C++ sk_sp::getCanvas方法代码示例

void FatBits::drawTriangle(SkCanvas* canvas, SkPoint pts[3]) {
    SkPaint paint;

    fInverse.mapPoints(pts, 3);

    if (fGrid) {
        apply_grid(pts, 3);
    }

    SkPath path;
    path.moveTo(pts[0]);
    path.lineTo(pts[1]);
    path.lineTo(pts[2]);
    path.close();

    erase(fMinSurface.get());
    this->setupPaint(&paint);
    paint.setColor(FAT_PIXEL_COLOR);
    fMinSurface->getCanvas()->drawPath(path, paint);
    this->copyMinToMax();

    SkCanvas* max = fMaxSurface->getCanvas();

    fMatrix.mapPoints(pts, 3);
    this->drawTriangleSkeleton(max, pts);

    fMaxSurface->draw(canvas, 0, 0, nullptr);
}

void FatBits::drawRect(SkCanvas* canvas, SkPoint pts[2]) {
    SkPaint paint;

    fInverse.mapPoints(pts, 2);

    if (fGrid) {
        apply_grid(pts, 2);
    }

    SkRect r;
    r.set(pts, 2);

    erase(fMinSurface.get());
    this->setupPaint(&paint);
    paint.setColor(FAT_PIXEL_COLOR);
    {
        SkCanvas* c = fMinSurface->getCanvas();
        fRectAsOval ? c->drawOval(r, paint) : c->drawRect(r, paint);
    }
    this->copyMinToMax();

    SkCanvas* max = fMaxSurface->getCanvas();

    fMatrix.mapPoints(pts, 2);
    r.set(pts, 2);
    this->drawRectSkeleton(max, r);

    fMaxSurface->draw(canvas, 0, 0, nullptr);
}

void FatBits::drawLine(SkCanvas* canvas, SkPoint pts[]) {
    SkPaint paint;

    fInverse.mapPoints(pts, 2);

    if (fGrid) {
        apply_grid(pts, 2);
    }

    erase(fMinSurface.get());
    this->setupPaint(&paint);
    paint.setColor(FAT_PIXEL_COLOR);
    if (fUseClip) {
        fMinSurface->getCanvas()->save();
        SkRect r = fClipRect;
        r.inset(SK_Scalar1/3, SK_Scalar1/3);
        fMinSurface->getCanvas()->clipRect(r, kIntersect_SkClipOp, true);
    }
    fMinSurface->getCanvas()->drawLine(pts[0], pts[1], paint);
    if (fUseClip) {
        fMinSurface->getCanvas()->restore();
    }
    this->copyMinToMax();

    SkCanvas* max = fMaxSurface->getCanvas();

    fMatrix.mapPoints(pts, 2);
    this->drawLineSkeleton(max, pts);

    fMaxSurface->draw(canvas, 0, 0, nullptr);
}

    void onDraw(int loops, SkCanvas* canvas) override {
        if (!fSurface) {
            GrContext* context = canvas->getGrContext();
            if (nullptr == context) {
                return;
            }
            SkImageInfo info = SkImageInfo::Make(fW, fH, kN32_SkColorType, kPremul_SkAlphaType,
                                                 kSRGB_SkColorProfileType);
            fSurface = SkSurface::MakeRenderTarget(context, SkBudgeted::kNo, info);
        }

        // Clear surface once:
        fSurface->getCanvas()->clear(SK_ColorBLACK);

        SkPaint paint;
        paint.setFilterQuality(kMedium_SkFilterQuality);

        for (int i = 0; i < loops; i++) {
            // Touch surface so mips are dirtied
            fSurface->getCanvas()->drawPoint(0, 0, SK_ColorWHITE);

            // Draw reduced version of surface to original canvas, to trigger mip generation
            canvas->save();
            canvas->scale(0.1f, 0.1f);
            canvas->drawImage(fSurface->makeImageSnapshot(SkBudgeted::kNo), 0, 0, &paint);
            canvas->restore();
        }
    }

void WindowContext::presentRenderSurface(sk_sp<SkSurface> renderSurface, sk_sp<GrRenderTarget> rt,
                                         int colorBits) {
    if (!this->isGpuContext() || colorBits > 24 ||
        kRGBA_F16_SkColorType == fDisplayParams.fColorType) {
        // We made/have an off-screen surface. Get the contents as an SkImage:
        SkImageInfo info = SkImageInfo::Make(fWidth, fHeight,
                                             fDisplayParams.fColorType,
                                             kUnknown_SkAlphaType,
                                             fDisplayParams.fColorSpace);
        SkBitmap bm;
        bm.allocPixels(info);
        renderSurface->getCanvas()->readPixels(&bm, 0, 0);
        SkPixmap pm;
        bm.peekPixels(&pm);
        sk_sp<SkImage> image(SkImage::MakeTextureFromPixmap(fContext, pm,
                             SkBudgeted::kNo));
        GrTexture* texture = as_IB(image)->peekTexture();
        SkASSERT(texture);

        // With ten-bit output, we need to manually apply the gamma of the output device
        // (unless we're in non-gamma correct mode, in which case our data is already
        // fake-sRGB, like we're expected to put in the 10-bit buffer):
        bool doGamma = (colorBits == 30) && SkImageInfoIsGammaCorrect(info);
        fContext->applyGamma(rt.get(), texture, doGamma ? 1.0f / 2.2f : 1.0f);
    }
}

// Exercise the public API of SkSpecialSurface (e.g., getCanvas, newImageSnapshot)
static void test_surface(const sk_sp<SkSpecialSurface>& surf,
                         skiatest::Reporter* reporter,
                         int offset) {

    const SkIRect surfSubset = TestingSpecialSurfaceAccess::Subset(surf.get());
    REPORTER_ASSERT(reporter, offset == surfSubset.fLeft);
    REPORTER_ASSERT(reporter, offset == surfSubset.fTop);
    REPORTER_ASSERT(reporter, kSmallerSize == surfSubset.width());
    REPORTER_ASSERT(reporter, kSmallerSize == surfSubset.height());

    SkCanvas* canvas = surf->getCanvas();
    SkASSERT_RELEASE(canvas);

    canvas->clear(SK_ColorRED);

    sk_sp<SkSpecialImage> img(surf->makeImageSnapshot());
    REPORTER_ASSERT(reporter, img);

    const SkIRect imgSubset = img->subset();
    REPORTER_ASSERT(reporter, surfSubset == imgSubset);

    // the canvas was invalidated by the newImageSnapshot call
    REPORTER_ASSERT(reporter, !surf->getCanvas());
}

    void copyMinToMax() {
        erase(fMaxSurface.get());
        SkCanvas* canvas = fMaxSurface->getCanvas();
        canvas->save();
        canvas->concat(fMatrix);
        fMinSurface->draw(canvas, 0, 0, nullptr);
        canvas->restore();

        SkPaint paint;
        paint.setBlendMode(SkBlendMode::kClear);
        for (int iy = 1; iy < fH; ++iy) {
            SkScalar y = SkIntToScalar(iy * fZoom);
            canvas->drawLine(0, y - SK_ScalarHalf, 999, y - SK_ScalarHalf, paint);
        }
        for (int ix = 1; ix < fW; ++ix) {
            SkScalar x = SkIntToScalar(ix * fZoom);
            canvas->drawLine(x - SK_ScalarHalf, 0, x - SK_ScalarHalf, 999, paint);
        }
    }

 Status draw(Src* src) override {
     auto size = src->size();
     surface = SkSurface::MakeRaster(info.makeWH(size.width(), size.height()));
     return src->draw(surface->getCanvas());
 }