From 997a8f12d15cd20c41adc4fe497163ebaf4f1441 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop+git@gmail.com>
Date: Sun, 18 Jan 2009 16:51:51 +0000
Subject: [PATCH] updated Matrix, Transform, main Makefile

git-svn-id: svn://anubis/fart/trunk@7 7f9b0f55-74a9-4bce-be96-3c2cd072584d
---
 Makefile          |  1 +
 util/Matrix.cc    | 44 ++++++++++++++++++++++++++++++++++++++++++++
 util/Matrix.h     | 23 +++++++++++++++++++++++
 util/Transform.cc | 12 ++++++++++++
 util/Transform.h  | 19 +++++++++++++++++++
 5 files changed, 99 insertions(+)
 create mode 100644 util/Matrix.cc
 create mode 100644 util/Matrix.h
 create mode 100644 util/Transform.cc
 create mode 100644 util/Transform.h

diff --git a/Makefile b/Makefile
index 472f9a8..2bde60d 100644
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,7 @@ endif
 
 all: $(TARGET)
 
+.PHONY: $(TARGET)
 $(TARGET):
 	make -C util
 	make -C shapes
diff --git a/util/Matrix.cc b/util/Matrix.cc
new file mode 100644
index 0000000..e20aa62
--- /dev/null
+++ b/util/Matrix.cc
@@ -0,0 +1,44 @@
+
+#include "Matrix.h"
+
+Matrix Matrix::identity()
+{
+    Matrix res;
+    for (int i = 0; i < 4; i++)
+    {
+        for (int j = 0; j < 4; j++)
+        {
+            res[i][j] = i == j ? 1.0 : 0.0;
+        }
+    }
+    return res;
+}
+
+Matrix operator*(const Matrix & m1, const Matrix & m2)
+{
+    Matrix res;
+    for (int i = 0; i < 4; i++)
+    {
+        for (int j = 0; j < 4; j++)
+        {
+            res[i][j] = m1[i][0] * m2[0][j]
+                      + m1[i][1] * m2[1][j]
+                      + m1[i][2] * m2[2][j]
+                      + m1[i][3] * m2[3][j];
+        }
+    }
+    return res;
+}
+
+Vector operator*(const Matrix & m, const Vector & v)
+{
+    Vector res;
+    for (int i = 0; i < 4; i++)
+    {
+        res[i] = m[i][0] * v[0]
+               + m[i][1] * v[1]
+               + m[i][2] * v[2]
+               + m[i][3]; /* v[3] is implicitly 1.0 */
+    }
+    return res;
+}
diff --git a/util/Matrix.h b/util/Matrix.h
new file mode 100644
index 0000000..275c0b5
--- /dev/null
+++ b/util/Matrix.h
@@ -0,0 +1,23 @@
+
+#ifndef MATRIX_H
+#define MATRIX_H MATRIX_H
+
+#include "Vector.h"
+
+class Matrix
+{
+    public:
+        typedef double Matrix_row_t[4];
+        Matrix_row_t & operator[](int idx) { return m_matrix[idx]; }
+        const Matrix_row_t & operator[](int idx) const { return m_matrix[idx]; }
+        static Matrix identity();
+
+    protected:
+        double m_matrix[4][4];
+};
+
+Matrix operator*(const Matrix & m1, const Matrix & m2);
+Vector operator*(const Matrix & m, const Vector & v);
+
+#endif
+
diff --git a/util/Transform.cc b/util/Transform.cc
new file mode 100644
index 0000000..276d6cb
--- /dev/null
+++ b/util/Transform.cc
@@ -0,0 +1,12 @@
+
+#include "Transform.h"
+
+void Transform::push()
+{
+    m_matrices.push(m_matrices.top());
+}
+
+void Transform::pop()
+{
+    m_matrices.pop();
+}
diff --git a/util/Transform.h b/util/Transform.h
new file mode 100644
index 0000000..5f65879
--- /dev/null
+++ b/util/Transform.h
@@ -0,0 +1,19 @@
+
+#ifndef TRANSFORM_H
+#define TRANSFORM_H TRANSFORM_H
+
+#include "Matrix.h"
+#include <stack>
+
+class Transform
+{
+    public:
+        void push();
+        void pop();
+
+    protected:
+        std::stack<Matrix>  m_matrices;
+};
+
+#endif
+