From ac644c16a4d6ff2f9dca12bc6d10cae6e76c270b Mon Sep 17 00:00:00 2001
From: Jakub Melka <Jakub.Melka@seznam.cz>
Date: Sat, 19 Oct 2019 11:08:37 +0200
Subject: [PATCH] Mask image

---
 PdfForQtLib/sources/pdfcolorspaces.cpp |  2 +-
 PdfForQtLib/sources/pdfcolorspaces.h   |  4 +++-
 PdfForQtLib/sources/pdfimage.cpp       | 26 ++++++++++++++++++++++----
 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/PdfForQtLib/sources/pdfcolorspaces.cpp b/PdfForQtLib/sources/pdfcolorspaces.cpp
index 7cae05c..0f12f86 100644
--- a/PdfForQtLib/sources/pdfcolorspaces.cpp
+++ b/PdfForQtLib/sources/pdfcolorspaces.cpp
@@ -1088,7 +1088,7 @@ PDFColorSpacePointer PDFIndexedColorSpace::createIndexedColorSpace(const PDFDict
     const int colorCount = maxValue - MIN_VALUE + 1;
     const int componentCount = static_cast<int>(baseColorSpace->getColorComponentCount());
     const int byteCount = colorCount * componentCount;
-    if (byteCount != colors.size())
+    if (byteCount > colors.size())
     {
         throw PDFException(PDFTranslationContext::tr("Invalid colors for indexed color space. Color space has %1 colors, %2 color components and must have %3 size. Provided size is %4.").arg(colorCount).arg(componentCount).arg(byteCount).arg(colors.size()));
     }
diff --git a/PdfForQtLib/sources/pdfcolorspaces.h b/PdfForQtLib/sources/pdfcolorspaces.h
index 1dec59a..67b36d4 100644
--- a/PdfForQtLib/sources/pdfcolorspaces.h
+++ b/PdfForQtLib/sources/pdfcolorspaces.h
@@ -85,7 +85,6 @@ public:
     {
         None,
         ColorKeyMasking,    ///< Masking by color key
-        Image,              ///< Masking by image with alpha mask
         ImageMask,          ///< Masking by 1-bit image (see "ImageMask" entry in image's dictionary), current color from the graphic state is used to paint an image
         SoftMask,           ///< Image is masked by soft mask
     };
@@ -136,6 +135,9 @@ public:
     const std::vector<PDFReal>& getDecode() const { return m_decode; }
     const std::vector<PDFReal>& getMatte() const { return m_matte; }
 
+    void setMaskingType(MaskingType maskingType) { m_maskingType = maskingType; }
+    void setDecode(std::vector<PDFReal> decode) { m_decode = qMove(decode); }
+
     /// Returns number of color channels
     unsigned int getColorChannels() const { return m_components; }
 
diff --git a/PdfForQtLib/sources/pdfimage.cpp b/PdfForQtLib/sources/pdfimage.cpp
index 81f577f..638cd0c 100644
--- a/PdfForQtLib/sources/pdfimage.cpp
+++ b/PdfForQtLib/sources/pdfimage.cpp
@@ -125,10 +125,28 @@ PDFImage PDFImage::createImage(const PDFDocument* document,
         }
         else if (object.isStream())
         {
-            // TODO: Implement Mask Image
-            PDFImage maskImage = createImage(document, object.getStream(), colorSpace, false, renderingIntent, errorReporter);
-            maskingType = PDFImageData::MaskingType::Image;
-            throw PDFRendererException(RenderErrorType::NotImplemented, PDFTranslationContext::tr("Mask image is not implemented."));
+            PDFImage softMaskImage = createImage(document, object.getStream(), colorSpace, false, renderingIntent, errorReporter);
+
+            if (softMaskImage.m_imageData.getMaskingType() != PDFImageData::MaskingType::ImageMask ||
+                softMaskImage.m_imageData.getColorChannels() != 1 ||
+                softMaskImage.m_imageData.getBitsPerComponent() != 1)
+            {
+                throw PDFRendererException(RenderErrorType::NotImplemented, PDFTranslationContext::tr("Invalid mask image."));
+            }
+
+            // We must alter decode, because it has opposite meaning (it is transparency)
+            std::vector<PDFReal> decode = softMaskImage.m_imageData.getDecode();
+            if (decode.size() < 2)
+            {
+                decode = { 0.0, 1.0};
+            }
+            std::swap(decode[0], decode[1]);
+
+            // Create soft mask from image
+            maskingType = PDFImageData::MaskingType::SoftMask;
+            image.m_softMask = qMove(softMaskImage.m_imageData);
+            image.m_softMask.setMaskingType(PDFImageData::MaskingType::None);
+            image.m_softMask.setDecode(qMove(decode));
         }
     }
     else if (dictionary->hasKey("SMask"))