src/common/rgncmn.cpp

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