C++ DrawTarget::GetNativeSurface方法代碼示例

already_AddRefed<Path>
ScaledFontBase::GetPathForGlyphs(const GlyphBuffer &aBuffer, const DrawTarget *aTarget)
{
#ifdef USE_SKIA
  if (aTarget->GetBackendType() == BackendType::SKIA) {
    SkPath path = GetSkiaPathForGlyphs(aBuffer);
    return MakeAndAddRef<PathSkia>(path, FillRule::FILL_WINDING);
  }
#endif
#ifdef USE_CAIRO
  if (aTarget->GetBackendType() == BackendType::CAIRO) {
    MOZ_ASSERT(mScaledFont);

    DrawTarget *dt = const_cast<DrawTarget*>(aTarget);
    cairo_t *ctx = static_cast<cairo_t*>(dt->GetNativeSurface(NativeSurfaceType::CAIRO_CONTEXT));

    bool isNewContext = !ctx;
    if (!ctx) {
      ctx = cairo_create(DrawTargetCairo::GetDummySurface());
      cairo_matrix_t mat;
      GfxMatrixToCairoMatrix(aTarget->GetTransform(), mat);
      cairo_set_matrix(ctx, &mat);
    }

    cairo_set_scaled_font(ctx, mScaledFont);

    // Convert our GlyphBuffer into an array of Cairo glyphs.
    std::vector<cairo_glyph_t> glyphs(aBuffer.mNumGlyphs);
    for (uint32_t i = 0; i < aBuffer.mNumGlyphs; ++i) {
      glyphs[i].index = aBuffer.mGlyphs[i].mIndex;
      glyphs[i].x = aBuffer.mGlyphs[i].mPosition.x;
      glyphs[i].y = aBuffer.mGlyphs[i].mPosition.y;
    }

    cairo_new_path(ctx);

    cairo_glyph_path(ctx, &glyphs[0], aBuffer.mNumGlyphs);

    RefPtr<PathCairo> newPath = new PathCairo(ctx);
    if (isNewContext) {
      cairo_destroy(ctx);
    }

    return newPath.forget();
  }
#endif
  return nullptr;
}

HDC
gfxWindowsNativeDrawing::BeginNativeDrawing()
{
    if (mRenderState == RENDER_STATE_INIT) {
        RefPtr<gfxASurface> surf;
        DrawTarget* drawTarget = mContext->GetDrawTarget();
        cairo_t* cairo = nullptr;
        if (drawTarget->GetBackendType() == BackendType::CAIRO) {
            cairo = static_cast<cairo_t*>
                (drawTarget->GetNativeSurface(NativeSurfaceType::CAIRO_CONTEXT));
            if (cairo) {
                cairo_surface_t* s = cairo_get_target(cairo);
                if (s) {
                    mDeviceOffset = mContext->GetDeviceOffset();
                    surf = gfxASurface::Wrap(s);
                }
            }
        }

        if (surf && surf->CairoStatus() != 0)
            return nullptr;

        gfxMatrix m = mContext->CurrentMatrix();
        if (!m.HasNonTranslation())
            mTransformType = TRANSLATION_ONLY;
        else if (m.HasNonAxisAlignedTransform())
            mTransformType = COMPLEX;
        else
            mTransformType = AXIS_ALIGNED_SCALE;

        // if this is a native win32 surface, we don't have to
        // redirect rendering to our own HDC; in some cases,
        // we may be able to use the HDC from the surface directly.
        if (surf &&
            ((surf->GetType() == gfxSurfaceType::Win32 ||
              surf->GetType() == gfxSurfaceType::Win32Printing) &&
              (surf->GetContentType() == gfxContentType::COLOR ||
               (surf->GetContentType() == gfxContentType::COLOR_ALPHA &&
               (mNativeDrawFlags & CAN_DRAW_TO_COLOR_ALPHA)))))
        {
            // grab the DC. This can fail if there is a complex clipping path,
            // in which case we'll have to fall back.
            mWinSurface = static_cast<gfxWindowsSurface*>(static_cast<gfxASurface*>(surf.get()));
            mDC = cairo_win32_get_dc_with_clip(cairo);

            if (mDC) {
                if (mTransformType == TRANSLATION_ONLY) {
                    mRenderState = RENDER_STATE_NATIVE_DRAWING;

                    mTranslation = m.GetTranslation();
                } else if (((mTransformType == AXIS_ALIGNED_SCALE)
                            && (mNativeDrawFlags & CAN_AXIS_ALIGNED_SCALE)) ||
                           (mNativeDrawFlags & CAN_COMPLEX_TRANSFORM))
                {
                    mWorldTransform.eM11 = (FLOAT) m._11;
                    mWorldTransform.eM12 = (FLOAT) m._12;
                    mWorldTransform.eM21 = (FLOAT) m._21;
                    mWorldTransform.eM22 = (FLOAT) m._22;
                    mWorldTransform.eDx  = (FLOAT) m._31;
                    mWorldTransform.eDy  = (FLOAT) m._32;

                    mRenderState = RENDER_STATE_NATIVE_DRAWING;
                }
            }
        }

        // If we couldn't do native drawing, then we have to do two-buffer drawing
        // and do alpha recovery
        if (mRenderState == RENDER_STATE_INIT) {
            mRenderState = RENDER_STATE_ALPHA_RECOVERY_BLACK;

            // We round out our native rect here, that way the snapping will
            // happen correctly.
            mNativeRect.RoundOut();

            // we only do the scale bit if we can do an axis aligned
            // scale; otherwise we scale (if necessary) after
            // rendering with cairo.  Note that if we're doing alpha recovery,
            // we cannot do a full complex transform with win32 (I mean, we could, but
            // it would require more code that's not here.)
            if (mTransformType == TRANSLATION_ONLY || !(mNativeDrawFlags & CAN_AXIS_ALIGNED_SCALE)) {
                mScale = gfxSize(1.0, 1.0);

                // Add 1 to the surface size; it's guaranteed to not be incorrect,
                // and it fixes bug 382458
                // There's probably a better fix, but I haven't figured out
                // the root cause of the problem.
                mTempSurfaceSize =
                    IntSize((int32_t) ceil(mNativeRect.Width() + 1),
                               (int32_t) ceil(mNativeRect.Height() + 1));
            } else {
                // figure out the scale factors
                mScale = m.ScaleFactors(true);

                mWorldTransform.eM11 = (FLOAT) mScale.width;
                mWorldTransform.eM12 = 0.0f;
                mWorldTransform.eM21 = 0.0f;
                mWorldTransform.eM22 = (FLOAT) mScale.height;
                mWorldTransform.eDx  = 0.0f;
                mWorldTransform.eDy  = 0.0f;
//.........這裏部分代碼省略.........

void
gfxXlibNativeRenderer::Draw(gfxContext* ctx, nsIntSize size,
                            uint32_t flags, Screen *screen, Visual *visual)
{
    gfxMatrix matrix = ctx->CurrentMatrix();

    // We can only draw direct or onto a copied background if pixels align and
    // native drawing is compatible with the current operator.  (The matrix is
    // actually also pixel-exact for flips and right-angle rotations, which
    // would permit copying the background but not drawing direct.)
    bool matrixIsIntegerTranslation = !matrix.HasNonIntegerTranslation();
    bool canDrawOverBackground = matrixIsIntegerTranslation &&
        ctx->CurrentOperator() == gfxContext::OPERATOR_OVER;

    // The padding of 0.5 for non-pixel-exact transformations used here is
    // the same as what _cairo_pattern_analyze_filter uses.
    const gfxFloat filterRadius = 0.5;
    gfxRect affectedRect(0.0, 0.0, size.width, size.height);
    if (!matrixIsIntegerTranslation) {
        // The filter footprint means that the affected rectangle is a
        // little larger than the drawingRect;
        affectedRect.Inflate(filterRadius);

        NATIVE_DRAWING_NOTE("FALLBACK: matrix not integer translation");
    } else if (!canDrawOverBackground) {
        NATIVE_DRAWING_NOTE("FALLBACK: unsupported operator");
    }

    // Clipping to the region affected by drawing allows us to consider only
    // the portions of the clip region that will be affected by drawing.
    gfxRect clipExtents;
    {
        gfxContextAutoSaveRestore autoSR(ctx);
        ctx->Clip(affectedRect);

        clipExtents = ctx->GetClipExtents();
        if (clipExtents.IsEmpty())
            return; // nothing to do

        if (canDrawOverBackground &&
            DrawDirect(ctx, size, flags, screen, visual))
          return;
    }

    IntRect drawingRect(IntPoint(0, 0), size);
    // Drawing need only be performed within the clip extents
    // (and padding for the filter).
    if (!matrixIsIntegerTranslation) {
        // The source surface may need to be a little larger than the clip
        // extents due to the filter footprint.
        clipExtents.Inflate(filterRadius);
    }
    clipExtents.RoundOut();

    IntRect intExtents(int32_t(clipExtents.X()),
                         int32_t(clipExtents.Y()),
                         int32_t(clipExtents.Width()),
                         int32_t(clipExtents.Height()));
    drawingRect.IntersectRect(drawingRect, intExtents);

    gfxPoint offset(drawingRect.x, drawingRect.y);

    DrawingMethod method;
    DrawTarget* drawTarget = ctx->GetDrawTarget();
    Matrix dtTransform = drawTarget->GetTransform();
    gfxPoint deviceTranslation = gfxPoint(dtTransform._31, dtTransform._32);
    cairo_surface_t* cairoTarget = static_cast<cairo_surface_t*>
            (drawTarget->GetNativeSurface(NativeSurfaceType::CAIRO_SURFACE));

    cairo_surface_t* tempXlibSurface =
        CreateTempXlibSurface(cairoTarget, drawTarget, size,
                              canDrawOverBackground, flags, screen, visual,
                              &method);
    if (!tempXlibSurface)
        return;

    bool drawIsOpaque = (flags & DRAW_IS_OPAQUE) != 0;
    if (!drawIsOpaque) {
        cairo_t* tmpCtx = cairo_create(tempXlibSurface);
        if (method == eCopyBackground) {
            NS_ASSERTION(cairoTarget, "eCopyBackground only used when there's a cairoTarget");
            cairo_set_operator(tmpCtx, CAIRO_OPERATOR_SOURCE);
            gfxPoint pt = -(offset + deviceTranslation);
            cairo_set_source_surface(tmpCtx, cairoTarget, pt.x, pt.y);
            // The copy from the tempXlibSurface to the target context should
            // use operator SOURCE, but that would need a mask to bound the
            // operation.  Here we only copy opaque backgrounds so operator
            // OVER will behave like SOURCE masked by the surface.
            NS_ASSERTION(cairo_surface_get_content(tempXlibSurface) == CAIRO_CONTENT_COLOR,
                         "Don't copy background with a transparent surface");
        } else {
            cairo_set_operator(tmpCtx, CAIRO_OPERATOR_CLEAR);
        }
        cairo_paint(tmpCtx);
        cairo_destroy(tmpCtx);
    }

    if (!DrawOntoTempSurface(tempXlibSurface, -drawingRect.TopLeft())) {
        cairo_surface_destroy(tempXlibSurface);
        return;
//.........這裏部分代碼省略.........

TemporaryRef<Path>
ScaledFontBase::GetPathForGlyphs(const GlyphBuffer &aBuffer, const DrawTarget *aTarget)
{
#ifdef USE_SKIA
  if (aTarget->GetType() == BACKEND_SKIA) {
    SkPaint paint;
    paint.setTypeface(GetSkTypeface());
    paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
    paint.setTextSize(SkFloatToScalar(mSize));

    std::vector<uint16_t> indices;
    std::vector<SkPoint> offsets;
    indices.resize(aBuffer.mNumGlyphs);
    offsets.resize(aBuffer.mNumGlyphs);

    for (unsigned int i = 0; i < aBuffer.mNumGlyphs; i++) {
      indices[i] = aBuffer.mGlyphs[i].mIndex;
      offsets[i].fX = SkFloatToScalar(aBuffer.mGlyphs[i].mPosition.x);
      offsets[i].fY = SkFloatToScalar(aBuffer.mGlyphs[i].mPosition.y);
    }

    SkPath path;
    paint.getPosTextPath(&indices.front(), aBuffer.mNumGlyphs*2, &offsets.front(), &path);
    return new PathSkia(path, FILL_WINDING);
  }
#endif
#ifdef USE_CAIRO
  if (aTarget->GetType() == BACKEND_CAIRO) {
    MOZ_ASSERT(mScaledFont);

    DrawTarget *dt = const_cast<DrawTarget*>(aTarget);
    cairo_t *ctx = static_cast<cairo_t*>(dt->GetNativeSurface(NATIVE_SURFACE_CAIRO_CONTEXT));

    bool isNewContext = !ctx;
    if (!ctx) {
      ctx = cairo_create(DrawTargetCairo::GetDummySurface());
      cairo_matrix_t mat;
      GfxMatrixToCairoMatrix(aTarget->GetTransform(), mat);
      cairo_set_matrix(ctx, &mat);
    }

    cairo_set_scaled_font(ctx, mScaledFont);

    // Convert our GlyphBuffer into an array of Cairo glyphs.
    std::vector<cairo_glyph_t> glyphs(aBuffer.mNumGlyphs);
    for (uint32_t i = 0; i < aBuffer.mNumGlyphs; ++i) {
      glyphs[i].index = aBuffer.mGlyphs[i].mIndex;
      glyphs[i].x = aBuffer.mGlyphs[i].mPosition.x;
      glyphs[i].y = aBuffer.mGlyphs[i].mPosition.y;
    }

    cairo_glyph_path(ctx, &glyphs[0], aBuffer.mNumGlyphs);

    RefPtr<PathCairo> newPath = new PathCairo(ctx);
    if (isNewContext) {
      cairo_destroy(ctx);
    }

    return newPath;
  }
#endif
  return nullptr;
}