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 // Copyright:   (c) Robin Dunn
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 // ============================================================================
  12 // declarations
  13 // ============================================================================
  14
  15 // For compilers that support precompilation, includes "wx.h".
  16 #include "wx/wxprec.h"
  17
  18 #ifdef __BORLANDC__
  19     #pragma hdrstop
  20 #endif
  21
  22 #include "wx/region.h"
  23
  24 #ifndef WX_PRECOMP
  25     #include "wx/dcmemory.h"
  26     #include "wx/bitmap.h"
  27     #include "wx/image.h"
  28 #endif //WX_PRECOMP
  29
  30 // ============================================================================
  31 // wxRegionBase implementation
  32 // ============================================================================
  33
  34 // ----------------------------------------------------------------------------
  35 // region comparison
  36 // ----------------------------------------------------------------------------
  37
  38 bool wxRegionBase::IsEqual(const wxRegion& region) const
  39 {
  40     if ( m_refData == region.GetRefData() )
  41     {
  42         // regions are identical, hence equal
  43         return true;
  44     }
  45
  46     if ( !m_refData || !region.GetRefData() )
  47     {
  48         // one, but not both, of the regions is invalid
  49         return false;
  50     }
  51
  52     return DoIsEqual(region);
  53 }
  54
  55 // ----------------------------------------------------------------------------
  56 // region to/from bitmap conversions
  57 // ----------------------------------------------------------------------------
  58
  59 wxBitmap wxRegionBase::ConvertToBitmap() const
  60 {
  61     wxRect box = GetBox();
  62     wxBitmap bmp(box.GetRight() + 1, box.GetBottom() + 1);
  63     wxMemoryDC dc;
  64     dc.SelectObject(bmp);
  65     dc.SetBackground(*wxBLACK_BRUSH);
  66     dc.Clear();
  67     dc.SetDeviceClippingRegion(*static_cast<const wxRegion *>(this));
  68     dc.SetBackground(*wxWHITE_BRUSH);
  69     dc.Clear();
  70     dc.SelectObject(wxNullBitmap);
  71     return bmp;
  72 }
  73
  74 #if wxUSE_IMAGE
  75
  76 static bool DoRegionUnion(wxRegionBase& region,
  77                           const wxImage& image,
  78                           unsigned char loR,
  79                           unsigned char loG,
  80                           unsigned char loB,
  81                           int tolerance)
  82 {
  83     unsigned char hiR, hiG, hiB;
  84
  85     hiR = (unsigned char)wxMin(0xFF, loR + tolerance);
  86     hiG = (unsigned char)wxMin(0xFF, loG + tolerance);
  87     hiB = (unsigned char)wxMin(0xFF, loB + tolerance);
  88
  89     // Loop through the image row by row, pixel by pixel, building up
  90     // rectangles to add to the region.
  91     int width = image.GetWidth();
  92     int height = image.GetHeight();
  93     for (int y=0; y < height; y++)
  94     {
  95         wxRect rect;
  96         rect.y = y;
  97         rect.height = 1;
  98
  99         for (int x=0; x < width; x++)
 100         {
 101             // search for a continuous range of non-transparent pixels
 102             int x0 = x;
 103             while ( x < width)
 104             {
 105                 unsigned char R = image.GetRed(x,y);
 106                 unsigned char G = image.GetGreen(x,y);
 107                 unsigned char B = image.GetBlue(x,y);
 108                 if (( R >= loR && R <= hiR) &&
 109                     ( G >= loG && G <= hiG) &&
 110                     ( B >= loB && B <= hiB))  // It's transparent
 111                     break;
 112                 x++;
 113             }
 114
 115             // Add the run of non-transparent pixels (if any) to the region
 116             if (x > x0) {
 117                 rect.x = x0;
 118                 rect.width = x - x0;
 119                 region.Union(rect);
 120             }
 121         }
 122     }
 123
 124     return true;
 125 }
 126
 127
 128 bool wxRegionBase::Union(const wxBitmap& bmp)
 129 {
 130     if (bmp.GetMask())
 131     {
 132         wxImage image = bmp.ConvertToImage();
 133         wxASSERT_MSG( image.HasMask(), wxT("wxBitmap::ConvertToImage doesn't preserve mask?") );
 134         return DoRegionUnion(*this, image,
 135                              image.GetMaskRed(),
 136                              image.GetMaskGreen(),
 137                              image.GetMaskBlue(),
 138                              0);
 139     }
 140     else
 141     {
 142         return Union(0, 0, bmp.GetWidth(), bmp.GetHeight());
 143     }
 144 }
 145
 146 bool wxRegionBase::Union(const wxBitmap& bmp,
 147                          const wxColour& transColour,
 148                          int   tolerance)
 149 {
 150     wxImage image = bmp.ConvertToImage();
 151     return DoRegionUnion(*this, image,
 152                          transColour.Red(),
 153                          transColour.Green(),
 154                          transColour.Blue(),
 155                          tolerance);
 156 }
 157
 158 #endif // wxUSE_IMAGE
 159
 160 #ifdef wxHAS_REGION_COMBINE
 161 // ============================================================================
 162 // wxRegionWithCombine
 163 // ============================================================================
 164
 165 // implement some wxRegionBase pure virtuals in terms of Combine()
 166 bool wxRegionWithCombine::DoUnionWithRect(const wxRect& rect)
 167 {
 168     return Combine(rect, wxRGN_OR);
 169 }
 170
 171 bool wxRegionWithCombine::DoUnionWithRegion(const wxRegion& region)
 172 {
 173     return DoCombine(region, wxRGN_OR);
 174 }
 175
 176 bool wxRegionWithCombine::DoIntersect(const wxRegion& region)
 177 {
 178     return DoCombine(region, wxRGN_AND);
 179 }
 180
 181 bool wxRegionWithCombine::DoSubtract(const wxRegion& region)
 182 {
 183     return DoCombine(region, wxRGN_DIFF);
 184 }
 185
 186 bool wxRegionWithCombine::DoXor(const wxRegion& region)
 187 {
 188     return DoCombine(region, wxRGN_XOR);
 189 }
 190
 191 #endif // wxHAS_REGION_COMBINE