1 files changed, 72 insertions, 0 deletions
diff --git a/src/ru/olamedia/math/FrustumUtil.java b/src/ru/olamedia/math/FrustumUtil.java
new file mode 100644
index 0000000..80b01fb
--- /dev/null
+++ b/src/ru/olamedia/math/FrustumUtil.java
@@ -0,0 +1,72 @@
+package ru.olamedia.math;
+
+public class FrustumUtil {
+	public static Plane[] extractPlanes(javax.vecmath.Matrix4f m, boolean normalize) {
+
+		Plane[] planes = new Plane[6];
+		for (int j = 0; j < 6; j++) {
+			planes[j] = new Plane();
+		}
+		// Left: [30+00, 31+01, 32+02, 33+03]
+
+		planes[0].n.x = m.m30 + m.m00;
+		planes[0].n.y = m.m31 + m.m01;
+		planes[0].n.z = m.m32 + m.m02;
+		planes[0].d = m.m33 + m.m03;
+
+		// Right: [30-00, 31-01, 32-02, 33-03]
+
+		planes[1].n.x = m.m30 - m.m00;
+		planes[1].n.y = m.m31 - m.m01;
+		planes[1].n.z = m.m32 - m.m02;
+		planes[1].d = m.m33 - m.m03;
+
+		// Bottom: [30+10, 31+11, 32+12, 33+13]
+
+		planes[2].n.x = m.m30 + m.m10;
+		planes[2].n.y = m.m31 + m.m11;
+		planes[2].n.z = m.m32 + m.m12;
+		planes[2].d = m.m33 + m.m13;
+
+		// Top: [30-10, 31-11, 32-12, 33-13]
+
+		planes[3].n.x = m.m30 - m.m10;
+		planes[3].n.y = m.m31 - m.m11;
+		planes[3].n.z = m.m32 - m.m12;
+		planes[3].d = m.m33 - m.m13;
+
+		// Near: [30+20, 31+21, 32+22, 33+23]
+
+		planes[4].n.x = m.m30 + m.m20;
+		planes[4].n.y = m.m31 + m.m21;
+		planes[4].n.z = m.m32 + m.m22;
+		planes[4].d = m.m33 + m.m23;
+
+		// Far: [30-20, 31-21, 32-22, 33-23]
+
+		planes[5].n.x = m.m30 - m.m20;
+		planes[5].n.y = m.m31 - m.m21;
+		planes[5].n.z = m.m32 - m.m22;
+		planes[5].d = m.m33 - m.m23;
+
+		// Normalize
+		if (normalize) {
+			for (int i = 0; i < 6; ++i) {
+				planes[i].normalize();
+			}
+		}
+		return planes;
+	}
+
+	public static Frustum extractFrustum(javax.vecmath.Matrix4f m) {
+		Frustum f = new Frustum();
+		Plane[] planes = extractPlanes(m, true);
+		f.leftPlane.set(planes[0]);
+		f.rightPlane.set(planes[1]);
+		f.bottomPlane.set(planes[2]);
+		f.topPlane.set(planes[3]);
+		f.nearPlane.set(planes[4]);
+		f.farPlane.set(planes[5]);
+		return f;
+	}
+}