Implemented kraken::Matrix2

src/matrix2.cpp

@@ -0,0 +1,205 @@
+//
+//  matrix2.cpp
+//  Kraken
+//
+//  Copyright 2018 Kearwood Gilbert. 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 KEARWOOD GILBERT ''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 KEARWOOD GILBERT 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.
+//
+//  The views and conclusions contained in the software and documentation are those of the
+//  authors and should not be interpreted as representing official policies, either expressed
+//  or implied, of Kearwood Gilbert.
+//
+
+#include "../include/kraken-math.h"
+
+#include <string.h>
+
+namespace kraken {
+
+void Matrix2::init() {
+    // Default constructor - Initialize with an identity matrix
+    static const float IDENTITY_MATRIX[] = {
+        1.0, 0.0,
+        0.0, 1.0
+    };
+    memcpy(c, IDENTITY_MATRIX, sizeof(float) * 4);
+    
+}
+
+void Matrix2::init(float *pMat) {
+    memcpy(c, pMat, sizeof(float) * 4);
+}
+
+void Matrix2::init(const Vector2 &new_axis_x, const Vector2 &new_axis_y)
+{
+    c[0]  = new_axis_x.x;    c[1]  = new_axis_x.y;
+    c[2]  = new_axis_y.x;    c[3]  = new_axis_y.y;
+}
+
+void Matrix2::init(const Matrix2 &m) {
+    memcpy(c, m.c, sizeof(float) * 4);
+}
+
+float *Matrix2::getPointer() {
+    return c;
+}
+
+float& Matrix2::operator[](unsigned i) {
+    return c[i];
+}
+
+float Matrix2::operator[](unsigned i) const {
+    return c[i];
+}
+
+// Overload comparison operator
+bool Matrix2::operator==(const Matrix2 &m) const {
+    return memcmp(c, m.c, sizeof(float) * 4) == 0;
+}
+
+// Overload compound multiply operator
+Matrix2& Matrix2::operator*=(const Matrix2 &m) {
+    float temp[4];
+    
+    int x,y;
+    
+    for (x=0; x < 2; x++)
+    {
+        for(y=0; y < 2; y++)
+        {
+            temp[y + (x*2)] = (c[x*2]   * m.c[y]) +
+                              (c[x*2+1] * m.c[y+2]);
+        }
+    }
+    
+    memcpy(c, temp, sizeof(float) * 4);
+    return *this;
+}
+
+// Overload multiply operator
+Matrix2 Matrix2::operator*(const Matrix2 &m) const {
+    Matrix2 ret = *this;
+    ret *= m;
+    return ret;
+}
+
+/* Rotate a matrix by an angle on a X, Y, or Z axis */
+void Matrix2::rotate(float angle) {
+    
+    Matrix2 newMatrix; // Create new identity matrix
+    newMatrix.init();
+    newMatrix.c[0] = cos(angle);
+    newMatrix.c[1] = -sin(angle);
+    newMatrix.c[2] = -newMatrix.c[1];
+    newMatrix.c[3] = newMatrix.c[0];
+    
+    *this *= newMatrix;
+}
+
+/* Scale matrix by separate x, y, and z amounts */
+void Matrix2::scale(float x, float y) {
+    Matrix2 newMatrix; // Create new identity matrix
+    newMatrix.init();
+    
+    newMatrix.c[0] = x;
+    newMatrix.c[3] = y;
+    
+    *this *= newMatrix;
+}
+
+void Matrix2::scale(const Vector2 &v) {
+    scale(v.x, v.y);
+}
+
+/* Scale all dimensions equally */
+void Matrix2::scale(float s) {
+    scale(s,s);
+}
+
+/* Replace matrix with its inverse */
+bool Matrix2::invert() {
+    float det = 1.0f / (c[0] * c[3] + c[1] * c[2]);
+    if (det == 0) {
+        return false;
+    }
+    float invdet = 1.0f / det;
+    c[0] = c[3] * invdet;
+    c[1] = -c[1] * invdet;
+    c[2] = -c[2] * invdet;
+    c[3] = c[0] * invdet;
+    
+    return true;
+}
+
+void Matrix2::transpose() {
+    float tmp = c[1];
+    c[1] = c[2];
+    c[2] = tmp;
+}
+
+/* Dot Product, returning Vector2 */
+Vector2 Matrix2::Dot(const Matrix2 &m, const Vector2 &v) {
+    return Vector2::Create(
+        v.c[0] * m.c[0] + v.c[1] * m.c[2],
+        v.c[0] * m.c[1] + v.c[1] * m.c[3]
+    );
+}
+
+Matrix2 Matrix2::Invert(const Matrix2 &m)
+{
+    Matrix2 matInvert = m;
+    matInvert.invert();
+    return matInvert;
+}
+
+Matrix2 Matrix2::Transpose(const Matrix2 &m)
+{
+    Matrix2 matTranspose = m;
+    matTranspose.transpose();
+    return matTranspose;
+}
+
+Matrix2 Matrix2::Rotation(float angle)
+{
+    Matrix2 m;
+    m.init();
+    m.rotate(angle);
+    return m;
+}
+
+Matrix2 Matrix2::Scaling(const Vector2 &v)
+{
+    Matrix2 m;
+    m.init();
+    m.scale(v);
+    return m;
+}
+
+Matrix2 Matrix2::Identity()
+{
+    Matrix2 m;
+    m.init();
+    return m;
+}
+
+} // namespace kraken
+