SkPDF: Implement drawImage*() properly

src/pdf/SkPDFBitmap.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorPriv.h"
 #include "SkData.h"
 #include "SkDeflate.h"
-#include "SkImageGenerator.h"
+#include "SkImage_Base.h"
 #include "SkJpegInfo.h"
 #include "SkPDFBitmap.h"
 #include "SkPDFCanon.h"
-#include "SkPixelRef.h"
 #include "SkStream.h"
 #include "SkUnPreMultiply.h"
 
 ////////////////////////////////////////////////////////////////////////////////
 
 static void pdf_stream_begin(SkWStream* stream) {
     static const char streamBegin[] = " stream\n";
     stream->write(streamBegin, strlen(streamBegin));
 }
 
@@ skipping 212 matching lines @@
             SkDEBUGFAIL("unexpected color type");
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 namespace {
 // This SkPDFObject only outputs the alpha layer of the given bitmap.
 class PDFAlphaBitmap : public SkPDFObject {
 public:
-    PDFAlphaBitmap(const SkBitmap& bm) : fBitmap(bm) {}
+    PDFAlphaBitmap(const SkImage* image) : fImage(SkRef(image)) {}
     ~PDFAlphaBitmap() {}
     void emitObject(SkWStream*,
                     const SkPDFObjNumMap&,
                     const SkPDFSubstituteMap&) const override;
 
 private:
-    const SkBitmap fBitmap;
+    SkAutoTUnref<const SkImage> fImage;
 };
 
 void PDFAlphaBitmap::emitObject(SkWStream* stream,
                                 const SkPDFObjNumMap& objNumMap,
                                 const SkPDFSubstituteMap& substitutes) const {
-    SkAutoLockPixels autoLockPixels(fBitmap);
-    SkASSERT(fBitmap.colorType() != kIndex_8_SkColorType ||
-             fBitmap.getColorTable());
+    // Should we lock as a SkPixMap, not a SkBitmap?
+    SkBitmap bitmap;
+    SkISize size = fImage->dimensions();
+    if (!as_IB(fImage.get())->getROPixels(&bitmap) ||
+        bitmap.dimensions() != size) {
+        bitmap.reset();  // bitmap_alpha_to_a8 will fill with zeroes.
+    }
+    SkAutoLockPixels autoLockPixels(bitmap);
+    SkASSERT(bitmap.colorType() != kIndex_8_SkColorType ||
+             bitmap.getColorTable());
 
     // Write to a temporary buffer to get the compressed length.
     SkDynamicMemoryWStream buffer;
     SkDeflateWStream deflateWStream(&buffer);
-    bitmap_alpha_to_a8(fBitmap, &deflateWStream);
+    bitmap_alpha_to_a8(bitmap, &deflateWStream);
     deflateWStream.finalize();  // call before detachAsStream().
     SkAutoTDelete<SkStreamAsset> asset(buffer.detachAsStream());
 
     SkPDFDict pdfDict("XObject");
     pdfDict.insertName("Subtype", "Image");
-    pdfDict.insertInt("Width", fBitmap.width());
-    pdfDict.insertInt("Height", fBitmap.height());
+    pdfDict.insertInt("Width", size.width());
+    pdfDict.insertInt("Height", size.height());
     pdfDict.insertName("ColorSpace", "DeviceGray");
     pdfDict.insertInt("BitsPerComponent", 8);
     pdfDict.insertName("Filter", "FlateDecode");
     pdfDict.insertInt("Length", asset->getLength());
     pdfDict.emitObject(stream, objNumMap, substitutes);
 
     pdf_stream_begin(stream);
     stream->writeStream(asset.get(), asset->getLength());
     pdf_stream_end(stream);
 }
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 
 namespace {
-class PDFDefaultBitmap : public SkPDFBitmap {
+class PDFDefaultBitmap : public SkPDFObject {
 public:
-    const SkAutoTUnref<SkPDFObject> fSMask;
     void emitObject(SkWStream*,
                     const SkPDFObjNumMap&,
                     const SkPDFSubstituteMap&) const override;
     void addResources(SkPDFObjNumMap*,
                       const SkPDFSubstituteMap&) const override;
-    PDFDefaultBitmap(const SkBitmap& bm, SkPDFObject* smask)
-        : SkPDFBitmap(bm), fSMask(smask) {}
+    PDFDefaultBitmap(const SkImage* image, SkPDFObject* smask)
+        : fImage(SkRef(image)), fSMask(smask) {}
+
+private:
+    SkAutoTUnref<const SkImage> fImage;
+    const SkAutoTUnref<SkPDFObject> fSMask;
 };
 }  // namespace
 
 void PDFDefaultBitmap::addResources(
         SkPDFObjNumMap* catalog,
         const SkPDFSubstituteMap& substitutes) const {
     if (fSMask.get()) {
         SkPDFObject* obj = substitutes.getSubstitute(fSMask.get());
         SkASSERT(obj);
         if (catalog->addObject(obj)) {
@@ skipping 28 matching lines @@
         tablePtr += 3;
     }
     SkString tableString(tableArray, 3 * table->count());
     result->appendString(tableString);
     return result;
 }
 
 void PDFDefaultBitmap::emitObject(SkWStream* stream,
                                   const SkPDFObjNumMap& objNumMap,
                                   const SkPDFSubstituteMap& substitutes) const {
-    SkAutoLockPixels autoLockPixels(fBitmap);
-    SkASSERT(fBitmap.colorType() != kIndex_8_SkColorType ||
-             fBitmap.getColorTable());
+    SkBitmap bitmap;  // Should we lock as a SkPixMap, not a SkBitmap?
+    SkISize size = fImage->dimensions();
+    if (!as_IB(fImage.get())->getROPixels(&bitmap) ||
+        bitmap.dimensions() != size) {
+        bitmap.reset();  // bitmap_to_pdf_pixels will fill with zeroes.
+    }
+    SkAutoLockPixels autoLockPixels(bitmap);  // TODO(halcanry): test
+                                              // with malformed images?
+    SkASSERT(bitmap.colorType() != kIndex_8_SkColorType ||
+             bitmap.getColorTable());
 
     // Write to a temporary buffer to get the compressed length.
     SkDynamicMemoryWStream buffer;
     SkDeflateWStream deflateWStream(&buffer);
-    bitmap_to_pdf_pixels(fBitmap, &deflateWStream);
+    bitmap_to_pdf_pixels(bitmap, &deflateWStream);
     deflateWStream.finalize();  // call before detachAsStream().
     SkAutoTDelete<SkStreamAsset> asset(buffer.detachAsStream());
 
     SkPDFDict pdfDict("XObject");
     pdfDict.insertName("Subtype", "Image");
-    pdfDict.insertInt("Width", fBitmap.width());
-    pdfDict.insertInt("Height", fBitmap.height());
-    if (fBitmap.colorType() == kIndex_8_SkColorType) {
-        SkASSERT(1 == pdf_color_component_count(fBitmap.colorType()));
+    pdfDict.insertInt("Width", bitmap.width());
+    pdfDict.insertInt("Height", bitmap.height());
+    if (bitmap.colorType() == kIndex_8_SkColorType) {
+        SkASSERT(1 == pdf_color_component_count(bitmap.colorType()));
         pdfDict.insertObject("ColorSpace",
-                             make_indexed_color_space(fBitmap.getColorTable()));
-    } else if (1 == pdf_color_component_count(fBitmap.colorType())) {
+                             make_indexed_color_space(bitmap.getColorTable()));
+    } else if (1 == pdf_color_component_count(bitmap.colorType())) {
         pdfDict.insertName("ColorSpace", "DeviceGray");
     } else {
         pdfDict.insertName("ColorSpace", "DeviceRGB");
     }
     pdfDict.insertInt("BitsPerComponent", 8);
     if (fSMask) {
         pdfDict.insertObjRef("SMask", SkRef(fSMask.get()));
     }
     pdfDict.insertName("Filter", "FlateDecode");
     pdfDict.insertInt("Length", asset->getLength());
     pdfDict.emitObject(stream, objNumMap, substitutes);
 
     pdf_stream_begin(stream);
     stream->writeStream(asset.get(), asset->getLength());
     pdf_stream_end(stream);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-static const SkBitmap& immutable_bitmap(const SkBitmap& bm, SkBitmap* copy) {
-    if (bm.isImmutable()) {
-        return bm;
-    }
-    bm.copyTo(copy);
-    copy->setImmutable();
-    return *copy;
-}
-
 namespace {
 /**
- *  This PDFObject assumes that its constructor was handed YUV JFIF
- *  Jpeg-encoded data that can be directly embedded into a PDF.
+ *  This PDFObject assumes that its constructor was handed YUV or
+ *  Grayscale JFIF Jpeg-encoded data that can be directly embedded
+ *  into a PDF.
  */
-class PDFJpegBitmap : public SkPDFBitmap {
+class PDFJpegBitmap : public SkPDFObject {
 public:
+    SkISize fSize;
     SkAutoTUnref<SkData> fData;
     bool fIsYUV;
-    PDFJpegBitmap(const SkBitmap& bm, SkData* data, bool isYUV)
-        : SkPDFBitmap(bm), fData(SkRef(data)), fIsYUV(isYUV) {}
+    PDFJpegBitmap(SkISize size, SkData* data, bool isYUV)
+        : fSize(size), fData(SkRef(data)), fIsYUV(isYUV) {}
     void emitObject(SkWStream*,
                     const SkPDFObjNumMap&,
                     const SkPDFSubstituteMap&) const override;
 };
 
 void PDFJpegBitmap::emitObject(SkWStream* stream,
                                const SkPDFObjNumMap& objNumMap,
                                const SkPDFSubstituteMap& substituteMap) const {
     SkPDFDict pdfDict("XObject");
     pdfDict.insertName("Subtype", "Image");
-    pdfDict.insertInt("Width", fBitmap.width());
-    pdfDict.insertInt("Height", fBitmap.height());
+    pdfDict.insertInt("Width", fSize.width());
+    pdfDict.insertInt("Height", fSize.height());
     if (fIsYUV) {
         pdfDict.insertName("ColorSpace", "DeviceRGB");
     } else {
         pdfDict.insertName("ColorSpace", "DeviceGray");
     }
     pdfDict.insertInt("BitsPerComponent", 8);
     pdfDict.insertName("Filter", "DCTDecode");
     pdfDict.insertInt("ColorTransform", 0);
     pdfDict.insertInt("Length", SkToInt(fData->size()));
     pdfDict.emitObject(stream, objNumMap, substituteMap);
     pdf_stream_begin(stream);
     stream->write(fData->data(), fData->size());
     pdf_stream_end(stream);
 }
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 
-SkPDFBitmap* SkPDFBitmap::Create(SkPDFCanon* canon, const SkBitmap& bitmap) {
-    SkASSERT(canon);
-    if (!SkColorTypeIsValid(bitmap.colorType()) ||
-        kUnknown_SkColorType == bitmap.colorType()) {
-        return nullptr;
-    }
-    SkBitmap copy;
-    const SkBitmap& bm = immutable_bitmap(bitmap, &copy);
-    if (bm.drawsNothing()) {
-        return nullptr;
-    }
-    if (SkPDFBitmap* canonBitmap = canon->findBitmap(bm)) {
-        return SkRef(canonBitmap);
-    }
-
-    if (bm.pixelRef() && bm.pixelRefOrigin().isZero() &&
-        bm.dimensions() == bm.pixelRef()->info().dimensions()) {
-        // Requires the bitmap to be backed by lazy pixels.
-        SkAutoTUnref<SkData> data(bm.pixelRef()->refEncodedData());
-        SkJFIFInfo info;
-        if (data && SkIsJFIF(data, &info)) {
-            bool yuv = info.fType == SkJFIFInfo::kYCbCr;
-            SkPDFBitmap* pdfBitmap = new PDFJpegBitmap(bm, data, yuv);
-            canon->addBitmap(pdfBitmap);
-            return pdfBitmap;
+SkPDFObject* SkPDFCreateBitmapObject(const SkImage* image) {
+    SkAutoTUnref<SkData> data(image->refEncoded());
+    SkJFIFInfo info;
+    if (data && SkIsJFIF(data, &info)) {
+        bool yuv = info.fType == SkJFIFInfo::kYCbCr;
+        if (info.fSize == image->dimensions()) {  // Sanity check.
+            // hold on to data, not image.
+            return new PDFJpegBitmap(info.fSize, data, yuv);
         }
     }
-
-    SkPDFObject* smask = nullptr;
-    if (!bm.isOpaque() && !SkBitmap::ComputeIsOpaque(bm)) {
-        smask = new PDFAlphaBitmap(bm);
-    }
-    SkPDFBitmap* pdfBitmap = new PDFDefaultBitmap(bm, smask);
-    canon->addBitmap(pdfBitmap);
-    return pdfBitmap;
+    SkPDFObject* smask =
+            image->isOpaque() ? nullptr : new PDFAlphaBitmap(image);
+    return new PDFDefaultBitmap(image, smask);
 }