The Tor Browser: gfx/skia/trunk/src/images/SkMovie

gfx/skia/trunk/src/images/SkMovie_gif.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/images/SkMovie_gif.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkMovie.h"
 #include "SkColor.h"
 #include "SkColorPriv.h"
 #include "SkStream.h"
 #include "SkTemplates.h"
 #include "SkUtils.h"
 #include "gif_lib.h"
 class SkGIFMovie : public SkMovie {
 public:
     SkGIFMovie(SkStream* stream);
     virtual ~SkGIFMovie();
 protected:
     virtual bool onGetInfo(Info*);
     virtual bool onSetTime(SkMSec);
     virtual bool onGetBitmap(SkBitmap*);
 private:
     GifFileType* fGIF;
     int fCurrIndex;
     int fLastDrawIndex;
     SkBitmap fBackup;
 };
 static int Decode(GifFileType* fileType, GifByteType* out, int size) {
     SkStream* stream = (SkStream*) fileType->UserData;
     return (int) stream->read(out, size);
 }
 SkGIFMovie::SkGIFMovie(SkStream* stream)
 {
 #if GIFLIB_MAJOR < 5
     fGIF = DGifOpen( stream, Decode );
 #else
     fGIF = DGifOpen( stream, Decode, NULL );
 #endif
     if (NULL == fGIF)
         return;
     if (DGifSlurp(fGIF) != GIF_OK)
     {
         DGifCloseFile(fGIF);
         fGIF = NULL;
     }
     fCurrIndex = -1;
     fLastDrawIndex = -1;
 }
 SkGIFMovie::~SkGIFMovie()
 {
     if (fGIF)
         DGifCloseFile(fGIF);
 }
 static SkMSec savedimage_duration(const SavedImage* image)
 {
     for (int j = 0; j < image->ExtensionBlockCount; j++)
     {
         if (image->ExtensionBlocks[j].Function == GRAPHICS_EXT_FUNC_CODE)
         {
             SkASSERT(image->ExtensionBlocks[j].ByteCount >= 4);
             const uint8_t* b = (const uint8_t*)image->ExtensionBlocks[j].Bytes;
             return ((b[2] << 8) | b[1]) * 10;
         }
     }
     return 0;
 }
 bool SkGIFMovie::onGetInfo(Info* info)
 {
     if (NULL == fGIF)
         return false;
     SkMSec dur = 0;
     for (int i = 0; i < fGIF->ImageCount; i++)
         dur += savedimage_duration(&fGIF->SavedImages[i]);
     info->fDuration = dur;
     info->fWidth = fGIF->SWidth;
     info->fHeight = fGIF->SHeight;
     info->fIsOpaque = false;    // how to compute?
     return true;
 }
 bool SkGIFMovie::onSetTime(SkMSec time)
 {
     if (NULL == fGIF)
         return false;
     SkMSec dur = 0;
     for (int i = 0; i < fGIF->ImageCount; i++)
     {
         dur += savedimage_duration(&fGIF->SavedImages[i]);
         if (dur >= time)
         {
             fCurrIndex = i;
             return fLastDrawIndex != fCurrIndex;
         }
     }
     fCurrIndex = fGIF->ImageCount - 1;
     return true;
 }
 static void copyLine(uint32_t* dst, const unsigned char* src, const ColorMapObject* cmap,
                      int transparent, int width)
 {
     for (; width > 0; width--, src++, dst++) {
         if (*src != transparent) {
             const GifColorType& col = cmap->Colors[*src];
             *dst = SkPackARGB32(0xFF, col.Red, col.Green, col.Blue);
         }
     }
 }
 #if GIFLIB_MAJOR < 5
 static void copyInterlaceGroup(SkBitmap* bm, const unsigned char*& src,
                                const ColorMapObject* cmap, int transparent, int copyWidth,
                                int copyHeight, const GifImageDesc& imageDesc, int rowStep,
                                int startRow)
 {
     int row;
     // every 'rowStep'th row, starting with row 'startRow'
     for (row = startRow; row < copyHeight; row += rowStep) {
         uint32_t* dst = bm->getAddr32(imageDesc.Left, imageDesc.Top + row);
         copyLine(dst, src, cmap, transparent, copyWidth);
         src += imageDesc.Width;
     }
     // pad for rest height
     src += imageDesc.Width * ((imageDesc.Height - row + rowStep - 1) / rowStep);
 }
 static void blitInterlace(SkBitmap* bm, const SavedImage* frame, const ColorMapObject* cmap,
                           int transparent)
 {
     int width = bm->width();
     int height = bm->height();
     GifWord copyWidth = frame->ImageDesc.Width;
     if (frame->ImageDesc.Left + copyWidth > width) {
         copyWidth = width - frame->ImageDesc.Left;
     }
     GifWord copyHeight = frame->ImageDesc.Height;
     if (frame->ImageDesc.Top + copyHeight > height) {
         copyHeight = height - frame->ImageDesc.Top;
     }
     // deinterlace
     const unsigned char* src = (unsigned char*)frame->RasterBits;
     // group 1 - every 8th row, starting with row 0
     copyInterlaceGroup(bm, src, cmap, transparent, copyWidth, copyHeight, frame->ImageDesc, 8, 0);
     // group 2 - every 8th row, starting with row 4
     copyInterlaceGroup(bm, src, cmap, transparent, copyWidth, copyHeight, frame->ImageDesc, 8, 4);
     // group 3 - every 4th row, starting with row 2
     copyInterlaceGroup(bm, src, cmap, transparent, copyWidth, copyHeight, frame->ImageDesc, 4, 2);
     copyInterlaceGroup(bm, src, cmap, transparent, copyWidth, copyHeight, frame->ImageDesc, 2, 1);
 }
 #endif
 static void blitNormal(SkBitmap* bm, const SavedImage* frame, const ColorMapObject* cmap,
                        int transparent)
 {
     int width = bm->width();
     int height = bm->height();
     const unsigned char* src = (unsigned char*)frame->RasterBits;
     uint32_t* dst = bm->getAddr32(frame->ImageDesc.Left, frame->ImageDesc.Top);
     GifWord copyWidth = frame->ImageDesc.Width;
     if (frame->ImageDesc.Left + copyWidth > width) {
         copyWidth = width - frame->ImageDesc.Left;
     }
     GifWord copyHeight = frame->ImageDesc.Height;
     if (frame->ImageDesc.Top + copyHeight > height) {
         copyHeight = height - frame->ImageDesc.Top;
     }
     for (; copyHeight > 0; copyHeight--) {
         copyLine(dst, src, cmap, transparent, copyWidth);
         src += frame->ImageDesc.Width;
         dst += width;
     }
 }
 static void fillRect(SkBitmap* bm, GifWord left, GifWord top, GifWord width, GifWord height,
                      uint32_t col)
 {
     int bmWidth = bm->width();
     int bmHeight = bm->height();
     uint32_t* dst = bm->getAddr32(left, top);
     GifWord copyWidth = width;
     if (left + copyWidth > bmWidth) {
         copyWidth = bmWidth - left;
     }
     GifWord copyHeight = height;
     if (top + copyHeight > bmHeight) {
         copyHeight = bmHeight - top;
     }
     for (; copyHeight > 0; copyHeight--) {
         sk_memset32(dst, col, copyWidth);
         dst += bmWidth;
     }
 }
 static void drawFrame(SkBitmap* bm, const SavedImage* frame, const ColorMapObject* cmap)
 {
     int transparent = -1;
     for (int i = 0; i < frame->ExtensionBlockCount; ++i) {
         ExtensionBlock* eb = frame->ExtensionBlocks + i;
         if (eb->Function == GRAPHICS_EXT_FUNC_CODE &&
             eb->ByteCount == 4) {
             bool has_transparency = ((eb->Bytes[0] & 1) == 1);
             if (has_transparency) {
                 transparent = (unsigned char)eb->Bytes[3];
             }
         }
     }
     if (frame->ImageDesc.ColorMap != NULL) {
         // use local color table
         cmap = frame->ImageDesc.ColorMap;
     }
     if (cmap == NULL || cmap->ColorCount != (1 << cmap->BitsPerPixel)) {
         SkDEBUGFAIL("bad colortable setup");
         return;
     }
 #if GIFLIB_MAJOR < 5
     // before GIFLIB 5, de-interlacing wasn't done by library at load time
     if (frame->ImageDesc.Interlace) {
         blitInterlace(bm, frame, cmap, transparent);
         return;
     }
 #endif
     blitNormal(bm, frame, cmap, transparent);
 }
 static bool checkIfWillBeCleared(const SavedImage* frame)
 {
     for (int i = 0; i < frame->ExtensionBlockCount; ++i) {
         ExtensionBlock* eb = frame->ExtensionBlocks + i;
         if (eb->Function == GRAPHICS_EXT_FUNC_CODE &&
             eb->ByteCount == 4) {
             // check disposal method
             int disposal = ((eb->Bytes[0] >> 2) & 7);
             if (disposal == 2 || disposal == 3) {
                 return true;
             }
         }
     }
     return false;
 }
 static void getTransparencyAndDisposalMethod(const SavedImage* frame, bool* trans, int* disposal)
 {
     *trans = false;
     *disposal = 0;
     for (int i = 0; i < frame->ExtensionBlockCount; ++i) {
         ExtensionBlock* eb = frame->ExtensionBlocks + i;
         if (eb->Function == GRAPHICS_EXT_FUNC_CODE &&
             eb->ByteCount == 4) {
             *trans = ((eb->Bytes[0] & 1) == 1);
             *disposal = ((eb->Bytes[0] >> 2) & 7);
         }
     }
 }
 // return true if area of 'target' is completely covers area of 'covered'
 static bool checkIfCover(const SavedImage* target, const SavedImage* covered)
 {
     if (target->ImageDesc.Left <= covered->ImageDesc.Left
         && covered->ImageDesc.Left + covered->ImageDesc.Width <=
                target->ImageDesc.Left + target->ImageDesc.Width
         && target->ImageDesc.Top <= covered->ImageDesc.Top
         && covered->ImageDesc.Top + covered->ImageDesc.Height <=
                target->ImageDesc.Top + target->ImageDesc.Height) {
         return true;
     }
     return false;
 }
 static void disposeFrameIfNeeded(SkBitmap* bm, const SavedImage* cur, const SavedImage* next,
                                  SkBitmap* backup, SkColor color)
 {
     // We can skip disposal process if next frame is not transparent
     // and completely covers current area
     bool curTrans;
     int curDisposal;
     getTransparencyAndDisposalMethod(cur, &curTrans, &curDisposal);
     bool nextTrans;
     int nextDisposal;
     getTransparencyAndDisposalMethod(next, &nextTrans, &nextDisposal);
     if ((curDisposal == 2 || curDisposal == 3)
         && (nextTrans || !checkIfCover(next, cur))) {
         switch (curDisposal) {
         // restore to background color
         // -> 'background' means background under this image.
         case 2:
             fillRect(bm, cur->ImageDesc.Left, cur->ImageDesc.Top,
                      cur->ImageDesc.Width, cur->ImageDesc.Height,
                      color);
             break;
         // restore to previous
         case 3:
             bm->swap(*backup);
             break;
         }
     }
     // Save current image if next frame's disposal method == 3
     if (nextDisposal == 3) {
         const uint32_t* src = bm->getAddr32(0, 0);
         uint32_t* dst = backup->getAddr32(0, 0);
         int cnt = bm->width() * bm->height();
         memcpy(dst, src, cnt*sizeof(uint32_t));
     }
 }
 bool SkGIFMovie::onGetBitmap(SkBitmap* bm)
 {
     const GifFileType* gif = fGIF;
     if (NULL == gif)
         return false;
     if (gif->ImageCount < 1) {
         return false;
     }
     const int width = gif->SWidth;
     const int height = gif->SHeight;
     if (width <= 0 || height <= 0) {
         return false;
     }
     // no need to draw
     if (fLastDrawIndex >= 0 && fLastDrawIndex == fCurrIndex) {
         return true;
     }
     int startIndex = fLastDrawIndex + 1;
     if (fLastDrawIndex < 0 || !bm->readyToDraw()) {
         // first time
         startIndex = 0;
         // create bitmap
         if (!bm->allocPixels(SkImageInfo::MakeN32Premul(width, height))) {
             return false;
         }
         // create bitmap for backup
         if (!fBackup.allocPixels(SkImageInfo::MakeN32Premul(width, height))) {
             return false;
         }
     } else if (startIndex > fCurrIndex) {
         // rewind to 1st frame for repeat
         startIndex = 0;
     }
     int lastIndex = fCurrIndex;
     if (lastIndex < 0) {
         // first time
         lastIndex = 0;
     } else if (lastIndex > fGIF->ImageCount - 1) {
         // this block must not be reached.
         lastIndex = fGIF->ImageCount - 1;
     }
     SkColor bgColor = SkPackARGB32(0, 0, 0, 0);
     if (gif->SColorMap != NULL) {
         const GifColorType& col = gif->SColorMap->Colors[fGIF->SBackGroundColor];
         bgColor = SkColorSetARGB(0xFF, col.Red, col.Green, col.Blue);
     }
     static SkColor paintingColor = SkPackARGB32(0, 0, 0, 0);
     // draw each frames - not intelligent way
     for (int i = startIndex; i <= lastIndex; i++) {
         const SavedImage* cur = &fGIF->SavedImages[i];
         if (i == 0) {
             bool trans;
             int disposal;
             getTransparencyAndDisposalMethod(cur, &trans, &disposal);
             if (!trans && gif->SColorMap != NULL) {
                 paintingColor = bgColor;
             } else {
                 paintingColor = SkColorSetARGB(0, 0, 0, 0);
             }
             bm->eraseColor(paintingColor);
             fBackup.eraseColor(paintingColor);
         } else {
             // Dispose previous frame before move to next frame.
             const SavedImage* prev = &fGIF->SavedImages[i-1];
             disposeFrameIfNeeded(bm, prev, cur, &fBackup, paintingColor);
         }
         // Draw frame
         // We can skip this process if this index is not last and disposal
         // method == 2 or method == 3
         if (i == lastIndex || !checkIfWillBeCleared(cur)) {
             drawFrame(bm, cur, gif->SColorMap);
         }
     }
     // save index
     fLastDrawIndex = lastIndex;
     return true;
 }
 ///////////////////////////////////////////////////////////////////////////////
 #include "SkTRegistry.h"
 SkMovie* Factory(SkStreamRewindable* stream) {
     char buf[GIF_STAMP_LEN];
     if (stream->read(buf, GIF_STAMP_LEN) == GIF_STAMP_LEN) {
         if (memcmp(GIF_STAMP,   buf, GIF_STAMP_LEN) == 0 ||
                 memcmp(GIF87_STAMP, buf, GIF_STAMP_LEN) == 0 ||
                 memcmp(GIF89_STAMP, buf, GIF_STAMP_LEN) == 0) {
             // must rewind here, since our construct wants to re-read the data
             stream->rewind();
             return SkNEW_ARGS(SkGIFMovie, (stream));
         }
     }
     return NULL;
 }
 static SkTRegistry<SkMovie*(*)(SkStreamRewindable*)> gReg(Factory);

The Tor Browser / annotate

gfx/skia/trunk/src/images/SkMovie_gif.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/images/SkMovie_gif.cpp