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