計算機圖形學畫圓方法

浙江大學城市學院實驗報告課程名稱計算機圖形學實驗項目名稱畫圓方法實驗成績指導老師（簽名）日期一.實驗目的和要求通過實驗加深對Bresenham圓生成算法的理解。二.實驗內(nèi)容和原理數(shù)據(jù)輸入項（或者函數(shù)參數(shù)）為：圓心坐標與半徑輸出圓。三.實驗設計與分析Besenham圓①創(chuàng)建一個application，將其全部保存，②雙擊劃圓按扭，定義參數(shù)如下：x,y,x0,y0,r,direction:integer;delta,delta1,delta2:integer;color1:integer;③編寫代碼如下ifself.Edit1.Text=''thenbeginApplication.MessageBox('圓心坐標X沒有輸入！','提示',0);abort;endelseifself.Edit2.Text=''thenbeginApplication.MessageBox('圓心坐標Y沒有輸入！','提示',0);abort;endelseifself.Edit3.Text=''thenbeginApplication.MessageBox('圓半徑?jīng)]有輸入！','提示',0);abort;endelsex0:=strtoint(Edit1.Text);y0:=strtoint(Edit2.Text);r:=strtoint(Edit3.Text);x:=0;y:=r;delta:=2*(1-r);color1:=clGreen;whiley>=0dobeginimage1.canvas.Pixels[x0+x,y0+y]:=color1;image1.canvas.Pixels[x0-x,y0+y]:=color1;image1.canvas.Pixels[x0+x,y0-y]:=color1;image1.canvas.Pixels[x0-x,y0-y]:=color1;ifdelta<0thenbegindelta1:=2*(delta+y)-1;ifdelta1<=0thendirection:=1elsedirection:=2;endelseifdelta>0thenbegindelta2:=2*(delta-x)-1;ifdelta2<=0thendirection:=2elsedirection:=3;endelsedirection:=2;casedirectionof1:begininc(x);delta:=delta+2*x+1;end;2:begininc(x);dec(y);delta:=delta+2*(x-y+1);end;3:begindec(y);delta:=delta+(-2*y+1);end;end;end;end;④雙擊演示按扭，定義參數(shù)如下：x,y,x0,y0,r,direction:integer;delta,delta1,delta2:integer;color1:integer;⑤編寫代碼如下 ifself.Edit1.Text=''thenbeginApplication.MessageBox('圓心坐標X沒有輸入！','提示',0);abort;endelseifself.Edit2.Text=''thenbeginApplication.MessageBox('圓心坐標Y沒有輸入！','提示',0);abort;endelseifself.Edit3.Text=''thenbeginApplication.MessageBox('圓半徑?jīng)]有輸入！','提示',0);abort;endelsex0:=strtoint(Edit1.Text);y0:=strtoint(Edit2.Text);r:=strtoint(Edit3.Text);x:=0;y:=r;delta:=2*(1-r);color1:=clGreen;whiley>=0dobeginimage1.canvas.Pixels[x0+x,y0+y]:=color1;image1.canvas.Pixels[x0-x,y0+y]:=color1;image1.canvas.Pixels[x0+x,y0-y]:=color1;image1.canvas.Pixels[x0-x,y0-y]:=color1;ifdelta<0thenbegindelta1:=2*(delta+y)-1;ifdelta1<=0thendirection:=1elsedirection:=2;endelseifdelta>0thenbegindelta2:=2*(delta-x)-1;ifdelta2<=0thendirection:=2elsedirection:=3;endelsedirection:=2;casedirectionof1:begininc(x);delta:=delta+2*x+1;end;2:begininc(x);dec(y);delta:=delta+2*(x-y+1);end;3:begindec(y);delta:=delta+(-2*y+1);end;end;end;⑥雙擊退出按扭，編寫代碼如下： Close；⑦雙擊清屏按扭，編寫代碼如下：image1.Canvas.Brush.Color:=clwhit