diff options
| -rw-r--r-- | src/images/SkMovie_gif.cpp | 370 |
1 files changed, 295 insertions, 75 deletions
diff --git a/src/images/SkMovie_gif.cpp b/src/images/SkMovie_gif.cpp index 1138044..0a85c2d 100644 --- a/src/images/SkMovie_gif.cpp +++ b/src/images/SkMovie_gif.cpp @@ -20,6 +20,7 @@ #include "SkColorPriv.h" #include "SkStream.h" #include "SkTemplates.h" +#include "SkUtils.h" #include "gif_lib.h" @@ -35,7 +36,9 @@ protected: private: GifFileType* fGIF; - SavedImage* fCurrSavedImage; + int fCurrIndex; + int fLastDrawIndex; + SkBitmap fBackup; }; static int Decode(GifFileType* fileType, GifByteType* out, int size) { @@ -54,7 +57,8 @@ SkGIFMovie::SkGIFMovie(SkStream* stream) DGifCloseFile(fGIF); fGIF = NULL; } - fCurrSavedImage = NULL; + fCurrIndex = -1; + fLastDrawIndex = -1; } SkGIFMovie::~SkGIFMovie() @@ -105,29 +109,242 @@ bool SkGIFMovie::onSetTime(SkMSec time) dur += savedimage_duration(&fGIF->SavedImages[i]); if (dur >= time) { - SavedImage* prev = fCurrSavedImage; - fCurrSavedImage = &fGIF->SavedImages[i]; - return prev != fCurrSavedImage; + fCurrIndex = i; + return fLastDrawIndex != fCurrIndex; } } - fCurrSavedImage = &fGIF->SavedImages[fGIF->ImageCount - 1]; + 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); + } + } +} + +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); +} + +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; + } + + int srcPad, dstPad; + dstPad = width - copyWidth; + srcPad = frame->ImageDesc.Width - copyWidth; + 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)) { + SkASSERT(!"bad colortable setup"); + return; + } + + if (frame->ImageDesc.Interlace) { + blitInterlace(bm, frame, cmap, transparent); + } else { + 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) { - GifFileType* gif = fGIF; + const GifFileType* gif = fGIF; if (NULL == gif) return false; - // should we check for the Image cmap or the global (SColorMap) first? - ColorMapObject* cmap = gif->SColorMap; - if (cmap == NULL) - cmap = gif->Image.ColorMap; - - if (cmap == NULL || gif->ImageCount < 1 || cmap->ColorCount != (1 << cmap->BitsPerPixel)) - { - SkASSERT(!"bad colortable setup"); + if (gif->ImageCount < 1) { return false; } @@ -137,76 +354,79 @@ bool SkGIFMovie::onGetBitmap(SkBitmap* bm) return false; } - SavedImage* gif_image = fCurrSavedImage; - SkBitmap::Config config = SkBitmap::kIndex8_Config; + // no need to draw + if (fLastDrawIndex >= 0 && fLastDrawIndex == fCurrIndex) { + return true; + } - SkColorTable* colorTable = SkNEW_ARGS(SkColorTable, (cmap->ColorCount)); - SkAutoUnref aur(colorTable); + int startIndex = fLastDrawIndex + 1; + if (fLastDrawIndex < 0 || !bm->readyToDraw()) { + // first time - bm->setConfig(config, width, height, 0); - if (!bm->allocPixels(colorTable)) { - return false; - } + startIndex = 0; - int transparent = -1; - for (int i = 0; i < gif_image->ExtensionBlockCount; ++i) { - ExtensionBlock* eb = gif_image->ExtensionBlocks + i; - if (eb->Function == 0xF9 && - eb->ByteCount == 4) { - bool has_transparency = ((eb->Bytes[0] & 1) == 1); - if (has_transparency) { - transparent = (unsigned char)eb->Bytes[3]; + // create bitmap + bm->setConfig(SkBitmap::kARGB_8888_Config, width, height, 0); + if (!bm->allocPixels(NULL)) { + return false; } - } + // create bitmap for backup + fBackup.setConfig(SkBitmap::kARGB_8888_Config, width, height, 0); + if (!fBackup.allocPixels(NULL)) { + return false; + } + } else if (startIndex > fCurrIndex) { + // rewind to 1st frame for repeat + startIndex = 0; } - SkPMColor* colorPtr = colorTable->lockColors(); + 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; + } - if (transparent >= 0) - memset(colorPtr, 0, cmap->ColorCount * 4); - else - colorTable->setFlags(colorTable->getFlags() | SkColorTable::kColorsAreOpaque_Flag); + 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); + } - for (int index = 0; index < cmap->ColorCount; index++) - { - if (transparent != index) - colorPtr[index] = SkPackARGB32(0xFF, cmap->Colors[index].Red, - cmap->Colors[index].Green, cmap->Colors[index].Blue); - } - colorTable->unlockColors(true); - - unsigned char* in = (unsigned char*)gif_image->RasterBits; - unsigned char* out = bm->getAddr8(0, 0); - if (gif->Image.Interlace) { - - // deinterlace - int row; - // group 1 - every 8th row, starting with row 0 - for (row = 0; row < height; row += 8) { - memcpy(out + width * row, in, width); - in += width; - } - - // group 2 - every 8th row, starting with row 4 - for (row = 4; row < height; row += 8) { - memcpy(out + width * row, in, width); - in += width; - } - - // group 3 - every 4th row, starting with row 2 - for (row = 2; row < height; row += 4) { - memcpy(out + width * row, in, width); - in += width; - } - - for (row = 1; row < height; row += 2) { - memcpy(out + width * row, in, width); - in += width; - } + 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); + } - } else { - memcpy(out, in, width * height); + // 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; } |