wasm的 surface.makeSurface

wasm的 surface.makeSurface js中：
  

CanvasKit.Surface.prototype.makeSurface = function(imageInfo) {
    CanvasKit.setCurrentContext(this._context);
    var s = this._makeSurface(imageInfo);
    s._context = this._context;
    return s;
  };

 
  
c++中  
 

 .function("_makeSurface", optional_override([](SkSurface& self, SimpleImageInfo sii)->sk_sp<SkSurface> {
            return self.makeSurface(toSkImageInfo(sii));
        }), allow_raw_pointers())
        
        

SkImageInfo toSkImageInfo(const SimpleImageInfo& sii) {
    return SkImageInfo::Make(sii.width, sii.height, sii.colorType, sii.alphaType,
                             sii.colorSpace ? sii.colorSpace : SkColorSpace::MakeSRGB());
} 

實現類中：

sk_sp<SkSurface> SkSurface::makeSurface(const SkImageInfo& info) {
    return asSB(this)->onNewSurface(info);
}

最終到gpu中：

sk_sp<SkSurface> SkSurface::MakeRenderTarget(GrRecordingContext* rContext,
                                             const SkSurfaceCharacterization& c,
                                             SkBudgeted budgeted) {
    if (!rContext || !c.isValid()) {
        return nullptr;
    }

    if (c.usesGLFBO0()) {
        // If we are making the surface we will never use FBO0.
        return nullptr;
    }

    if (c.vulkanSecondaryCBCompatible()) {
        return nullptr;
    }

    auto device = rContext->priv().createDevice(budgeted, c.imageInfo(), SkBackingFit::kExact,
                                                c.sampleCount(), GrMipmapped(c.isMipMapped()),
                                                c.isProtected(), c.origin(), c.surfaceProps(),
                                                skgpu::BaseDevice::InitContents::kClear);
    if (!device) {
        return nullptr;
    }

    sk_sp<SkSurface> result = sk_make_sp<SkSurface_Gpu>(std::move(device));
#ifdef SK_DEBUG
    if (result) {
        SkASSERT(result->isCompatible(c));
    }
#endif

    return result;
}