計算機圖形學(xué)實驗報告4

1、計算機圖形學(xué)實驗報告實驗九 二維圖形變換一、實驗教學(xué)目標與基本要求1.掌握圖形變換的基本算法原理；2.實現(xiàn)若干典型二維圖形變換算法。二理論基礎(chǔ)1.生成前幾次實驗中的基本圖形；2.對生成的基本圖形進行平移、旋轉(zhuǎn)、放縮、對稱等變換。3. 對計算機繪圖的原理有一定的認識。三算法設(shè)計與分析1二維變換1. 平移變換2.比例變換 sx sy 1 等比例變換 sx sy 1 放大 sx sy 1 縮小 sx sy 13.對稱變換當(dāng)b=d=0, a=-1, e=1時關(guān)于y軸對稱當(dāng)b=d=0, a=1, e=-1時關(guān)于x軸對稱當(dāng)b=d=0, a=-1, e=-1時關(guān)于原點對稱當(dāng)b=d=1, a=e=0時關(guān)于直線

2、y=x對稱當(dāng)b=d=-1, a=e=0時關(guān)于直線y=-x對稱4.旋轉(zhuǎn)變換繞原點逆時針旋轉(zhuǎn)5.錯切變換 當(dāng)d=0時,x*=x+by,y*=y，沿x方向錯切位移 當(dāng)b=0時,x*=x,y*=dx+y, 沿y方向錯切位移 當(dāng)b0時,當(dāng)d0時,x*=x+by,y=dx+y 6.復(fù)合變換-復(fù)合平移 對同一圖形做兩次平移相當(dāng)于將兩次的平移兩加起來：復(fù)合變換-復(fù)合縮放 復(fù)合變換-復(fù)合旋轉(zhuǎn)復(fù)合變換-關(guān)于f (xf,yf)點的縮放變換先把坐標系平移到(xf,yf),在新的坐標系下做比例變換，然后再將坐標原點平移回去。復(fù)合變換-繞f(xf,yf)點的旋轉(zhuǎn)變換先把坐標系平移到f(xf,yf),在新的坐標系下做旋轉(zhuǎn)變

3、換，然后再將坐標原點平移回去四、程序調(diào)試及結(jié)果的分析本程序運行環(huán)境為vc下的mfc環(huán)境。實驗代碼：void czuobiaobianhuanview:oncgpingyi() /平移/ todo: add your command handler code herefor(int i=0;i<3;i+) pti.x+=5; / pti.y+=5;redrawwindow();void czuobiaobianhuanview:oncgxuanzhuan() /旋轉(zhuǎn)變換float dangle=15.0*pi/180.0;for(int i=0;i<3;i+)pti.x=(pti.x

4、-500)*cos(dangle)-(pti.y-240)*sin(dangle)+500;pti.y=(pti.x-500)*sin(dangle)+(pti.y-240)*cos(dangle)+240;/ todo: add your command handler code hereredrawwindow();void czuobiaobianhuanview:oncgduicheng() /對稱變換/ todo: add your command handler code herefor(int i=0;i<3;i+)pti.x=2*500-pti.x;pti.y=pti.y

5、;redrawwindow();void czuobiaobianhuanview:oncgshuofang() /縮放變換/ todo: add your command handler code herefloat dscalex=1.1;float dscaley=1.1;for(int i=0;i<3;i+)pti.x*=dscalex;pti.y*=dscaley;redrawwindow();void czuobiaobianhuanview:oncgcuoqiebianhuan() /錯切變換/ todo: add your command handler code her

6、eint b=0,d=2;for(int i=0;i<3;i+)pti.x=pti.x-500+b*(pti.y-240)+500;pti.y=pti.y-240+d*(pti.x-500)+240;redrawwindow();void czuobiaobianhuanview:oncgjianpan() / todo: add your command handler code here/onkeydown(nchar,nrepcnt,nflags);void czuobiaobianhuanview:onkeydown(uint nchar, uint nrepcnt, uint

7、nflags) / todo: add your message handler code here and/or call defaultint i=0;cpoint temp=pt0;switch(nchar)case vk_up:for(i=0;i<3;i+)pti.y-=5;break;case vk_down:for(i=0;i<3;i+)pti.y+=5;break;case vk_left:for(i=0;i<3;i+)pti.x-=5;break;case vk_right:for(i=0;i<3;i+)pti.x+=5;break;case 0x5a:

8、for(i=0;i<3;i+)pti.x=(pti.x-500)*0.8+500;pti.y=(pti.y-240)*0.8+240;break;case 0x58:for(i=0;i<3;i+)pti.x=(pti.x-500)*1.1+500;pti.y=(pti.y-240)*1.1+240;break;case 0x52:float dangle=15.0*pi/180.0;for(int i=0;i<3;i+)pti.x=(pti.x-500)*cos(dangle)-(pti.y-240)*sin(dangle)+500;pti.y=(pti.x-500)*sin

9、(dangle)+(pti.y-240)*cos(dangle)+240;break;redrawwindow();cview:onkeydown(nchar,nrepcnt,nflags);void czuobiaobianhuanview:ondraw(cdc* pdc)czuobiaobianhuandoc* pdoc = getdocument();assert_valid(pdoc);/ todo: add draw code for native data herecpen penred(ps_solid,3,rgb(255,0,0);/定義紅色筆 pdc->selectob

10、ject(&penred);pdc->moveto(pt0);pdc->lineto(pt1);pdc->lineto(pt2);pdc->lineto(pt0); pdc->moveto(100,240); pdc->lineto(900,240); pdc->moveto(500,5); pdc->lineto(500,400); /yuandian(500,240) pdc->textout(15,10,"平移變換，鍵盤方向鍵"); pdc->textout(15,28,"縮放變換，z縮小，

11、x放大"); pdc->textout(15,46,"旋轉(zhuǎn)變換，鍵盤r鍵"); pdc->textout(15,66,"還可以根據(jù)上面的菜單欄中的圖形變換進行選擇"); /onkeydown(nchar,nrepcnt,nflags);運行結(jié)果展示：原圖:旋轉(zhuǎn)變換后:對稱變換后:錯切變換后:實驗十 三維圖形變換一、實驗教學(xué)目標與基本要求1實習(xí)三維圖形的坐標系之間的變換；2三維圖形幾何變換；3掌握三維圖形的坐標系之間的變換算法及三維圖形幾何變換的原理和實現(xiàn)。二理論基礎(chǔ)實現(xiàn)三維圖形的坐標系之間的變換（世界坐標、物坐標、屏幕坐標）以及三維

12、圖形幾何變換。三算法設(shè)計與分析三維變換變換矩陣比例、錯切、旋轉(zhuǎn)變換1.平移變換 若點(x*, y*, z*)是由點(x,y,z)在x,y和z軸方向分別移動距離tx, ty和tz得到的，則這兩點間的坐標關(guān)系為： x* = x + tx y* = y + ty z* = z + tz 該式的矩陣形式為：2.比例變換設(shè)點(x,y,z)經(jīng)過縮放變換后得到點(x*,y*,z*)，這兩點坐標間的關(guān)系為： x* = sx x ; y* = sy y ; z* = sz z ; 其中，sx，sy，sz 分別為沿x軸，y軸和z軸方向放大或縮小的比例。它們可以相當(dāng)，也可以不相等。上式的矩陣形式如下所示：3. 旋轉(zhuǎn)

13、變換在右手坐標系下，設(shè)給定點的坐標為(x,y,z) = (rcos,rsin,z),則它繞z軸旋轉(zhuǎn)角后，得點(x,y,z)，則 x = rcos(+) = xcos ysin ; y = rsin(+) = xsin+ ycos ; z = z ; 所以，旋轉(zhuǎn)變換對應(yīng)的變換矩陣為：4.對稱變換n 相對于xy平面對稱：坐標變換后有 x = x, y = y, z = -z; 則變換矩陣為：參數(shù)圖形的幾何變換n 對于一般的線框圖，可以利用基于點的幾何變換（前面所講），但對于參數(shù)表示的點、曲線、曲面圖形，通過基于點的幾何變換進行變換，則計算的工作量和存儲空間都會非常大，所以一般對其方程式直接進行參數(shù)

14、變換（基于數(shù)學(xué)運算）。n 其變換依然是通過變換矩陣進行變換。2.參數(shù)曲線、曲面的幾何變換(3) 比例變換比例系數(shù)為s，對參數(shù)曲線作變比例變換，只要對其幾何系數(shù)矩陣b作變比例變換就可以了。結(jié)果：b*= sb(4) 對稱反射變換 b*=brf四、程序調(diào)試及結(jié)果的分析實驗代碼:bool cshiwutuxingview:setwindowpixelformat(hdc hdc)/定義窗口的像素格式 pixelformatdescriptor pixeldesc= sizeof(pixelformatdescriptor),1,pfd_draw_to_window|pfd_support_opengl

15、|pfd_doublebuffer|pfd_support_gdi,pfd_type_rgba,24,0,0,0,0,0,0,0,0,0,0,0,0,0,32,0,0,pfd_main_plane,0,0,0,0 ; this->m_glpixelindex = choosepixelformat(hdc,&pixeldesc); if(this->m_glpixelindex=0) this->m_glpixelindex = 1; if(describepixelformat(hdc,this->m_glpixelindex,sizeof(pixelform

16、atdescriptor),&pixeldesc)=0) return false; if(setpixelformat(hdc,this->m_glpixelindex,&pixeldesc)=false) return false; return true;bool cshiwutuxingview:createviewglcontext(hdc hdc) this->m_hglcontext = wglcreatecontext(hdc); if(this->m_hglcontext=null) /創(chuàng)建失敗 return false; if(wglmak

17、ecurrent(hdc,this->m_hglcontext)=false) /選為當(dāng)前rc失敗 return false; return true; void cshiwutuxingview:ondestroy() cview:ondestroy();cview:ondestroy(); / todo: add your message handler code here if(wglgetcurrentcontext()!=null) wglmakecurrent(null,null); if(this->m_hglcontext!=null) wgldeleteconte

18、xt(this->m_hglcontext); this->m_hglcontext = null; / todo: add your message handler code hereint cshiwutuxingview:oncreate(lpcreatestruct lpcreatestruct) if (cview:oncreate(lpcreatestruct) = -1) return -1; / todo: add your specialized creation code here hwnd hwnd = this->getsafehwnd(); hdc

19、hdc = :getdc(hwnd); if(this->setwindowpixelformat(hdc)=false) return 0; if(this->createviewglcontext(hdc)=false) return 0; return 0;/ todo: add your specialized creation code herereturn 0;void cshiwutuxingview:onpaint() /cpaintdc dc(this); / device context for painting/ todo: add your message

20、handler code here/ do not call cview:onpaint() for painting messagescpaintdc dc(this); / device context for painting / todo: add your message handler code here / do not call cview:onpaint() for painting messages glloadidentity(); glclear(gl_color_buffer_bit); glbegin(gl_polygon);glcolor4f(1.0f,0.0f,

21、0.0f,1.0f);/glvertex2f(100.0f,50.0f);glvertex2f(pt0.x,pt0.y);glcolor4f(0.0f,1.0f,0.0f,1.0f);/glvertex2f(450.0f,400.0f);glvertex2f(pt1.x,pt1.y);glcolor4f(0.0f,0.0f,1.0f,1.0f);/glvertex2f(450.0f,50.0f);glvertex2f(pt2.x,pt2.y); glend();/auxwirebox(100,100,100); glflush();void cshiwutuxingview:onsize(ui

22、nt ntype, int cx, int cy) /cview:onsize(ntype, cx, cy);/ todo: add your message handler code herecview:onsize(ntype, cx, cy); / todo: add your message handler code here glsizei width,height; gldouble aspect; width = cx; height = cy; if(cy=0) aspect = (gldouble)width; else aspect = (gldouble)width/(g

23、ldouble)height; glviewport(0,0,width,height); glmatrixmode(gl_projection); glloadidentity(); gluortho2d(0.0,500.0*aspect,0.0,500.0); glmatrixmode(gl_modelview); glloadidentity();void cshiwutuxingview:onkeydown(uint nchar, uint nrepcnt, uint nflags) / todo: add your message handler code here and/or c

24、all defaultcview:onkeydown(nchar, nrepcnt, nflags);int i;/glloadidentity();switch(nchar) case vk_up:/*for(i=0;i<3;i+) pti.y+=5;*/glloadidentity ();gltranslatef (0.0, -5.0, 0.0);draw_triangle();break;case vk_down:/*for(i=0;i<3;i+)pti.y-=5;*/gltranslatef (0.0, 5.0, 0.0);draw_triangle();break;case vk_left:/*for(i=0;i<3;i+)