Magpie/EffectCommon/EffectBase.h

#pragma once
#include <d2d1effectauthor.h>
#include <d2d1effecthelpers.h>


// 自定义 Effect 的基类
class EffectBase : public ID2D1EffectImpl {
public:
    virtual ~EffectBase() = default;

    /*
    * 以下为 ID2D1EffectImpl 的方法
    */

    IFACEMETHODIMP Initialize(
        _In_ ID2D1EffectContext* pEffectContext,
        _In_ ID2D1TransformGraph* pTransformGraph
    ) override {
        return E_NOTIMPL;
    }

    IFACEMETHODIMP PrepareForRender(D2D1_CHANGE_TYPE changeType) override {
        return S_OK;
    }

    IFACEMETHODIMP SetGraph(_In_ ID2D1TransformGraph* pGraph) override {
        return E_NOTIMPL;
    }

    /*
    * 以下为 IUnkown 的方法
    */
    
    IFACEMETHODIMP_(ULONG) AddRef() override {
        InterlockedIncrement(&_cRef);
        return _cRef;
    }

    IFACEMETHODIMP_(ULONG) Release() override {
	    const ULONG ulRefCount = InterlockedDecrement(&_cRef);
        if (0 == _cRef) {
            delete this;
        }
        return ulRefCount;
    }

    IFACEMETHODIMP QueryInterface(_In_ REFIID riid, _Outptr_ void** ppOutput) override {
        // Always set out parameter to NULL, validating it first.
        if (!ppOutput)
            return E_INVALIDARG;

        *ppOutput = NULL;
        if (riid == __uuidof(ID2D1EffectImpl)
            || riid == __uuidof(IUnknown)
            ) {
            // Increment the reference count and return the pointer.
            *ppOutput = static_cast<LPVOID>(this);
            AddRef();
            return NOERROR;
        }
        return E_NOINTERFACE;
    }

protected:
    // 实现不能公开构造函数
    EffectBase() {}

private:
    ULONG _cRef = 1;
};