GCanvas/node/binding/Canvas.cc

#include "Canvas.h"
#include "TextMetrics.h"
namespace NodeBinding
{
    Napi::FunctionReference Canvas::constructor;

    Canvas::Canvas(const Napi::CallbackInfo &info) : Napi::ObjectWrap<Canvas>(info)
    {
        Napi::Env env = info.Env();
        Napi::HandleScope scope(env);

        checkArgs(info, 2);
        mWidth = info[0].As<Napi::Number>().Int32Value();
        mHeight = info[1].As<Napi::Number>().Int32Value();
        mRenderContext = std::make_shared<GRenderContext>(mWidth, mHeight);
        mRenderContext->initRenderEnviroment();

        
    }

    int Canvas::getWidth()
    {
        return mWidth;
    }

    int Canvas::getHeight()
    {
        return mHeight;
    }

    Napi::Value Canvas::getWidth(const Napi::CallbackInfo &info)
    {
        return Napi::Number::New(info.Env(), mWidth);
    }

    Napi::Value Canvas::getHeight(const Napi::CallbackInfo &info)
    {
        return Napi::Number::New(info.Env(), mHeight);
    }

    void Canvas::Init(Napi::Env env, Napi::Object exports)
    {
        Napi::HandleScope scope(env);

        Napi::Function func =
            DefineClass(env,
                        "Canvas",
                        {
                            InstanceAccessor("width", &Canvas::getWidth, nullptr),
                            InstanceAccessor("height", &Canvas::getHeight, nullptr),
                            InstanceMethod("getContext", &Canvas::getContext),
                            InstanceMethod("createPNG", &Canvas::createPNG),
                            InstanceMethod("createJPEG", &Canvas::createJPEG),
                            InstanceMethod("createPNGStreamSync", &Canvas::createPNGStreamSync),
                            InstanceMethod("createJPGStreamSync", &Canvas::createJPGStreamSync),
                        });              
        constructor = Napi::Persistent(func);
        constructor.SuppressDestruct();
        return;
    }

    Napi::Object Canvas::NewInstance(Napi::Env env, Napi::Value arg, Napi::Value arg2)
    {
        Napi::Object obj = constructor.New({arg, arg2});
        obj.Set("name", Napi::String::New(env, "gcanvas"));
        Canvas *canvas = Napi::ObjectWrap<Canvas>::Unwrap(obj);
        canvas->mRef = Napi::ObjectReference::New(obj);
        return obj;
    }

    Napi::Value Canvas::getContext(const Napi::CallbackInfo &info)
    {
        Napi::Env env = info.Env();
        checkArgs(info, 1);
        std::string type = info[0].As<Napi::String>().Utf8Value();
        if (type == "2d")
        {
            if (this->context2dRef.IsEmpty())
            {
                Napi::Object obj = Context2D::NewInstance(env);
                this->context2dRef = Napi::ObjectReference::New(obj);
                Context2D *ctx = Napi::ObjectWrap<Context2D>::Unwrap(obj);
                ctx->setRenderContext(this->mRenderContext);
                ctx->setCanvasRef(this);
                return obj;
            }
            else
            {
                return this->context2dRef.Value();
            }
        }
        else
        {
            throwError(info, "only support 2d now");
            return Napi::Object::New(env);
        }
    }
    void Canvas::createPNG(const Napi::CallbackInfo &info)
    {
        NodeBinding::checkArgs(info, 1);
        std::string arg = info[0].As<Napi::String>().Utf8Value();
        if (this->mRenderContext)
        {
            this->mRenderContext->makeCurrent();
            this->mRenderContext->drawFrame();
            this->mRenderContext->render2file(arg.c_str(), PNG_FORAMT);
        }
        return;
    }
    void Canvas::createJPEG(const Napi::CallbackInfo &info)
    {
        NodeBinding::checkArgs(info, 1);
        std::string arg = info[0].As<Napi::String>().Utf8Value();
        if (this->mRenderContext)
        {
            this->mRenderContext->makeCurrent();
            this->mRenderContext->drawFrame();
            this->mRenderContext->render2file(arg.c_str(), JPEG_FORMAT);
        }
        return;
    }
    Napi::Value Canvas::createJPGStreamSync(const Napi::CallbackInfo &info)
    {
        NodeBinding::checkArgs(info, 2);
        Napi::Function callback = info[0].As<Napi::Function>();
        if (this->mRenderContext)
        {
            this->mRenderContext->makeCurrent();
            this->mRenderContext->drawFrame();
        }
        unsigned char *data = (unsigned char *)malloc(1 * sizeof(unsigned char));
        unsigned long size = 0;
        int ret = this->mRenderContext->getImagePixelJPG(&data, size);
        if (ret == 0 && size > 0)
        {
            //handlescope 表示作用域,一般调用callback函数时使用
            Napi::HandleScope scope(info.Env());
            Napi::Buffer<unsigned char> buffer = Napi::Buffer<unsigned char>::Copy(info.Env(), data, size);
            callback.Call({info.Env().Null(),
                           buffer,
                           Napi::Number::New(info.Env(), size)});
        }
        else
        {
            Napi::HandleScope scope(info.Env());
            callback.Call({Napi::String::New(Env(), "createJPGStreamFail"),
                           info.Env().Null(),
                           info.Env().Null()});
        }
        if (data)
        {
            delete data;
            data = nullptr;
        }
    }

    Napi::Value Canvas::createPNGStreamSync(const Napi::CallbackInfo &info)
    {
        NodeBinding::checkArgs(info, 2);
        Napi::Function callback = info[0].As<Napi::Function>();
        if (this->mRenderContext)
        {
            this->mRenderContext->makeCurrent();
            this->mRenderContext->drawFrame();
        }
        std::vector<unsigned char> in;
        int ret = this->mRenderContext->getImagePixelPNG(in);
        if (ret == 0)
        {
            //handlescope 表示作用域,一般调用callback函数时使用
            Napi::HandleScope scope(info.Env());
            Napi::Buffer<unsigned char> buffer = Napi::Buffer<unsigned char>::Copy(info.Env(), &in[0], in.size());
            callback.Call({info.Env().Null(),
                           buffer,
                           Napi::Number::New(info.Env(), in.size())});
        }
        else
        {
            Napi::HandleScope scope(info.Env());
            callback.Call({Napi::String::New(Env(), "createPNGStreamFail"),
                           info.Env().Null(),
                           info.Env().Null()});
        }
    }
    Canvas::~Canvas()
    {
        this->mRenderContext = nullptr;
    }
} // namespace NodeBinding