Add PerspectivePlane distortion filter

orx-fx/README.md

@@ -70,6 +70,7 @@ All distortion effects are opacity preserving
  - `StackRepeat` - repeats the source input in a stack fashion
  - `HorizontalWave` - applies a horizontal wave effect on the source input
  - `VerticalWave` - applies a vertical wave effect on the source input
+ - `PerspectivePlane` - applies a planar perspective distortion on the source input
  
 ### Dither
  - `ADither` - a selection of dithering effects

orx-fx/src/main/kotlin/distort/Raycast.kt

@@ -0,0 +1,60 @@
+package org.openrndr.extra.fx.distort
+
+import org.openrndr.draw.*
+import org.openrndr.extra.fx.filterFragmentCode
+import org.openrndr.extra.parameters.BooleanParameter
+import org.openrndr.extra.parameters.Description
+import org.openrndr.extra.parameters.DoubleParameter
+import org.openrndr.math.Vector3
+import org.openrndr.math.transforms.transform
+
+@Description("Perspective plane")
+class PerspectivePlane : Filter(Shader.createFromCode(filterVertexCode, filterFragmentCode("distort/perspective-plane.frag"))) {
+
+//    @DoubleParameter("camera x", -1.0, 1.0, order = 0)
+    var cameraX : Double = 0.0
+//    @DoubleParameter("camera y", -1.0, 1.0, order = 1)
+    var cameraY : Double = 0.0
+//    @DoubleParameter("camera z", -1.0, 1.0, order = 2)
+    var cameraZ : Double = 1.0
+
+
+    @DoubleParameter("plane x", -1.0, 1.0, order = 3)
+    var planeX : Double = 0.0
+    @DoubleParameter("plane y", -1.0, 1.0, order = 4)
+    var planeY : Double = 0.0
+    @DoubleParameter("plane z", -1.0, 1.0, order = 5)
+    var planeZ : Double = 0.5
+
+    @DoubleParameter("plane yaw", -180.0, 180.0, order = 6)
+    var planeYaw : Double = 0.0
+    @DoubleParameter("plane pitch", -180.0, 180.0, order = 7)
+    var planePitch : Double = 0.0
+    @DoubleParameter("plane roll", -180.0, 180.0, order = 8)
+    var planeRoll : Double = 0.0
+
+
+    @BooleanParameter("tile input")
+    var tile: Boolean by parameters
+
+    var seconds:Double by parameters
+    init {
+        seconds = 0.0
+        tile = false
+    }
+
+    override fun apply(source: Array<ColorBuffer>, target: Array<ColorBuffer>) {
+        source[0].generateMipmaps()
+        source[0].filter(MinifyingFilter.LINEAR_MIPMAP_LINEAR, MagnifyingFilter.LINEAR)
+        source[0].wrapU = WrapMode.REPEAT
+        source[0].wrapV = WrapMode.REPEAT
+        parameters["cameraPosition"] = Vector3(cameraX, cameraY, cameraZ)
+        parameters["planePosition"] = Vector3(planeX, planeY, planeZ)
+        parameters["planeMatrix"] = transform {
+            rotate(Vector3.UNIT_X, planePitch)
+            rotate(Vector3.UNIT_Y, planeYaw)
+            rotate(Vector3.UNIT_Z, planeRoll)
+        }
+        super.apply(source, target)
+    }
+}

orx-fx/src/main/resources/org/openrndr/extra/fx/gl3/distort/perspective-plane.frag

@@ -0,0 +1,46 @@
+#version 330 core
+
+// based on https://www.shadertoy.com/view/wsBSWG by bloxard
+
+uniform sampler2D tex0;
+in vec2 v_texCoord0;
+uniform vec3 cameraPosition;
+uniform vec3 planePosition;
+uniform float seconds;
+uniform mat4 planeMatrix;
+uniform bool tile;
+uniform vec2 targetSize;
+out vec4 o_color;
+
+void main() {
+    vec3 vCamPos = cameraPosition;
+    vec3 vPlanePos = planePosition;
+    vec3 vPlaneRight = vec3(1.0, 0.0, 0.0);
+    vec3 vPlaneUp = vec3(0.0, 1.0, 0.0);
+
+    mat3 m = mat3(planeMatrix);
+    vPlaneUp *= m;
+    vPlaneRight *= m;
+
+    vec3 vPlaneNormal = normalize(cross(vPlaneRight,vPlaneUp));
+    float fPlaneDeltaNormalDistance = dot(vPlanePos,vPlaneNormal) - dot(vPlaneNormal,vCamPos);
+    vec4 color = vec4(0.);
+    for (int m = 0; m < 2; m++) {
+        for (int n = 0; n < 2; n++) {
+            vec2 s = (v_texCoord0 - vec2(0.5)) * 2.0;
+            s*= vec2(1.0, targetSize.y / targetSize.x);
+            vec3 vRayDir = normalize(vec3(s, -1.0));
+            float t = fPlaneDeltaNormalDistance / dot(vPlaneNormal,vRayDir);
+            vec3 hitPos = vCamPos + vRayDir*t;
+            vec3 delta = hitPos - vPlanePos;
+            vec2 bary = vec2(dot(delta, vPlaneRight),dot(delta, vPlaneUp));
+
+            bary /= vec2(1.0, targetSize.y/targetSize.x);
+            bary += vec2(0.5);
+            if ( (tile || (bary.x >= 0.0 && bary.x <= 1.0 && bary.y >=0.0 && bary.y <= 1.0)) && t > 0.0) {
+                color += texture(tex0, bary);
+            }
+        }
+    }
+    o_color = color*0.25;
+}