dc.h

wxWidgets 是一个跨平台的 GUI 框架。它给开发人员提供了统一的接口

/////////////////////////////////////////////////////////////////////////////
// Name:        wx/motif/dc.h
// Purpose:     wxDC class
// Author:      Julian Smart
// Modified by:
// Created:     17/09/98
// RCS-ID:      $Id: dc.h,v 1.23 2006/09/05 20:46:11 VZ Exp $
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#ifndef _WX_DC_H_
#define _WX_DC_H_

#include "wx/pen.h"
#include "wx/brush.h"
#include "wx/icon.h"
#include "wx/font.h"
#include "wx/gdicmn.h"

//-----------------------------------------------------------------------------
// constants
//-----------------------------------------------------------------------------

#ifndef MM_TEXT
#define MM_TEXT         0
#define MM_ISOTROPIC    1
#define MM_ANISOTROPIC  2
#define MM_LOMETRIC     3
#define MM_HIMETRIC     4
#define MM_TWIPS        5
#define MM_POINTS       6
#define MM_METRIC       7
#endif

//-----------------------------------------------------------------------------
// wxDC
//-----------------------------------------------------------------------------

class WXDLLEXPORT wxDC : public wxDCBase
{
    DECLARE_DYNAMIC_CLASS(wxDC)

public:
    wxDC();
    virtual ~wxDC() { }

    // implement base class pure virtuals
    // ----------------------------------

    virtual wxSize GetPPI() const;

    virtual void SetMapMode(int mode);
    virtual void SetUserScale(double x, double y);
    virtual void SetLogicalScale(double x, double y);
    virtual void SetLogicalOrigin(wxCoord x, wxCoord y);
    virtual void SetDeviceOrigin(wxCoord x, wxCoord y);
    virtual void SetAxisOrientation(bool xLeftRight, bool yBottomUp);

protected:
    virtual void DoDrawIcon(const wxIcon& icon, wxCoord x, wxCoord y);
    virtual void DoDrawBitmap(const wxBitmap &bmp, wxCoord x, wxCoord y,
        bool useMask = false);

    virtual void DoSetClippingRegion(wxCoord x, wxCoord y,
        wxCoord width, wxCoord height);
    virtual void DoGetSize(int *width, int *height) const;
    virtual void DoGetSizeMM(int* width, int* height) const;

public:
    virtual void ComputeScaleAndOrigin();

    wxCoord XDEV2LOG(wxCoord x) const
    {
        wxCoord new_x = x - m_deviceOriginX;
        if (new_x > 0)
            return (wxCoord)((double)(new_x) / m_scaleX + 0.5) * m_signX + m_logicalOriginX;
        else
            return (wxCoord)((double)(new_x) / m_scaleX - 0.5) * m_signX + m_logicalOriginX;
    }
    wxCoord XDEV2LOGREL(wxCoord x) const
    {
        if (x > 0)
            return (wxCoord)((double)(x) / m_scaleX + 0.5);
        else
            return (wxCoord)((double)(x) / m_scaleX - 0.5);
    }
    wxCoord YDEV2LOG(wxCoord y) const
    {
        wxCoord new_y = y - m_deviceOriginY;
        if (new_y > 0)
            return (wxCoord)((double)(new_y) / m_scaleY + 0.5) * m_signY + m_logicalOriginY;
        else
            return (wxCoord)((double)(new_y) / m_scaleY - 0.5) * m_signY + m_logicalOriginY;
    }
    wxCoord YDEV2LOGREL(wxCoord y) const
    {
        if (y > 0)
            return (wxCoord)((double)(y) / m_scaleY + 0.5);
        else
            return (wxCoord)((double)(y) / m_scaleY - 0.5);
    }
    wxCoord XLOG2DEV(wxCoord x) const
    {
        wxCoord new_x = x - m_logicalOriginX;
        if (new_x > 0)
            return (wxCoord)((double)(new_x) * m_scaleX + 0.5) * m_signX + m_deviceOriginX;
        else
            return (wxCoord)((double)(new_x) * m_scaleX - 0.5) * m_signX + m_deviceOriginX;
    }
    // Without device translation, for backing pixmap purposes
    wxCoord XLOG2DEV_2(wxCoord x) const
    {
        wxCoord new_x = x - m_logicalOriginX;
        if (new_x > 0)
            return (wxCoord)((double)(new_x) * m_scaleX + 0.5) * m_signX;
        else
            return (wxCoord)((double)(new_x) * m_scaleX - 0.5) * m_signX;
    }
    wxCoord XLOG2DEVREL(wxCoord x) const
    {
        if (x > 0)
            return (wxCoord)((double)(x) * m_scaleX + 0.5);
        else
            return (wxCoord)((double)(x) * m_scaleX - 0.5);
    }
    wxCoord YLOG2DEV(wxCoord y) const
    {
        wxCoord new_y = y - m_logicalOriginY;
        if (new_y > 0)
            return (wxCoord)((double)(new_y) * m_scaleY + 0.5) * m_signY + m_deviceOriginY;
        else
            return (wxCoord)((double)(new_y) * m_scaleY - 0.5) * m_signY + m_deviceOriginY;
    }
    // Without device translation, for backing pixmap purposes
    wxCoord YLOG2DEV_2(wxCoord y) const
    {
        wxCoord new_y = y - m_logicalOriginY;
        if (new_y > 0)
            return (wxCoord)((double)(new_y) * m_scaleY + 0.5) * m_signY;
        else
            return (wxCoord)((double)(new_y) * m_scaleY - 0.5) * m_signY;
    }
    wxCoord YLOG2DEVREL(wxCoord y) const
    {
        if (y > 0)
            return (wxCoord)((double)(y) * m_scaleY + 0.5);
        else
            return (wxCoord)((double)(y) * m_scaleY - 0.5);
    }

public:
    // not sure what for, but what is a mm on a screen you don't know the size of?
    double       m_mm_to_pix_x,m_mm_to_pix_y;

    // recompute scale?
    bool         m_needComputeScaleX, m_needComputeScaleY;

};

#endif
// _WX_DC_H_