wxWidgets/samples/image/image.cpp

/*
 * Program: image
 *
 * Author: Robert Roebling
 *
 * Copyright: (C) 1998, Robert Roebling
 *
 */

// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif

#include "wx/image.h"

// derived classes

class MyFrame;
class MyApp;

// MyCanvas

class MyCanvas: public wxScrolledWindow
{
public:
    MyCanvas() {};
    MyCanvas( wxWindow *parent, wxWindowID, const wxPoint &pos, const wxSize &size );
    ~MyCanvas();
    void OnPaint( wxPaintEvent &event );
    void CreateAntiAliasedBitmap();

    wxBitmap  *my_horse;
    wxBitmap  *my_square;
    wxBitmap  *my_anti;

    DECLARE_DYNAMIC_CLASS(MyCanvas)
    DECLARE_EVENT_TABLE()
};

// MyFrame

class MyFrame: public wxFrame
{
public:
    MyFrame();

    void OnAbout( wxCommandEvent &event );
    void OnQuit( wxCommandEvent &event );

    MyCanvas         *m_canvas;

    DECLARE_DYNAMIC_CLASS(MyFrame)
    DECLARE_EVENT_TABLE()
};

// MyApp

class MyApp: public wxApp
{
public:
    virtual bool OnInit();
};

// main program

IMPLEMENT_APP(MyApp)

// MyCanvas

IMPLEMENT_DYNAMIC_CLASS(MyCanvas, wxScrolledWindow)

BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
  EVT_PAINT(MyCanvas::OnPaint)
END_EVENT_TABLE()

MyCanvas::MyCanvas( wxWindow *parent, wxWindowID id,
                    const wxPoint &pos, const wxSize &size )
        : wxScrolledWindow( parent, id, pos, size, wxSUNKEN_BORDER )
{
  my_horse = (wxBitmap*) NULL;
  my_square = (wxBitmap*) NULL;
  my_anti = (wxBitmap*) NULL;

  SetBackgroundColour(* wxWHITE);

  wxBitmap bitmap( 100, 100 );

  wxMemoryDC dc;
  dc.SelectObject( bitmap );
  dc.SetBrush( wxBrush( "orange", wxSOLID ) );
  dc.SetPen( *wxWHITE_PEN );
  dc.DrawRectangle( 0, 0, 100, 100 );
  dc.SelectObject( wxNullBitmap );

  wxString dir("");

#ifdef __WXGTK__
  dir = wxString("../");
#endif

  wxImage image( bitmap );
  image.SaveFile( dir + wxString("test.png"), wxBITMAP_TYPE_PNG );
  
  image.LoadFile( dir + wxString("horse.png"), wxBITMAP_TYPE_PNG );
  my_horse = new wxBitmap( image.ConvertToBitmap() );
  
  image.LoadFile( dir + wxString("test.png"), wxBITMAP_TYPE_PNG );
  my_square = new wxBitmap( image.ConvertToBitmap() );
  
  CreateAntiAliasedBitmap();
}

MyCanvas::~MyCanvas()
{
  delete my_horse;
  delete my_square;
  delete my_anti;
}

void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
{
  wxPaintDC dc( this );
  PrepareDC( dc );

  dc.DrawText( "Loaded image", 30, 10 );
  if (my_square && my_square->Ok()) dc.DrawBitmap( *my_square, 30, 30 );

  dc.DrawText( "Drawn directly", 150, 10 );
  dc.SetBrush( wxBrush( "orange", wxSOLID ) );
  dc.SetPen( *wxWHITE_PEN );
  dc.DrawRectangle( 150, 30, 100, 100 );

  if (my_anti && my_anti->Ok()) dc.DrawBitmap( *my_anti, 250, 140 );
  
  if (my_horse && my_horse->Ok()) dc.DrawBitmap( *my_horse, 30, 140 );
}

void MyCanvas::CreateAntiAliasedBitmap()
{
  wxBitmap bitmap( 300, 300 );

  wxMemoryDC dc;

  dc.SelectObject( bitmap );

  dc.Clear();
  
  dc.SetFont( wxFont( 24, wxDECORATIVE, wxDEFAULT, wxDEFAULT ) );
  dc.SetTextForeground( "RED" );
  dc.DrawText( "This is anti-aliased Text.", 20, 20 );
  dc.DrawText( "And a Rectangle.", 20, 60 );
  
  dc.SetBrush( *wxRED_BRUSH );
  dc.DrawRoundedRectangle( 20, 100, 200, 180, 20 );
  
  wxImage original( bitmap );
  wxImage anti( 150, 150 );

  /* This is quite slow, but safe. Use wxImage::GetData() for speed instead. */
  
  for (int y = 1; y < 149; y++)
    for (int x = 1; x < 149; x++)
    {
       int red = original.GetRed( x*2, y*2 ) +
                 original.GetRed( x*2-1, y*2 ) + 
                 original.GetRed( x*2, y*2+1 ) + 
                 original.GetRed( x*2+1, y*2+1 );
       red = red/4; 
       
       int green = original.GetGreen( x*2, y*2 ) +
                   original.GetGreen( x*2-1, y*2 ) + 
                   original.GetGreen( x*2, y*2+1 ) + 
                   original.GetGreen( x*2+1, y*2+1 );
       green = green/4; 
       
       int blue = original.GetBlue( x*2, y*2 ) +
                  original.GetBlue( x*2-1, y*2 ) + 
                  original.GetBlue( x*2, y*2+1 ) + 
                  original.GetBlue( x*2+1, y*2+1 );
       blue = blue/4; 
       anti.SetRGB( x, y, red, green, blue );
    }
  my_anti = new wxBitmap( anti.ConvertToBitmap() );
}

// MyFrame

const int ID_QUIT  = 108;
const int ID_ABOUT = 109;

IMPLEMENT_DYNAMIC_CLASS( MyFrame, wxFrame )

BEGIN_EVENT_TABLE(MyFrame,wxFrame)
  EVT_MENU    (ID_ABOUT, MyFrame::OnAbout)
  EVT_MENU    (ID_QUIT,  MyFrame::OnQuit)
END_EVENT_TABLE()

MyFrame::MyFrame()
       : wxFrame( (wxFrame *)NULL, -1, "wxImage sample",
                  wxPoint(20,20), wxSize(470,360) )
{
  wxMenu *file_menu = new wxMenu();
  file_menu->Append( ID_ABOUT, "About..");
  file_menu->Append( ID_QUIT, "Exit");

  wxMenuBar *menu_bar = new wxMenuBar();
  menu_bar->Append(file_menu, "File");

  SetMenuBar( menu_bar );

  CreateStatusBar(2);
  int widths[] = { -1, 100 };
  SetStatusWidths( 2, widths );

  m_canvas = new MyCanvas( this, -1, wxPoint(0,0), wxSize(10,10) );
  m_canvas->SetScrollbars( 10, 10, 50, 50 );
}

void MyFrame::OnQuit( wxCommandEvent &WXUNUSED(event) )
{
  Close( TRUE );
}

void MyFrame::OnAbout( wxCommandEvent &WXUNUSED(event) )
{
  (void)wxMessageBox( "wxImage demo\n"
                      "Robert Roebling (c) 1998",
                      "About wxImage Demo", wxICON_INFORMATION | wxOK );
}

//-----------------------------------------------------------------------------
// MyApp
//-----------------------------------------------------------------------------

bool MyApp::OnInit()
{
#if wxUSE_LIBPNG
  wxImage::AddHandler( new wxPNGHandler );
#endif

#if wxUSE_LIBJPEG
  wxImage::AddHandler( new wxJPEGHandler );
#endif

  wxFrame *frame = new MyFrame();
  frame->Show( TRUE );

  return TRUE;
}