SkMipmapAccessor Class Reference

#include <SkMipmapAccessor.h>

Inheritance diagram for SkMipmapAccessor:

Public Member Functions
std::pair< SkPixmap, SkMatrix >	level () const
std::pair< SkPixmap, SkMatrix >	lowerLevel () const
float	lowerWeight () const
	SkMipmapAccessor (const SkImage_Base *, const SkMatrix &inv, SkMipmapMode requestedMode)

Static Public Member Functions
static SkMipmapAccessor *	Make (SkArenaAlloc *, const SkImage *, const SkMatrix &inv, SkMipmapMode)

Detailed Description

Definition at line 26 of file SkMipmapAccessor.h.

Constructor & Destructor Documentation

SkMipmapAccessor()

SkMipmapAccessor::SkMipmapAccessor	(	const SkImage_Base *	image,
		const SkMatrix &	inv,
		SkMipmapMode	requestedMode
	)

Definition at line 35 of file SkMipmapAccessor.cpp.

                                                               {
    SkMipmapMode resolvedMode = requestedMode;
    fLowerWeight = 0;
 
    auto load_upper_from_base = [&]() {
        // only do this once
        if (fBaseStorage.getPixels() == nullptr) {
            auto dContext = as_IB(image)->directContext();
            (void)image->getROPixels(dContext, &fBaseStorage);
            fUpper.reset(fBaseStorage.info(), fBaseStorage.getPixels(), fBaseStorage.rowBytes());
        }
    };
 
    float level = 0;
    if (requestedMode != SkMipmapMode::kNone) {
        SkSize scale;
        if (!inv.decomposeScale(&scale, nullptr)) {
            resolvedMode = SkMipmapMode::kNone;
        } else {
            level = SkMipmap::ComputeLevel({1/scale.width(), 1/scale.height()});
            if (level <= 0) {
                resolvedMode = SkMipmapMode::kNone;
                level = 0;
            }
        }
    }
 
    auto scale = [image](const SkPixmap& pm) {
        return SkMatrix::Scale(SkIntToScalar(pm.width())  / image->width(),
                               SkIntToScalar(pm.height()) / image->height());
    };
 
    // Nearest mode uses this level, so we round to pick the nearest. In linear mode we use this
    // level as the lower of the two to interpolate between, so we take the floor.
    int levelNum = resolvedMode == SkMipmapMode::kNearest ? sk_float_round2int(level)
                                                          : sk_float_floor2int(level);
    float lowerWeight = level - levelNum;   // fract(level)
    SkASSERT(levelNum >= 0);
 
    if (levelNum == 0) {
        load_upper_from_base();
    }
    // load fCurrMip if needed
    if (levelNum > 0 || (resolvedMode == SkMipmapMode::kLinear && lowerWeight > 0)) {
        fCurrMip = try_load_mips(image);
        if (!fCurrMip) {
            load_upper_from_base();
            resolvedMode = SkMipmapMode::kNone;
        } else {
            SkMipmap::Level levelRec;
 
            SkASSERT(resolvedMode != SkMipmapMode::kNone);
            if (levelNum > 0) {
                if (fCurrMip->getLevel(levelNum - 1, &levelRec)) {
                    fUpper = levelRec.fPixmap;
                } else {
                    load_upper_from_base();
                    resolvedMode = SkMipmapMode::kNone;
                }
            }
 
            if (resolvedMode == SkMipmapMode::kLinear) {
                if (fCurrMip->getLevel(levelNum, &levelRec)) {
                    fLower = levelRec.fPixmap;
                    fLowerWeight = lowerWeight;
                    fLowerInv = scale(fLower);
                } else {
                    resolvedMode = SkMipmapMode::kNearest;
                }
            }
        }
    }
    fUpperInv = scale(fUpper);
}

Member Function Documentation

level()

std::pair< SkPixmap, SkMatrix > SkMipmapAccessor::level ( ) const

inline

Definition at line 31 of file SkMipmapAccessor.h.

                                              {
        SkASSERT(fUpper.addr() != nullptr);
        return std::make_pair(fUpper, fUpperInv);
    }

lowerLevel()

std::pair< SkPixmap, SkMatrix > SkMipmapAccessor::lowerLevel ( ) const

inline

Definition at line 36 of file SkMipmapAccessor.h.

                                                   {
        SkASSERT(fLower.addr() != nullptr);
        return std::make_pair(fLower, fLowerInv);
    }

lowerWeight()

float SkMipmapAccessor::lowerWeight ( ) const

inline

Definition at line 42 of file SkMipmapAccessor.h.

{ return fLowerWeight; }

Make()

SkMipmapAccessor * SkMipmapAccessor::Make ( SkArenaAlloc *  alloc, const SkImage *  image, const SkMatrix &  inv, SkMipmapMode  mipmap  )

static

Definition at line 111 of file SkMipmapAccessor.cpp.

                                                                                   {
    auto* access = alloc->make<SkMipmapAccessor>(as_IB(image), inv, mipmap);
    // return null if we failed to get the level (so the caller won't try to use it)
    return access->fUpper.addr() ? access : nullptr;
}

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

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