//A.3 三维Sierpinski镂垫的递归程序/* Recursive subdivision of a tetrahedron to form 3D Sierpinski gasket *//* number of recursive steps given on command line */#include <stdlib.h>#include <GL/glut.h>/* initial tetrahedron */GLfloat v[4][3]={{0.0, 0.0, 1.0},{0.0, 0.942809, -0.33333},{-0.816497, -0.471405, -0.333333},{0.816497, -0.471405, -0.333333}};GLfloat colors[4][3]={{1.0,0.0,0.0},{0.0,1.0,0.0},{0.0,0.0,1.0},{0.0,0.0,0.0}};int n;void triangle( GLfloat *va, GLfloat *vb, GLfloat *vc){glVertex3fv(va);glVertex3fv(vb);glVertex3fv(vc);}void tetra(GLfloat *a, GLfloat *b, GLfloat *c, GLfloat *d){glColor3fv(colors[0]);triangle(a,b,c);glColor3fv(colors[1]);triangle(a,c,d);glColor3fv(colors[2]);triangle(a,d,b);glColor3fv(colors[3]);triangle(b,d,c);}void divide_tetra(GLfloat *a, GLfloat *b, GLfloat *c, GLfloat *d, int m){GLfloat mid[6][3];int j;if(m>0){/* compute six midpoints */for(j=0; j<3; j++) mid[0][j]=(a[j]+b[j])/2;for(j=0; j<3; j++) mid[1][j]=(a[j]+c[j])/2;for(j=0; j<3; j++) mid[2][j]=(a[j]+d[j])/2;for(j=0; j<3; j++) mid[3][j]=(b[j]+c[j])/2;for(j=0; j<3; j++) mid[4][j]=(c[j]+d[j])/2;for(j=0; j<3; j++) mid[5][j]=(b[j]+d[j])/2;/* create 4 tetrahedrons by subdivision */divide_tetra(a,mid[0],mid[1],mid[2], m-1);divide_tetra(mid[0],b,mid[3],mid[5], m-1);divide_tetra(mid[1],mid[3],c,mid[4], m-1);divide_tetra(mid[2],mid[4],d,mid[5], m-1);}else tetra(a,b,c,d); /* draw tetrahedron at end of recursion */}void display(void){glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);glBegin(GL_TRIANGLES);divide_tetra(v[0],v[1],v[2],v[3],n);glEnd();glFlush();}void myReshape(int w, int h){glViewport(0, 0, w, h);glMatrixMode(GL_PROJECTION);glLoadIdentity();if (w <= h)glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w,2.0 * (GLfloat) h / (GLfloat) w, -10.0, 10.0);elseglOrtho(-2.0 * (GLfloat) w / (GLfloat) h,2.0 * (GLfloat) w / (GLfloat) h, -2.0, 2.0, -10.0, 10.0);glMatrixMode(GL_MODELVIEW);glutPostRedisplay();}void main(int argc, char **argv){n=10;//n=atoi(argv[1]); /* or set number of subdivision steps here *///注意，上句若是在VS或VC++中直接使用会报错，因为需要输入一个参数。//可以考虑使用命令提示行，在windows下打开项目的debug文件夹，按住shift键右击//选择：在当前位置打开命令提示行。//输入：Main.exe 10//其中，Main.exe根据自己情况确定，后面的10是递归次数，可以自定义//实际检测，当数字大于15会出现卡死状态，数字大于20直接死机glutInit(&argc, argv);glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);glutInitWindowSize(500, 500);glutCreateWindow("3D Gasket");glutReshapeFunc(myReshape);glutDisplayFunc(display);glEnable(GL_DEPTH_TEST); glClearColor (1.0, 1.0, 1.0, 1.0);glutMainLoop();}
