src/common/rgncmn.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        rgncmn.cpp
   3 // Purpose:     Methods of wxRegion that have a generic implementation
   4 // Author:      Robin Dunn
   5 // Modified by:
   6 // Created:     27-Mar-2003
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Robin Dunn
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  13 #pragma implementation "rgncmn.h"
  14 #endif
  15
  16
  17 // For compilers that support precompilation, includes "wx.h".
  18 #include "wx/wxprec.h"
  19
  20 #ifdef __BORLANDC__
  21 #pragma hdrstop
  22 #endif
  23
  24 #include "wx/region.h"
  25 #include "wx/bitmap.h"
  26 #if wxUSE_IMAGE
  27 #include "wx/image.h"
  28 #endif
  29 #include "wx/dcmemory.h"
  30
  31
  32 //---------------------------------------------------------------------------
  33
  34
  35
  36 wxBitmap wxRegion::ConvertToBitmap() const
  37 {
  38     wxRect box = GetBox();
  39     wxBitmap bmp(box.GetRight(), box.GetBottom());
  40     wxMemoryDC dc;
  41     dc.SelectObject(bmp);
  42     dc.SetBackground(*wxBLACK_BRUSH);
  43     dc.Clear();
  44     dc.SetClippingRegion(*this);
  45     dc.SetBackground(*wxWHITE_BRUSH);
  46     dc.Clear();
  47     dc.SelectObject(wxNullBitmap);
  48     return bmp;
  49 }
  50
  51 //---------------------------------------------------------------------------
  52
  53 #if wxUSE_IMAGE
  54 static bool DoRegionUnion(wxRegion& region,
  55                           const wxImage& image,
  56                           unsigned char loR,
  57                           unsigned char loG,
  58                           unsigned char loB,
  59                           int tolerance)
  60 {
  61     unsigned char hiR, hiG, hiB;
  62
  63     hiR = (unsigned char)wxMin(0xFF, loR + tolerance);
  64     hiG = (unsigned char)wxMin(0xFF, loG + tolerance);
  65     hiB = (unsigned char)wxMin(0xFF, loB + tolerance);
  66
  67     // Loop through the image row by row, pixel by pixel, building up
  68     // rectangles to add to the region.
  69     int width = image.GetWidth();
  70     int height = image.GetHeight();
  71     for (int y=0; y < height; y++)
  72     {
  73         wxRect rect;
  74         rect.y = y;
  75         rect.height = 1;
  76
  77         for (int x=0; x < width; x++)
  78         {
  79             // search for a continuous range of non-transparent pixels
  80             int x0 = x;
  81             while ( x < width)
  82             {
  83                 unsigned char R = image.GetRed(x,y);
  84                 unsigned char G = image.GetGreen(x,y);
  85                 unsigned char B = image.GetBlue(x,y);
  86                 if (( R >= loR && R <= hiR) &&
  87                     ( G >= loG && G <= hiG) &&
  88                     ( B >= loB && B <= hiB))  // It's transparent
  89                     break;
  90                 x++;
  91             }
  92
  93             // Add the run of non-transparent pixels (if any) to the region
  94             if (x > x0) {
  95                 rect.x = x0;
  96                 rect.width = x - x0;
  97                 region.Union(rect);
  98             }
  99         }
 100     }
 101
 102     return true;
 103 }
 104
 105
 106 bool wxRegion::Union(const wxBitmap& bmp)
 107 {
 108     if (bmp.GetMask())
 109     {
 110         wxImage image = bmp.ConvertToImage();
 111         wxASSERT_MSG( image.HasMask(), _T("wxBitmap::ConvertToImage doesn't preserve mask?") );
 112         return DoRegionUnion(*this, image,
 113                              image.GetMaskRed(),
 114                              image.GetMaskGreen(),
 115                              image.GetMaskBlue(),
 116                              0);
 117     }
 118     else
 119     {
 120         return Union(0, 0, bmp.GetWidth(), bmp.GetHeight());
 121     }
 122 }
 123
 124 bool wxRegion::Union(const wxBitmap& bmp,
 125                      const wxColour& transColour,
 126                      int   tolerance)
 127 {
 128     wxImage image = bmp.ConvertToImage();
 129     return DoRegionUnion(*this, image,
 130                          transColour.Red(),
 131                          transColour.Green(),
 132                          transColour.Blue(),
 133                          tolerance);
 134 }
 135
 136 #else
 137
 138 bool wxRegion::Union(const wxBitmap& WXUNUSED(bmp))
 139 {
 140     // No wxImage support
 141     return false;
 142 }
 143
 144 bool wxRegion::Union(const wxBitmap& WXUNUSED(bmp),
 145                      const wxColour& WXUNUSED(transColour),
 146                      int   WXUNUSED(tolerance))
 147 {
 148     // No wxImage support
 149     return false;
 150 }
 151
 152 #endif
 153
 154 //---------------------------------------------------------------------------