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 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20     #pragma hdrstop
  21 #endif
  22
  23 #include "wx/region.h"
  24
  25 #ifndef WX_PRECOMP
  26     #include "wx/dcmemory.h"
  27     #include "wx/bitmap.h"
  28     #include "wx/image.h"
  29 #endif //WX_PRECOMP
  30
  31 // ============================================================================
  32 // wxRegionBase implementation
  33 // ============================================================================
  34
  35 // ----------------------------------------------------------------------------
  36 // region comparision
  37 // ----------------------------------------------------------------------------
  38
  39 bool wxRegionBase::IsEqual(const wxRegion& region) const
  40 {
  41     if ( m_refData == region.GetRefData() )
  42     {
  43         // regions are identical, hence equal
  44         return true;
  45     }
  46
  47     if ( !m_refData || !region.GetRefData() )
  48     {
  49         // one, but not both, of the regions is invalid
  50         return false;
  51     }
  52
  53     return DoIsEqual(region);
  54 }
  55
  56 // ----------------------------------------------------------------------------
  57 // region to/from bitmap conversions
  58 // ----------------------------------------------------------------------------
  59
  60 wxBitmap wxRegionBase::ConvertToBitmap() const
  61 {
  62     wxRect box = GetBox();
  63     wxBitmap bmp(box.GetRight(), box.GetBottom());
  64     wxMemoryDC dc;
  65     dc.SelectObject(bmp);
  66     dc.SetBackground(*wxBLACK_BRUSH);
  67     dc.Clear();
  68     dc.SetClippingRegion(*wx_static_cast(const wxRegion *, this));
  69     dc.SetBackground(*wxWHITE_BRUSH);
  70     dc.Clear();
  71     dc.SelectObject(wxNullBitmap);
  72     return bmp;
  73 }
  74
  75 #if wxUSE_IMAGE
  76
  77 static bool DoRegionUnion(wxRegionBase& region,
  78                           const wxImage& image,
  79                           unsigned char loR,
  80                           unsigned char loG,
  81                           unsigned char loB,
  82                           int tolerance)
  83 {
  84     unsigned char hiR, hiG, hiB;
  85
  86     hiR = (unsigned char)wxMin(0xFF, loR + tolerance);
  87     hiG = (unsigned char)wxMin(0xFF, loG + tolerance);
  88     hiB = (unsigned char)wxMin(0xFF, loB + tolerance);
  89
  90     // Loop through the image row by row, pixel by pixel, building up
  91     // rectangles to add to the region.
  92     int width = image.GetWidth();
  93     int height = image.GetHeight();
  94     for (int y=0; y < height; y++)
  95     {
  96         wxRect rect;
  97         rect.y = y;
  98         rect.height = 1;
  99
 100         for (int x=0; x < width; x++)
 101         {
 102             // search for a continuous range of non-transparent pixels
 103             int x0 = x;
 104             while ( x < width)
 105             {
 106                 unsigned char R = image.GetRed(x,y);
 107                 unsigned char G = image.GetGreen(x,y);
 108                 unsigned char B = image.GetBlue(x,y);
 109                 if (( R >= loR && R <= hiR) &&
 110                     ( G >= loG && G <= hiG) &&
 111                     ( B >= loB && B <= hiB))  // It's transparent
 112                     break;
 113                 x++;
 114             }
 115
 116             // Add the run of non-transparent pixels (if any) to the region
 117             if (x > x0) {
 118                 rect.x = x0;
 119                 rect.width = x - x0;
 120                 region.Union(rect);
 121             }
 122         }
 123     }
 124
 125     return true;
 126 }
 127
 128
 129 bool wxRegionBase::Union(const wxBitmap& bmp)
 130 {
 131     if (bmp.GetMask())
 132     {
 133         wxImage image = bmp.ConvertToImage();
 134         wxASSERT_MSG( image.HasMask(), _T("wxBitmap::ConvertToImage doesn't preserve mask?") );
 135         return DoRegionUnion(*this, image,
 136                              image.GetMaskRed(),
 137                              image.GetMaskGreen(),
 138                              image.GetMaskBlue(),
 139                              0);
 140     }
 141     else
 142     {
 143         return Union(0, 0, bmp.GetWidth(), bmp.GetHeight());
 144     }
 145 }
 146
 147 bool wxRegionBase::Union(const wxBitmap& bmp,
 148                          const wxColour& transColour,
 149                          int   tolerance)
 150 {
 151     wxImage image = bmp.ConvertToImage();
 152     return DoRegionUnion(*this, image,
 153                          transColour.Red(),
 154                          transColour.Green(),
 155                          transColour.Blue(),
 156                          tolerance);
 157 }
 158
 159 #endif // wxUSE_IMAGE