From daeb5a85b6ded478aaac942c439ef5fd6bb8874f Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Mon, 24 Dec 2018 16:28:08 -0500
Subject: Transformation matrix

---
 libqpdf/QPDFMatrix.cc | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 libqpdf/QPDFMatrix.cc

(limited to 'libqpdf/QPDFMatrix.cc')

diff --git a/libqpdf/QPDFMatrix.cc b/libqpdf/QPDFMatrix.cc
new file mode 100644
index 00000000..28a338f0
--- /dev/null
+++ b/libqpdf/QPDFMatrix.cc
@@ -0,0 +1,90 @@
+#include <qpdf/QPDFMatrix.hh>
+#include <qpdf/QUtil.hh>
+
+QPDFMatrix::QPDFMatrix() :
+    a(1.0),
+    b(0.0),
+    c(0.0),
+    d(1.0),
+    e(0.0),
+    f(0.0)
+{
+}
+
+QPDFMatrix::QPDFMatrix(double a, double b, double c,
+                       double d, double e, double f) :
+    a(a),
+    b(b),
+    c(c),
+    d(d),
+    e(e),
+    f(f)
+{
+}
+
+std::string
+QPDFMatrix::unparse() const
+{
+    return (QUtil::double_to_string(a, 5) + " " +
+            QUtil::double_to_string(b, 5) + " " +
+            QUtil::double_to_string(c, 5) + " " +
+            QUtil::double_to_string(d, 5) + " " +
+            QUtil::double_to_string(e, 5) + " " +
+            QUtil::double_to_string(f, 5));
+}
+
+void
+QPDFMatrix::concat(QPDFMatrix const& other)
+{
+    double ap = (this->a * other.a) + (this->c * other.b);
+    double bp = (this->b * other.a) + (this->d * other.b);
+    double cp = (this->a * other.c) + (this->c * other.d);
+    double dp = (this->b * other.c) + (this->d * other.d);
+    double ep = (this->a * other.e) + (this->c * other.f) + this->e;
+    double fp = (this->b * other.e) + (this->d * other.f) + this->f;
+    this-> a = ap;
+    this-> b = bp;
+    this-> c = cp;
+    this-> d = dp;
+    this-> e = ep;
+    this-> f = fp;
+}
+
+void
+QPDFMatrix::scale(double sx, double sy)
+{
+    concat(QPDFMatrix(sx, 0, 0, sy, 0, 0));
+}
+
+void
+QPDFMatrix::translate(double tx, double ty)
+{
+    concat(QPDFMatrix(1, 0, 0, 1, tx, ty));
+}
+
+void
+QPDFMatrix::rotatex90(int angle)
+{
+    switch (angle)
+    {
+      case 90:
+        concat(QPDFMatrix(0, 1, -1, 0, 0, 0));
+        break;
+      case 180:
+        concat(QPDFMatrix(-1, 0, 0, -1, 0, 0));
+        break;
+      case 270:
+        concat(QPDFMatrix(0, -1, 1, 0, 0, 0));
+        break;
+      default:
+        // ignore
+        break;
+    }
+}
+
+void
+QPDFMatrix::transform(double x, double y, double& xp, double& yp)
+{
+    xp = (this->a * x) + (this->c * y) + this->e;
+    yp = (this->b * x) + (this->d * y) + this->f;
+}
-- 
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