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:     wxWidgets 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 bool wxRegion::Union(const wxBitmap& bmp,
  55                      const wxColour& transColour,
  56                      int   tolerance)
  57 #else
  58 bool wxRegion::Union(const wxBitmap& WXUNUSED(bmp),
  59                      const wxColour& WXUNUSED(transColour),
  60                      int   WXUNUSED(tolerance))
  61 #endif
  62 {
  63 #if wxUSE_IMAGE
  64     unsigned char loR, loG, loB;
  65     unsigned char hiR, hiG, hiB;
  66
  67     wxCHECK_MSG((bmp.GetMask() != NULL) || transColour.Ok(),
  68                 FALSE,
  69                 wxT("Either the bitmap should have a mask or a colour should be given."));
  70
  71     wxImage image = bmp.ConvertToImage();
  72
  73     if (image.HasMask())
  74     {
  75         loR = image.GetMaskRed();
  76         loG = image.GetMaskGreen();
  77         loB = image.GetMaskBlue();
  78     }
  79     else
  80     {
  81         loR = transColour.Red();
  82         loG = transColour.Green();
  83         loB = transColour.Blue();
  84     }
  85
  86     hiR = wxMin(0xFF, loR + tolerance);
  87     hiG = wxMin(0xFF, loG + tolerance);
  88     hiB = 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                 Union(rect);
 121             }
 122         }
 123     }
 124
 125     return true;
 126 #else
 127     // No wxImage support
 128     return false;
 129 #endif
 130 }
 131
 132 //---------------------------------------------------------------------------