
         sourceOffsetX = 0.0
         sourceOffsetY = 0.0
         sourceScale = 0.0
+        bicubicFiltering = true
     }
 }

orx-fx/src/commonMain/kotlin/distort/Lenses.kt

@@ -0,0 +1,45 @@
+package org.openrndr.extra.fx.distort
+
+import org.openrndr.draw.ColorBuffer
+import org.openrndr.draw.Filter
+import org.openrndr.draw.MagnifyingFilter
+import org.openrndr.draw.MinifyingFilter
+import org.openrndr.extra.fx.fx_lenses
+import org.openrndr.extra.fx.mppFilterShader
+import org.openrndr.extra.parameters.BooleanParameter
+import org.openrndr.extra.parameters.Description
+import org.openrndr.extra.parameters.DoubleParameter
+
+@Description("Lenses")
+class Lenses : Filter(mppFilterShader(fx_lenses, "block-repeat")) {
+    @DoubleParameter("block width", 0.0, 1.0, order = 0)
+    var blockWidth: Double by parameters
+
+    @DoubleParameter("block height", 0.0, 1.0, order = 1)
+    var blockHeight: Double by parameters
+
+
+    @DoubleParameter("scale", 0.5, 1.5, order = 2)
+    var scale: Double by parameters
+
+    @DoubleParameter("rotation", -180.0, 180.0, order = 3)
+    var rotation: Double by parameters
+
+    @BooleanParameter("bicubic filtering")
+    var bicubicFiltering: Boolean by parameters
+
+    override fun apply(source: Array<ColorBuffer>, target: Array<ColorBuffer>) {
+        if (bicubicFiltering && source.isNotEmpty()) {
+            source[0].generateMipmaps()
+            source[0].filter(MinifyingFilter.LINEAR_MIPMAP_LINEAR, MagnifyingFilter.LINEAR)
+        }
+        super.apply(source, target)
+    }
+
+    init {
+        blockWidth = 0.25
+        blockHeight = 0.25
+
+        bicubicFiltering = true
+    }
+}

orx-fx/src/demo/kotlin/DemoDistortLenses01.kt

@@ -0,0 +1,24 @@
+import org.openrndr.application
+import org.openrndr.draw.createEquivalent
+import org.openrndr.draw.loadImage
+import org.openrndr.extra.fx.distort.Lenses
+import kotlin.math.cos
+
+fun main() = application {
+    configure {
+        width = 640
+        height = 480
+
+    }
+    program {
+        val image = loadImage("demo-data/images/image-001.png")
+        val lenses = Lenses()
+        val edges = image.createEquivalent()
+        extend {
+            lenses.apply(image, edges)
+            lenses.rotation = 0.0
+            lenses.scale = 1.4
+            drawer.image(edges)
+        }
+    }
+}

orx-fx/src/shaders/glsl/distort/block-repeat.frag

@@ -34,6 +34,8 @@ void main() {
 //    float f = smoothstep(0.0, 0.01, blockUV.x) * smoothstep(0.0, 0.01, blockUV.y);
 
     vec2 sourceOffset = vec2(sourceOffsetX, sourceOffsetY);
-    vec4 c = texture(tex0, mod(tUV + sourceOffset, vec2(1.0)));
+    vec2 gx = dFdx(tUV);
+    vec2 gy = dFdy(tUV);
+    vec4 c = textureGrad(tex0, mod(tUV + sourceOffset, vec2(1.0)), gx, gy );
     o_color = c;
 }

orx-fx/src/shaders/glsl/distort/lenses.frag

@@ -0,0 +1,30 @@
+in vec2 v_texCoord0;
+uniform sampler2D tex0;// input
+uniform float scale;
+uniform float rotation;
+
+out vec4 o_color;
+void main() {
+    vec2 uv = v_texCoord0;
+    vec2 blockSize = vec2(1.0/8.0, 1.0/6.0);
+
+    vec2 blockIndex = floor(uv / blockSize);
+    vec2 blockCenter = (blockIndex+0.5) * blockSize;
+
+    float ca = cos(radians(rotation));
+    float sa = sin(radians(rotation));
+
+    vec2 ts = textureSize(tex0, 0);
+
+    mat2 rm =mat2(1.0, 0.0, 0.0, ts.x/ts.y) * mat2(vec2(ca, sa), vec2(-sa, ca)) * mat2(1.0, 0.0, 0.0, ts.y/ts.x);
+    vec2 cuv = (rm * (uv - blockCenter)
+    * scale + blockCenter);
+
+
+
+    float sx = step(0.0, cuv.x) * (1.0 - step(1.0, cuv.x));
+    float sy = step(0.0, cuv.y) * (1.0 - step(1.0, cuv.y));
+    vec4 c = texture(tex0, cuv) * sx * sy;
+
+    o_color = c;
+}