[API CHANGE] tdf#136836 emfio: set size hint on inner PDF if used as shape fill

The bugdoc has a shape, its bitmap fill is an EMF, which is actually a
PDF. The PDF is has a height of 5cm, but the shape has a height of 14
cm.

Inform vcl::RenderPDFBitmaps() about the size of the shape, so the
result won't be blurry. This approach makes sure that we don't
unconditionally render at higher resolution, i.e. the "load a PDF of 100
pages into Online" use-case won't use more memory than before.

API CHANGE, because the EMF reader is only available via UNO, though
it's likely that no actual external code would ever invoke it directly.

(cherry picked from commit 01024ee24c6e89044c68051f6fd5f1264905e90c)

Conflicts:
        emfio/qa/cppunit/emf/EmfImportTest.cxx
        include/vcl/pdfread.hxx
        include/vcl/vectorgraphicdata.hxx
        vcl/source/gdi/vectorgraphicdata.cxx

Change-Id: If1d8def0136d408a31a0cc54777a7f26430a0ff3
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/103101
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

1 files changed, 19 insertions, 4 deletions

diff --git a/vcl/source/filter/ipdf/pdfread.cxx b/vcl/source/filter/ipdf/pdfread.cxx
index 5574f4a67778..2fb7a11bb681 100644
--- a/vcl/source/filter/ipdf/pdfread.cxx
+++ b/vcl/source/filter/ipdf/pdfread.cxx
@@ -23,6 +23,7 @@
 #include <unotools/datetime.hxx>
 
 #include <vcl/filter/PDFiumLibrary.hxx>
+#include <sal/log.hxx>
 
 using namespace com::sun::star;
 
@@ -146,9 +147,10 @@ VectorGraphicDataArray createVectorGraphicDataArray(SvStream& rStream)
 namespace vcl
 {
 size_t RenderPDFBitmaps(const void* pBuffer, int nSize, std::vector<Bitmap>& rBitmaps,
-                        const size_t nFirstPage, int nPages, const double fResolutionDPI)
+                        const size_t nFirstPage, int nPages, const basegfx::B2DTuple* pSizeHint)
 {
 #if HAVE_FEATURE_PDFIUM
+    const double fResolutionDPI = 96;
     auto pPdfium = vcl::pdf::PDFiumLibrary::get();
 
     // Load the buffer using pdfium.
@@ -167,9 +169,19 @@ size_t RenderPDFBitmaps(const void* pBuffer, int nSize, std::vector<Bitmap>& rBi
         if (!pPdfPage)
             break;
 
+        // Calculate the bitmap size in points.
+        size_t nPageWidthPoints = FPDF_GetPageWidth(pPdfPage);
+        size_t nPageHeightPoints = FPDF_GetPageHeight(pPdfPage);
+        if (pSizeHint && pSizeHint->getX() && pSizeHint->getY())
+        {
+            // Have a size hint, prefer that over the logic size from the PDF.
+            nPageWidthPoints = convertMm100ToTwip(pSizeHint->getX()) / 20;
+            nPageHeightPoints = convertMm100ToTwip(pSizeHint->getY()) / 20;
+        }
+
         // Returned unit is points, convert that to pixel.
-        const size_t nPageWidth = pointToPixel(FPDF_GetPageWidth(pPdfPage), fResolutionDPI);
-        const size_t nPageHeight = pointToPixel(FPDF_GetPageHeight(pPdfPage), fResolutionDPI);
+        const size_t nPageWidth = pointToPixel(nPageWidthPoints, fResolutionDPI);
+        const size_t nPageHeight = pointToPixel(nPageHeightPoints, fResolutionDPI);
         FPDF_BITMAP pPdfBitmap = FPDFBitmap_Create(nPageWidth, nPageHeight, /*alpha=*/1);
         if (!pPdfBitmap)
             break;
@@ -207,7 +219,7 @@ size_t RenderPDFBitmaps(const void* pBuffer, int nSize, std::vector<Bitmap>& rBi
     (void)rBitmaps;
     (void)nFirstPage;
     (void)nPages;
-    (void)fResolutionDPI;
+    (void)pSizeHint;
     return 0;
 #endif // HAVE_FEATURE_PDFIUM
 }
@@ -216,7 +228,10 @@ bool ImportPDF(SvStream& rStream, Graphic& rGraphic)
 {
     VectorGraphicDataArray aPdfDataArray = createVectorGraphicDataArray(rStream);
     if (!aPdfDataArray.hasElements())
+    {
+        SAL_WARN("vcl.filter", "ImportPDF: empty PDF data array");
         return false;
+    }
 
     auto aVectorGraphicDataPtr = std::make_shared<VectorGraphicData>(aPdfDataArray, OUString(),
                                                                      VectorGraphicDataType::Pdf);