Copied JOGL_2_SANDBOX r350 on to trunk; JOGL_2_SANDBOX branch is now closed

git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/../svn-server-sync/jogl-demos/trunk@352 3298f667-5e0e-4b4a-8ed4-a3559d26a5f4

1 files changed, 169 insertions, 0 deletions

diff --git a/src/gleem/linalg/Mat2f.java b/src/gleem/linalg/Mat2f.java
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+++ b/src/gleem/linalg/Mat2f.java
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+/*
+ * gleem -- OpenGL Extremely Easy-To-Use Manipulators.
+ * Copyright (C) 1998-2003 Kenneth B. Russell ([email protected])
+ *
+ * Copying, distribution and use of this software in source and binary
+ * forms, with or without modification, is permitted provided that the
+ * following conditions are met:
+ *
+ * Distributions of source code must reproduce the copyright notice,
+ * this list of conditions and the following disclaimer in the source
+ * code header files; and Distributions of binary code must reproduce
+ * the copyright notice, this list of conditions and the following
+ * disclaimer in the documentation, Read me file, license file and/or
+ * other materials provided with the software distribution.
+ *
+ * The names of Sun Microsystems, Inc. ("Sun") and/or the copyright
+ * holder may not be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS," WITHOUT A WARRANTY OF ANY
+ * KIND. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
+ * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, NON-INTERFERENCE, ACCURACY OF
+ * INFORMATIONAL CONTENT OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. THE
+ * COPYRIGHT HOLDER, SUN AND SUN'S LICENSORS SHALL NOT BE LIABLE FOR
+ * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
+ * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL THE
+ * COPYRIGHT HOLDER, SUN OR SUN'S LICENSORS BE LIABLE FOR ANY LOST
+ * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
+ * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
+ * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
+ * INABILITY TO USE THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGES. YOU ACKNOWLEDGE THAT THIS SOFTWARE IS NOT
+ * DESIGNED, LICENSED OR INTENDED FOR USE IN THE DESIGN, CONSTRUCTION,
+ * OPERATION OR MAINTENANCE OF ANY NUCLEAR FACILITY. THE COPYRIGHT
+ * HOLDER, SUN AND SUN'S LICENSORS DISCLAIM ANY EXPRESS OR IMPLIED
+ * WARRANTY OF FITNESS FOR SUCH USES.
+ */
+
+package gleem.linalg;
+
+/** 2x2 matrix class useful for simple linear algebra. Representation
+    is (as Mat4f) in row major order and assumes multiplication by
+    column vectors on the right. */
+
+public class Mat2f {
+  private float[] data;
+
+  /** Creates new matrix initialized to the zero matrix */
+  public Mat2f() {
+    data = new float[4];
+  }
+
+  /** Initialize to the identity matrix. */
+  public void makeIdent() {
+    for (int i = 0; i < 2; i++) {
+      for (int j = 0; j < 2; j++) {
+        if (i == j) {
+          set(i, j, 1.0f);
+        } else {
+          set(i, j, 0.0f);
+        }
+      }
+    }
+  }
+  
+  /** Gets the (i,j)th element of this matrix, where i is the row
+      index and j is the column index */
+  public float get(int i, int j) {
+    return data[2 * i + j];
+  }
+
+  /** Sets the (i,j)th element of this matrix, where i is the row
+      index and j is the column index */
+  public void set(int i, int j, float val) {
+    data[2 * i + j] = val;
+  }
+
+  /** Set column i (i=[0..1]) to vector v. */
+  public void setCol(int i, Vec2f v) {
+    set(0, i, v.x());
+    set(1, i, v.y());
+  }
+
+  /** Set row i (i=[0..1]) to vector v. */
+  public void setRow(int i, Vec2f v) {
+    set(i, 0, v.x());
+    set(i, 1, v.y());
+  }
+
+  /** Transpose this matrix in place. */
+  public void transpose() {
+    float t = get(0, 1);
+    set(0, 1, get(1, 0));
+    set(1, 0, t);
+  }
+
+  /** Return the determinant. */
+  public float determinant() {
+    return (get(0, 0) * get(1, 1) - get(1, 0) * get(0, 1));
+  }  
+
+  /** Full matrix inversion in place. If matrix is singular, returns
+      false and matrix contents are untouched. If you know the matrix
+      is orthonormal, you can call transpose() instead. */
+  public boolean invert() {
+    float det = determinant();
+    if (det == 0.0f)
+      return false;
+
+    // Create transpose of cofactor matrix in place
+    float t = get(0, 0);
+    set(0, 0, get(1, 1));
+    set(1, 1, t);
+    set(0, 1, -get(0, 1));
+    set(1, 0, -get(1, 0));
+  
+    // Now divide by determinant
+    for (int i = 0; i < 4; i++) {
+      data[i] /= det;
+    }
+    return true;
+  }
+
+  /** Multiply a 2D vector by this matrix. NOTE: src and dest must be
+      different vectors. */
+  public void xformVec(Vec2f src, Vec2f dest) {
+    dest.set(get(0, 0) * src.x() +
+             get(0, 1) * src.y(),
+
+             get(1, 0) * src.x() +
+             get(1, 1) * src.y());
+  }
+
+  /** Returns this * b; creates new matrix */
+  public Mat2f mul(Mat2f b) {
+    Mat2f tmp = new Mat2f();
+    tmp.mul(this, b);
+    return tmp;
+  }
+
+  /** this = a * b */
+  public void mul(Mat2f a, Mat2f b) {
+    for (int rc = 0; rc < 2; rc++)
+      for (int cc = 0; cc < 2; cc++) {
+        float tmp = 0.0f;
+        for (int i = 0; i < 2; i++)
+          tmp += a.get(rc, i) * b.get(i, cc);
+        set(rc, cc, tmp);
+      }
+  }
+
+  public Matf toMatf() {
+    Matf out = new Matf(2, 2);
+    for (int i = 0; i < 2; i++) {
+      for (int j = 0; j < 2; j++) {
+        out.set(i, j, get(i, j));
+      }
+    }
+    return out;
+  }
+
+  public String toString() {
+    String endl = System.getProperty("line.separator");
+    return "(" +
+      get(0, 0) + ", " + get(0, 1) + endl +
+      get(1, 0) + ", " + get(1, 1) + ")";
+  }
+}