SkSampler Class Reference

#include <SkSampler.h>

Inheritance diagram for SkSampler:

Public Member Functions
int	setSampleX (int sampleX)
void	setSampleY (int sampleY)
int	sampleY () const
bool	rowNeeded (int row) const
virtual int	fillWidth () const =0
	SkSampler ()
virtual	~SkSampler ()
Public Member Functions inherited from SkNoncopyable
	SkNoncopyable ()=default
	SkNoncopyable (SkNoncopyable &&)=default
SkNoncopyable &	operator= (SkNoncopyable &&)=default

Static Public Member Functions
static void	Fill (const SkImageInfo &info, void *dst, size_t rowBytes, SkCodec::ZeroInitialized zeroInit)

Private Member Functions
virtual int	onSetSampleX (int)=0

Detailed Description

Definition at line 19 of file SkSampler.h.

Constructor & Destructor Documentation

SkSampler()

SkSampler::SkSampler ( )

inline

Definition at line 78 of file SkSampler.h.

        : fSampleY(1)
    {}

~SkSampler()

virtual SkSampler::~SkSampler ( )

inlinevirtual

Definition at line 82 of file SkSampler.h.

{}

Member Function Documentation

Fill()

void SkSampler::Fill ( const SkImageInfo &  info, void *  dst, size_t  rowBytes, SkCodec::ZeroInitialized  zeroInit  )

static

Fill the remainder of the destination with 0.

0 has a different meaning depending on the SkColorType. For color types with transparency, this means transparent. For k565 and kGray, 0 is black.

Parameters

info	Contains the color type of the rows to fill. Contains the pixel width of the destination rows to fill Contains the number of rows that we need to fill.
dst	The destination row to fill.
rowBytes	Stride in bytes of the destination.
zeroInit	Indicates whether memory is already zero initialized.

Definition at line 20 of file SkSampler.cpp.

                                                      {
    SkASSERT(dst != nullptr);
 
    if (SkCodec::kYes_ZeroInitialized == zeroInit) {
        return;
    }
 
    const int width = info.width();
    const int numRows = info.height();
 
    // Use the proper memset routine to fill the remaining bytes
    switch (info.colorType()) {
        case kRGBA_8888_SkColorType:
        case kBGRA_8888_SkColorType: {
            uint32_t* dstRow = (uint32_t*) dst;
            for (int row = 0; row < numRows; row++) {
                SkOpts::memset32(dstRow, 0, width);
                dstRow = SkTAddOffset<uint32_t>(dstRow, rowBytes);
            }
            break;
        }
        case kRGB_565_SkColorType: {
            uint16_t* dstRow = (uint16_t*) dst;
            for (int row = 0; row < numRows; row++) {
                SkOpts::memset16(dstRow, 0, width);
                dstRow = SkTAddOffset<uint16_t>(dstRow, rowBytes);
            }
            break;
        }
        case kGray_8_SkColorType: {
            uint8_t* dstRow = (uint8_t*) dst;
            for (int row = 0; row < numRows; row++) {
                memset(dstRow, 0, width);
                dstRow = SkTAddOffset<uint8_t>(dstRow, rowBytes);
            }
            break;
        }
        case kRGBA_F16_SkColorType: {
            uint64_t* dstRow = (uint64_t*) dst;
            for (int row = 0; row < numRows; row++) {
                SkOpts::memset64(dstRow, 0, width);
                dstRow = SkTAddOffset<uint64_t>(dstRow, rowBytes);
            }
            break;
        }
        default:
            SkCodecPrintf("Error: Unsupported dst color type for fill().  Doing nothing.\n");
            SkASSERT(false);
            break;
    }
}

fillWidth()

virtual int SkSampler::fillWidth ( ) const

pure virtual

Implemented in SkBmpRLESampler, SkMaskSwizzler, and SkSwizzler.

onSetSampleX()

virtual int SkSampler::onSetSampleX ( int  )

privatepure virtual

Implemented in SkBmpRLESampler, SkMaskSwizzler, and SkSwizzler.

rowNeeded()

bool SkSampler::rowNeeded ( int  row ) const

inline

Based on fSampleY, return whether this row belongs in the output.

Parameters

row	Row of the image, starting with the first row in the subset.

Definition at line 48 of file SkSampler.h.

                                  {
        return (row - get_start_coord(fSampleY)) % fSampleY == 0;
    }

sampleY()

int SkSampler::sampleY ( ) const

inline

Retrieve the value set for sampleY.

Definition at line 39 of file SkSampler.h.

                        {
        return fSampleY;
    }

setSampleX()

int SkSampler::setSampleX ( int  sampleX )

inline

Update the sampler to sample every sampleX'th pixel. Returns the width after sampling.

Definition at line 25 of file SkSampler.h.

                                {
        return this->onSetSampleX(sampleX);
    }

setSampleY()

void SkSampler::setSampleY ( int  sampleY )

inline

Update the sampler to sample every sampleY'th row.

Definition at line 32 of file SkSampler.h.

                                 {
        fSampleY = sampleY;
    }

---

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

• third_party/skia/src/codec/SkSampler.h
• third_party/skia/src/codec/SkSampler.cpp