opengl 消除棱角

/*************************************************************************
	> File Name: Star.c
	> Author: halfopen
	> Mail: halfopen@yeah.net
	> Created Time: 2015年11月11日 星期四 17时12分46秒
 ************************************************************************/

#include<stdio.h>
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#include<math.h>

#define PI 3.14159262423

int width=400, height=400;
static double	y=sin(PI/5)*tan(PI/5)-cos(PI/5); 
static GLint axis = 2;
static GLfloat theta[] = {0.0,0.0,0.0};

float points[10][3] = {-1,-1,1,
	1,-1,1,
	1,-1,-1,
	-1,-1,-1,
	-1,1,1,
	1,1,1,
	1,1,-1,
	-1,1,-1,
	0,3,0,
	3,0,0};
int faces[16][3]={1,2,5,
	2,6,5,

	2,10,6,
	6,10,7,
	2,3,10,
	3,7,10,
	
	5,6,9,
	6,7,9,

	7,8,9,
	5,9,8,

	1,5,4,
	5,8,4,
	
	1,4,2,
	4,3,2,

	8,7,4,
	7,3,4
	};
int points_list[10]={0};

float c = PI / 180.0f; //弧度和角度转换参数
int du = 90, oldmy = -1, oldmx = -1; //du是视点绕y轴的角度,opengl里默认y轴是上方向
float r = 1.5f, h = 0.0f; //r是视点绕y轴的半径,h是视点高度即在y轴上的坐标
GLfloat scale = 1.0;
void drawModel()
{
		glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
		glColor3f(255,255,255);
		for(int i=0;i<16;i++)
		{	glBegin(GL_POLYGON); 
				glVertex3f(points[ faces[i][0] -1][0] , points[faces[i][0]-1][1],points[faces[i][0]-1][2] );
				glVertex3f(points[ faces[i][1] -1][0] , points[faces[i][1]-1][1],points[faces[i][1]-1][2] );
				glVertex3f(points[ faces[i][2] -1][0] , points[faces[i][2]-1][1],points[faces[i][2]-1][2]);
			glEnd();	
		}
		glFlush();
}

void smooth()
{	for(int i=0;i<10;i++)
	{	printf("point:%d->%.2f %.2f %.2f\n",i+1,points[i][0],points[i][1],points[i][2]);
		//printf("change to:\n");
//		points[i][0] = points[i][0] /2.0;
//		points[i][1] = points[i][1] /3.0;
//		points[i][2] = points[i][2] /4.0;
		
		for(int j=0;j<16;j++)points_list[j]=0;
		for(int j=0;j<16;j++)
		{	if(faces[j][0]==i+1 || faces[j][1]==i+1 || faces[j][2]==i+1)
			{	points_list[ faces[j][0]-1 ]=1;
				points_list[ faces[j][1]-1 ]=1;
				points_list[ faces[j][2]-1 ]=1;
			}
		}
		printf("find:");
		float x=0,y=0,z=0;	//
		int count = 0;
		for(int l=0;l<16;l++)
		{	if(points_list[l] == 1)
			{	//printf("->%d ",l+1);
				count++;
				x += points[i][0] - points[l][0];
				y += points[i][1] - points[l][1];
				z += points[i][2] - points[l][2];
//				printf("(%f %f %f)-(%f %f %f)=(%f %f %f)\n",points[i][0], points[i][1],points[i][2], 
//					points[l][0],points[l][1],points[l][2],
//					x,y,z);
			}
		}
		x = x/(count-1);
		y = y/(count-1);
		z = z/(count -1);
		printf(" ->x:%f y:%f z:%f\n",x,y,z);
		points[i][0] = points[i][0] /(1 + 0.1*fabs(x));
		points[i][1] = points[i][1] /(1 + 0.1*fabs(y));
		points[i][2] = points[i][2] /(1 + 0.1*fabs(z));
		glutPostRedisplay();
	}
}

static void display(void)
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	//printf("At:%.2f %.2f %.2f\n",r*cos(c*du),h,r*sin(c*du)); //这就是视点的坐标
	glPushMatrix();
	glLoadIdentity();
	glRotatef(theta[0]/2, 1.0, 0.0, 0.0);
	glRotatef(theta[1]/2, 0.0, 1.0, 0.0);
	glRotatef(theta[2]/2, 0.0, 0.0, 1.0);		
	glScalef(scale, scale, scale);
	glColor3f(1.0f, 0.0f, 0.0f);
	drawModel();
	glPopMatrix();
	glFlush();
	
	glutSwapBuffers(); 
}


/* This routine inputs new control points */
static void mouse(int button, int state, int x, int y)
{
        glFlush();

}

void init(void) 
{
		glClearColor(0.0,0.0,0.0,0.0);     
	
}

/* This routine handles keystroke commands */
void keyboard(unsigned char key, int x, int y)
{	
        switch (key)
    		{
				case 'j':
					axis = 0;
					theta[axis] += 2.0;
					if( theta[axis] > 360.0 ) theta[axis] -= 360.0;
					glutPostRedisplay();break;
				case 'k':
					axis = 1;
					theta[axis] += 2.0;
					if( theta[axis] > 360.0 ) theta[axis] -= 360.0;
					glutPostRedisplay();break;
				case 'l':
					axis = 2;
					theta[axis] += 2.0;
					if( theta[axis] > 360.0 ) theta[axis] -= 360.0;
					glutPostRedisplay();break;
                case 'q': case 'Q':
                    exit(0);
                    break;
                case 'c': case 'C':
					glTranslatef(0.0f,-20.0f,-40.0f);
					puts("c");
                    break;
                case 'e': case 'E':
                    break;
                case 'b': case 'B':
                    break;
                case 'i': case 'I':
                    break;
				case 'h': case 'H':scale+=0.1;glutPostRedisplay();
                    break;
				case 'n': case 'N':scale-=0.1;glutPostRedisplay();
                    break;
                case 's': case 'S':
					smooth();
                    break;
            
    }

}

void spinCube()
{
		theta[axis] += 2.0;
		if( theta[axis] > 360.0 ) theta[axis] -= 360.0;
		glutPostRedisplay();
}

void reshape(int w, int h)
{
        width = w;
        height = h;

        /* Set the transformations */
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
        glMatrixMode(GL_MODELVIEW);
        glViewport(0, 0, w, h);

}
int main(int argc, char **argv)
{
        /* Intialize the program */
        glutInit(&argc, argv);
        glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
        glutInitWindowSize(width, height);
        glutCreateWindow("star");

        /* Register the callbacks */
        glutDisplayFunc(display);

        glutMouseFunc(mouse);
        glutKeyboardFunc(keyboard);
        glutReshapeFunc(reshape);
        glClearColor(1.0, 1.0, 1.0, 1.0);
        glEnable(GL_MAP1_VERTEX_3);

		init();
		glutMainLoop();
		return 0;
}

原图形:

转换之后: