1 //
2 // This file is part of the aMule Project.
3 //
4 // Copyright (c) 2003-2011 aMule Team ( admin@amule.org / http://www.amule.org )
5 // Copyright (c) 2002-2011 Merkur ( devs@emule-project.net / http://www.emule-project.net )
6 //
7 // Any parts of this program derived from the xMule, lMule or eMule project,
8 // or contributed by third-party developers are copyrighted by their
9 // respective authors.
10 //
11 // This program is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU General Public License as published by
13 // the Free Software Foundation; either version 2 of the License, or
14 // (at your option) any later version.
15 //
16 // This program is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 // GNU General Public License for more details.
20 //
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
24 //
25
26 #include "CaptchaGenerator.h"
27 #include "RandomFunctions.h"
28 #include "MemFile.h"
29 #include <wx/bitmap.h>
30 #include <wx/dcmemory.h>
31 #include <wx/font.h>
32
33
34 #define LETTERSIZE 32
35 #define CROWDEDSIZE 20
36
37 // fairly simply captcha generator, might be improved is spammers think its really worth it solving captchas on aMule
38
CCaptchaGenerator(uint32 nLetterCount)39 CCaptchaGenerator::CCaptchaGenerator(uint32 nLetterCount)
40 {
41 ReGenerateCaptcha(nLetterCount);
42 }
43
ReGenerateCaptcha(uint32 nLetterCount)44 void CCaptchaGenerator::ReGenerateCaptcha(uint32 nLetterCount)
45 {
46 static wxString schCaptchaContent = wxT("ABCDEFGHJKLMNPQRSTUVWXYZ123456789");
47 m_strCaptchaText.Clear();
48 // Bitmap must be created with full depth, or it will fail on GTK
49 wxBitmap pimgResult(LETTERSIZE + (nLetterCount-1)*CROWDEDSIZE, 36);
50 wxMemoryDC dc(pimgResult);
51 dc.SetBackground(*wxWHITE_BRUSH);
52 dc.Clear();
53 dc.SetTextForeground(*wxBLACK);
54 dc.SetTextBackground(*wxWHITE);
55 double lastrotate = 15.0;
56
57 for (uint32 i = 0; i < nLetterCount; i++) {
58 wxString strLetter(schCaptchaContent[GetRandomUint16() % schCaptchaContent.length()]);
59 m_strCaptchaText += strLetter;
60
61 uint16 nRandomSize = 30 - GetRandomUint16() % 12;
62 wxFont font(nRandomSize, wxFONTFAMILY_SWISS, wxFONTSTYLE_NORMAL, wxFONTWEIGHT_BOLD);
63 dc.SetFont(font);
64 uint16 nRandomOffset = 3 + GetRandomUint16() % 8;
65 uint16 maxRotate = 50 - nRandomSize; // rotate small letters more than large letters
66 double fRotate = (double)(maxRotate - (GetRandomUint16() % (maxRotate*2)));
67 // limit angle diff - it causes too much overlap since wx rotates at the corner
68 // (maybe I'll redo that with some coordinate transformation one day)
69 if (fRotate - lastrotate > 20) {
70 fRotate = lastrotate + 20;
71 } else if (fRotate - lastrotate < -20) {
72 fRotate = lastrotate - 20;
73 }
74 dc.DrawRotatedText(strLetter, nRandomOffset + i * CROWDEDSIZE, 0, fRotate);
75 }
76 m_pimgCaptcha = pimgResult.ConvertToImage();
77 // wx always saves as 24 bpp except when it gets this WELL DOCUMENTED option...
78 m_pimgCaptcha.SetOption(wxIMAGE_OPTION_BMP_FORMAT, wxBMP_1BPP);
79 // m_pimgCaptcha.SaveFile(wxT("captcha.bmp"), wxBITMAP_TYPE_BMP);
80 }
81
WriteCaptchaImage(wxMemoryOutputStream & file)82 bool CCaptchaGenerator::WriteCaptchaImage(wxMemoryOutputStream& file)
83 {
84 return m_pimgCaptcha.SaveFile(file, wxBITMAP_TYPE_BMP);
85 }
86