Converted ShatteredPD to Build from Gradle

Major Changes:
- Shattered now builds effortlessly either from gradle CLI or android studio
- Much better dependency management through gradle (although it's not really used atm)
- Separate PD-classes repo is now SPD-classes module within main repo

SPD-classes/src/main/java/com/watabou/glwrap/Matrix.java

@@ -0,0 +1,103 @@
+/*
+ * Pixel Dungeon
+ * Copyright (C) 2012-2015  Oleg Dolya
+ *
+ * Shattered Pixel Dungeon
+ * Copyright (C) 2014-2016 Evan Debenham
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package com.watabou.glwrap;
+
+public class Matrix {
+
+	public static final float G2RAD = 0.01745329251994329576923690768489f;
+	
+	public static float[] clone( float[] m ) {
+		
+		int n = m.length;
+		float[] res = new float[n];
+		do {
+			res[--n] = m[n];
+		} while (n > 0);
+		
+		return res;
+	}
+	
+	public static void copy( float[] src, float[] dst ) {
+		
+		int n = src.length;
+		do {
+			dst[--n] = src[n];
+		} while (n > 0);
+
+	}
+	
+	public static void setIdentity( float[] m ) {
+		for (int i=0 ; i < 16 ; i++) {
+			m[i] = 0f;
+		}
+		for (int i = 0; i < 16; i += 5) {
+			m[i] = 1f;
+		}
+	}
+
+	public static void rotate( float[] m, float a ) {
+		a *= G2RAD;
+		float sin = (float)Math.sin( a );
+		float cos = (float)Math.cos( a );
+		float m0 = m[0];
+		float m1 = m[1];
+		float m4 = m[4];
+		float m5 = m[5];
+		m[0] = m0 * cos + m4 * sin;
+		m[1] = m1 * cos + m5 * sin;
+		m[4] = -m0 * sin + m4 * cos;
+		m[5] = -m1 * sin + m5 * cos;
+	}
+	
+	public static void skewX( float[] m, float a ) {
+		double t = Math.tan( a * G2RAD );
+		m[4] += -m[0] * t;
+		m[5] += -m[1] * t;
+	}
+	
+	public static void skewY( float[] m, float a ) {
+		double t = Math.tan( a * G2RAD );
+		m[0] += m[4] * t;
+		m[1] += m[5] * t;
+	}
+	
+	public static void scale( float[] m, float x, float y ) {
+		m[0] *= x;
+		m[1] *= x;
+		m[2] *= x;
+		m[3] *= x;
+		m[4] *= y;
+		m[5] *= y;
+		m[6] *= y;
+		m[7] *= y;
+	//	android.opengl.Matrix.scaleM( m, 0, x, y, 1 );
+	}
+	
+	public static void translate( float[] m, float x, float y ) {
+		m[12] += m[0] * x + m[4] * y;
+		m[13] += m[1] * x + m[5] * y;
+	}
+	
+	public static void multiply( float[] left, float right[], float[] result ) {
+		android.opengl.Matrix.multiplyMM( result, 0, left, 0, right, 0 );
+	}
+}