- Qt 5.5
- Qt Widgets
- Composition Modes
- composition.h Example File
- Qt 5.5.1 Reference Documentation

# composition.h Example File

painting/composition/composition.h

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the demonstration applications of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:LGPL21$
    ** Commercial License Usage
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    ** GNU Lesser General Public License Usage
    ** Alternatively, this file may be used under the terms of the GNU Lesser
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    ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
    ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
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    #ifndef COMPOSITION_H
    #define COMPOSITION_H

    #include "arthurwidgets.h"

    #include <QPainter>
    #include <QEvent>

    class QPushButton;
    class QRadioButton;

    #ifdef QT_OPENGL_SUPPORT
    #include <QtOpenGL>
    #endif

    class CompositionWidget : public QWidget
    {
        Q_OBJECT

    public:
        CompositionWidget(QWidget *parent);

    public slots:
    void nextMode();

    private:
        bool m_cycle_enabled;

        QRadioButton *rbClear;
        QRadioButton *rbSource;
        QRadioButton *rbDest;
        QRadioButton *rbSourceOver;
        QRadioButton *rbDestOver;
        QRadioButton *rbSourceIn;
        QRadioButton *rbDestIn;
        QRadioButton *rbSourceOut;
        QRadioButton *rbDestOut;
        QRadioButton *rbSourceAtop;
        QRadioButton *rbDestAtop;
        QRadioButton *rbXor;

        QRadioButton *rbPlus;
        QRadioButton *rbMultiply;
        QRadioButton *rbScreen;
        QRadioButton *rbOverlay;
        QRadioButton *rbDarken;
        QRadioButton *rbLighten;
        QRadioButton *rbColorDodge;
        QRadioButton *rbColorBurn;
        QRadioButton *rbHardLight;
        QRadioButton *rbSoftLight;
        QRadioButton *rbDifference;
        QRadioButton *rbExclusion;
    };

    class CompositionRenderer : public ArthurFrame
    {
        Q_OBJECT

        enum ObjectType { NoObject, Circle, Rectangle, Image };

        Q_PROPERTY(int circleColor READ circleColor WRITE setCircleColor)
        Q_PROPERTY(int circleAlpha READ circleAlpha WRITE setCircleAlpha)
        Q_PROPERTY(bool animation READ animationEnabled WRITE setAnimationEnabled)

    public:
        CompositionRenderer(QWidget *parent);

        void paint(QPainter *) Q_DECL_OVERRIDE;

        void setCirclePos(const QPointF &pos);

        QSize sizeHint() const Q_DECL_OVERRIDE { return QSize(500, 400); }

        bool animationEnabled() const { return m_animation_enabled; }
        int circleColor() const { return m_circle_hue; }
        int circleAlpha() const { return m_circle_alpha; }

    protected:
        void mousePressEvent(QMouseEvent *) Q_DECL_OVERRIDE;
        void mouseMoveEvent(QMouseEvent *) Q_DECL_OVERRIDE;
        void mouseReleaseEvent(QMouseEvent *) Q_DECL_OVERRIDE;
        void timerEvent(QTimerEvent *) Q_DECL_OVERRIDE;

    public slots:
        void setClearMode() { m_composition_mode = QPainter::CompositionMode_Clear; update(); }
        void setSourceMode() { m_composition_mode = QPainter::CompositionMode_Source; update(); }
        void setDestMode() { m_composition_mode = QPainter::CompositionMode_Destination; update(); }
        void setSourceOverMode() { m_composition_mode = QPainter::CompositionMode_SourceOver; update(); }
        void setDestOverMode() { m_composition_mode = QPainter::CompositionMode_DestinationOver; update(); }
        void setSourceInMode() { m_composition_mode = QPainter::CompositionMode_SourceIn; update(); }
        void setDestInMode() { m_composition_mode = QPainter::CompositionMode_DestinationIn; update(); }
        void setSourceOutMode() { m_composition_mode = QPainter::CompositionMode_SourceOut; update(); }
        void setDestOutMode() { m_composition_mode = QPainter::CompositionMode_DestinationOut; update(); }
        void setSourceAtopMode() { m_composition_mode = QPainter::CompositionMode_SourceAtop; update(); }
        void setDestAtopMode() { m_composition_mode = QPainter::CompositionMode_DestinationAtop; update(); }
        void setXorMode() { m_composition_mode = QPainter::CompositionMode_Xor; update(); }

        void setPlusMode() { m_composition_mode = QPainter::CompositionMode_Plus; update(); }
        void setMultiplyMode() { m_composition_mode = QPainter::CompositionMode_Multiply; update(); }
        void setScreenMode() { m_composition_mode = QPainter::CompositionMode_Screen; update(); }
        void setOverlayMode() { m_composition_mode = QPainter::CompositionMode_Overlay; update(); }
        void setDarkenMode() { m_composition_mode = QPainter::CompositionMode_Darken; update(); }
        void setLightenMode() { m_composition_mode = QPainter::CompositionMode_Lighten; update(); }
        void setColorDodgeMode() { m_composition_mode = QPainter::CompositionMode_ColorDodge; update(); }
        void setColorBurnMode() { m_composition_mode = QPainter::CompositionMode_ColorBurn; update(); }
        void setHardLightMode() { m_composition_mode = QPainter::CompositionMode_HardLight; update(); }
        void setSoftLightMode() { m_composition_mode = QPainter::CompositionMode_SoftLight; update(); }
        void setDifferenceMode() { m_composition_mode = QPainter::CompositionMode_Difference; update(); }
        void setExclusionMode() { m_composition_mode = QPainter::CompositionMode_Exclusion; update(); }

        void setCircleAlpha(int alpha) { m_circle_alpha = alpha; update(); }
        void setCircleColor(int hue) { m_circle_hue = hue; update(); }
        void setAnimationEnabled(bool enabled);

    private:
        void updateCirclePos();
        void drawBase(QPainter &p);
        void drawSource(QPainter &p);

        QPainter::CompositionMode m_composition_mode;

        QImage m_image;
        QImage m_buffer;
        QImage m_base_buffer;

        int m_circle_alpha;
        int m_circle_hue;

        QPointF m_circle_pos;
        QPointF m_offset;

        ObjectType m_current_object;
        bool m_animation_enabled;
        int m_animationTimer;

    #ifdef QT_OPENGL_SUPPORT
        QGLPixelBuffer *m_pbuffer;
        GLuint m_base_tex;
        GLuint m_compositing_tex;
        int m_pbuffer_size; // width==height==size of pbuffer
        QSize m_previous_size;
    #endif
    };

    #endif // COMPOSITION_H