first commit

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 225 insertions, 0 deletions

diff --git a/src/v/VMaths.java b/src/v/VMaths.java
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+/**
+ * Copyright (c) 2013, Mattias Andrée
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met: 
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer. 
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution. 
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package v;
+
+/**
+ * Orthonormalised vector maths
+ */
+public class VMaths
+{
+
+    public static float[] createRotation(String side)
+    {
+	switch (side.toLowerCase())
+	{
+	    case "x":
+	    case "xz":
+	    case "zx":
+		return new float[] {  0f, -1f,  0f };
+	    
+	    case "y":
+	    case "yz":
+	    case "zy":
+		return new float[] { -1f,  0f,  0f };
+	    
+	    case "xy":
+	    case "yx":
+		return new float[] {  0f,  0f, +1f };
+	}
+	
+	return null;
+    }
+    
+    public static float[][] createRotation(String side, float thetaDegrees)
+    {
+	switch (side.toLowerCase())
+	{
+	    case "x":
+	    case "xz":
+	    case "zx":
+		return createRotation( 0f, -1f,  0f, thetaDegrees);
+	    
+	    case "y":
+	    case "yz":
+	    case "zy":
+		return createRotation(-1f,  0f,  0f, thetaDegrees);
+	    
+	    case "xy":
+	    case "yx":
+		return createRotation( 0f,  0f, +1f, thetaDegrees);
+	}
+	
+	return null;
+    }
+    
+    public static float[][] createRotation(float x, float y, float z, float thetaDegrees)
+    {
+	float theta = thetaDegrees * (float)(Math.PI) / 180f;
+	float[][] m = new float[3][3];
+	
+	float cos = (float)(Math.cos(theta));
+	float sin = (float)(Math.sin(theta));
+	float _cos = 1f - cos;
+	
+	m[0][0] = x * x * _cos + cos;
+	m[1][0] = x * y * _cos + z * sin;
+	m[2][0] = x * z * _cos - y * sin;
+	
+	m[0][1] = y * x * _cos - z * sin;
+	m[1][1] = y * y * _cos + cos;
+	m[2][1] = y * z * _cos + x * sin;
+	
+	m[0][2] = z * x * _cos + y * sin;
+	m[1][2] = z * y * _cos - x * sin;
+	m[2][2] = z * z * _cos + cos;
+	
+	return m;
+    }
+    
+    public static float[][] createRotation(float[] v, float thetaDegrees)
+    {
+	return createRotation(v[0], v[1], v[2], thetaDegrees);
+    }
+    
+    public static float[] mul(float[][] m, float[] v)
+    {
+	int n, k = v.length;
+	float[] rc = new float[n = m.length];
+	
+	for (int r = 0; r < n; r++)
+	    for (int i = 0; i < k; i++)
+		rc[r] += m[r][i] * v[i];
+	
+	return rc;
+    }
+    
+    public static float[] mul(float[][] m, float x, float y, float z)
+    {
+	int n;
+	float[] rc = new float[n = m.length];
+	
+	for (int i = 0; i < n; i++)
+	    rc[i] = m[i][0] * x
+		  + m[i][1] * y
+		  + m[i][2] * z;
+	
+	return rc;
+    }
+    
+    public static float[][] mul(float[][] a, float[][] b)
+    {
+	int n, m, k = b.length;
+	float[][] rc = new float[n = a.length][m = b[0].length];
+	
+	for (int r = 0; r < n; r++)
+	    for (int c = 0; c < m; c++)
+		for (int i = 0; i < k; i++)
+		    rc[r][c] += a[i][r] * b[c][i];
+	
+	return rc;
+    }
+    
+    public static float[][] mul(float a, float[][] b)
+    {
+	int n, m;
+	float[][] rc = new float[n = b.length][m = b[0].length];
+	
+	for (int r = 0; r < n; r++)
+	    for (int c = 0; c < m; c++)
+		rc[r][c] = a * b[r][c];
+	
+	return rc;
+    }
+    
+    public static float[] mul(float a, float[] b)
+    {
+	int n;
+	float[] rc = new float[n = b.length];
+	
+	for (int r = 0; r < n; r++)
+	    rc[r] = a * b[r];
+	
+	return rc;
+    }
+    
+    public static float[][] add(float[][] a, float[][] b)
+    {
+	int n, m;
+	float[][] rc = new float[n = a.length][m = b[0].length];
+	
+	for (int r = 0; r < n; r++)
+	    for (int c = 0; c < m; c++)
+		rc[r][c] = a[r][c] + b[r][c];
+	
+	return rc;
+    }
+    
+    public static float[] add(float[] a, float[] b)
+    {
+	int n;
+	float[] rc = new float[n = a.length];
+	
+	for (int r = 0; r < n; r++)
+	    rc[r] = a[r] + b[r];
+	
+	return rc;
+    }
+    
+    public static float length(float[] v)
+    {
+	int n = v.length;
+	float length = 0;
+	
+	for (int r = 0; r < n; r++)
+	    length += v[r] * v[r];
+	
+	length = (float)Math.sqrt(length);
+	
+	return length;
+    }
+    
+    public static float[] normalise(float[] v)
+    {
+	int n;
+	float[] rc = new float[n = v.length];
+	float length = length(v);
+	
+	if (length * length == 0f)
+	{
+	    for (int r = 0; r < n; r++)
+		rc[r] = 0;
+	    rc[0] = 1;
+	}
+	else
+	    for (int r = 0; r < n; r++)
+		rc[r] = v[r] / length;
+	
+	return rc;
+    }
+    
+    
+    
+}
+