雪花曲线c/c++(分形学)

/************************ *filename:snowcurve.cpp* *Author:luosunny126 * *15:28 2008-3-29 * ************************/ #include"snowcurve.h" #include<malloc.h> #include<stdio.h> #include<math.h> #include<windows.h> // 获取一个可供画图的DC，我这里就直接用桌面算了 HDC hdc = GetWindowDC( GetDesktopWindow() ); // 创建红色1像素宽度的实线画笔 HPEN hpen1 = CreatePen( PS_SOLID, 1, RGB(255,0,0) ); // 将hpen1和hbrush1选进HDC，并保存HDC原来的画笔 HPEN hpen_old = (HPEN)SelectObject( hdc, hpen1 ); SCurve *head; int drawSnowCurve(int n,int side,SNOW center) { SCurve *Q1,*Q2; if(n>SnowCN || n<1) return ERROR; InitSnowCurve(side,center); getSnowCurve( n ); Q1=head->next; Q2=Q1->next; while(Q2!=NULL) { drawLine( Q1->data,Q2->data ); Q1=Q2; Q2=Q2->next; } freeSCoords();//释放空间 return OK; } void getSnowCurve(int n) { int m=1; SCurve *p1,*p2; while(m<=n) { p1=head->next; p2=p1->next; while(p2!=NULL) { getThreeCoords( p1 ); p1=p2; p2=p2->next; } m++; } } int getThreeCoords(SCurve *p) { SNOW cd1,cd2,cd3,cd4,cd5; cd1=p->data; cd2=p->next->data; cd3.x=cd1.x + (cd2.x-cd1.x)/3 ; cd3.y=cd1.y + (cd2.y-cd1.y)/3 ; cd4.x=cd1.x + 2*(cd2.x-cd1.x)/3 ; cd4.y=cd1.y + 2*(cd2.y-cd1.y)/3 ; int flag=(cd2.y-cd1.y) / (cd2.x-cd1.x); if(flag == 0) { cd5.x=(cd1.x+cd2.x)/2 ; cd5.y=(int)( sqrt(3.0)*(cd4.x-cd3.x)/2 ) +cd3.y; } else if(flag > 0) { cd5.x=2*cd3.x - cd4.x; cd5.y=cd4.y; } else { cd5.x=2*cd4.x - cd3.x; cd5.y=cd3.y; } if(insertSCoord(p,cd3)) if(insertSCoord(p->next,cd5)) if(insertSCoord(p->next->next,cd4)) return OK; return ERROR ; } int insertSCoord(SCurve *p,SNOW cd) { SCurve *p1; p1=(SCurve *)malloc(sizeof(SCurve)); if(p1==NULL) return OVERFLOW; p1->data=cd; p1->next=p->next; p->next=p1; return OK; } int InitSnowCurve(int side,SNOW center) { int i; SCurve *pi; SNOW coord[4]; head=(SCurve *)malloc(sizeof(SCurve)); if(head==NULL) return OVERFLOW; head->next=NULL; pi=head; coord[0].x=center.x - side/2 ; coord[0].y=center.y + (int)( sqrt(3.0)*side/6 ); coord[1].x=center.x +side/2 ; coord[1].y=coord[0].y; coord[2].x=center.x ; coord[2].y=coord[0].y - (int)( sqrt(3.0)*side/2 ); coord[3] = coord[0]; for(i=0;i<4;i++) { insertSCoord( pi, coord[i]); pi=pi->next; } return OK; } void drawLine(SNOW cd1,SNOW cd2) { MoveToEx( hdc, cd1.x, cd1.y, NULL ); LineTo( hdc, cd2.x, cd2.y ); } void freeSCoords() { SCurve *q, *p=head; while(p!=NULL) { q=p; p=p->next; free(q);q=NULL; } }