Rectangle clipping Algorithm _python3 final version

Environment Preparation:The Python version is 3.5.1. Use PIP command: Pip install pyopengl install PYOPENGL modulealso note that you need to copy OpenGL files (open File link or Baidu) to the system disk System32 (32-bit system) or SYSWOW64 (64-bit system) directory, or may or error. I met this problem at the school lab today, and the error message seems to be that the Glutinit function cannot be used. Description:The teacher's request is to realize the keyboard input and mouse click Two Interactive way, can't, had to encapsulate the function, convenient call. Code:

#encoding = ' Utf-8 ' #python3.5.1#author by Zhang Jinwei 2016/6/21# rectangle clipping algorithm from opengl.glut import *from opengl.gl import *import Sysblue= (0.0,0.0,1.0) green= (0.0,1.0,0.0) red= (1.0,0.0,0.0) color=bluewinx=400 #窗口宽度winy =400 #窗口高度l1 =[]; #存储坐标class Point:x=0 #x坐标 y=0 #y坐标 pl=0 #相对于矩形裁剪区域左边, the position of this point, 0 for the inside, 1 for the outer pt=0 #相对于矩形裁剪区域上边, the position of this point, 0 for the inside, 1 for the outer pr=0 #相对于矩形裁剪区域右边,        The position of this point, 0 for the inside, 1 for the outer pb=0 #相对于矩形裁剪区域下边, the position of this point, 0 for the inside, 1 for the outer def __init__ (SELF,X,Y,PL,PT,PR,PB): Self.x=x self.y=y SELF.PL=PL self.pt=pt self.pr=pr self.pb=pbi=point (0,0,0,0,0,0) #函数: Gets the position of the cropped area vertex coordinates relative to the clipping area four edges def J        Udgepositon (I,PRT,PLB): #判断左边 if (i.x<plb.x): i.pl=1 else:i.pl=0 #判断上边 if (I.Y&LT;PRT.Y): I.pt=0 else:i.pt=1 #判断右边 if (i.x<prt.x): i.pr=0 else:i.pr=1 #判断下边 if (i    . Y<plb.y): I.pb=1 else:i.pb=0def Leftclip (prt,plb,*l): l=l[0] l2=[] #左边裁剪 print (l[0].x) For I in Range (0,len (l)): if (i==Len (L)-1): if (l[i].pl==0): #都在内部, leave the second vertex if (l[0].pl==0): L2.ap                    Pend (L[0]) #一内一外, reserved intersection else:k= (L[I].Y-L[0].Y)/(l[i].x-l[0].x)                     b=l[i].y-k*l[i].x x=plb.x y=x*k+b temp=point (x,y,0,0,0,0)                    L2.append (temp) Else: #一外一内, keep the intersection with the inside if (l[0].pl==0):                    k= (L[I].Y-L[0].Y)/(l[i].x-l[0].x) b=l[i].y-k*l[i].x x=plb.x Y=x*k+b temp=point (x,y,0,0,0,0) l2.append (temp) l2.append (l[0                ]) #都在外部, discard all Else:pass else:if (l[i].pl==0):                #都在内部, retains the second vertex if (l[i+1].pl==0): L2.append (l[i+1]) #一内一外, preserving the intersection point         Else           k= (L[I].Y-L[I+1].Y)/(l[i].x-l[i+1].x) b=l[i].y-k*l[i].x x=plb.x                Y=x*k+b temp=point (x,y,0,0,0,0) l2.append (temp) Else:                    #一外一内, reserved intersection with inner if (l[i+1].pl==0): k= (L[I].Y-L[I+1].Y)/(l[i].x-l[i+1].x)                    b=l[i].y-k*l[i].x x=plb.x y=x*k+b temp=point (x,y,0,0,0,0)                     L2.append (temp) l2.append (l[i+1]) #都在外部, discard else: Pass return l2def Topclip (prt,plb,*l): L2=l[0] l=[] for I in range (0,len (L2)): if (i==le N (L2)-1): if (l2[i].pt==0): #都在内部, retains the second vertex if (l2[0].pt==0): L.ap                        Pend (L2[0]) #一内一外, retain the intersection else:if (l2[i].x==l2[0].x):              x=l2[i].x          Y=prt.y temp=point (x,y,0,0,0,0) l.append (temp)                        else:k= (L2[I].Y-L2[0].Y)/(l2[i].x-l2[0].x) b=l2[i].y-k*l2[i].x Y=prt.y if k!=0:x= (y-b)/k temp=p Oint (x,y,0,0,0,0) l.append (temp) Else: #一外一内, preserve the intersection with the inner if (l2[                        0].pt==0): if (l2[i].x==l2[0].x): x=l2[i].x y=prt.y                    Temp=point (x,y,0,0,0,0) l.append (temp) l.append (l2[0]) else:k= (L2[I].Y-L2[0].Y)/(l2[i].x-l2[0].x) B=l2[i].y-k*l2[i]                        . x y=prt.y if k!=0:x= (y-b)/k Temp=point (x,y,0,0,0, 0) L.append (temp) l.append (l2[0]) #都在外部, discard all Else:pass else:if (l2[i].pt==0): #都在内部, leave the second vertex if (l2[i +1].pt==0): L.append (l2[i+1]) #一内一外, preserving the intersection else:if ( l2[i].x==l2[i+1].x): x=l2[i].x y=prt.y temp=point (x, y , 0,0,0,0) l.append (temp) else:k= (L2[I].Y-L2[I+1].Y)/ (l2[i].x-l2[i+1].x) b=l2[i].y-k*l2[i].x Y=prt.y if k! =0:x= (y-b)/k temp=point (x,y,0,0,0,0) l.append (te MP) Else: #一外一内, preserving the intersection with the inner if (l2[i+1].pt==0): if (l2[i].x==l2[i+1].                     x):   x=l2[i].x y=prt.y temp=point (x,y,0,0,0,0) l.append (temp) l.append (l2[i+1]) else:k= (L2[I].Y-L2[I+1].Y)/(l2[                            i].x-l2[i+1].x) b=l2[i].y-k*l2[i].x Y=prt.y if k!=0:                        x= (y-b)/k temp=point (x,y,0,0,0,0) l.append (temp) L.append (l2[i+1]) #都在外部, discard all Else:pass return Ldef Rightclip (prt,plb,*l): L=l[0] l2=[] for I in range (0,len (l)): if (I==len (L)-1): if (l[i].pr= =0): #都在内部, retains the second vertex if (l[0].pr==0): L2.append (l[0]) #一内一外, reserved                    Intersection else:k= (L[I].Y-L[0].Y)/(l[i].x-l[0].x) b=l[i].y-k*l[i].x      X=prt.x              Y=x*k+b temp=point (x,y,0,0,0,0) l2.append (temp) Else:                    #一外一内, reserved intersection with inner if (l[0].pr==0): k= (L[I].Y-L[0].Y)/(l[i].x-l[0].x)                    b=l[i].y-k*l[i].x x=prt.x y=x*k+b temp=point (x,y,0,0,0,0)                    L2.append (temp) l2.append (l[0]) #都在外部, discard else:                    Pass Else:if (l[i].pr==0): #都在内部, keep the second vertex if (l[i+1].pr==0): L2.append (l[i+1]) #一内一外, retain the intersection else:k= (L[I].Y-L[I+1].Y)/(l[i                    ].x-l[i+1].x) b=l[i].y-k*l[i].x X=prt.x y=x*k+b Temp=point (x,y,0,0,0,0) l2.append (temp) Else: #一外一内, preserving the intersection with the inside I        F (l[i+1].pr==0):            k= (L[I].Y-L[I+1].Y)/(l[i].x-l[i+1].x) b=l[i].y-k*l[i].x x=prt.x Y=x*k+b temp=point (x,y,0,0,0,0) l2.append (temp) L2.app     End (L[i+1]) #都在外部, discard Else:pass return l2def bottomclip (prt,plb,*l): L2=L[0] l=[] for I in range (0,len (L2)): if (I==len (L2)-1): if (l2[i].pb==0): #都在内                     , preserving the second vertex if (l2[0].pb==0): L.append (l2[0]) #一内一外, preserving the intersection of else:                        if (l2[i].x==l2[0].x): x=l2[i].x y=plb.y Temp=point (x,y,0,0,0,0) l.append (temp) else:k= (L2                        [I].y-l2[0].y]/(l2[i].x-l2[0].x) b=l2[i].y-k*l2[i].x y=plb.y        If k!=0:                    x= (y-b)/k temp=point (x,y,0,0,0,0) l.append (temp)                        else: #一外一内, preserve the in-intersection if (l2[0].pb==0): if (l2[i].x==l2[0].x):                        x=l2[i].x y=plb.y Temp=point (x,y,0,0,0,0) L.append (temp) l.append (l2[0]) else:k= (L2[I].Y-L2[0].Y)/ (l2[i].x-l2[0].x) b=l2[i].y-k*l2[i].x y=plb.y if k!=0 : x= (Y-b)/k temp=point (x,y,0,0,0,0) l.append (temp ) L.append (l2[0]) #都在外部, discard all Else:pass els E:if (l2[i].pb==0): #都在内部, retain the second vertex if (l2[i+1].pb==0): L.append (l 2[I+1]) #One inside Out, reserved intersection else:if (l2[i].x==l2[i+1].x): x=l2[i].x Y=plb.y temp=point (x,y,0,0,0,0) l.append (temp) El                        se:k= (L2[I].Y-L2[I+1].Y)/(l2[i].x-l2[i+1].x) b=l2[i].y-k*l2[i].x Y=plb.y if k!=0:x= (y-b)/k Temp=poin T (x,y,0,0,0,0) l.append (temp) Else: #一外一内, preserve the intersection with the inner if (l2[i+1                        ].pb==0): if (l2[i].x==l2[i+1].x): x=l2[i].x y=plb.y                    Temp=point (x,y,0,0,0,0) l.append (temp) l.append (l2[i+1]) else:k= (L2[I].Y-L2[I+1].Y)/(l2[i].x-l2[i+1].x) b=l2[i].y-               k*l2[i].x         Y=plb.y if k!=0:x= (y-b)/k temp=point (x,                y,0,0,0,0) l.append (temp) l.append (l2[i+1]) #都在外部, discard all Else:pass return l# The upper-left corner of the window is (0,0), and Pyopengl paint takes the center of the window (0,0) and the maximum x and y coordinates are 100. #因此需要将鼠标获取的坐标转换成PyOpengl画图坐标.        def translate (point): A=WINX/2 B=WINY/2 if Point.x < A and Point.y < b:point.x= (point.x/a) *100-100 point.y=100-(point.y/b) *100 elif point.x > A and Point.y < b:point.x= ((POINT.X-A)/a) *100 PO int.y=100-(point.y/b) *100 elif Point.x < A and Point.y > b:point.x= (point.x/a) *100-100 point.y= (p    Oint.y-b)/b) *100* ( -1) else:point.x= ((point.x-a)/a) *100 point.y= ((point.y-b)/b) *100* ( -1) def display ():              Glclearcolor (0.0,0.0,0.0,0.0) #背景色 = black, Rgba is all 0 glclear (gl_color_buffer_bit) #清除颜色缓冲区 GLCOLOR3FV (COLOR) #设置下面绘制物体的颜色   #f表示参数类型为浮点类型, v indicates that the accepted parameter is in the array form #glRectf ( -10.0,-20.0,20.0,10.0) #画填充矩形 #绘制坐标系 glcolor3f (1.0, 1.0, 1.0) Glbegi N (gl_lines) glvertex2f (0.0, 0.0) glvertex2f (0.0, 95.0) glvertex2f (0.0, 95.0) glvertex2f (4.0, 92.0) glver      tex2f (0.0, 95.0) glvertex2f ( -4.0, 92.0) glvertex2f (0.0, 0.0) glvertex2f (0.0, -95.0) glvertex2f (0.0, 0.0)    GLVERTEX2F (95.0,0.0) glvertex2f (95.0,0.0) glvertex2f (92.0,4.0) glvertex2f (95.0,0.0) glvertex2f (92.0,-4.0)    glvertex2f (0.0, 0.0) glvertex2f ( -95.0,0.0) glend () glcolor3f (0.0,0.0,1.0) glbegin (gl_points);    Glvertex2i (0,0);    Glend (); Glflush () def reshape (winx,winy): Glviewport (0,0,winx,winy) #定义相对视窗大小 (Pixel range) Glmatrixmode (gl_projection) #选择投影                                   Matrix glloadidentity () #读取规范化的单位矩阵 Glortho ( -100.0,100.0, -100.0,100.0, 0.0,100.0) #定义空间坐标系范围 Glmatrixmode (Gl_modelview) #选择模型视图矩阵 glloadidentity () def key (Key,mousex,mousey): GlobAl Color if (key==b ' Q '): #按下q按键时 print (' exit ') Glutdestroywindow (Winid) #根据ID结束窗口 s    Ys.exit () elif (key==b ' e '): L1.clear () print (' Initialize interface ') Glutpostredisplay () #重绘, the display will be called Elif (key==b ' G '): #以绿线画裁剪后图形并输出裁剪后坐标 if l1[0].x<l1[1].x: #矩形裁剪区域: The coordinates of the lower left point Plb=point (l 1[0].x,l1[0].y,0,0,0,0) #矩形裁剪区域: Coordinates prt=point (l1[1].x,l1[1].y,0,0,0,0) else on upper right point: #矩 Shape clipping area: The lower-left point coordinates plb=point (l1[1].x,l1[1].y,0,0,0,0) #矩形裁剪区域: The coordinates of the upper-right point Prt=point (L1[0].X,L1[0].Y, 0,0,0,0) #输出 print (' lower left point of crop area: ') print (PLB.X,PLB.Y) print (' Crop area top right point coordinate: ') print (prt.x,prt        . Y) #被裁剪区域顶点坐标 l=l1[2:] #调用函数, fully initialize the trimmed area vertex coordinates for I in L1:judgepositon (I,PRT,PLB)        #测试输出被裁剪区域顶点坐标 Print ("init:") for I in L:print (I.X,I.Y,I.PL,I.PT,I.PR,I.PB) #左边裁剪 #调用左边裁减函数 L=leftclip (prt,plb,l) #初始化左裁剪后顶点坐标相对裁剪区域的位置 for I in L:judgepositon (I,PRT,PLB) #输出左裁剪后顶点坐标        Print ("Leftclip:") for I in L:print (I.X,I.Y,I.PL,I.PT,I.PR,I.PB) #上边裁剪 #调用上边裁剪函数 L=topclip (prt,plb,l) #初始化上裁剪后顶点坐标相对裁剪区域的位置 for I in L:judgepositon (I,PRT,PLB) #输出上 Cropped vertex coordinates print ("Topclip:") for I in L:print (I.X,I.Y,I.PL,I.PT,I.PR,I.PB) #右边裁剪 #调用右        Edge clipping function L=rightclip (prt,plb,l) #初始化右裁剪后顶点坐标相对裁剪区域的位置 for I in L:judgepositon (I,PRT,PLB)        #输出右裁剪后顶点坐标 print ("Rightclip:") for I in L:print (I.X,I.Y,I.PL,I.PT,I.PR,I.PB) #下边裁剪 #调用下边裁剪函数 L=bottomclip (prt,plb,l) #初始化下裁剪后顶点坐标相对裁剪区域的位置 for I in L:judgepositon (i,p        RT,PLB) #输出下裁剪后顶点坐标 print ("Bottomclip:") for I in L:print (I.X,I.Y,I.PL,I.PT,I.PR,I.PB) #以绿线画裁剪后区域 COlor=green GLCOLOR3FV (color) print (' clip polygon with Green Line ') for I in Range (0,len (l)): if (I==len (l)-1 ): Glbegin (gl_lines) #画线 glvertex2f (L[I].X,L[I].Y) glvertex2f (l[0].x,l[0].y                  ) Glend () Glflush () Else:glbegin (gl_lines) #画线            GLVERTEX2F (L[I].X,L[I].Y) glvertex2f (L[I+1].X,L[I+1].Y) glend () Glflush () Elif (key==b ' R '): #以红色画矩形裁剪窗口 color=red glcolor3fv (color) print (' Rectangle clipping window in red Line ') Glbegi N (gl_lines) #画线 glvertex2f (L1[0].X,L1[0].Y) glvertex2f (L1[0].X,L1[1].Y) glvertex2f (l1[0].x,         L1[1].Y) glvertex2f (L1[1].X,L1[1].Y) glvertex2f (L1[1].X,L1[1].Y) glvertex2f (L1[1].X,L1[0].Y)         GLVERTEX2F (L1[1].X,L1[0].Y) glvertex2f (L1[0].X,L1[0].Y) glend () Glflush () elif (key==b ' B '):      Color=blue  GLCOLOR3FV (color) print (' Crop polygon with Blue Line ') for I in range (2,len (L1)): if (I==len (L1)-1):                  Glbegin (gl_lines) #画线 glvertex2f (L1[I].X,L1[I].Y) glvertex2f (L1[2].X,L1[2].Y) Glend () Glflush () Else:glbegin (gl_lines) #画线 glVertex2 F (l1[i].x,l1[i].y) glvertex2f (L1[I+1].X,L1[I+1].Y) glend () Glflush () Eli        F (key==b ' K '): Print (' Please enter the bottom left point x coordinate: ') lx=float (input ()) print (' Please enter the lower left point y coordinate: ') ly=float (inputs ())        Print (' Please enter the bottom right point x coordinate: ') rx=float (input ()) print (' Please enter the lower right point y-coordinate: ') ry=float (input ()) L1.clear ()        Plb=point (lx,ly,0,0,0,0) prt=point (rx,ry,0,0,0,0) l1.append (PLB) l1.append (PRT) #矩形顶点坐标             For I in L1:print (I.X,I.Y) print ("Input clipped polygon vertex number:") N=int (Input ()) for I in Range (0,n): Print (' Please enter%d vertex x coordinate '% (i+1)) tempx=float (input ()) print (' Please enter%d point y coordinates '% (i+1)) tempy=float (input ()) Temp=point (tempx,tempy,0,0,0,0) l1.append (temp) print (' Press \ ' r\ ' key to draw the cropping area. Print (' Press \ ' b\ ' key to draw the cropped area ') print (' Press \ ' g\ ' key to draw the cropped area ') def Mouse (button,state,x,y): #鼠标左键按下 if button = = G        Lut_left_button and state = = GLUT_DOWN:GLCOLOR3FV (color) temp=point (x,y,0,0,0,0) Translate (temp) L1.append (temp) print (' Instructions: ') print (' 1. Mouse click: ') print (' Click on the mouse to determine the lower-left and lower-right coordinates of the rectangle clipping area, press \ ' R\ ' key to draw the clipping area ') print (' Click on the mouse to determine the coordinates of the cropped area, press \ ' b\ ' key to draw the cropped area ') print (' Press \ ' g\ ' key to draw the cropped area ') print (' Press \ ' e\ ' key Initialization interface ') print (' Press \ ' q\ ' key to exit the program ') print (' Press \ ' K\ ') Key to enter coordinates from the command line to crop ') Glutinit (SYS.ARGV) Glutinitdisplaymode (glut_single| Glut_rgba) glutinitwindowsize (winx,winy) glutinitwindowposition (100,100) Winid=glutcreatewindow (b "main") # The ID of the build window returns to Winidglutdisplayfunc (display) Glutreshapefunc (reshape) glutkeyboardfunc (key) Glutmousefunc (mouse) Glutmainloop ()

Rectangle clipping Algorithm _python3 final version