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