C++ SkScalarInvert函数代码示例

 void draw(SkCanvas* canvas,
           const SkRect& rect,
           const SkSize& deviceSize,
           SkPaint::FilterLevel filterLevel,
           SkImageFilter* input = NULL) {
     SkRect dstRect;
     canvas->getTotalMatrix().mapRect(&dstRect, rect);
     canvas->save();
     SkScalar deviceScaleX = SkScalarDiv(deviceSize.width(), dstRect.width());
     SkScalar deviceScaleY = SkScalarDiv(deviceSize.height(), dstRect.height());
     canvas->translate(rect.x(), rect.y());
     canvas->scale(deviceScaleX, deviceScaleY);
     canvas->translate(-rect.x(), -rect.y());
     SkMatrix matrix;
     matrix.setScale(SkScalarInvert(deviceScaleX),
                     SkScalarInvert(deviceScaleY));
     SkAutoTUnref<SkImageFilter> imageFilter(
         SkMatrixImageFilter::Create(matrix, filterLevel, input));
     SkPaint filteredPaint;
     filteredPaint.setImageFilter(imageFilter.get());
     canvas->saveLayer(&rect, &filteredPaint);
     SkPaint paint;
     paint.setColor(0xFF00FF00);
     SkRect ovalRect = rect;
     ovalRect.inset(SkIntToScalar(4), SkIntToScalar(4));
     canvas->drawOval(ovalRect, paint);
     canvas->restore(); // for saveLayer
     canvas->restore();
 }

    PaintingData(const SkISize& tileSize, SkScalar seed,
                 SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                 const SkMatrix& matrix)
    {
        SkVector wavelength = SkVector::Make(SkScalarInvert(baseFrequencyX),
                                             SkScalarInvert(baseFrequencyY));
        matrix.mapVectors(&wavelength, 1);
        fBaseFrequency.fX = SkScalarInvert(wavelength.fX);
        fBaseFrequency.fY = SkScalarInvert(wavelength.fY);
        SkVector sizeVec = SkVector::Make(SkIntToScalar(tileSize.fWidth),
                                          SkIntToScalar(tileSize.fHeight));
        matrix.mapVectors(&sizeVec, 1);
        fTileSize.fWidth = SkScalarRoundToInt(sizeVec.fX);
        fTileSize.fHeight = SkScalarRoundToInt(sizeVec.fY);
        this->init(seed);
        if (!fTileSize.isEmpty()) {
            this->stitch();
        }

#if SK_SUPPORT_GPU
        fPermutationsBitmap.setInfo(SkImageInfo::MakeA8(kBlockSize, 1));
        fPermutationsBitmap.setPixels(fLatticeSelector);

        fNoiseBitmap.setInfo(SkImageInfo::MakeN32Premul(kBlockSize, 4));
        fNoiseBitmap.setPixels(fNoise[0][0]);
#endif
    }

    PaintingData(const SkISize& tileSize, SkScalar seed,
                 SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                 const SkMatrix& matrix)
    {
        SkVector vec[2] = {
            { SkScalarInvert(baseFrequencyX),   SkScalarInvert(baseFrequencyY)  },
            { SkIntToScalar(tileSize.fWidth),   SkIntToScalar(tileSize.fHeight) },
        };
        matrix.mapVectors(vec, 2);

        fBaseFrequency.set(SkScalarInvert(vec[0].fX), SkScalarInvert(vec[0].fY));
        fTileSize.set(SkScalarRoundToInt(vec[1].fX), SkScalarRoundToInt(vec[1].fY));
        this->init(seed);
        if (!fTileSize.isEmpty()) {
            this->stitch();
        }

#if SK_SUPPORT_GPU
        fPermutationsBitmap.setInfo(SkImageInfo::MakeA8(kBlockSize, 1));
        fPermutationsBitmap.setPixels(fLatticeSelector);

        fNoiseBitmap.setInfo(SkImageInfo::MakeN32Premul(kBlockSize, 4));
        fNoiseBitmap.setPixels(fNoise[0][0]);
#endif
    }

SkTileGrid::SkTileGrid(int xTiles, int yTiles, const SkTileGridFactory::TileGridInfo& info)
    : fXTiles(xTiles)
    , fYTiles(yTiles)
    , fInvWidth( SkScalarInvert(info.fTileInterval.width()))
    , fInvHeight(SkScalarInvert(info.fTileInterval.height()))
    , fMarginWidth (info.fMargin.fWidth +1)  // Margin is offset by 1 as a provision for AA and
    , fMarginHeight(info.fMargin.fHeight+1)  // to cancel the outset applied by getClipDeviceBounds.
    , fOffset(SkPoint::Make(info.fOffset.fX, info.fOffset.fY))
    , fGridBounds(SkRect::MakeWH(xTiles * info.fTileInterval.width(),
                                 yTiles * info.fTileInterval.height()))
    , fTiles(SkNEW_ARRAY(SkTDArray<unsigned>, xTiles * yTiles)) {}

/*
 *  Modulo internal errors, this should always succeed *if* the matrix is downscaling
 *  (in this case, we have the inverse, so it succeeds if fInvMatrix is upscaling)
 */
bool SkDefaultBitmapControllerState::processMediumRequest(const SkBitmapProvider& provider) {
    SkASSERT(fQuality <= kMedium_SkFilterQuality);
    if (fQuality != kMedium_SkFilterQuality) {
        return false;
    }

    // Our default return state is to downgrade the request to Low, w/ or w/o setting fBitmap
    // to a valid bitmap.
    fQuality = kLow_SkFilterQuality;

    SkSize invScaleSize;
    if (!fInvMatrix.decomposeScale(&invScaleSize, nullptr)) {
        return false;
    }

    SkDestinationSurfaceColorMode colorMode = provider.dstColorSpace()
        ? SkDestinationSurfaceColorMode::kGammaAndColorSpaceAware
        : SkDestinationSurfaceColorMode::kLegacy;
    if (invScaleSize.width() > SK_Scalar1 || invScaleSize.height() > SK_Scalar1) {
        fCurrMip.reset(SkMipMapCache::FindAndRef(provider.makeCacheDesc(), colorMode));
        if (nullptr == fCurrMip.get()) {
            SkBitmap orig;
            if (!provider.asBitmap(&orig)) {
                return false;
            }
            fCurrMip.reset(SkMipMapCache::AddAndRef(orig, colorMode));
            if (nullptr == fCurrMip.get()) {
                return false;
            }
        }
        // diagnostic for a crasher...
        SkASSERT_RELEASE(fCurrMip->data());

        const SkSize scale = SkSize::Make(SkScalarInvert(invScaleSize.width()),
                                          SkScalarInvert(invScaleSize.height()));
        SkMipMap::Level level;
        if (fCurrMip->extractLevel(scale, &level)) {
            const SkSize& invScaleFixup = level.fScale;
            fInvMatrix.postScale(invScaleFixup.width(), invScaleFixup.height());

            // todo: if we could wrap the fCurrMip in a pixelref, then we could just install
            //       that here, and not need to explicitly track it ourselves.
            return fResultBitmap.installPixels(level.fPixmap);
        } else {
            // failed to extract, so release the mipmap
            fCurrMip.reset(nullptr);
        }
    }
    return false;
}

bool SkPathContainsPoint(SkPath* originalPath, const FloatPoint& point, SkPath::FillType ft)
{
	SkRegion rgn;
	SkRegion clip;

	SkPath::FillType originalFillType = originalPath->getFillType();

	const SkPath* path = originalPath;
	SkPath scaledPath;
	int scale = 1;

	SkRect bounds = originalPath->getBounds();

	// We can immediately return false if the point is outside the bounding
	// rect.  We don't use bounds.contains() here, since it would exclude
	// points on the right and bottom edges of the bounding rect, and we want
	// to include them.
	SkScalar fX = SkFloatToScalar(point.x());
	SkScalar fY = SkFloatToScalar(point.y());
	if (fX < bounds.fLeft || fX > bounds.fRight || fY < bounds.fTop || fY > bounds.fBottom)
		return false;

	originalPath->setFillType(ft);

	// Skia has trouble with coordinates close to the max signed 16-bit values
	// If we have those, we need to scale. 
	//
	// TODO: remove this code once Skia is patched to work properly with large
	// values
	const SkScalar kMaxCoordinate = SkIntToScalar(1<<15);
	SkScalar biggestCoord = std::max(std::max(std::max(bounds.fRight, bounds.fBottom), -bounds.fLeft), -bounds.fTop);

	if (biggestCoord > kMaxCoordinate) {
		scale = SkScalarCeil(SkScalarDiv(biggestCoord, kMaxCoordinate));

		SkMatrix m;
		m.setScale(SkScalarInvert(SkIntToScalar(scale)), SkScalarInvert(SkIntToScalar(scale)));
		originalPath->transform(m, &scaledPath);
		path = &scaledPath;
	}

	int x = static_cast<int>(floorf(point.x() / scale));
	int y = static_cast<int>(floorf(point.y() / scale));
	clip.setRect(x - 1, y - 1, x + 1, y + 1);

	bool contains = rgn.setPath(*path, clip);

	originalPath->setFillType(originalFillType);
	return contains;
}

SkPathStroker::SkPathStroker(const SkPath& src,
                             SkScalar radius, SkScalar miterLimit,
                             SkPaint::Cap cap, SkPaint::Join join)
        : fRadius(radius) {

    /*  This is only used when join is miter_join, but we initialize it here
        so that it is always defined, to fis valgrind warnings.
    */
    fInvMiterLimit = 0;

    if (join == SkPaint::kMiter_Join) {
        if (miterLimit <= SK_Scalar1) {
            join = SkPaint::kBevel_Join;
        } else {
            fInvMiterLimit = SkScalarInvert(miterLimit);
        }
    }
    fCapper = SkStrokerPriv::CapFactory(cap);
    fJoiner = SkStrokerPriv::JoinFactory(join);
    fSegmentCount = -1;
    fPrevIsLine = false;

    // Need some estimate of how large our final result (fOuter)
    // and our per-contour temp (fInner) will be, so we don't spend
    // extra time repeatedly growing these arrays.
    //
    // 3x for result == inner + outer + join (swag)
    // 1x for inner == 'wag' (worst contour length would be better guess)
    fOuter.incReserve(src.countPoints() * 3);
    fInner.incReserve(src.countPoints());
}

void GrColorCubeEffect::GLProcessor::setData(const GrGLProgramDataManager& pdman,
                                             const GrProcessor& proc) {
    const GrColorCubeEffect& colorCube = proc.cast<GrColorCubeEffect>();
    SkScalar size = SkIntToScalar(colorCube.colorCubeSize());
    pdman.set1f(fColorCubeSizeUni, SkScalarToFloat(size));
    pdman.set1f(fColorCubeInvSizeUni, SkScalarToFloat(SkScalarInvert(size)));
}

bool SkMagnifierImageFilter::asFragmentProcessor(GrFragmentProcessor** fp,
                                                 GrProcessorDataManager* procDataManager,
                                                 GrTexture* texture, const SkMatrix&,
                                                 const SkIRect&bounds) const {
    if (fp) {
        SkScalar yOffset = texture->origin() == kTopLeft_GrSurfaceOrigin ? fSrcRect.y() :
           texture->height() - fSrcRect.height() * texture->height() / bounds.height()
                             - fSrcRect.y();
        int boundsY = (texture->origin() == kTopLeft_GrSurfaceOrigin) ? bounds.y() :
                      (texture->height() - bounds.height());
        SkRect effectBounds = SkRect::MakeXYWH(
            SkIntToScalar(bounds.x()) / texture->width(),
            SkIntToScalar(boundsY) / texture->height(),
            SkIntToScalar(texture->width()) / bounds.width(),
            SkIntToScalar(texture->height()) / bounds.height());
        SkScalar invInset = fInset > 0 ? SkScalarInvert(fInset) : SK_Scalar1;
        *fp = GrMagnifierEffect::Create(procDataManager,
                                        texture,
                                        effectBounds,
                                        fSrcRect.x() / texture->width(),
                                        yOffset / texture->height(),
                                        fSrcRect.width() / bounds.width(),
                                        fSrcRect.height() / bounds.height(),
                                        bounds.width() * invInset,
                                        bounds.height() * invInset);
    }
    return true;
}

void SkColorCubeFilter::ColorCubeProcesingCache::initProcessingLuts(
    SkColorCubeFilter::ColorCubeProcesingCache* cache) {
    static const SkScalar inv8bit = SkScalarInvert(SkIntToScalar(255));

    // We need 256 int * 2 for fColorToIndex, so a total of 512 int.
    // We need 256 SkScalar * 2 for fColorToFactors and 256 SkScalar
    // for fColorToScalar, so a total of 768 SkScalar.
    cache->fLutStorage.reset(512 * sizeof(int) + 768 * sizeof(SkScalar));
    uint8_t* storage = (uint8_t*)cache->fLutStorage.get();
    cache->fColorToIndex[0] = (int*)storage;
    cache->fColorToIndex[1] = cache->fColorToIndex[0] + 256;
    cache->fColorToFactors[0] = (SkScalar*)(storage + (512 * sizeof(int)));
    cache->fColorToFactors[1] = cache->fColorToFactors[0] + 256;
    cache->fColorToScalar = cache->fColorToFactors[1] + 256;

    SkScalar size = SkIntToScalar(cache->fCubeDimension);
    SkScalar scale = (size - SK_Scalar1) * inv8bit;

    for (int i = 0; i < 256; ++i) {
        SkScalar index = scale * i;
        cache->fColorToIndex[0][i] = SkScalarFloorToInt(index);
        cache->fColorToIndex[1][i] = cache->fColorToIndex[0][i] + 1;
        cache->fColorToScalar[i] = inv8bit * i;
        if (cache->fColorToIndex[1][i] < cache->fCubeDimension) {
            cache->fColorToFactors[1][i] = index - SkIntToScalar(cache->fColorToIndex[0][i]);
            cache->fColorToFactors[0][i] = SK_Scalar1 - cache->fColorToFactors[1][i];
        } else {
            cache->fColorToIndex[1][i] = cache->fColorToIndex[0][i];
            cache->fColorToFactors[0][i] = SK_Scalar1;
            cache->fColorToFactors[1][i] = 0;
        }
    }
}

    void onSetData(const GrGLSLProgramDataManager& pdman,
                   const GrFragmentProcessor& _proc) override {
        const GrCircleEffect& _outer = _proc.cast<GrCircleEffect>();
        auto edgeType = _outer.edgeType;
        (void)edgeType;
        auto center = _outer.center;
        (void)center;
        auto radius = _outer.radius;
        (void)radius;
        UniformHandle& circle = circleVar;
        (void)circle;

        if (radius != prevRadius || center != prevCenter) {
            SkScalar effectiveRadius = radius;
            if (GrProcessorEdgeTypeIsInverseFill((GrClipEdgeType)edgeType)) {
                effectiveRadius -= 0.5f;
                // When the radius is 0.5 effectiveRadius is 0 which causes an inf * 0 in the
                // shader.
                effectiveRadius = SkTMax(0.001f, effectiveRadius);
            } else {
                effectiveRadius += 0.5f;
            }
            pdman.set4f(circle, center.fX, center.fY, effectiveRadius,
                        SkScalarInvert(effectiveRadius));
            prevCenter = center;
            prevRadius = radius;
        }
    }

/* Generate Type 4 function code to map t=[0,1) to the passed gradient,
   clamping at the edges of the range.  The generated code will be of the form:
       if (t < 0) {
           return colorData[0][r,g,b];
       } else {
           if (t < info.fColorOffsets[1]) {
               return linearinterpolation(colorData[0][r,g,b],
                                          colorData[1][r,g,b]);
           } else {
               if (t < info.fColorOffsets[2]) {
                   return linearinterpolation(colorData[1][r,g,b],
                                              colorData[2][r,g,b]);
               } else {

                ...    } else {
                           return colorData[info.fColorCount - 1][r,g,b];
                       }
                ...
           }
       }
 */
static void gradientFunctionCode(const SkShader::GradientInfo& info,
                                 SkString* result) {
    /* We want to linearly interpolate from the previous color to the next.
       Scale the colors from 0..255 to 0..1 and determine the multipliers
       for interpolation.
       C{r,g,b}(t, section) = t - offset_(section-1) + t * Multiplier{r,g,b}.
     */
    static const int kColorComponents = 3;
    typedef SkScalar ColorTuple[kColorComponents];
    SkAutoSTMalloc<4, ColorTuple> colorDataAlloc(info.fColorCount);
    ColorTuple *colorData = colorDataAlloc.get();
    const SkScalar scale = SkScalarInvert(SkIntToScalar(255));
    for (int i = 0; i < info.fColorCount; i++) {
        colorData[i][0] = SkScalarMul(SkColorGetR(info.fColors[i]), scale);
        colorData[i][1] = SkScalarMul(SkColorGetG(info.fColors[i]), scale);
        colorData[i][2] = SkScalarMul(SkColorGetB(info.fColors[i]), scale);
    }

    // Clamp the initial color.
    result->append("dup 0 le {pop ");
    result->appendScalar(colorData[0][0]);
    result->append(" ");
    result->appendScalar(colorData[0][1]);
    result->append(" ");
    result->appendScalar(colorData[0][2]);
    result->append(" }\n");

    // The gradient colors.
    int gradients = 0;
    for (int i = 1 ; i < info.fColorCount; i++) {
        if (info.fColorOffsets[i] == info.fColorOffsets[i - 1]) {
            continue;
        }
        gradients++;

        result->append("{dup ");
        result->appendScalar(info.fColorOffsets[i]);
        result->append(" le {");
        if (info.fColorOffsets[i - 1] != 0) {
            result->appendScalar(info.fColorOffsets[i - 1]);
            result->append(" sub\n");
        }

        interpolateColorCode(info.fColorOffsets[i] - info.fColorOffsets[i - 1],
                             colorData[i], colorData[i - 1], result);
        result->append("}\n");
    }

    // Clamp the final color.
    result->append("{pop ");
    result->appendScalar(colorData[info.fColorCount - 1][0]);
    result->append(" ");
    result->appendScalar(colorData[info.fColorCount - 1][1]);
    result->append(" ");
    result->appendScalar(colorData[info.fColorCount - 1][2]);

    for (int i = 0 ; i < gradients + 1; i++) {
        result->append("} ifelse\n");
    }
}

void computeDisplacement(Extractor ex, const SkVector& scale, SkBitmap* dst,
                         const SkBitmap& displ, const SkIPoint& offset,
                         const SkBitmap& src,
                         const SkIRect& bounds) {
    static const SkScalar Inv8bit = SkScalarInvert(255);
    const int srcW = src.width();
    const int srcH = src.height();
    const SkVector scaleForColor = SkVector::Make(scale.fX * Inv8bit, scale.fY * Inv8bit);
    const SkVector scaleAdj = SkVector::Make(SK_ScalarHalf - scale.fX * SK_ScalarHalf,
                                             SK_ScalarHalf - scale.fY * SK_ScalarHalf);
    SkPMColor* dstPtr = dst->getAddr32(0, 0);
    for (int y = bounds.top(); y < bounds.bottom(); ++y) {
        const SkPMColor* displPtr = displ.getAddr32(bounds.left() + offset.fX, y + offset.fY);
        for (int x = bounds.left(); x < bounds.right(); ++x, ++displPtr) {
            SkPMColor c = unpremul_pm(*displPtr);

            SkScalar displX = scaleForColor.fX * ex.getX(c) + scaleAdj.fX;
            SkScalar displY = scaleForColor.fY * ex.getY(c) + scaleAdj.fY;
            // Truncate the displacement values
            const int32_t srcX = Sk32_sat_add(x, SkScalarTruncToInt(displX));
            const int32_t srcY = Sk32_sat_add(y, SkScalarTruncToInt(displY));
            *dstPtr++ = ((srcX < 0) || (srcX >= srcW) || (srcY < 0) || (srcY >= srcH)) ?
                      0 : *(src.getAddr32(srcX, srcY));
        }
    }
}

void SkGlyphCache::dump() const {
    const SkTypeface* face = fScalerContext->getTypeface();
    const SkScalerContextRec& rec = fScalerContext->getRec();
    SkMatrix matrix;
    rec.getSingleMatrix(&matrix);
    matrix.preScale(SkScalarInvert(rec.fTextSize), SkScalarInvert(rec.fTextSize));
    SkString name;
    face->getFamilyName(&name);

    SkString msg;
    SkFontStyle style = face->fontStyle();
    msg.printf("cache typeface:%x %25s:(%d,%d,%d)\n %s glyphs:%3d",
               face->uniqueID(), name.c_str(), style.weight(), style.width(), style.slant(),
               rec.dump().c_str(), fGlyphMap.count());
    SkDebugf("%s\n", msg.c_str());
}

static void draw_clipped_filter(SkCanvas* canvas, sk_sp<SkImageFilter> filter, size_t i,
                                const SkRect& primBounds, const SkRect& clipBounds) {
    SkPaint paint;
    paint.setColor(SK_ColorWHITE);
    paint.setImageFilter(std::move(filter));
    paint.setAntiAlias(true);
    canvas->save();
    canvas->clipRect(clipBounds);
    if (5 == i) {
        canvas->translate(SkIntToScalar(16), SkIntToScalar(-32));
    } else if (6 == i) {
        canvas->scale(SkScalarInvert(RESIZE_FACTOR_X), SkScalarInvert(RESIZE_FACTOR_Y));
    }
    canvas->drawCircle(primBounds.centerX(), primBounds.centerY(),
                       primBounds.width() * 2 / 5, paint);
    canvas->restore();
}