SkAAClipBlitter Class Reference

#include <SkAAClip.h>

Inheritance diagram for SkAAClipBlitter:

Public Member Functions
	SkAAClipBlitter ()
	~SkAAClipBlitter () override
void	init (SkBlitter *blitter, const SkAAClip *aaclip)
void	blitH (int x, int y, int width) override
	Blit a horizontal run of one or more pixels.
void	blitAntiH (int x, int y, const SkAlpha[], const int16_t runs[]) override
void	blitV (int x, int y, int height, SkAlpha alpha) override
	Blit a vertical run of pixels with a constant alpha value.
void	blitRect (int x, int y, int width, int height) override
	Blit a solid rectangle one or more pixels wide.
void	blitMask (const SkMask &, const SkIRect &clip) override
Public Member Functions inherited from SkBlitter
virtual	~SkBlitter ()
virtual void	blitAntiRect (int x, int y, int width, int height, SkAlpha leftAlpha, SkAlpha rightAlpha)
void	blitFatAntiRect (const SkRect &rect)
virtual void	blitAntiH2 (int x, int y, U8CPU a0, U8CPU a1)
virtual void	blitAntiV2 (int x, int y, U8CPU a0, U8CPU a1)
virtual bool	isNullBlitter () const
virtual int	requestRowsPreserved () const
virtual void *	allocBlitMemory (size_t sz)
void	blitRectRegion (const SkIRect &rect, const SkRegion &clip)
void	blitRegion (const SkRegion &clip)

Additional Inherited Members
Static Public Member Functions inherited from SkBlitter
static bool	UseLegacyBlitter (const SkPixmap &, const SkPaint &, const SkMatrix &)
static SkBlitter *	Choose (const SkPixmap &dst, const SkMatrix &ctm, const SkPaint &paint, SkArenaAlloc *, bool drawCoverage, sk_sp< SkShader > clipShader, const SkSurfaceProps &props)
static SkBlitter *	ChooseSprite (const SkPixmap &dst, const SkPaint &, const SkPixmap &src, int left, int top, SkArenaAlloc *, sk_sp< SkShader > clipShader)
Protected Attributes inherited from SkBlitter
SkAutoMalloc	fBlitMemory

Detailed Description

Definition at line 91 of file SkAAClip.h.

Constructor & Destructor Documentation

SkAAClipBlitter()

SkAAClipBlitter::SkAAClipBlitter ( )

inline

Definition at line 93 of file SkAAClip.h.

: fScanlineScratch(nullptr) {}

~SkAAClipBlitter()

SkAAClipBlitter::~SkAAClipBlitter ( )

override

Definition at line 1649 of file SkAAClip.cpp.

                                  {
    sk_free(fScanlineScratch);
}

Member Function Documentation

blitAntiH()

void SkAAClipBlitter::blitAntiH ( int  x, int  y, const SkAlpha  antialias[], const int16_t  runs[]  )

overridevirtual

Blit a horizontal run of antialiased pixels; runs[] is a sparse zero-terminated run-length encoding of spans of constant alpha values. The runs[] and antialias[] work together to represent long runs of pixels with the same alphas. The runs[] contains the number of pixels with the same alpha, and antialias[] contain the coverage value for that number of pixels. The runs[] (and antialias[]) are encoded in a clever way. The runs array is zero terminated, and has enough entries for each pixel plus one, in most cases some of the entries will not contain valid data. An entry in the runs array contains the number of pixels (np) that have the same alpha value. The next np value is found np entries away. For example, if runs[0] = 7, then the next valid entry will by at runs[7]. The runs array and antialias[] are coupled by index. So, if the np entry is at runs[45] = 12 then the alpha value can be found at antialias[45] = 0x88. This would mean to use an alpha value of 0x88 for the next 12 pixels starting at pixel 45.

Implements SkBlitter.

Definition at line 1735 of file SkAAClip.cpp.

                                                      {
 
    const uint8_t* row = fAAClip->findRow(y);
    int initialCount;
    row = fAAClip->findX(row, x, &initialCount);
 
    this->ensureRunsAndAA();
 
    merge(row, initialCount, aa, runs, fAA, fRuns, fAAClipBounds.width());
    fBlitter->blitAntiH(x, y, fAA, fRuns);
}

blitH()

void SkAAClipBlitter::blitH ( int  x, int  y, int  width  )

overridevirtual

Blit a horizontal run of one or more pixels.

Implements SkBlitter.

Definition at line 1665 of file SkAAClip.cpp.

                                                   {
    SkASSERT(width > 0);
    SkASSERT(fAAClipBounds.contains(x, y));
    SkASSERT(fAAClipBounds.contains(x + width  - 1, y));
 
    const uint8_t* row = fAAClip->findRow(y);
    int initialCount;
    row = fAAClip->findX(row, x, &initialCount);
 
    if (initialCount >= width) {
        SkAlpha alpha = row[1];
        if (0 == alpha) {
            return;
        }
        if (0xFF == alpha) {
            fBlitter->blitH(x, y, width);
            return;
        }
    }
 
    this->ensureRunsAndAA();
    expandToRuns(row, initialCount, width, fRuns, fAA);
 
    fBlitter->blitAntiH(x, y, fAA, fRuns);
}

blitMask()

void SkAAClipBlitter::blitMask ( const SkMask &  mask, const SkIRect &  clip  )

overridevirtual

Blit a pattern of pixels defined by a rectangle-clipped mask; typically used for text.

Reimplemented from SkBlitter.

Definition at line 1909 of file SkAAClip.cpp.

                                                                          {
    SkASSERT(fAAClip->getBounds().contains(clip));
 
    if (fAAClip->quickContains(clip)) {
        fBlitter->blitMask(origMask, clip);
        return;
    }
 
    const SkMask* mask = &origMask;
 
    // if we're BW, we need to upscale to A8 (ugh)
    SkMaskBuilder  grayMask;
    if (SkMask::kBW_Format == origMask.fFormat) {
        grayMask.format() = SkMask::kA8_Format;
        grayMask.bounds() = origMask.fBounds;
        grayMask.rowBytes() = origMask.fBounds.width();
        size_t size = grayMask.computeImageSize();
        grayMask.image() = reinterpret_cast<uint8_t*>(
            fGrayMaskScratch.reset(size, SkAutoMalloc::kReuse_OnShrink));
 
        upscaleBW2A8(&grayMask, origMask);
        mask = &grayMask;
    }
 
    this->ensureRunsAndAA();
 
    // HACK -- we are devolving 3D into A8, need to copy the rest of the 3D
    // data into a temp block to support it better (ugh)
 
    const void* src = mask->getAddr(clip.fLeft, clip.fTop);
    const size_t srcRB = mask->fRowBytes;
    const int width = clip.width();
    MergeAAProc mergeProc = find_merge_aa_proc(mask->fFormat);
 
    SkMaskBuilder rowMask;
    rowMask.format() = SkMask::k3D_Format == mask->fFormat ? SkMask::kA8_Format : mask->fFormat;
    rowMask.bounds().fLeft = clip.fLeft;
    rowMask.bounds().fRight = clip.fRight;
    rowMask.rowBytes() = mask->fRowBytes; // doesn't matter, since our height==1
    rowMask.image() = (uint8_t*)fScanlineScratch;
 
    int y = clip.fTop;
    const int stopY = y + clip.height();
 
    do {
        int localStopY SK_INIT_TO_AVOID_WARNING;
        const uint8_t* row = fAAClip->findRow(y, &localStopY);
        // findRow returns last Y, not stop, so we add 1
        localStopY = std::min(localStopY + 1, stopY);
 
        int initialCount;
        row = fAAClip->findX(row, clip.fLeft, &initialCount);
        do {
            mergeProc(src, width, row, initialCount, rowMask.image());
            rowMask.bounds().fTop = y;
            rowMask.bounds().fBottom = y + 1;
            fBlitter->blitMask(rowMask, rowMask.fBounds);
            src = (const void*)((const char*)src + srcRB);
        } while (++y < localStopY);
    } while (y < stopY);
}

blitRect()

void SkAAClipBlitter::blitRect ( int  x, int  y, int  width, int  height  )

overridevirtual

Blit a solid rectangle one or more pixels wide.

Reimplemented from SkBlitter.

Definition at line 1776 of file SkAAClip.cpp.

                                                                  {
    if (fAAClip->quickContains(x, y, x + width, y + height)) {
        fBlitter->blitRect(x, y, width, height);
        return;
    }
 
    while (--height >= 0) {
        this->blitH(x, y, width);
        y += 1;
    }
}

blitV()

void SkAAClipBlitter::blitV ( int  x, int  y, int  height, SkAlpha  alpha  )

overridevirtual

Blit a vertical run of pixels with a constant alpha value.

Reimplemented from SkBlitter.

Definition at line 1748 of file SkAAClip.cpp.

                                                                   {
    if (fAAClip->quickContains(x, y, x + 1, y + height)) {
        fBlitter->blitV(x, y, height, alpha);
        return;
    }
 
    for (;;) {
        int lastY SK_INIT_TO_AVOID_WARNING;
        const uint8_t* row = fAAClip->findRow(y, &lastY);
        int dy = lastY - y + 1;
        if (dy > height) {
            dy = height;
        }
        height -= dy;
 
        row = fAAClip->findX(row, x);
        SkAlpha newAlpha = SkMulDiv255Round(alpha, row[1]);
        if (newAlpha) {
            fBlitter->blitV(x, y, dy, newAlpha);
        }
        SkASSERT(height >= 0);
        if (height <= 0) {
            break;
        }
        y = lastY + 1;
    }
}

init()

void SkAAClipBlitter::init ( SkBlitter *  blitter, const SkAAClip *  aaclip  )

inline

Definition at line 96 of file SkAAClip.h.

                                                          {
        SkASSERT(aaclip && !aaclip->isEmpty());
        fBlitter = blitter;
        fAAClip = aaclip;
        fAAClipBounds = aaclip->getBounds();
    }

---

The documentation for this class was generated from the following files:

• third_party/skia/src/core/SkAAClip.h
• third_party/skia/src/core/SkAAClip.cpp