qt5: FixedRotation annotations' coordinate conversion

FixedRotation(=flagNoRotate) annotations use a different coordinate
system than regular annotations. This patch implements transparent
conversion so that qt5 clients don't notice the difference.

Important! When dealing with FixedRotation annotations, poppler-qt5
clients will need to set geometry-related annotation properties in
the following order:
 1) flags (because we need to know if this is a FixedRotation
    annotation or not)
 2) boundary (because we need to know what the topleft corner is,
    so that we can construct the conversion matrix)
 3) anything else

This requirement will be documented in the next patch

2 files changed, 92 insertions, 26 deletions

diff --git a/qt5/src/poppler-annotation-private.h b/qt5/src/poppler-annotation-private.h
index 3bfb5daf..c755eb35 100644
--- a/qt5/src/poppler-annotation-private.h
+++ b/qt5/src/poppler-annotation-private.h
@@ -1,7 +1,7 @@
 /* poppler-annotation-private.h: qt interface to poppler
  * Copyright (C) 2007, Pino Toscano <pino@kde.org>
  * Copyright (C) 2012, Tobias Koenig <tokoe@kdab.com>
- * Copyright (C) 2012, Fabio D'Urso <fabiodurso@hotmail.it>
+ * Copyright (C) 2012, 2013 Fabio D'Urso <fabiodurso@hotmail.it>
  * Copyright (C) 2012, Albert Astals Cid <aacid@kde.org>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -87,9 +87,10 @@ class AnnotationPrivate : public QSharedData
 
         /* The following helpers only work if pdfPage is set */
         void flushBaseAnnotationProperties();
-        void fillMTX(double MTX[6]) const;
+        void fillNormalizationMTX(double MTX[6], int pageRotation) const;
+        void fillTransformationMTX(double MTX[6]) const;
         QRectF fromPdfRectangle(const PDFRectangle &r) const;
-        PDFRectangle toPdfRectangle(const QRectF &r) const;
+        PDFRectangle boundaryToPdfRectangle(const QRectF &r, int flags) const;
         AnnotPath * toAnnotPath(const QLinkedList<QPointF> &l) const;
 
         /* Scan page for annotations, parentId=0 searches for root annotations */
diff --git a/qt5/src/poppler-annotation.cc b/qt5/src/poppler-annotation.cc
index 35cef49a..c32771e5 100644
--- a/qt5/src/poppler-annotation.cc
+++ b/qt5/src/poppler-annotation.cc
@@ -27,6 +27,7 @@
 #include <QtCore/QtAlgorithms>
 #include <QtXml/QDomElement>
 #include <QtGui/QColor>
+#include <QtGui/QTransform>
 
 // local includes
 #include "poppler-annotation.h"
@@ -198,19 +199,21 @@ void AnnotationPrivate::flushBaseAnnotationProperties()
     revisions.clear();
 }
 
-void AnnotationPrivate::fillMTX(double MTX[6]) const
+// Returns matrix to convert from user space coords (oriented according to the
+// specified rotation) to normalized coords
+void AnnotationPrivate::fillNormalizationMTX(double MTX[6], int pageRotation) const
 {
     Q_ASSERT ( pdfPage );
 
     // build a normalized transform matrix for this page at 100% scale
-    GfxState * gfxState = new GfxState( 72.0, 72.0, pdfPage->getCropBox(), pdfPage->getRotate(), gTrue );
+    GfxState * gfxState = new GfxState( 72.0, 72.0, pdfPage->getCropBox(), pageRotation, gTrue );
     double * gfxCTM = gfxState->getCTM();
 
     double w = pdfPage->getCropWidth();
     double h = pdfPage->getCropHeight();
 
     // Swap width and height if the page is rotated landscape or seascape
-    if ( pdfPage->getRotate() == 90 || pdfPage->getRotate() == 270 )
+    if ( pageRotation == 90 || pageRotation == 270 )
     {
         double t = w;
         w = h;
@@ -225,10 +228,51 @@ void AnnotationPrivate::fillMTX(double MTX[6]) const
     delete gfxState;
 }
 
+// Returns matrix to convert from user space coords (i.e. those that are stored
+// in the PDF file) to normalized coords (i.e. those that we expose to clients).
+// This method also applies a rotation around the top-left corner if the
+// FixedRotation flag is set.
+void AnnotationPrivate::fillTransformationMTX(double MTX[6]) const
+{
+    Q_ASSERT ( pdfPage );
+    Q_ASSERT ( pdfAnnot );
+
+    const int pageRotate = pdfPage->getRotate();
+
+    if ( pageRotate == 0 || ( pdfAnnot->getFlags() & Annot::flagNoRotate ) == 0 )
+    {
+        // Use the normalization matrix for this page's rotation
+        fillNormalizationMTX( MTX, pageRotate );
+    }
+    else
+    {
+        // Clients expect coordinates relative to this page's rotation, but
+        // FixedRotation annotations internally use unrotated coordinates:
+        // construct matrix to both normalize and rotate coordinates using the
+        // top-left corner as rotation pivot
+
+        double MTXnorm[6];
+        fillNormalizationMTX( MTXnorm, pageRotate );
+
+        QTransform transform( MTXnorm[0], MTXnorm[1], MTXnorm[2],
+                              MTXnorm[3], MTXnorm[4], MTXnorm[5] );
+        transform.translate( +pdfAnnot->getXMin(), +pdfAnnot->getYMax() );
+        transform.rotate( pageRotate );
+        transform.translate( -pdfAnnot->getXMin(), -pdfAnnot->getYMax() );
+
+        MTX[0] = transform.m11();
+        MTX[1] = transform.m12();
+        MTX[2] = transform.m21();
+        MTX[3] = transform.m22();
+        MTX[4] = transform.dx();
+        MTX[5] = transform.dy();
+    }
+}
+
 QRectF AnnotationPrivate::fromPdfRectangle(const PDFRectangle &r) const
 {
     double swp, MTX[6];
-    fillMTX(MTX);
+    fillTransformationMTX(MTX);
 
     QPointF p1, p2;
     XPDFReader::transform( MTX, r.x1, r.y1, p1 );
@@ -256,10 +300,20 @@ QRectF AnnotationPrivate::fromPdfRectangle(const PDFRectangle &r) const
     return QRectF( QPointF(tl_x,tl_y) , QPointF(br_x,br_y) );
 }
 
-PDFRectangle AnnotationPrivate::toPdfRectangle(const QRectF &r) const
+// This function converts a boundary QRectF in normalized coords to a
+// PDFRectangle in user coords. If the FixedRotation flag is set, this function
+// also applies a rotation around the top-left corner: it's the inverse of
+// the transformation produced by fillTransformationMTX, but we can't use
+// fillTransformationMTX here because it relies on the native annotation
+// object's boundary rect to be already set up.
+PDFRectangle AnnotationPrivate::boundaryToPdfRectangle(const QRectF &r, int flags) const
 {
+    Q_ASSERT ( pdfPage );
+
+    const int pageRotate = pdfPage->getRotate();
+
     double MTX[6];
-    fillMTX(MTX);
+    fillNormalizationMTX( MTX, pageRotate );
 
     double tl_x, tl_y, br_x, br_y, swp;
     XPDFReader::invTransform( MTX, r.topLeft(), tl_x, tl_y );
@@ -279,7 +333,18 @@ PDFRectangle AnnotationPrivate::toPdfRectangle(const QRectF &r) const
         br_y = swp;
     }
 
-    return PDFRectangle(tl_x, tl_y, br_x, br_y);
+    const int rotationFixUp = ( flags & Annotation::FixedRotation ) ? pageRotate : 0;
+    const double width = br_x - tl_x;
+    const double height = br_y - tl_y;
+
+    if ( rotationFixUp == 0 )
+        return PDFRectangle(tl_x, tl_y, br_x, br_y);
+    else if ( rotationFixUp == 90 )
+        return PDFRectangle(tl_x, tl_y - width, tl_x + height, tl_y);
+    else if ( rotationFixUp == 180 )
+        return PDFRectangle(br_x, tl_y - height, br_x + width, tl_y);
+    else // rotationFixUp == 270
+        return PDFRectangle(br_x, br_y - width, br_x + height, br_y);
 }
 
 AnnotPath * AnnotationPrivate::toAnnotPath(const QLinkedList<QPointF> &list) const
@@ -288,7 +353,7 @@ AnnotPath * AnnotationPrivate::toAnnotPath(const QLinkedList<QPointF> &list) con
     AnnotCoord **ac = (AnnotCoord **) gmallocn(count, sizeof(AnnotCoord*));
 
     double MTX[6];
-    fillMTX(MTX);
+    fillTransformationMTX(MTX);
 
     int pos = 0;
     foreach (const QPointF &p, list)
@@ -1302,7 +1367,7 @@ void Annotation::setBoundary( const QRectF &boundary )
         return;
     }
 
-    PDFRectangle rect = d->toPdfRectangle(boundary);
+    PDFRectangle rect = d->boundaryToPdfRectangle( boundary, flags() );
     d->pdfAnnot->setRect(&rect);
     d->pdfAnnot->invalidateAppearance();
 }
@@ -1598,7 +1663,7 @@ Annot* TextAnnotationPrivate::createNativeAnnot(::Page *destPage, DocumentData *
     parentDoc = doc;
 
     // Set pdfAnnot
-    PDFRectangle rect = toPdfRectangle(boundary);
+    PDFRectangle rect = boundaryToPdfRectangle(boundary, flags);
     if (textType == TextAnnotation::Linked)
     {
         pdfAnnot = new AnnotText(destPage->getDoc(), &rect);
@@ -1909,7 +1974,7 @@ QVector<QPointF> TextAnnotation::calloutPoints() const
         return QVector<QPointF>();
 
     double MTX[6];
-    d->fillMTX(MTX);
+    d->fillTransformationMTX(MTX);
 
     const AnnotCalloutMultiLine * callout_v6 = dynamic_cast<const AnnotCalloutMultiLine*>(callout);
     QVector<QPointF> res(callout_v6 ? 3 : 2);
@@ -1951,7 +2016,7 @@ void TextAnnotation::setCalloutPoints( const QVector<QPointF> &points )
     AnnotCalloutLine *callout;
     double x1, y1, x2, y2;
     double MTX[6];
-    d->fillMTX(MTX);
+    d->fillTransformationMTX(MTX);
 
     XPDFReader::invTransform( MTX, points[0], x1, y1 );
     XPDFReader::invTransform( MTX, points[1], x2, y2 );
@@ -2050,7 +2115,7 @@ Annot* LineAnnotationPrivate::createNativeAnnot(::Page *destPage, DocumentData *
     parentDoc = doc;
 
     // Set pdfAnnot
-    PDFRectangle rect = toPdfRectangle(boundary);
+    PDFRectangle rect = boundaryToPdfRectangle(boundary, flags);
     if (lineType == LineAnnotation::StraightLine)
     {
         pdfAnnot = new AnnotLine(doc->doc, &rect);
@@ -2226,7 +2291,7 @@ QLinkedList<QPointF> LineAnnotation::linePoints() const
         return d->linePoints;
 
     double MTX[6];
-    d->fillMTX(MTX);
+    d->fillTransformationMTX(MTX);
 
     QLinkedList<QPointF> res;
     if (d->pdfAnnot->getType() == Annot::typeLine)
@@ -2274,7 +2339,7 @@ void LineAnnotation::setLinePoints( const QLinkedList<QPointF> &points )
         }
         double x1, y1, x2, y2;
         double MTX[6];
-        d->fillMTX(MTX);
+        d->fillTransformationMTX(MTX);
         XPDFReader::invTransform( MTX, points.first(), x1, y1 );
         XPDFReader::invTransform( MTX, points.last(), x2, y2 );
         lineann->setVertices(x1, y1, x2, y2);
@@ -2666,7 +2731,7 @@ Annot* GeomAnnotationPrivate::createNativeAnnot(::Page *destPage, DocumentData *
         type = Annot::typeCircle;
 
     // Set pdfAnnot
-    PDFRectangle rect = toPdfRectangle(boundary);
+    PDFRectangle rect = boundaryToPdfRectangle(boundary, flags);
     pdfAnnot = new AnnotGeometry(destPage->getDoc(), &rect, type);
 
     // Set properties
@@ -2844,7 +2909,7 @@ QList< HighlightAnnotation::Quad > HighlightAnnotationPrivate::fromQuadrilateral
     const int quadsCount = hlquads->getQuadrilateralsLength();
 
     double MTX[6];
-    fillMTX(MTX);
+    fillTransformationMTX(MTX);
 
     for (int q = 0; q < quadsCount; ++q)
     {
@@ -2876,7 +2941,7 @@ AnnotQuadrilaterals * HighlightAnnotationPrivate::toQuadrilaterals(const QList<
             gmallocn( count, sizeof(AnnotQuadrilaterals::AnnotQuadrilateral*) );
 
     double MTX[6];
-    fillMTX(MTX);
+    fillTransformationMTX(MTX);
 
     int pos = 0;
     foreach (const HighlightAnnotation::Quad &q, quads)
@@ -2903,7 +2968,7 @@ Annot* HighlightAnnotationPrivate::createNativeAnnot(::Page *destPage, DocumentD
     parentDoc = doc;
 
     // Set pdfAnnot
-    PDFRectangle rect = toPdfRectangle(boundary);
+    PDFRectangle rect = boundaryToPdfRectangle(boundary, flags);
     pdfAnnot = new AnnotTextMarkup(destPage->getDoc(), &rect, toAnnotSubType(highlightType));
 
     // Set properties
@@ -3113,7 +3178,7 @@ Annot* StampAnnotationPrivate::createNativeAnnot(::Page *destPage, DocumentData
     parentDoc = doc;
 
     // Set pdfAnnot
-    PDFRectangle rect = toPdfRectangle(boundary);
+    PDFRectangle rect = boundaryToPdfRectangle(boundary, flags);
     pdfAnnot = new AnnotStamp(destPage->getDoc(), &rect);
 
     // Set properties
@@ -3252,7 +3317,7 @@ Annot* InkAnnotationPrivate::createNativeAnnot(::Page *destPage, DocumentData *d
     parentDoc = doc;
 
     // Set pdfAnnot
-    PDFRectangle rect = toPdfRectangle(boundary);
+    PDFRectangle rect = boundaryToPdfRectangle(boundary, flags);
     pdfAnnot = new AnnotInk(destPage->getDoc(), &rect);
 
     // Set properties
@@ -3377,7 +3442,7 @@ QList< QLinkedList<QPointF> > InkAnnotation::inkPaths() const
         return QList< QLinkedList<QPointF> >();
 
     double MTX[6];
-    d->fillMTX(MTX);
+    d->fillTransformationMTX(MTX);
 
     const int pathsNumber = inkann->getInkListLength();
     QList< QLinkedList<QPointF> > inkPaths;
@@ -3798,7 +3863,7 @@ Annot* CaretAnnotationPrivate::createNativeAnnot(::Page *destPage, DocumentData
     parentDoc = doc;
 
     // Set pdfAnnot
-    PDFRectangle rect = toPdfRectangle(boundary);
+    PDFRectangle rect = boundaryToPdfRectangle(boundary, flags);
     pdfAnnot = new AnnotCaret(destPage->getDoc(), &rect);
 
     // Set properties