Move rectangle transformation into QPDFMatrix

Jay Berkenbilt
1 parent 8cb24573
Showing 4 changed files with 84 additions and 24 deletions
libqpdf/QPDFAnnotationObjectHelper.cc
libqpdf/QPDFMatrix.cc
libqpdf/qpdf/QPDFMatrix.hh
libtests/matrix.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);
 #include <qpdf/QPDFMatrix.hh>
 #include <qpdf/QUtil.hh>
+#include <algorithm>
 QPDFMatrix::QPDFMatrix() :
     a(1.0),
@@ -32,16 +33,30 @@ QPDFMatrix::QPDFMatrix(QPDFObjectHandle::Matrix const&amp; 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&amp; xp, double&amp; 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()));
+}
@@ -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;
@@ -22,6 +22,25 @@ static void check_xy(double x, double y, std::string const&amp; exp)
     }
 }
+static void check_rect(QPDFObjectHandle::Rectangle const& r,
+                       double llx, double lly, double urx, double ury)
+{
+    std::string actual = (
+        QUtil::double_to_string(r.llx, 2) + " " +
+        QUtil::double_to_string(r.lly, 2) + " " +
+        QUtil::double_to_string(r.urx, 2) + " " +
+        QUtil::double_to_string(r.ury, 2));
+    std::string wanted = (
+        QUtil::double_to_string(llx, 2) + " " +
+        QUtil::double_to_string(lly, 2) + " " +
+        QUtil::double_to_string(urx, 2) + " " +
+        QUtil::double_to_string(ury, 2));
+    if (actual != wanted)
+    {
+        std::cout << "got " << actual << ", wanted " << wanted << std::endl;
+    }
+}
+
 int main()
 {
     QPDFMatrix m;
@@ -30,8 +49,14 @@ int main()
     check(m, "1.00000 0.00000 0.00000 1.00000 10.00000 20.00000");
     m.scale(1.5, 2);
     check(m, "1.50000 0.00000 0.00000 2.00000 10.00000 20.00000");
+    double xp = 0;
+    double yp = 0;
+    m.transform(10, 100, xp, yp);
+    check_xy(xp, yp, "25.00 220.00");
     m.translate(30, 40);
     check(m, "1.50000 0.00000 0.00000 2.00000 55.00000 100.00000");
+    m.transform(10, 100, xp, yp);
+    check_xy(xp, yp, "70.00 300.00");
     m.concat(QPDFMatrix(1, 2, 3, 4, 5, 6));
     check(m, "1.50000 4.00000 4.50000 8.00000 62.50000 112.00000");
     m.rotatex90(90);
@@ -45,8 +70,6 @@ int main()
     m.rotatex90(12345);
     check(m, "1.50000 4.00000 4.50000 8.00000 62.50000 112.00000");
-    double xp = 0;
-    double yp = 0;
     m.transform(240, 480, xp, yp);
     check_xy(xp, yp, "2582.50 4912.00");
@@ -55,6 +78,13 @@ int main()
                   "[3 1 4 1 5 9.26535]").getArrayAsMatrix()),
           "3.00000 1.00000 4.00000 1.00000 5.00000 9.26535");
+    m = QPDFMatrix();
+    m.rotatex90(90);
+    m.translate(200, -100);
+    check_rect(
+        m.transformRectangle(QPDFObjectHandle::Rectangle(10, 20, 30, 50)),
+        50, 210, 80, 230);
+
     std::cout << "matrix tests done" << std::endl;
     return 0;
 }