C++ SkPaint::getShader方法代码示例

DEF_TEST(Color4f_shader, reporter) {
    struct {
        sk_sp<SkShader> (*fFact)();
        bool            fSupports4f;
        float           fTolerance;
    } recs[] = {
        { make_color_sh, true,  1.0f/255   },
        // PMColor 4f gradients are interpolated in 255-multiplied values, so we need a
        // slightly relaxed tolerance to accommodate the cumulative precision deviation.
        { make_grad_sh,  true,  1.001f/255 },
        { make_image_sh, false, 1.0f/255   },
        { make_cf_sh,    true,  1.0f/255   },
    };

    SkPaint paint;
    for (const auto& rec : recs) {
        uint32_t storage[300];
        paint.setShader(rec.fFact());
        // Encourage 4f context selection. At some point we may need
        // to instantiate two separate contexts for optimal 4b/4f selection.
        const SkShader::ContextRec contextRec(paint, SkMatrix::I(), nullptr,
                                              SkShader::ContextRec::kPM4f_DstType);
        SkASSERT(paint.getShader()->contextSize(contextRec) <= sizeof(storage));
        SkShader::Context* ctx = paint.getShader()->createContext(contextRec, storage);
        if (rec.fSupports4f) {
            const int N = 100;
            SkPM4f buffer4f[N];
            ctx->shadeSpan4f(0, 0, buffer4f, N);
            SkPMColor buffer4b[N];
            ctx->shadeSpan(0, 0, buffer4b, N);
            REPORTER_ASSERT(reporter, compare_spans(buffer4f, buffer4b, N, rec.fTolerance));
        }
        ctx->~Context();
    }
}

void
DrawTargetSkia::MaskSurface(const Pattern &aSource,
                            SourceSurface *aMask,
                            Point aOffset,
                            const DrawOptions &aOptions)
{
  MarkChanged();
  AutoPaintSetup paint(mCanvas.get(), aOptions, aSource);

  TempBitmap bitmap = GetBitmapForSurface(aMask);
  if (bitmap.mBitmap.colorType() == kAlpha_8_SkColorType) {
    mCanvas->drawBitmap(bitmap.mBitmap, aOffset.x, aOffset.y, &paint.mPaint);
  } else {
    SkPaint maskPaint;
    TempBitmap tmpBitmap;
    SetPaintPattern(maskPaint, SurfacePattern(aMask, ExtendMode::CLAMP), tmpBitmap);

    SkMatrix transform = maskPaint.getShader()->getLocalMatrix();
    transform.postTranslate(SkFloatToScalar(aOffset.x), SkFloatToScalar(aOffset.y));
    maskPaint.getShader()->setLocalMatrix(transform);

    SkLayerRasterizer::Builder builder;
    builder.addLayer(maskPaint);
    SkAutoTUnref<SkRasterizer> raster(builder.detachRasterizer());
    paint.mPaint.setRasterizer(raster.get());

    IntSize size = aMask->GetSize();
    Rect rect = Rect(aOffset.x, aOffset.y, size.width, size.height);
    mCanvas->drawRect(RectToSkRect(rect), paint.mPaint);
  }
}

void
DrawTargetSkia::MaskSurface(const Pattern &aSource,
                            SourceSurface *aMask,
                            Point aOffset,
                            const DrawOptions &aOptions)
{
  MarkChanged();
  AutoPaintSetup paint(mCanvas.get(), aOptions, aSource);

  SkPaint maskPaint;
  TempBitmap tmpBitmap;
  SetPaintPattern(maskPaint, SurfacePattern(aMask, ExtendMode::CLAMP), tmpBitmap);

  SkMatrix transform = maskPaint.getShader()->getLocalMatrix();
  transform.postTranslate(SkFloatToScalar(aOffset.x), SkFloatToScalar(aOffset.y));
  maskPaint.getShader()->setLocalMatrix(transform);

  SkLayerRasterizer *raster = new SkLayerRasterizer();
  raster->addLayer(maskPaint);
  SkSafeUnref(paint.mPaint.setRasterizer(raster));

  IntSize size = aMask->GetSize();
  Rect rect = Rect(aOffset.x, aOffset.y, size.width, size.height);
  mCanvas->drawRect(RectToSkRect(rect), paint.mPaint);
}

bool SkPaintPriv::ShouldDither(const SkPaint& p, SkColorType dstCT) {
    // The paint dither flag can veto.
    if (!p.isDither()) {
        return false;
    }

    // We always dither 565 or 4444 when requested.
    if (dstCT == kRGB_565_SkColorType || dstCT == kARGB_4444_SkColorType) {
        return true;
    }

    // Otherwise, dither is only needed for non-const paints.
    return p.getImageFilter() || p.getMaskFilter()
        || !p.getShader() || !as_SB(p.getShader())->isConstant();
}

    void onDrawContent(SkCanvas* canvas) override {
        const int nu = 10;
        const int nv = 10;

        SkPaint paint;
        paint.setDither(true);
        paint.setFilterQuality(kLow_SkFilterQuality);

        canvas->translate(DX, DY);

        Patch   patch;

        paint.setShader(fShader0);
        if (fSize0.fX == 0) {
            fSize0.fX = 1;
        }
        if (fSize0.fY == 0) {
            fSize0.fY = 1;
        }
        patch.setBounds(fSize0.fX, fSize0.fY);

        patch.setPatch(fPts);
        drawpatches(canvas, paint, nu, nv, &patch);

        paint.setShader(nullptr);
        paint.setAntiAlias(true);
        paint.setStrokeWidth(SkIntToScalar(5));
        canvas->drawPoints(SkCanvas::kPoints_PointMode, SK_ARRAY_COUNT(fPts), fPts, paint);

        canvas->translate(0, SkIntToScalar(300));

        paint.setAntiAlias(false);
        paint.setShader(fShader1);
        if (true) {
            SkMatrix m;
            m.setSkew(1, 0);
            SkShader* s = SkShader::CreateLocalMatrixShader(paint.getShader(), m);
            paint.setShader(s)->unref();
        }
        if (true) {
            SkMatrix m;
            m.setRotate(fAngle);
            SkShader* s = SkShader::CreateLocalMatrixShader(paint.getShader(), m);
            paint.setShader(s)->unref();
        }
        patch.setBounds(fSize1.fX, fSize1.fY);
        drawpatches(canvas, paint, nu, nv, &patch);
    }

SkPaint SkColorSpaceXformer::apply(const SkPaint& src) {
    const AutoCachePurge autoPurge(this);

    SkPaint dst = src;

    // All SkColorSpaces have the same black point.
    if (src.getColor() & 0xffffff) {
        dst.setColor(this->apply(src.getColor()));
    }

    if (auto shader = src.getShader()) {
        dst.setShader(this->apply(shader));
    }

    if (auto cf = src.getColorFilter()) {
        dst.setColorFilter(this->apply(cf));
    }

    if (auto looper = src.getDrawLooper()) {
        dst.setDrawLooper(looper->makeColorSpace(this));
    }

    if (auto imageFilter = src.getImageFilter()) {
        dst.setImageFilter(this->apply(imageFilter));
    }

    return dst;
}

void GrBlurUtils::drawPathWithMaskFilter(GrContext* context,
                                         GrDrawContext* drawContext,
                                         const GrClip& clip,
                                         const SkPath& origPath,
                                         const SkPaint& paint,
                                         const SkMatrix& origViewMatrix,
                                         const SkMatrix* prePathMatrix,
                                         const SkIRect& clipBounds,
                                         bool pathIsMutable) {
    SkASSERT(!pathIsMutable || origPath.isVolatile());

    GrStyle style(paint);
    // If we have a prematrix, apply it to the path, optimizing for the case
    // where the original path can in fact be modified in place (even though
    // its parameter type is const).

    const SkPath* path = &origPath;
    SkTLazy<SkPath> tmpPath;

    SkMatrix viewMatrix = origViewMatrix;

    if (prePathMatrix) {
        // Styling, blurs, and shading are supposed to be applied *after* the prePathMatrix.
        if (!paint.getMaskFilter() && !paint.getShader() && !style.applies()) {
            viewMatrix.preConcat(*prePathMatrix);
        } else {
            SkPath* result = pathIsMutable ? const_cast<SkPath*>(path) : tmpPath.init();
            pathIsMutable = true;
            path->transform(*prePathMatrix, result);
            path = result;
            result->setIsVolatile(true);
        }
    }
    // at this point we're done with prePathMatrix
    SkDEBUGCODE(prePathMatrix = (const SkMatrix*)0x50FF8001;)

bool SkPaint2GrPaint(GrContext* context, GrRenderTarget* rt, const SkPaint& skPaint,
                     const SkMatrix& viewM, bool constantColor, GrPaint* grPaint) {
    SkShader* shader = skPaint.getShader();
    if (NULL == shader) {
        return SkPaint2GrPaintNoShader(context, rt, skPaint, SkColor2GrColor(skPaint.getColor()),
                                       constantColor, grPaint);
    }

    GrColor paintColor = SkColor2GrColor(skPaint.getColor());

    // Start a new block here in order to preserve our context state after calling
    // asFragmentProcessor(). Since these calls get passed back to the client, we don't really
    // want them messing around with the context.
    {
        // Allow the shader to modify paintColor and also create an effect to be installed as
        // the first color effect on the GrPaint.
        GrFragmentProcessor* fp = NULL;
        if (!shader->asFragmentProcessor(context, skPaint, viewM, NULL, &paintColor,
                                         grPaint->getProcessorDataManager(), &fp)) {
            return false;
        }
        if (fp) {
            grPaint->addColorProcessor(fp)->unref();
            constantColor = false;
        }
    }

    // The grcolor is automatically set when calling asFragmentProcessor.
    // If the shader can be seen as an effect it returns true and adds its effect to the grpaint.
    return SkPaint2GrPaintNoShader(context, rt, skPaint, paintColor, constantColor, grPaint);
}

void SkOverdrawCanvas::onDrawPaint(const SkPaint& paint) {
    if (0 == paint.getColor() && !paint.getColorFilter() && !paint.getShader()) {
        // This is a clear, ignore it.
    } else {
        fList[0]->onDrawPaint(this->overdrawPaint(paint));
    }
}

SkRGB16_Black_Blitter::SkRGB16_Black_Blitter(const SkPixmap& device, const SkPaint& paint)
    : INHERITED(device, paint) {
    SkASSERT(paint.getShader() == nullptr);
    SkASSERT(paint.getColorFilter() == nullptr);
    SkASSERT(paint.isSrcOver());
    SkASSERT(paint.getColor() == SK_ColorBLACK);
}

/* Hit a few SkPicture::Analysis cases not handled elsewhere. */
static void test_analysis(skiatest::Reporter* reporter) {
    SkPictureRecorder recorder;

    SkCanvas* canvas = recorder.beginRecording(100, 100);
    {
        canvas->drawRect(SkRect::MakeWH(10, 10), SkPaint ());
    }
    sk_sp<SkPicture> picture(recorder.finishRecordingAsPicture());
    REPORTER_ASSERT(reporter, !picture->willPlayBackBitmaps());

    canvas = recorder.beginRecording(100, 100);
    {
        SkPaint paint;
        // CreateBitmapShader is too smart for us; an empty (or 1x1) bitmap shader
        // gets optimized into a non-bitmap form, so we create a 2x2 bitmap here.
        SkBitmap bitmap;
        bitmap.allocPixels(SkImageInfo::MakeN32Premul(2, 2));
        bitmap.eraseColor(SK_ColorBLUE);
        *(bitmap.getAddr32(0, 0)) = SK_ColorGREEN;
        paint.setShader(SkShader::MakeBitmapShader(bitmap, SkShader::kClamp_TileMode,
                                                   SkShader::kClamp_TileMode));
        REPORTER_ASSERT(reporter, paint.getShader()->isABitmap());

        canvas->drawRect(SkRect::MakeWH(10, 10), paint);
    }
    REPORTER_ASSERT(reporter, recorder.finishRecordingAsPicture()->willPlayBackBitmaps());
}

bool SkPaintToGrPaintWithTexture(GrContext* context,
                                 const SkPaint& paint,
                                 const SkMatrix& viewM,
                                 const GrFragmentProcessor* fp,
                                 bool textureIsAlphaOnly,
                                 GrPaint* grPaint) {
    SkAutoTUnref<const GrFragmentProcessor> shaderFP;
    if (textureIsAlphaOnly) {
        if (const SkShader* shader = paint.getShader()) {
            shaderFP.reset(shader->asFragmentProcessor(context,
                                                       viewM,
                                                       nullptr,
                                                       paint.getFilterQuality()));
            if (!shaderFP) {
                return false;
            }
            const GrFragmentProcessor* fpSeries[] = { shaderFP.get(), fp };
            shaderFP.reset(GrFragmentProcessor::RunInSeries(fpSeries, 2));
        } else {
            shaderFP.reset(GrFragmentProcessor::MulOutputByInputUnpremulColor(fp));
        }
    } else {
        shaderFP.reset(GrFragmentProcessor::MulOutputByInputAlpha(fp));
    }

    return SkPaintToGrPaintReplaceShader(context, paint, shaderFP.get(), grPaint);
}

bool SkPaintToGrPaintWithTexture(GrContext* context,
                                 const GrColorSpaceInfo& colorSpaceInfo,
                                 const SkPaint& paint,
                                 const SkMatrix& viewM,
                                 std::unique_ptr<GrFragmentProcessor> fp,
                                 bool textureIsAlphaOnly,
                                 GrPaint* grPaint) {
    std::unique_ptr<GrFragmentProcessor> shaderFP;
    if (textureIsAlphaOnly) {
        if (const auto* shader = as_SB(paint.getShader())) {
            shaderFP = shader->asFragmentProcessor(GrFPArgs(
                    context, &viewM, nullptr, paint.getFilterQuality(), &colorSpaceInfo));
            if (!shaderFP) {
                return false;
            }
            std::unique_ptr<GrFragmentProcessor> fpSeries[] = { std::move(shaderFP), std::move(fp) };
            shaderFP = GrFragmentProcessor::RunInSeries(fpSeries, 2);
        } else {
            shaderFP = GrFragmentProcessor::MakeInputPremulAndMulByOutput(std::move(fp));
        }
    } else {
        shaderFP = GrFragmentProcessor::MulChildByInputAlpha(std::move(fp));
    }

    return SkPaintToGrPaintReplaceShader(context, colorSpaceInfo, paint, std::move(shaderFP),
                                         grPaint);
}

SkRGB16_Black_Blitter::SkRGB16_Black_Blitter(const SkBitmap& device, const SkPaint& paint)
    : INHERITED(device, paint) {
    SkASSERT(paint.getShader() == NULL);
    SkASSERT(paint.getColorFilter() == NULL);
    SkASSERT(paint.getXfermode() == NULL);
    SkASSERT(paint.getColor() == SK_ColorBLACK);
}

static void apply_paint_shader(const SkPaint& paint, Json::Value* target, bool sendBinaries) {
    SkFlattenable* shader = paint.getShader();
    if (shader != nullptr) {
        Json::Value jsonShader;
        flatten(shader, &jsonShader, sendBinaries);
        (*target)[SKJSONCANVAS_ATTRIBUTE_SHADER] = jsonShader;
    }
}