tricera.c

图形学分形演示程序

#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <unistd.h>
#include "tricera.h"

#define MAX_VERTEX 8000
#define MAX_FACE 16000

float v_sin[6284];
void sort(Face *s, int length);
Vertex static vx[MAX_VERTEX];
Face static fc[MAX_FACE];
int v_num=0, f_num=0;

void parser(char *line, Vertex *vx)
{
	char *pt=NULL, *result = NULL;
	int i=0;

	pt = strstr (line,"Face");
	if (pt!=NULL)
	{
		result=strtok(line," ");
		result=strtok(NULL,":");

		if (result[0]!='l' && result[3]!='t')
		{
			i=atoi(result);
			result=strtok(NULL,":");
			result=strtok(NULL,":");
				fc[i].a=atof(result);
			result=strtok(NULL,":");
				fc[i].b=atof(result);
			result=strtok(NULL,":");
				fc[i].c=atof(result);
			f_num++;
		}
		return;
	}

	pt = strstr (line,"Vertex");
	if (pt!=NULL)
	{
		result=strtok(line," ");
		result=strtok(NULL,":");

		if (result[0]!='l' && result[3]!='t')
		{
			i=atoi(result); 
			result=strtok(NULL,":");
			result=strtok(NULL,":");
				vx[i].x=atof(result);
			result=strtok(NULL,":");
				vx[i].y=atof(result);
			result=strtok(NULL,":");
				vx[i].z=atof(result);
			v_num++;
		}
	}
}

void init(int argc, char *argv[])
{
	FILE *fp;
	char line[1024];

	if (argc>1)
	{
		if ( !(fp=fopen(argv[1],"r")) )
		{
			perror("fopen");
			exit(0);
		}
		else
		{
			while (!feof(fp))
			{
				fgets(line,1023,fp);
					parser(line,vx);
			}
			fclose(fp);
			printf("Vertices: %d  Faces: %d\n",v_num,f_num);
		}
	}
	else
	{
		printf("Usage: tricera [FILE] (e.g. ./tricera asc/tricera.asc ).\n");
		exit (0);
	}
}

void qs(Vertex *vx_swap2,int left, int right)
{
	register int i,j;
	int a,b,c;
	float x;
	Face swap;

	i=left; j=right;

		a = fc[(left+right)/2].a;
		b = fc[(left+right)/2].b;
		c = fc[(left+right)/2].c;
			x = vx_swap2[a].z + vx_swap2[b].z + vx_swap2[c].z;

		do
		{
			while (
				((vx_swap2[fc[i].a].z + vx_swap2[fc[i].b].z + vx_swap2[fc[i].c].z)
				< x ) && (i<right)) i++;
		
			while (
				((vx_swap2[fc[j].a].z + vx_swap2[fc[j].b].z + vx_swap2[fc[j].c].z)
				> x ) && (j>left)) j--;

			if (i <= j)
			{
				swap = fc[i];
				fc[i] = fc[j];
				fc[j] = swap;
					i++; j--;
			}

		}while(i <= j);

		if (left < j) qs(vx_swap2, left, j);
		if (i < right) qs(vx_swap2, i, right);
}

void sort_q(Vertex *vx_swap2, int n)
{
	qs(vx_swap2, 0, n-1);
}

void init_math()
{
	float i;
	int n=0;

	for (i=0;i<6.283;i=i+.001)
	{
		v_sin[n]=sin(i);
		n++;
	}
}

float q_sin(float a)
{
	while (a>6.284) a=a-6.284;
	while (a<0) a=6.284+a;
	return v_sin[(int)(a*1000)];
}

float q_cos(float a)
{
	a=a+1.571;
	while (a>6.284) a=a-6.284;
	while (a<0) a=6.284+a;
	return v_sin[(int)(a*1000)];
}

void proc_3d(float ax, float ay, float az)
{
	Vertex static vx_swap1[MAX_VERTEX];
	Vertex static vx_swap2[MAX_VERTEX];
	int i,mx=DW/2,my=DH/2+60,zoom=70;
	XPoint ps[3];
	int a=0,b=0,c=0,m,n;

	for (i=0;i<v_num;i++)
	{
		vx_swap1[i].x = vx[i].x * q_cos(az) - vx[i].y * q_sin(az);
		vx_swap1[i].y = vx[i].x * q_sin(az) + vx[i].y * q_cos(az);
		vx_swap1[i].z = vx[i].z;

		vx_swap2[i].y = vx_swap1[i].y * q_cos(ax) - vx_swap1[i].z * q_sin(ax);
		vx_swap2[i].z = vx_swap1[i].y * q_sin(ax) + vx_swap1[i].z * q_cos(ax);
		vx_swap2[i].x = vx_swap1[i].x;

	//	vx_swap1[i].z = vx_swap2[i].z * q_cos(ay) - vx_swap2[i].x * q_sin(ay);
	//	vx_swap1[i].x = vx_swap2[i].z * q_sin(ay) + vx_swap2[i].x * q_cos(ay);
	//	vx_swap1[i].y = vx_swap2[i].y;
	}

	sort_q (vx_swap2,f_num);

	for(i=0;i<f_num;i++)
	{
		a=fc[i].a;
		b=fc[i].b;
		c=fc[i].c;

		ps[0].x=vx_swap2[a].x * zoom + mx;
		ps[0].y=vx_swap2[a].y * zoom + my;
		ps[1].x=vx_swap2[b].x * zoom + mx;
		ps[1].y=vx_swap2[b].y * zoom + my;
		ps[2].x=vx_swap2[c].x * zoom + mx;
		ps[2].y=vx_swap2[c].y * zoom + my;

		m= ((vx_swap2[a].z + vx_swap2[b].z + vx_swap2[c].z) + 4 ) /20 * 0xff;
			if (m>0xff) m=0xff;
			if (m<0x0) m=0x0;
				n = m * ( 0x10000 + 0x100 + 0x1);
					XSetForeground(dpy,gc,n);
		XFillPolygon(dpy,buffer,gc,ps,3,Convex,CoordModeOrigin);
	}
}

void tricera (float ax, float ay, float az)
{
	XSetForeground(dpy,gc,0x707070);
		XFillRectangle (dpy,buffer,gc,0,0,DW,DH);

		XSetForeground(dpy,gc,0x555555);
		XDrawLine(dpy,buffer,gc,DW/2,DH/2-100,DW/2,DH/2+100);
		XDrawLine(dpy,buffer,gc,DW/2-100,DH/2,DW/2+100,DH/2);
		proc_3d (ax,ay,az);
			draw_buffer(0,0,DW,DH);
}