diff options
author | msarett <msarett@google.com> | 2015-10-13 12:50:14 -0700 |
---|---|---|
committer | Commit bot <commit-bot@chromium.org> | 2015-10-13 12:50:14 -0700 |
commit | fdb47571a3b5e72469b67de44e32ac14d9352ab4 (patch) | |
tree | cc98e7952e756c3c8825e7f9af3b280b3fc7b449 /src/codec/SkSwizzler.cpp | |
parent | eb85b8321bc917169ba26c8fce76b64d2e3dfe81 (diff) |
Add subsetting to SkScanlineDecoder
This CL allows the SkScanlineDecoder to decode partial
scanlines.
This is a first step in efficiently implementing subsetting
in SkScaledCodec.
BUG=skia:4209
Review URL: https://codereview.chromium.org/1390213002
Diffstat (limited to 'src/codec/SkSwizzler.cpp')
-rw-r--r-- | src/codec/SkSwizzler.cpp | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/src/codec/SkSwizzler.cpp b/src/codec/SkSwizzler.cpp index 8d13e56bd2..95ed1d7b96 100644 --- a/src/codec/SkSwizzler.cpp +++ b/src/codec/SkSwizzler.cpp @@ -230,9 +230,6 @@ static SkSwizzler::ResultAlpha swizzle_index_to_index( // SkScaledBitmap sampler just guesses that it is opaque. This is dangerous // and probably wrong since gif and bmp (rarely) may have alpha. if (1 == deltaSrc) { - // A non-zero offset is only used when sampling, meaning that deltaSrc will be - // greater than 1. The below loop relies on the fact that src remains unchanged. - SkASSERT(0 == offset); memcpy(dst, src, dstWidth); for (int x = 0; x < dstWidth; x++) { UPDATE_RESULT_ALPHA(ctable[src[x]] >> SK_A32_SHIFT); @@ -514,8 +511,8 @@ static bool swizzle_rgba_to_n32_unpremul_skipZ(void* SK_RESTRICT dstRow, SkSwizzler* SkSwizzler::CreateSwizzler(SkSwizzler::SrcConfig sc, const SkPMColor* ctable, - const SkImageInfo& dstInfo, - SkCodec::ZeroInitialized zeroInit) { + const SkImageInfo& dstInfo, + const SkCodec::Options& options) { if (dstInfo.colorType() == kUnknown_SkColorType || kUnknown == sc) { return nullptr; } @@ -524,7 +521,7 @@ SkSwizzler* SkSwizzler::CreateSwizzler(SkSwizzler::SrcConfig sc, return nullptr; } RowProc proc = nullptr; - + SkCodec::ZeroInitialized zeroInit = options.fZeroInitialized; switch (sc) { case kBit: switch (dstInfo.colorType()) { @@ -683,28 +680,35 @@ SkSwizzler* SkSwizzler::CreateSwizzler(SkSwizzler::SrcConfig sc, return nullptr; } - // Store deltaSrc in bytes if it is an even multiple, otherwise use bits - int deltaSrc = SkIsAlign8(BitsPerPixel(sc)) ? BytesPerPixel(sc) : BitsPerPixel(sc); + // Store bpp in bytes if it is an even multiple, otherwise use bits + int bpp = SkIsAlign8(BitsPerPixel(sc)) ? BytesPerPixel(sc) : BitsPerPixel(sc); + + int srcOffset = 0; + int srcWidth = dstInfo.width(); + if (options.fSubset) { + srcOffset = options.fSubset->left(); + srcWidth = options.fSubset->width(); + } - return new SkSwizzler(proc, ctable, deltaSrc, dstInfo.width()); + return new SkSwizzler(proc, ctable, srcOffset, srcWidth, bpp); } -SkSwizzler::SkSwizzler(RowProc proc, const SkPMColor* ctable, - int deltaSrc, int srcWidth) +SkSwizzler::SkSwizzler(RowProc proc, const SkPMColor* ctable, int srcOffset, int srcWidth, int bpp) : fRowProc(proc) , fColorTable(ctable) - , fDeltaSrc(deltaSrc) + , fSrcOffset(srcOffset) + , fX0(srcOffset) , fSrcWidth(srcWidth) , fDstWidth(srcWidth) + , fBPP(bpp) , fSampleX(1) - , fX0(0) {} int SkSwizzler::onSetSampleX(int sampleX) { SkASSERT(sampleX > 0); // Surely there is an upper limit? Should there be // way to report failure? fSampleX = sampleX; - fX0 = get_start_coord(sampleX); + fX0 = get_start_coord(sampleX) + fSrcOffset; fDstWidth = get_scaled_dimension(fSrcWidth, sampleX); // check that fX0 is less than original width @@ -714,6 +718,5 @@ int SkSwizzler::onSetSampleX(int sampleX) { SkSwizzler::ResultAlpha SkSwizzler::swizzle(void* dst, const uint8_t* SK_RESTRICT src) { SkASSERT(nullptr != dst && nullptr != src); - return fRowProc(dst, src, fDstWidth, fDeltaSrc, fSampleX * fDeltaSrc, - fX0 * fDeltaSrc, fColorTable); + return fRowProc(dst, src, fDstWidth, fBPP, fSampleX * fBPP, fX0 * fBPP, fColorTable); } |