# HG changeset patch
# User postspectacular
# Date 1326688496 0
# Node ID 9ba0a16897f18de93e232d249e3934a5cf09bad6
# Parent  6012bfd45a1437fa52e7cd5b01546d9d03fd4a23
adding Box/Plane/MeshIntersector implementations of Intersector3D

diff -r 6012bfd45a1437fa52e7cd5b01546d9d03fd4a23 -r 9ba0a16897f18de93e232d249e3934a5cf09bad6 src.core/toxi/geom/BoxIntersector.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src.core/toxi/geom/BoxIntersector.java	Mon Jan 16 04:34:56 2012 +0000
@@ -0,0 +1,42 @@
+package toxi.geom;
+
+public class BoxIntersector implements Intersector3D {
+
+    private AABB box;
+    private final IsectData3D isec;
+
+    public BoxIntersector(AABB box) {
+        this.box = box;
+        this.isec = new IsectData3D();
+    }
+
+    /**
+     * @return the box
+     */
+    public AABB getBox() {
+        return box;
+    }
+
+    public IsectData3D getIntersectionData() {
+        return isec;
+    }
+
+    public boolean intersectsRay(Ray3D ray) {
+        final Vec3D pos = box.intersectsRay(ray, 0, Float.MAX_VALUE);
+        isec.pos = pos;
+        isec.isIntersection = pos != null;
+        if (isec.isIntersection) {
+            isec.normal = box.getNormalForPoint(pos);
+            isec.dist = ray.distanceTo(pos);
+        }
+        return isec.isIntersection;
+    }
+
+    /**
+     * @param box
+     *            the box to set
+     */
+    public void setBox(AABB box) {
+        this.box = box;
+    }
+}
diff -r 6012bfd45a1437fa52e7cd5b01546d9d03fd4a23 -r 9ba0a16897f18de93e232d249e3934a5cf09bad6 src.core/toxi/geom/PlaneIntersector.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src.core/toxi/geom/PlaneIntersector.java	Mon Jan 16 04:34:56 2012 +0000
@@ -0,0 +1,47 @@
+package toxi.geom;
+
+import toxi.math.MathUtils;
+
+public class PlaneIntersector implements Intersector3D {
+
+    private Plane plane;
+    private final IsectData3D isec;
+
+    public PlaneIntersector(Plane p) {
+        this.plane = p;
+        this.isec = new IsectData3D();
+    }
+
+    public IsectData3D getIntersectionData() {
+        return isec;
+    }
+
+    /**
+     * @return the box
+     */
+    public Plane getPlane() {
+        return plane;
+    }
+
+    public boolean intersectsRay(Ray3D ray) {
+        float d = -plane.normal.dot(plane);
+        float numer = plane.normal.dot(ray) + d;
+        float denom = plane.normal.dot(ray.dir);
+
+        // normal is orthogonal to vector, can't intersect
+        if (isec.isIntersection = (MathUtils.abs(denom) >= MathUtils.EPS)) {
+            isec.dist = -(numer / denom);
+            isec.pos = ray.getPointAtDistance(isec.dist);
+            isec.normal = plane.normal;
+        }
+        return isec.isIntersection;
+    }
+
+    /**
+     * @param box
+     *            the box to set
+     */
+    public void setPlane(Plane p) {
+        this.plane = p;
+    }
+}
diff -r 6012bfd45a1437fa52e7cd5b01546d9d03fd4a23 -r 9ba0a16897f18de93e232d249e3934a5cf09bad6 src.core/toxi/geom/mesh/MeshIntersector.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src.core/toxi/geom/mesh/MeshIntersector.java	Mon Jan 16 04:34:56 2012 +0000
@@ -0,0 +1,77 @@
+package toxi.geom.mesh;
+
+import toxi.geom.AABB;
+import toxi.geom.Intersector3D;
+import toxi.geom.IsectData3D;
+import toxi.geom.Ray3D;
+import toxi.geom.Vec3D;
+
+public class MeshIntersector implements Intersector3D {
+
+    private static final float EPS = 0.00001f;
+
+    private TriangleMesh mesh;
+    private AABB bounds;
+
+    private final IsectData3D isec;
+
+    public MeshIntersector(TriangleMesh mesh) {
+        setMesh(mesh);
+        this.isec = new IsectData3D();
+    }
+
+    public IsectData3D getIntersectionData() {
+        return isec;
+    }
+
+    public boolean intersectsRay(Ray3D ray) {
+        isec.isIntersection = false;
+        if (bounds.intersectsRay(ray, 0, Float.MAX_VALUE) != null) {
+            Vec3D dir = ray.getDirection();
+            float minD = Float.MAX_VALUE;
+            for (Face f : mesh.getFaces()) {
+                float d = intersectTriangle(f.a, f.b, f.c, ray, dir);
+                if (d >= 0.0 && d < minD) {
+                    isec.isIntersection = true;
+                    isec.normal = f.normal;
+                    minD = d;
+                }
+            }
+            if (isec.isIntersection) {
+                isec.pos = ray.getPointAtDistance(minD);
+                isec.dist = minD;
+                isec.dir = dir.getInverted();
+            }
+        }
+        return isec.isIntersection;
+    }
+
+    private float intersectTriangle(Vec3D a, Vec3D b, Vec3D c, Vec3D ro,
+            Vec3D dir) {
+        Vec3D e1 = b.sub(a);
+        Vec3D e2 = c.sub(a);
+        Vec3D pvec = dir.cross(e2);
+        float det = e1.dot(pvec);
+        if (det > -EPS && det < EPS) {
+            return -1;
+        }
+        float invDet = 1f / det;
+        Vec3D tvec = ro.sub(a);
+        float u = tvec.dot(pvec) * invDet;
+        if (u < 0.0 || u > 1.0) {
+            return -1;
+        }
+        Vec3D qvec = tvec.cross(e1);
+        float v = dir.dot(qvec) * invDet;
+        if (v < 0.0 || u + v > 1.0) {
+            return -1;
+        }
+        float t = e2.dot(qvec) * invDet;
+        return t;
+    }
+
+    public void setMesh(TriangleMesh mesh) {
+        this.mesh = mesh;
+        this.bounds = mesh.getBoundingBox();
+    }
+}