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: rgncmn.cpp 41901 2006-10-10 17:33:49Z PC $
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
39bool 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
60wxBitmap 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
77static 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
129bool 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
147bool 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
160
161#ifdef wxHAS_REGION_COMBINE
162// ============================================================================
163// wxRegionWithCombine
164// ============================================================================
165
166// implement some wxRegionBase pure virtuals in terms of Combine()
167bool wxRegionWithCombine::DoUnionWithRect(const wxRect& rect)
168{
169    return Combine(rect, wxRGN_OR);
170}
171
172bool wxRegionWithCombine::DoUnionWithRegion(const wxRegion& region)
173{
174    return DoCombine(region, wxRGN_OR);
175}
176
177bool wxRegionWithCombine::DoIntersect(const wxRegion& region)
178{
179    return DoCombine(region, wxRGN_AND);
180}
181
182bool wxRegionWithCombine::DoSubtract(const wxRegion& region)
183{
184    return DoCombine(region, wxRGN_DIFF);
185}
186
187bool wxRegionWithCombine::DoXor(const wxRegion& region)
188{
189    return DoCombine(region, wxRGN_XOR);
190}
191
192#endif // wxHAS_REGION_COMBINE
193