17.9.3  电子相册浏览模块的设计与实现（7）

所以对于封面翻页所需求的是页面2与页面1的路径，而左翻页到封底所需求的是页面2与页封底的路径。

01  if(m_turnType == type_head || m_turnType == type_rightToend)  
02  {  
03      GraphicsPath gpLeft,gpRight;  
04      int undersideOffset = width;  
05      if(m_turnType == type_head)         //封面翻页求页面2的路径  
06      {  
07          if(calculated_y < height)       //三角形时页面2的路径  
08          {  
09              gpLeft.AddLine( PointF(abs(width - m_x + undersideOffset),              height),  
10                          PointF(width + undersideOffset, height));  
11              gpLeft.AddLine( PointF(width + undersideOffset, height),  
12                          PointF(width + undersideOffset, (height –  
13                          (float)calculated_y)));  
14          }  
15          else                            //梯形时页面2的路径  
16          {  
17              gpLeft.AddLine(PointF(abs(width - m_x + undersideOffset),               height),  
18                              PointF(width + undersideOffset, height));  
19              gpLeft.AddLine(PointF(width + undersideOffset, height),  
20                              PointF(width + undersideOffset, 0));  
21              //绘制对称线  
22              calculated_x = height / tan(radians);   
23              gpLeft.AddLine( PointF(width + undersideOffset, 0),  
24                          PointF(abs(width - (m_x - (float)calculated_x) +  
25                                  undersideOffset), 0));  
26          }  
27          gpLeft.CloseFigure();  
28          Matrix PathTranslationMatrix;  
29          PathTranslationMatrix.Translate((float)m_photoFrameLeft,  
30                                      (float)m_photoFrameTop);  
31          gpLeft.Transform(&PathTranslationMatrix);   //原点平移  
32          Region oldRegion;  
33          g.GetClip(&oldRegion);  
34          g.SetClip(&gpLeft);                     //添加路径  
35          g.DrawPath(&penDraw,&gpLeft);           //绘制边框  
36          g.DrawImage(m_pPage[1],m_photoFrameLeft + m_pPage[1]-> 
            GetWidth(),  
37                      m_photoFrameTop,m_pPage[1]->GetWidth(),  
38                      m_pPage[1]->GetHeight());   //绘制页面2  
39          g.SetClip(&oldRegion);                  //恢复原属性  
40      }  
41      else                                //右翻页到封底时求页面2的路径  
42      {  
43          if(calculated_y < height)       //三角形时页面2的路径  
44          {  
45              gpLeft.AddLine( PointF(width , 0), PointF( width , height) );  
46              gpLeft.AddLine( PointF( width , height),  
47                          PointF(abs(width - m_x + undersideOffset),   
                            height));  
48              gpLeft.AddLine( PointF(abs(width - m_x + undersideOffset),   
                height),  
49                          PointF(width + undersideOffset,  
50                          (height - (float)calculated_y)));  
51              gpLeft.AddLine( PointF(width + undersideOffset,  
52                          (height - (float)calculated_y)),  
53                          PointF(width + undersideOffset, 0));  
54          }  
55          else                            //梯形时页面2的路径  
56          {  
57              gpLeft.AddLine(PointF(width, 0),PointF( width , height));  
58              gpLeft.AddLine(PointF( width , height) ,  
59                          PointF(abs(width - m_x + undersideOffset),   
                            height));  
60    
61              calculated_x = height / tan(radians);   
62              gpLeft.AddLine( PointF(abs(width - m_x + undersideOffset),              height),  
63                          PointF(abs(width - (m_x - (float)calculated_x)+  
64                          undersideOffset), 0));  
65          }  
66          gpLeft.CloseFigure();  
67          Matrix PathTranslationMatrix;  
68          PathTranslationMatrix.Translate((float)m_photoFrameLeft,  
69                                  (float)m_photoFrameTop);  
70          gpLeft.Transform(&PathTranslationMatrix);   //平移坐标原点  
71          Region oldRegion;  
72          g.GetClip(&oldRegion);                      //保存原属性  
73          g.SetClip(&gpLeft);                         //添加路径  
74          g.DrawPath(&penDraw,&gpLeft);               //绘制边框  
75          g.DrawImage(m_pPage[1],m_photoFrameLeft + m_pPage[1]-> 
            GetWidth(),  
76                      m_photoFrameTop,m_pPage[1]->GetWidth(),  
77                      m_pPage[1]->GetHeight());       //绘制界面2  
78          g.SetClip(&oldRegion);                      //恢复原属性  
79      }  
80      //创建临时画板  
81      Bitmap pageUndersideImage(width,height);          
82      undersideOffset =  width;  
83      if(calculated_y < height)                   //三角形时旋转区域大小  
84      {  
85          gpRight.AddLine( PointF(abs(width - m_x - undersideOffset),   
            height),  
86                      PointF(width - undersideOffset, height));  
87          gpRight.AddLine( PointF(width - undersideOffset, height),  
88                      PointF(width - undersideOffset, (height - (float)  
                        calculated_y)));  
89      }  
90      else                                        //梯形时旋转区域大小  
91      {  
92          gpRight.AddLine(PointF(abs(float(width) - m_x – underside-  
            Offset),height),  
93                      PointF(width - undersideOffset, height));  
94          gpRight.AddLine(PointF(width - undersideOffset, height),  
95                      PointF(width - undersideOffset, 0));  
96    
97          calculated_x = height / tan(radians);   
98          gpRight.AddLine( PointF(width - undersideOffset, 0),  
99                      PointF(abs(width - (m_x - (float)calculated_x) –  
00                      undersideOffset), 0));  
101     }  
102     Graphics ug(&pageUndersideImage);  
103     ug.SetClip(&gpRight);  
104     ug.DrawPath(&penDraw,&gpRight);         //添加路径  
105     if(m_turnType == type_rightToend)           //右翻页到封底时绘制封底  
106     {  
107         ug.DrawImage(m_pPage[5], 0,0,m_pPage[1]->GetWidth(),  
108                     m_pPage[1]->GetHeight());  
109         Matrix PathTranslationMatrix1;  
110         PathTranslationMatrix1.Translate(m_photoFrameLeft +  
111                                     m_pPage[1]->GetWidth()*2 - m_x,  
112                                     m_photoFrameTop +  
113                                     m_pPage[1]->GetHeight());  
114         PathTranslationMatrix1.Rotate((float)(pageUndersideRotation-  
            Angle ));  
115         g.SetTransform(&PathTranslationMatrix1);    //平移原点  
116         g.DrawImage(&pageUndersideImage, -int(m_x),-height ,width,  
            height );  
117     }  
118     else                                        //首页翻页绘制图像1  
119     {  
120         ug.DrawImage(m_pPage[0], 0,0,m_pPage[1]->GetWidth(),  
121                     m_pPage[1]->GetHeight());  
122         Matrix PathTranslationMatrix1;  
123         PathTranslationMatrix1.Translate(m_photoFrameLeft +   
124                                 m_pPage[1]->GetWidth()*2 -  
125                                 m_x, m_photoFrameTop +  
126                                 m_pPage[1]->GetHeight());  
127         PathTranslationMatrix1.Rotate((float)(pageUndersideRotation-  
            Angle ));  
128         g.SetTransform(&PathTranslationMatrix1);    //平移原点  
129         g.DrawImage(&pageUndersideImage, -int(m_x),-height ,width,  
            height );  
130     }  
131 }