From 68ccd87c9e950572e859eb5147453be2a528b944 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Sat, 26 Jan 2019 16:48:41 -0500
Subject: Move rectangle transformation into QPDFMatrix

---
 libqpdf/QPDFAnnotationObjectHelper.cc | 21 ++++------------
 libqpdf/QPDFMatrix.cc                 | 46 ++++++++++++++++++++++++++++++-----
 libqpdf/qpdf/QPDFMatrix.hh            |  7 ++++++
 3 files changed, 52 insertions(+), 22 deletions(-)

(limited to 'libqpdf')

diff --git a/libqpdf/QPDFAnnotationObjectHelper.cc b/libqpdf/QPDFAnnotationObjectHelper.cc
index 5e4be795..698f80e1 100644
--- a/libqpdf/QPDFAnnotationObjectHelper.cc
+++ b/libqpdf/QPDFAnnotationObjectHelper.cc
@@ -4,7 +4,6 @@
 #include <qpdf/QUtil.hh>
 #include <qpdf/QPDF.hh>
 #include <qpdf/QPDFNameTreeObjectHelper.hh>
-#include <algorithm>
 
 QPDFAnnotationObjectHelper::Members::~Members()
 {
@@ -258,18 +257,8 @@ QPDFAnnotationObjectHelper::getPageContentForAppearance(
 
     // Transform bounding box by matrix to get T
     QPDFObjectHandle::Rectangle bbox = bbox_obj.getArrayAsRectangle();
-    std::vector<double> bx(4);
-    std::vector<double> by(4);
-    matrix.transform(bbox.llx, bbox.lly, bx.at(0), by.at(0));
-    matrix.transform(bbox.llx, bbox.ury, bx.at(1), by.at(1));
-    matrix.transform(bbox.urx, bbox.lly, bx.at(2), by.at(2));
-    matrix.transform(bbox.urx, bbox.ury, bx.at(3), by.at(3));
-    // Find the transformed appearance box
-    double t_llx = *std::min_element(bx.begin(), bx.end());
-    double t_urx = *std::max_element(bx.begin(), bx.end());
-    double t_lly = *std::min_element(by.begin(), by.end());
-    double t_ury = *std::max_element(by.begin(), by.end());
-    if ((t_urx == t_llx) || (t_ury == t_lly))
+    QPDFObjectHandle::Rectangle T = matrix.transformRectangle(bbox);
+    if ((T.urx == T.llx) || (T.ury == T.lly))
     {
         // avoid division by zero
         return "";
@@ -277,9 +266,9 @@ QPDFAnnotationObjectHelper::getPageContentForAppearance(
     // Compute a matrix to transform the appearance box to the rectangle
     QPDFMatrix AA;
     AA.translate(rect.llx, rect.lly);
-    AA.scale((rect.urx - rect.llx) / (t_urx - t_llx),
-             (rect.ury - rect.lly) / (t_ury - t_lly));
-    AA.translate(-t_llx, -t_lly);
+    AA.scale((rect.urx - rect.llx) / (T.urx - T.llx),
+             (rect.ury - rect.lly) / (T.ury - T.lly));
+    AA.translate(-T.llx, -T.lly);
     if (do_rotate)
     {
         AA.rotatex90(rotate);
diff --git a/libqpdf/QPDFMatrix.cc b/libqpdf/QPDFMatrix.cc
index 3d410435..c78154aa 100644
--- a/libqpdf/QPDFMatrix.cc
+++ b/libqpdf/QPDFMatrix.cc
@@ -1,5 +1,6 @@
 #include <qpdf/QPDFMatrix.hh>
 #include <qpdf/QUtil.hh>
+#include <algorithm>
 
 QPDFMatrix::QPDFMatrix() :
     a(1.0),
@@ -32,16 +33,30 @@ QPDFMatrix::QPDFMatrix(QPDFObjectHandle::Matrix const& m) :
 {
 }
 
+static double fix_rounding(double d)
+{
+    if ((d > -0.00001) && (d < 0.00001))
+    {
+        d = 0.0;
+    }
+    return d;
+}
 
 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));
+    return (QUtil::double_to_string(fix_rounding(a), 5) + " " +
+            QUtil::double_to_string(fix_rounding(b), 5) + " " +
+            QUtil::double_to_string(fix_rounding(c), 5) + " " +
+            QUtil::double_to_string(fix_rounding(d), 5) + " " +
+            QUtil::double_to_string(fix_rounding(e), 5) + " " +
+            QUtil::double_to_string(fix_rounding(f), 5));
+}
+
+QPDFObjectHandle::Matrix
+QPDFMatrix::getAsMatrix() const
+{
+    return QPDFObjectHandle::Matrix(a, b, c, d, e, f);
 }
 
 void
@@ -99,3 +114,22 @@ 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;
 }
+
+QPDFObjectHandle::Rectangle
+QPDFMatrix::transformRectangle(QPDFObjectHandle::Rectangle r)
+{
+    // Transform a rectangle by creating a new rectangle the tightly
+    // bounds the polygon resulting from transforming the four
+    // corners.
+    std::vector<double> tx(4);
+    std::vector<double> ty(4);
+    transform(r.llx, r.lly, tx.at(0), ty.at(0));
+    transform(r.llx, r.ury, tx.at(1), ty.at(1));
+    transform(r.urx, r.lly, tx.at(2), ty.at(2));
+    transform(r.urx, r.ury, tx.at(3), ty.at(3));
+    return QPDFObjectHandle::Rectangle(
+        *std::min_element(tx.begin(), tx.end()),
+        *std::min_element(ty.begin(), ty.end()),
+        *std::max_element(tx.begin(), tx.end()),
+        *std::max_element(ty.begin(), ty.end()));
+}
diff --git a/libqpdf/qpdf/QPDFMatrix.hh b/libqpdf/qpdf/QPDFMatrix.hh
index 81bc51f1..7b19a665 100644
--- a/libqpdf/qpdf/QPDFMatrix.hh
+++ b/libqpdf/qpdf/QPDFMatrix.hh
@@ -19,6 +19,9 @@ class QPDFMatrix
     QPDF_DLL
     std::string unparse() const;
 
+    QPDF_DLL
+    QPDFObjectHandle::Matrix getAsMatrix() const;
+
     // This is not part of the public API. Just provide the methods we
     // need as we need them.
     QPDF_DLL
@@ -34,6 +37,10 @@ class QPDFMatrix
     QPDF_DLL
     void transform(double x, double y, double& xp, double& yp);
 
+    QPDF_DLL
+    QPDFObjectHandle::Rectangle transformRectangle(
+        QPDFObjectHandle::Rectangle r);
+
   private:
     double a;
     double b;
-- 
cgit v1.2.3-54-g00ecf