wxWidgets/interface/graphics.h

/////////////////////////////////////////////////////////////////////////////
// Name:        graphics.h
// Purpose:     interface of wxGraphicsPath
// Author:      wxWidgets team
// RCS-ID:      $Id$
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

/**
    @class wxGraphicsPath
    @wxheader{graphics.h}

    A wxGraphicsPath is a native representation of an geometric path. The contents
    are specific an private to the respective renderer. Instances are ref counted and can
    therefore be assigned as usual. The only way to get a valid instance is via a
    CreatePath call on the graphics context or the renderer instance.

    @library{wxcore}
    @category{FIXME}
*/
class wxGraphicsPath : public wxGraphicsObject
{
public:
    //@{
    /**

    */
    void AddArc(wxDouble x, wxDouble y, wxDouble r,
                wxDouble startAngle,
                wxDouble endAngle, bool clockwise);
    void AddArc(const wxPoint2DDouble& c, wxDouble r,
                wxDouble startAngle,
                wxDouble endAngle,
                bool clockwise);
    //@}

    /**
        Appends a an arc to two tangents connecting (current) to (x1,y1) and (x1,y1) to
        (x2,y2), also a straight line from (current) to (x1,y1).
    */
    void AddArcToPoint(wxDouble x1, wxDouble y1, wxDouble x2,
                       wxDouble y2,
                       wxDouble r);

    /**
        Appends a circle around (x,y) with radius r as a new closed subpath.
    */
    void AddCircle(wxDouble x, wxDouble y, wxDouble r);

    //@{
    /**

    */
    void AddCurveToPoint(wxDouble cx1, wxDouble cy1, wxDouble cx2,
                         wxDouble cy2,
                         wxDouble x,
                         wxDouble y);
    void AddCurveToPoint(const wxPoint2DDouble& c1,
                         const wxPoint2DDouble& c2,
                         const wxPoint2DDouble& e);
    //@}

    /**
        Appends an ellipse fitting into the passed in rectangle.
    */
    void AddEllipse(wxDouble x, wxDouble y, wxDouble w, wxDouble h);

    //@{
    /**

    */
    void AddLineToPoint(wxDouble x, wxDouble y);
    void AddLineToPoint(const wxPoint2DDouble& p);
    //@}

    /**
        Adds another path.
    */
    void AddPath(const wxGraphicsPath& path);

    /**
        Adds a quadratic Bezier curve from the current point, using a control point and
        an end point.
    */
    void AddQuadCurveToPoint(wxDouble cx, wxDouble cy, wxDouble x,
                             wxDouble y);

    /**
        Appends a rectangle as a new closed subpath.
    */
    void AddRectangle(wxDouble x, wxDouble y, wxDouble w, wxDouble h);

    /**
        Appends a rounded rectangle as a new closed subpath.
    */
    void AddRoundedRectangle(wxDouble x, wxDouble y, wxDouble w,
                             wxDouble h,
                             wxDouble radius);

    /**
        Closes the current sub-path.
    */
    void CloseSubpath();

    //@{
    /**
        Returns @true if the point is within the path.
    */
    bool Contains(const wxPoint2DDouble& c,
                  int fillStyle = wxODDEVEN_RULE) const;
    const bool Contains(wxDouble x, wxDouble y,
                        int fillStyle = wxODDEVEN_RULE) const;
    //@}

    //@{
    /**
        Gets the bounding box enclosing all points (possibly including control points).
    */
    wxRect2DDouble GetBox() const;
    const void GetBox(wxDouble* x, wxDouble* y, wxDouble* w,
                      wxDouble* h) const;
    //@}

    //@{
    /**
        Gets the last point of the current path, (0,0) if not yet set.
    */
    void GetCurrentPoint(wxDouble* x, wxDouble* y) const;
    const wxPoint2DDouble GetCurrentPoint() const;
    //@}

    /**
        Returns the native path (CGPathRef for Core Graphics, Path pointer for GDIPlus
        and a cairo_path_t pointer for cairo).
    */
    void* GetNativePath() const;

    //@{
    /**
        Begins a new subpath at (x,y)
    */
    void MoveToPoint(wxDouble x, wxDouble y);
    void MoveToPoint(const wxPoint2DDouble& p);
    //@}

    /**
        Transforms each point of this path by the matrix.
    */
    void Transform(const wxGraphicsMatrix& matrix);

    /**
        Gives back the native path returned by GetNativePath() because there might be
        some deallocations necessary (eg on cairo the native path returned by
        GetNativePath is newly allocated each time).
    */
    void UnGetNativePath(void* p) const;
};



/**
    @class wxGraphicsObject
    @wxheader{graphics.h}

    This class is the superclass of native graphics objects like pens etc. It
    allows reference counting. Not instantiated by user code.

    @library{wxcore}
    @category{FIXME}

    @see wxGraphicsBrush, wxGraphicsPen, wxGraphicsMatrix, wxGraphicsPath
*/
class wxGraphicsObject : public wxObject
{
public:
    /**
        Returns the renderer that was used to create this instance, or @NULL if it has
        not been initialized yet
    */
    wxGraphicsRenderer* GetRenderer() const;

    /**
        Is this object valid (@false) or still empty (@true)?
    */
    bool IsNull() const;
};



/**
    @class wxGraphicsContext
    @wxheader{graphics.h}

    A wxGraphicsContext instance is the object that is drawn upon. It is created by
    a renderer using wxGraphicsRenderer::CreateContext(). This can be either directly
    using a renderer instance, or indirectly using the static convenience Create()
    functions of wxGraphicsContext that always delegate the task to the default renderer.

    @code
    void MyCanvas::OnPaint(wxPaintEvent &event)
    {
        // Create paint DC
        wxPaintDC dc(this);
        
        // Create graphics context from it
        wxGraphicsContext *gc = wxGraphicsContext::Create( dc );
    
        if (gc)
        {
            // make a path that contains a circle and some lines
            gc->SetPen( *wxRED_PEN );
            wxGraphicsPath path = gc->CreatePath();
            path.AddCircle( 50.0, 50.0, 50.0 );
            path.MoveToPoint(0.0, 50.0);
            path.AddLineToPoint(100.0, 50.0);
            path.MoveToPoint(50.0, 0.0);
            path.AddLineToPoint(50.0, 100.0 );
            path.CloseSubpath();
            path.AddRectangle(25.0, 25.0, 50.0, 50.0);
        
            gc->StrokePath(path);
        
            delete gc;
        }
    }
    @endcode


    @library{wxcore}
    @category{FIXME}

    @see wxGraphicsRenderer::CreateContext(), wxGCDC, wxDC
*/
class wxGraphicsContext : public wxGraphicsObject
{
public:
    /**
        Creates a wxGraphicsContext from a wxWindow.

        @see wxGraphicsRenderer::CreateContext()
    */
    static wxGraphicsContext* Create( wxWindow* window ) ;
    
    /**
        Creates a wxGraphicsContext from a wxWindowDC

        @see wxGraphicsRenderer::CreateContext()
    */
    static wxGraphicsContext* Create( const wxWindowDC& dc) ;
    
    /**
        Creates a wxGraphicsContext from a wxMemoryDC

        @see wxGraphicsRenderer::CreateContext()
    */
    static wxGraphicsContext * Create( const wxMemoryDC& dc) ;
    
    /**
        Creates a wxGraphicsContext from a wxPrinterDC. Under
        GTK+, this will only work when using the GtkPrint
        printing backend which is available since GTK+ 2.10.

        @see wxGraphicsRenderer::CreateContext(), @ref overview_unixprinting "Printing under Unix"
    */
    static wxGraphicsContext * Create( const wxPrinterDC& dc) ;

    /**
        Clips drawings to the region
    */
    void Clip(const wxRegion& region);

    /**
        Clips drawings to the rectangle.
    */
    void Clip(wxDouble x, wxDouble y, wxDouble w, wxDouble h);

    /**
        Concatenates the passed in transform with the current transform of this context
    */
    void ConcatTransform(const wxGraphicsMatrix& matrix);


    /**
        Creates a native brush from a wxBrush.
    */
    wxGraphicsBrush CreateBrush(const wxBrush& brush) const;

    /**
        Creates a native graphics font from a wxFont and a text colour.
    */
    wxGraphicsFont CreateFont(const wxFont& font,
                              const wxColour& col = wxBLACK) const;

    /**
        Creates a wxGraphicsContext from a native context. This native context must be
        eg a CGContextRef for Core Graphics, a Graphics pointer for GDIPlus or a
        cairo_t pointer for cairo.

        @see wxGraphicsRenderer:: CreateContextFromNativeContext
    */
    wxGraphicsContext* CreateFromNative(void* context);

    /**
        Creates a wxGraphicsContext from a native window.

        @see wxGraphicsRenderer:: CreateContextFromNativeWindow
    */
    wxGraphicsContext* CreateFromNativeWindow(void* window);

    /**
        Creates a native brush, having a linear gradient, starting at (x1,y1) with
        color c1 to (x2,y2) with color c2
    */
    wxGraphicsBrush CreateLinearGradientBrush(wxDouble x1,
            wxDouble y1,
            wxDouble x2,
            wxDouble y2,
            const wxColouramp;c1,
            const wxColouramp;c2) const;

    /**
        Creates a native affine transformation matrix from the passed in values. The
        defaults result in an identity matrix.
    */
    wxGraphicsMatrix CreateMatrix(wxDouble a = 1.0, wxDouble b = 0.0,
                                  wxDouble c = 0.0,
                                  wxDouble d = 1.0,
                                  wxDouble tx = 0.0,
                                  wxDouble ty = 0.0) const;

    /**
        Creates a native graphics path which is initially empty.
    */
    wxGraphicsPath CreatePath() const;

    /**
        Creates a native pen from a wxPen.
    */
    wxGraphicsPen CreatePen(const wxPen& pen) const;

    /**
        Creates a native brush, having a radial gradient originating at (xo,yc) with
        color oColour and ends on a circle around (xc,yc) with radius r and color cColour
    */
    wxGraphicsBrush CreateRadialGradientBrush(wxDouble xo,
            wxDouble yo,
            wxDouble xc,
            wxDouble yc,
            wxDouble radius,
            const wxColour& oColor,
            const wxColour& cColor) const;

    /**
        Draws the bitmap. In case of a mono bitmap, this is treated as a mask and the
        current brushed is used for filling.
    */
    void DrawBitmap(const wxBitmap& bmp, wxDouble x, wxDouble y,
                    wxDouble w, wxDouble h);

    /**
        Draws an ellipse.
    */
    void DrawEllipse(wxDouble x, wxDouble y, wxDouble w, wxDouble h);

    /**
        Draws the icon.
    */
    void DrawIcon(const wxIcon& icon, wxDouble x, wxDouble y,
                  wxDouble w, wxDouble h);

    /**
        Draws a polygon.
    */
    void DrawLines(size_t n, const wxPoint2DDouble* points,
                   int fillStyle = wxODDEVEN_RULE);

    /**
        Draws the path by first filling and then stroking.
    */
    void DrawPath(const wxGraphicsPath& path,
                  int fillStyle = wxODDEVEN_RULE);

    /**
        Draws a rectangle.
    */
    void DrawRectangle(wxDouble x, wxDouble y, wxDouble w,
                       wxDouble h);

    /**
        Draws a rounded rectangle.
    */
    void DrawRoundedRectangle(wxDouble x, wxDouble y, wxDouble w,
                              wxDouble h,
                              wxDouble radius);

    //@{
    /**
        Draws a text at the defined position, at the given angle.
    */
    void DrawText(const wxString& str, wxDouble x, wxDouble y,
                  wxDouble angle);
    void DrawText(const wxString& str, wxDouble x, wxDouble y);
    //@}

    /**
        Fills the path with the current brush.
    */
    void FillPath(const wxGraphicsPath& path,
                  int fillStyle = wxODDEVEN_RULE);

    /**
        Returns the native context (CGContextRef for Core Graphics, Graphics pointer
        for GDIPlus and cairo_t pointer for cairo).
    */
    void* GetNativeContext();

    /**
        Fills the @a widths array with the widths from the beginning of
        @a text to the corresponding character of @e text.
    */
    void GetPartialTextExtents(const wxString& text,
                               wxArrayDouble& widths) const;

    /**
        Gets the dimensions of the string using the currently selected font.
        @e string is the text string to measure, @e w and @e h are
        the total width and height respectively, @a descent is the
        dimension from the baseline of the font to the bottom of the
        descender, and @a externalLeading is any extra vertical space added
        to the font by the font designer (usually is zero).
    */
    void GetTextExtent(const wxString& text, wxDouble* width,
                       wxDouble* height,
                       wxDouble* descent,
                       wxDouble* externalLeading) const;

    /**
        Gets the current transformation matrix of this context.
    */
    wxGraphicsMatrix GetTransform() const;

    /**
        Resets the clipping to original shape.
    */
    void ResetClip();

    /**
        Rotates the current transformation matrix (radians),
    */
    void Rotate(wxDouble angle);

    /**
        Scales the current transformation matrix.
    */
    void Scale(wxDouble xScale, wxDouble yScale);

    //@{
    /**
        Sets the brush for filling paths.
    */
    void SetBrush(const wxBrush& brush);
    void SetBrush(const wxGraphicsBrush& brush);
    //@}

    //@{
    /**
        Sets the font for drawing text.
    */
    void SetFont(const wxFont& font, const wxColour& colour);
    void SetFont(const wxGraphicsFont& font);
    //@}

    //@{
    /**
        Sets the pen used for stroking.
    */
    void SetPen(const wxGraphicsPen& pen);
    void SetPen(const wxPen& pen);
    //@}

    /**
        Sets the current transformation matrix of this context
    */
    void SetTransform(const wxGraphicsMatrix& matrix);

    /**
        Strokes a single line.
    */
    void StrokeLine(wxDouble x1, wxDouble y1, wxDouble x2,
                    wxDouble y2);

    //@{
    /**
        Stroke disconnected lines from begin to end points, fastest method available
        for this purpose.
    */
    void StrokeLines(size_t n, const wxPoint2DDouble* beginPoints,
                     const wxPoint2DDouble* endPoints);
    void StrokeLines(size_t n, const wxPoint2DDouble* points);
    //@}

    /**
        Strokes along a path with the current pen.
    */
    void StrokePath(const wxGraphicsPath& path);

    /**
        Translates the current transformation matrix.
    */
    void Translate(wxDouble dx, wxDouble dy);
};



/**
    @class wxGraphicsRenderer
    @wxheader{graphics.h}

    A wxGraphicsRenderer is the instance corresponding to the rendering engine
    used. There may be multiple instances on a system, if there are different
    rendering engines present, but there is always only one instance per engine.
    This instance is pointed back to by all objects created by it (wxGraphicsContext,
    wxGraphicsPath etc) and can be retrieved through their wxGraphicsObject::GetRenderer()
    method. Therefore you can create an additional instance of a path etc. by calling
    wxGraphicsObject::GetRenderer() and then using the appropriate CreateXXX function
    of that renderer.

    @code
    wxGraphicsPath *path = // from somewhere
    wxGraphicsBrush *brush = path->GetRenderer()->CreateBrush( *wxBLACK_BRUSH );
    @endcode

    @library{wxcore}
    @category{FIXME}
*/
class wxGraphicsRenderer : public wxObject
{
public:
    /**
        Creates a wxGraphicsContext from a wxWindow.
    */
    virtual wxGraphicsContext* CreateContext(wxWindow* window) = 0;
    
    /**
        Creates a wxGraphicsContext from a wxWindowDC
    */
    virtual wxGraphicsContext * CreateContext( const wxWindowDC& dc) = 0 ;
    
    /**
        Creates a wxGraphicsContext from a wxMemoryDC
    */
    virtual wxGraphicsContext * CreateContext( const wxMemoryDC& dc) = 0 ;
    
    /**
        Creates a wxGraphicsContext from a wxPrinterDC
    */
    virtual wxGraphicsContext * CreateContext( const wxPrinterDC& dc) = 0 ;

    /**
        Creates a native brush from a wxBrush.
    */
    wxGraphicsBrush CreateBrush(const wxBrush& brush);


    /**
        Creates a wxGraphicsContext from a native context. This native context must be
        eg a CGContextRef for Core Graphics, a Graphics pointer for GDIPlus or a cairo_t
        pointer for cairo.
    */
    wxGraphicsContext* CreateContextFromNativeContext(void* context);

    /**
        Creates a wxGraphicsContext from a native window.
    */
    wxGraphicsContext* CreateContextFromNativeWindow(void* window);

    /**
        Creates a native graphics font from a wxFont and a text colour.
    */
    wxGraphicsFont CreateFont(const wxFont& font,
                              const wxColour& col = wxBLACK);

    /**
        Creates a native brush, having a linear gradient, starting at (x1,y1) with
        color c1 to (x2,y2) with color c2
    */
    wxGraphicsBrush CreateLinearGradientBrush(wxDouble x1,
            wxDouble y1,
            wxDouble x2,
            wxDouble y2,
            const wxColouramp;c1,
            const wxColouramp;c2);

    /**
        Creates a native affine transformation matrix from the passed in values. The
        defaults result in an identity matrix.
    */
    wxGraphicsMatrix CreateMatrix(wxDouble a = 1.0, wxDouble b = 0.0,
                                  wxDouble c = 0.0,
                                  wxDouble d = 1.0,
                                  wxDouble tx = 0.0,
                                  wxDouble ty = 0.0);

    /**
        Creates a native graphics path which is initially empty.
    */
    wxGraphicsPath CreatePath();

    /**
        Creates a native pen from a wxPen.
    */
    wxGraphicsPen CreatePen(const wxPen& pen);

    /**
        Creates a native brush, having a radial gradient originating at (xo,yc) with
        color oColour and ends on a circle around (xc,yc) with radius r and color cColour
    */
    wxGraphicsBrush CreateRadialGradientBrush(wxDouble xo,
            wxDouble yo,
            wxDouble xc,
            wxDouble yc,
            wxDouble radius,
            const wxColour& oColour,
            const wxColour& cColour);

    /**
        Returns the default renderer on this platform. On OS X this is the Core
        Graphics (a.k.a. Quartz 2D) renderer, on MSW the GDIPlus renderer, and on GTK we currently default to the cairo renderer.
    */
    static wxGraphicsRenderer* GetDefaultRenderer();
};



/**
    @class wxGraphicsBrush
    @wxheader{graphics.h}


    @library{wxcore}
    @category{FIXME}
*/
class wxGraphicsBrush : public wxGraphicsObject
{
public:

};



/**
    @class wxGraphicsFont
    @wxheader{graphics.h}


    @library{wxcore}
    @category{FIXME}
*/
class wxGraphicsFont : public wxGraphicsObject
{
public:

};



/**
    @class wxGraphicsPen
    @wxheader{graphics.h}


    @library{wxcore}
    @category{FIXME}
*/
class wxGraphicsPen : public wxGraphicsObject
{
public:

};



/**
    @class wxGraphicsMatrix
    @wxheader{graphics.h}

    A wxGraphicsMatrix is a native representation of an affine matrix. The contents
    are specific and private to the respective renderer. Instances are ref counted and can therefore be assigned as usual. The only way to get a valid instance is via a CreateMatrix call on the graphics context or the renderer instance.

    @library{wxcore}
    @category{FIXME}
*/
class wxGraphicsMatrix : public wxGraphicsObject
{
public:
    //@{
    /**

    */
    void Concat(const wxGraphicsMatrix* t);
    void Concat(const wxGraphicsMatrix& t);
    //@}

    /**
        Returns the component values of the matrix via the argument pointers.
    */
    void Get(wxDouble* a = NULL, wxDouble* b = NULL, wxDouble* c = NULL,
             wxDouble* d = NULL, wxDouble* tx = NULL,
             wxDouble* ty = NULL) const;

    /**
        Returns the native representation of the matrix. For CoreGraphics this is a
        CFAffineMatrix pointer. For GDIPlus a Matrix Pointer and for Cairo a cairo_matrix_t pointer.
    */
    void* GetNativeMatrix() const;

    /**
        Inverts the matrix.
    */
    void Invert();

    /**
        Returns @true if the elements of the transformation matrix are equal.
    */
    bool IsEqual(const wxGraphicsMatrix& t) const;

    /**
        Return @true if this is the identity matrix.
    */
    bool IsIdentity() const;

    /**
        Rotates this matrix (radians).
    */
    void Rotate(wxDouble angle);

    /**
        Scales this matrix.
    */
    void Scale(wxDouble xScale, wxDouble yScale);

    /**
        Sets the matrix to the respective values (default values are the identity
        matrix)
    */
    void Set(wxDouble a = 1.0, wxDouble b = 0.0, wxDouble c = 0.0,
             wxDouble d = 1.0, wxDouble tx = 0.0,
             wxDouble ty = 0.0);

    /**
        Applies this matrix to a distance (ie. performs all transforms except
        translations)
    */
    void TransformDistance(wxDouble* dx, wxDouble* dy) const;

    /**
        Applies this matrix to a point.
    */
    void TransformPoint(wxDouble* x, wxDouble* y) const;

    /**
        Translates this matrix.
    */
    void Translate(wxDouble dx, wxDouble dy);
};