1 files changed, 179 insertions, 0 deletions
diff --git a/src/classes/com/sun/opengl/impl/nurbs/Knotvector.java b/src/classes/com/sun/opengl/impl/nurbs/Knotvector.java
new file mode 100755
index 000000000..1442fe17d
--- /dev/null
+++ b/src/classes/com/sun/opengl/impl/nurbs/Knotvector.java
@@ -0,0 +1,179 @@
+package com.sun.opengl.impl.nurbs;
+
+/*
+ ** License Applicability. Except to the extent portions of this file are
+ ** made subject to an alternative license as permitted in the SGI Free
+ ** Software License B, Version 1.1 (the "License"), the contents of this
+ ** file are subject only to the provisions of the License. You may not use
+ ** this file except in compliance with the License. You may obtain a copy
+ ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
+ ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
+ **
+ ** http://oss.sgi.com/projects/FreeB
+ **
+ ** Note that, as provided in the License, the Software is distributed on an
+ ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
+ ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
+ ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
+ ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
+ **
+ ** Original Code. The Original Code is: OpenGL Sample Implementation,
+ ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
+ ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
+ ** Copyright in any portions created by third parties is as indicated
+ ** elsewhere herein. All Rights Reserved.
+ **
+ ** Additional Notice Provisions: The application programming interfaces
+ ** established by SGI in conjunction with the Original Code are The
+ ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
+ ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
+ ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
+ ** Window System(R) (Version 1.3), released October 19, 1998. This software
+ ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
+ ** published by SGI, but has not been independently verified as being
+ ** compliant with the OpenGL(R) version 1.2.1 Specification.
+ */
+
+/**
+ * Knot vector used in curve specification
+ * 
+ * @author Tomas Hrasky
+ * 
+ */
+class Knotvector {
+
+  /**
+   * Tolerance used when comparing knots - when difference is smaller, knots
+   * are considered equal
+   */
+  public static final float TOLERANCE = 1.0e-5f;
+
+  /**
+   * Maximum curve order
+   */
+  private static final int MAXORDER = 24;
+
+  /**
+   * Number of knots
+   */
+  int knotcount;
+
+  /**
+   * Number of control points' coordinates
+   */
+  int stride;
+
+  /**
+   * Curve order
+   */
+  int order;
+
+  /**
+   * Knots
+   */
+  float[] knotlist;
+
+  /**
+   * Makes new knotvector
+   * 
+   * @param nknots
+   *            number of knots
+   * @param stride
+   *            number of ctrl points' corrdinates
+   * @param order
+   *            curve order
+   * @param knot
+   *            knots
+   */
+  public Knotvector(int nknots, int stride, int order, float[] knot) {
+    // DONE
+    init(nknots, stride, order, knot);
+  }
+
+  /**
+   * Initializes knotvector
+   * 
+   * @param nknots
+   *            number of knots
+   * @param stride
+   *            number of ctrl points' corrdinates
+   * @param order
+   *            curve order
+   * @param knot
+   *            knots
+   */
+  public void init(int nknots, int stride, int order, float[] knot) {
+    // DONE
+    this.knotcount = nknots;
+    this.stride = stride;
+    this.order = order;
+    this.knotlist = new float[nknots];
+    for (int i = 0; i < nknots; i++) {
+      this.knotlist[i] = knot[i];
+    }
+
+  }
+
+  /**
+   * Validates knot vector parameters
+   * 
+   * @return knot vector validity
+   */
+  public int validate() {
+    int kindex = knotcount - 1;
+    if (order < 1 || order > MAXORDER) {
+      return 1;
+    }
+    if (knotcount < 2 * order) {
+      return 2;
+    }
+    if (identical(knotlist[kindex - (order - 1)], knotlist[order - 1])) {
+      return 3;
+    }
+    for (int i = 0; i < kindex; i++) {
+      if (knotlist[i] > knotlist[i + 1])
+        return 4;
+    }
+    int multi = 1;
+    for (; kindex >= 1; kindex--) {
+      if (knotlist[kindex] - knotlist[kindex - 1] < TOLERANCE) {
+        multi++;
+        continue;
+      }
+      if (multi > order) {
+        return 5;
+      }
+      multi = 1;
+    }
+    if (multi > order) {
+      return 5;
+    }
+
+    return 0;
+  }
+
+  /**
+   * Show specified message
+   * 
+   * @param msg
+   *            message to be shown
+   */
+  public void show(String msg) {
+    // TODO Auto-generated method stub
+    //			System.out.println("TODO knotvector.show");
+
+  }
+
+  /**
+   * Compares two knots for equality
+   * 
+   * @param a
+   *            first knot
+   * @param b
+   *            second knot
+   * @return knots are/are not equal
+   */
+  public static boolean identical(float a, float b) {
+    return ((a - b) < TOLERANCE) ? true : false;
+  }
+}