[Java-game-lib-cvs] CVS: LWJGL/src/java/org/lwjgl/vector Matrix4f.java,1.4,1.5 Matrix3f.java,1.4,1.5

[Caspian Rychlik-P. <ci...@us...>]

Update of /cvsroot/java-game-lib/LWJGL/src/java/org/lwjgl/vector
In directory usw-pr-cvs1:/tmp/cvs-serv14858/src/java/org/lwjgl/vector

Modified Files:
	Matrix4f.java Matrix3f.java 
Log Message:
Determinants

Index: Matrix4f.java
CVS Browser:
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/java-game-lib/LWJGL/src/java/org/lwjgl/vector/Matrix4f.java
===================================================================
RCS file: /cvsroot/java-game-lib/LWJGL/src/java/org/lwjgl/vector/Matrix4f.java,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -d -r1.4 -r1.5
--- Matrix4f.java	24 Aug 2002 21:26:47 -0000	1.4
+++ Matrix4f.java	24 Aug 2002 21:35:20 -0000	1.5
@@ -395,8 +395,36 @@
 			m33 = dest.m33;
 		} else
 			transpose();
-		
+
 		return dest;
+	}
+
+	/**
+	 * @return the determinant of the matrix
+	 */
+	public float determinant() {
+		float f =
+			m00
+				* ((m11 * m22 * m33 + m12 * m23 * m31 + m13 * m21 * m32)
+					- m13 * m22 * m31
+					- m11 * m23 * m32
+					- m12 * m21 * m33);
+		f -= m01
+			* ((m10 * m22 * m33 + m12 * m23 * m30 + m13 * m20 * m32)
+				- m13 * m22 * m30
+				- m10 * m23 * m32
+				- m12 * m20 * m33);
+		f += m02
+			* ((m10 * m21 * m33 + m11 * m23 * m30 + m13 * m20 * m31)
+				- m13 * m21 * m30
+				- m10 * m23 * m31
+				- m11 * m20 * m33);
+		f -= m03
+			* ((m10 * m21 * m32 + m11 * m22 * m30 + m12 * m20 * m31)
+				- m12 * m21 * m30
+				- m10 * m22 * m31
+				- m11 * m20 * m32);
+		return f;
 	}
 		
 

Index: Matrix3f.java
CVS Browser:
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/java-game-lib/LWJGL/src/java/org/lwjgl/vector/Matrix3f.java
===================================================================
RCS file: /cvsroot/java-game-lib/LWJGL/src/java/org/lwjgl/vector/Matrix3f.java,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -d -r1.4 -r1.5
--- Matrix3f.java	24 Aug 2002 21:26:47 -0000	1.4
+++ Matrix3f.java	24 Aug 2002 21:35:20 -0000	1.5
@@ -288,10 +288,10 @@
 	 * @return the transposed matrix
 	 */
 	public Matrix3f transpose(Matrix3f dest) {
-		
+
 		if (dest == null)
 			dest = new Matrix3f();
-		
+
 		if (this != dest) {
 			m00 = dest.m00;
 			m01 = dest.m10;
@@ -304,9 +304,20 @@
 			m22 = dest.m22;
 		} else
 			transpose();
-		
+
 		return this;
-		
+
+	}
+
+	/**
+	 * @return the determinant of the matrix
+	 */
+	public float determinant() {
+		float f =
+			m00 * (m11 * m22 - m12 * m21)
+				+ m01 * (m12 * m20 - m10 * m22)
+				+ m02 * (m10 * m21 - m11 * m20);
+		return f;
 	}
 
 	/**