计算机图形学实验答案.doc

实验一、中点画直线算法#include #include void MidpointLine1(int x0,int y0,int x1, int y1,int color) int a, b, d1, d2, d, x, y;a=y0-y1; b=x1-x0; d=2*a+b;d1=2*a ; d2=2* (a+b);x=x0; y=y0;putpixel(x, y, color);while (xx1) if (d0) x+; y+; d+=d2; elsex+; d+=d1;putpixel (x, y, color); void MidpointLine2(int x0,int y0,int x1, int y1,int color) int a, b, d1, d2, d, x, y;a=y0-y1; b=x1-x0; d=2*a-b;d1=2*a ; d2=2* (a-b);x=x0; y=y0;putpixel(x, y, color);while (xx1)if (d0) x+; d+=d1; elsex+;y-; d+=d2; putpixel (x, y, color); void MidpointLine3(int x0,int y0,int x1, int y1,int color) int a, b, d1, d2, d, x, y;a=y0-y1; b=x1-x0; d=a+2*b;d1=2*b ; d2=2* (a+b);x=x0; y=y0;putpixel(x, y, color);while (xx1)if (d0) y+; d+=d1; else x+; y+; d+=d2; putpixel (x, y, color); void MidpointLine4(int x0,int y0,int x1, int y1,int color) int a, b, d1, d2, d, x, y;a=y0-y1; b=x1-x0; d=a-2*b;d1=-2*b ; d2=2* (a-b);x=x0; y=y0;putpixel(x, y, color);while (xx1)if (d0) x+;y-; d+=d2; else y-; d+=d1; putpixel (x, y, color); /当输入两端点的x坐标相同时，斜率为无穷大，调用以下函数画线LineV(int x,int y0,int y1,int color) int y,t;if(y1y0)t=y0;y0=y1;y1=t;for(y=y0;y=y1;y+)putpixel(x,y,color); main() int x0,y0,x1,y1,t;float k;int gdriver = DETECT , gmode ;scanf(%d%d%d%d,&x0,&y0,&x1,&y1);initgraph ( &gdriver , &gmode ,“c:tcbgi) ;if(x0=x1) LineV(x0,y0,y1,WHITE);elseif(x1=0&k1)MidpointLine1(x0,y0,x1,y1,WHITE);else if(k=-1)MidpointLine2(x0,y0,x1,y1,WHITE);else if(k1)MidpointLine3(x0,y0,x1,y1,WHITE);else MidpointLine4(x0,y0,x1,y1,WHITE); getch();closegraph ( ) ; 二、中点画圆#include #include void Midpoint_circle(r,color)int r,color;int x,y,deltax,deltay,e;x=0; y=r; e=1-r;deltax=3;deltay=2-r-r;putpixel(x,y,color);while(xy)if(e0)e+=deltax;deltax+=2;x+; elsee+=(deltax+deltay);deltax+=2;deltay+=2;x+; y-;putpixel(x+320,y+240,color);putpixel(-x+320,y+240,color);putpixel(x+320,-y+240,color);putpixel(-x+320,-y+240,color);putpixel(y+320,x+240,color);putpixel(-y+320,x+240,color);putpixel(y+320,-x+240,color);putpixel(-y+320,-x+240,color); int main()int r0,color;int gdriver=DETECT,gmode;initgraph(&gdriver,&gmode,C:tcBGI);scanf(%d,%d,&r0,&color);Midpoint_circle(r0,color);getch(); closegraph();return 0; 三、区域填充算法#include #include int edge_MarkFill(int n,int *p,int color)int insideFlag=0,c1=0,c2=0;int max,min;int x,y,i,j;max=min=p1;for(i=1,max=min=p1;in*2;i+=2) if(maxpi) min=pi; for(y=min+1;ymax;+y)for(x=0;x640;+x) c1=c2;c2=getpixel(x,y);if(c1=color&c2!=color)insideFlag=!insideFlag;if(insideFlag)putpixel(x,y,color); int main()int gdriver=DETECT,gmode,color=RED;int points=120,50,120,200,250,200,350,50,120,50;initgraph(&gdriver,&gmode,C:TCBGI);setbkcolor(BLACK);setcolor(color);drawpoly(5,points);edge_MarkFill(5,points,color);getch();closegraph();return 0; 4、 图形裁剪算法#include#define LEFT 1#define RIGHT 2#define BOTTOM 4#define TOP 8void encode(float x,float y,int* code,float XL,float XR,float YB,float YT)int c=0;if(xXR)c=c|RIGHT;if(yYT)c=c|TOP;*code=c;return; void SwapPoint(x1,y1,x2,y2)float *x1,*y1,*x2,*y2;float t;t=*x1; *x1=*x2; *x2=t;t=*y1; *y1=*y2; *y2=t; void SwapCode(code1,code2)int *code1,*code2;int t;t=*code1;*code1=*code2;*code2=t; C_S_Line_Clip(x1,y1,x2,y2,XL,XR,YB,YT)float x1,y1,x2,y2,XL,XR,YB,YT;int code1,code2,code;int x,y;encode(x1,y1,&code1,XL,XR,YB,YT);encode(x2,y2,&code2,XL,XR,YB,YT);while(code1!=0 | code2!=0)if(code1&code2!=0)return;if(code1=0) SwapPoint(&x1,&y1,&x1,&y2); SwapCode(&code1,&code2); code=code1;if(LEFT&code!=0)x=XL;y=y1+(y2-y1)*(XL-x1)/(x2-x1); else if(RIGHT&code!=0)x=XR;y=y1+(y2-y1)*(XR-x1)/(x2-x1); else if(BOTTOM&code!=0)y=YB;x=x1+(x2-x1)*(YB-y1)/(y2-y1); else if(TOP&code!=0)y=YT;x=x1+(x2-x1)*(YT-y1)/(y2-y1); x1=x;y1=y;encode(x,y,code,XL,XR,YB,YT);line(x1,x2,y1,y2);return; int main()int x1=12,x2=560,y1=202,y2=25;int XL=35,XR=358,YB=62,YT=310;int gdriver=DETECT,gmode;initgraph(&gdriver,&gmode,C:TCBGI);C_S_Line_Clip(x1,y1,x2,y2,XL,XR,YB,YT);getch();closegraph();return 0; 五、bezier曲线生成算法：de Casteljau算法#include#include#define N 4float Casteljau( int k, float controls10, float t)int r,i;float t1,controlsa10;t1=1.0-t;for(i=0;i=k;i+) controlsai=controlsi;for(r=1;r=k;r+)for(i=0;i=k-r;i+) controlsai=t1*controlsai+t*controlsai+1;return controlsa0; void draw_bezier_curve(int k,float controlx,float controly,int x0,int y0) int i,x,y; float u,delta; float controlp; delta=1.0/(float)(N); for(i=0,u=0;u=1.0;i+,u=u+delta) controlp=Casteljau(k,controlxi,u); if(i=0) moveto(x0+controlp,y0-controlp); lineto(x0+controlp,y0-controlp); void draw_polygon(float controlx,float controly,int originx,int originy) int i; for (i=0;iN;i+) if (i=0) moveto(originx+controlx0,originy-controly0); lineto(originx+controlxi,originy-controlyi); int main()float controlsx5,controlsy5;int gdriver=DETECT,gmode; int originx,originy; printf(input x0,y0,x1,y1,x2,y2,x3,y3,x4,y4:);scanf(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,&controlsx0,&controlsy0,&controlsx1,&controlsy1,&controlsx2,&controlsy2,&controlsx3,&controlsy3,&controlsx4,&controlsy4);initgraph(&gdriver,&gmode,C:TCBGI); originx=getmaxx()/2; originy=getmaxy()/2; setcolor(BLUE);draw_polygon(controlsx,controlsy,originx,originy); setcolor(RED);draw_bezier_curve(N,controlsx,controlsy,originx,originy); getch(); closegraph(); 6、二维几何图形变换：用户输入三角形的三个顶点以及屏幕上任意一个顶点P的坐标，使得该三角形相对于P瞬时针旋t弧度。#include#include#includefloat jzjs(float a33,float b33,float s33)int i,j,k;double sum;for(i=0;i3;+i)for(j=0;j3;+j)sum=0;for(k=0;k3;+k)sum+=aik*bkj;sij=sum; return 0; int main()int drive=DETECT,mode;float t;int i,j;float x0,y0,x1,y1,x2,y2,x3,y3;float T133=1,0,0,0,1,0,0,0,1,T233=0,0,0,0,0,0,0,0,1,T333=1,0,0,0,1,0,0,0,1,p33=0,0,1,0,0,1,0,0,1;float r33,s33,w33;initgraph(&drive,&mode,C:TCBGI);setcolor(RED);printf(please input the coordinate of P(x0,y0) and the radian(t):n);scanf(%f,%f,%f,&x0,&y0,&t);printf(please input the three points of triangle(x1,y1,x2,y2,x3,y3):n); scanf(%f,%f,%f,%f,%f,%f,&x1,&y1,&x2,&y2,&x3,&y3);line(x1,y1,x2,y2);line(x2,y2,x3,y3);line(x3,y3,x1,y1);T120 = -x0; T121 = -y0;T200 = cos(t);T201 = sin(t);T210 = -sin(t);T211 = cos(t);T320 = x0; T321 = y0;p00 = x1; p01 = y1;p10 = x2; p11 = y2;p20 = x3; p21 = y3; jzjs(T1,T2,r);jzjs(r,T3,s);jzjs(p,s,w);getch(); setcolor(GREEN); line(w00,w01,w10,w11);line(w10,w11,w20,w21);line(w20,w21,w00,w01);getch(); closegraph();return 0; 7、仿照多边形区域填充算法，写出圆域的填充算法。方法一：套用边界标志算法：#include edgeMarkFill(int x0,int y0,int r,int color) int insideFlag=0,c1=0,c2=0;int max,min;int i,j,x,y;max=y0+r;min=y0-r;for(y=min+1;ymax;y+)for(x=x0-r-1;x=x0+r;x+)c1=c2; c2=getpixel(x,y); if(c1=color&c2!=color)insideFlag=!insideFlag; if(insideFlag) putpixel(x,y,color); main ( ) int gd = DETECT , gm,color=RED;int x,y,r;scanf(%d%d%d,&x,&y,&r);initgraph ( &gd, &gm,d:turboc2) ;setbkcolor(BLUE);setcolor(color);circle(x,y,r);edgeMarkFill(x,y,r,color);getch ( ) ;closegraph (); 方法二：扫描圆弧时直接填充#include circleFill(int x0,int y0,int r, int color)int x,y,x1;float d;x=0;y=r;d=1.25-r;while(xy)for(x1=x0-x;x1=x0+x;x1+)putpixel(x1,y+y0,color);for(x1=x0-y;x1=x0+y;x1+)putpixel(x1,x+y0,color); for(x1=x0-x;x1=x0+x;x1+)putpixel(x1,-y+y0,color);for(x1=x0-y;x1=x0+y;x1+)putpixel(x1,-x+y0,color);if(d0) d+=2*x+3; x+; elsed+= 2*(x-y) + 5; x+;y-; main ( ) int gd = DETECT , gm,color=RED;int x,y,r;scanf(%d%d%d,&x,&y,&r);initgraph ( &gd, &gm,d:turboc2) ;circleFill(x,y,r,color);getch ( ) ;closegraph (); 8、编写一个程序实现绘制三个像素宽的斜率在之间的点划线。void MidpointLine(int x0,int y0,int x1, int y1,int color) int a, b, d1, d2, d, x, y;int pattern32=1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,i=0;a=y0-y1; b=