qml实现rgb曲线调节功能

环境：windows + qt5.6.0 + opencv342
效果图（注：该效果是项目中的截图，并非实际demo运行效果）：

demo源码地址（附带opencv库，运行的时候请将dll文件拷贝到exe同目录）：

demo源码地址

说明：
曲线的实现方式是通过继承QAbstractListModel来实现自定义模型（CCurvesModel和CCurveModel）,在qml页面中则是通过Instantiator和Canvas控件来动态生成每条曲线的256个点，画曲线方式有多种，我这只是其中一种而已，最重要的还是如何通过控制点的移动和改变去计算256个点的值(相关算法我也是从其它地方扣来的，如果涉及到侵权，我会删除资源下载)。

CCurvesModel头文件代码:

class CCurvesModel : public QAbstractListModel
{
	Q_OBJECT

public:
	enum TitleRoles
	{

	};
	explicit CCurvesModel(QObject* parent = nullptr);
	~CCurvesModel() override;

	int length() { return m_datas.count(); }
	void append(CCurveModel* p);
	void clear();

public:
	Q_INVOKABLE QVariantMap get(int row) const;

	QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;
	bool setData(const QModelIndex& index, const QVariant& value, int role) override;
	Q_INVOKABLE int rowCount(const QModelIndex& parent = QModelIndex()) const override;
	int columnCount(const QModelIndex&/*parent*/) const override;

    //生成效果图,在calcCurve处理完之后调用
    Q_INVOKABLE void updateImg();
    Q_INVOKABLE CCurveModel* getCurveModel(int index);

protected:
	QHash<int, QByteArray> roleNames() const override;

private:
	QHash<int, QByteArray> m_role_names;
	QList<CCurveModel*> m_datas;
};

说明：该模型用于管理rgb,r,g,b四条曲线
updateImg：调节曲线后生成效果图,在calcCurve处理完之后调用

CCurveModel头文件代码:

struct MyStruct
{
	QPoint pt;
	bool bSelect;
	MyStruct()
	{
		bSelect = false;
	}
	MyStruct(int x, int y, bool bSel)
	{
		pt = QPoint(x, y);
		bSelect = bSel;
	}
};

class CCurveModel : public QAbstractListModel
{
	Q_OBJECT

public:
	enum TitleRoles
	{
		PointRole = Qt::UserRole + 1,
		SelectgRole
	};
	explicit CCurveModel(QObject* parent = nullptr);
	~CCurveModel() override;

	int length() { return m_datas.count(); }
	void append(MyStruct* p);
	QList<MyStruct*>::iterator insert(QList<MyStruct*>::iterator it, MyStruct* p);
	QList<MyStruct*>::iterator erase(QList<MyStruct*>::iterator it);
	void clear();

	inline QList<MyStruct*> getValueList() { return m_datas; }
	inline int getTolerance() { return tolerance; }
    inline uchar* getPts() { return m_pts; }
	void setOnlySelect();

	QList<MyStruct*>::iterator find(int x);
	QList<MyStruct*>::iterator find(int x, int y);
	QList<MyStruct*>::iterator add(int x, int y);

public:
	Q_INVOKABLE QVariantMap get(int row) const;

	QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;
	bool setData(const QModelIndex& index, const QVariant& value, int role) override;
	Q_INVOKABLE int rowCount(const QModelIndex& parent = QModelIndex()) const override;
	int columnCount(const QModelIndex&/*parent*/) const override;

	Q_INVOKABLE int calcCurve();
	Q_INVOKABLE double getValue(int index);
	Q_INVOKABLE void mouseDown(int x, int y);
	Q_INVOKABLE bool mouseMove(int x, int y);
	Q_INVOKABLE void mouseUp(int x, int y);

protected:
	QHash<int, QByteArray> roleNames() const override;

private:
    QList<MyStruct*>::iterator current;//当前的控制点
	QHash<int, QByteArray> m_role_names;
	QList<MyStruct*> m_datas;
	int tolerance; //鼠标按下或移动时，捕获曲线点的误差范围
    uchar m_pts[256];//曲线256个点的值
	bool is_mouse_down;
};

说明：该模型用于管理256个点和控制点集合。
calcCurve：计算256个点的值。