Proiect Geometrie

main.c

// test.cpp : Defines the entry polong for the console application.
//
#include <GL/freeglut.h>
#include <stdio.h>

double long x[] ={10,10,55,20,60,55,80,60,96,50,49,55};
double long y[] ={10,60,20,35,50,55,61,50,40,65,29,14};

int nr=sizeof(x)/sizeof(double long)-1;
long aux[256];
long punctex[100];
long punctey[100];
long nrordine[100];
long i,j;
int status=0;
double a,b;

double long xs[256], ys[256];
double long h_nodes[256];
int h_nodes_len;
int len;

#define MAX(a,b) (a > b ? a : b)
#define MIN(a,b) (a < b ? a : b)

double long xrm;

int my_intersection(double long x1, double long y1, double long x2, double long y2, double long x3, double long y3, double long x4, double long y4, double long *xf, double long *yf)
{
	*xf = ((((x1 * y2) - (y1 * x2)) * (x3 - x4)) - ((x1 - x2) * ((x3 * y4) - (y3 * x4)))) / ((x1 - x2) * (y3 - y4) - (y1 - y2) * (x3 - x4));
	*yf = ((((x1 * y2) - (y1 * x2)) * (y3 - y4)) - ((y1 - y2) * ((x3 * y4) - (y3 * x4)))) / ((x1 - x2) * (y3 - y4) - (y1 - y2) * (x3 - x4));
    if (x3 == x4) 
        return ((MIN(y3, y4) <= *yf && MAX(y3, y4) >= *yf && MIN(x1, x2) <= x3 && MAX(x1, x2) >= x3));
	return ((MIN(x1, x2) < *xf) && (*xf < MAX(x1, x2)) && (MIN(x3, x4) < *xf) && (*xf < MAX(x3, x4)));
}

double long ecuatie(double long x, double long y, double long x1, double long y1, double long x2, double long y2)
{
	return (x*y1+x1*y2+y*x2-x2*y1-x1*y-x*y2);
}

long intersectie(double long x1, double long y1, double long x2, double long y2, double long x3, double long y3, double long x4, double long y4)
{
	if (((ecuatie(x3,y3,x1,y1,x2,y2) * ecuatie(x4,y4,x1,y1,x2,y2)) < 0) && ((ecuatie(x1,y1,x3,y3,x4,y4)*ecuatie(x2,y2,x3,y3,x4,y4))<0)) return 1;
	return 0;
}

double long coordXpunctintersectie(double long x1, double long y1, double long x2, double long y2, double long x3, double long y3, double long x4, double long y4) 
{
	return (((x1*y2-y1*x2)*(x3-x4)-(x1-x2)*(x3*y4-y3*x4))  /  ((x1-x2)*(y3-y4)-(y1-y2)*(x3-x4)));
}

double coordYpunctintersectie(double long x1, double long y1, double long x2, double long y2, double long x3, double long y3, double long x4, double long y4) 
{
	return (((x1*y2-y1*x2)*(y3-y4)-(y1-y2)*(x3*y4-y3*x4))  /  ((x1-x2)*(y3-y4)-(y1-y2)*(x3-x4)));
}

void init (void) // initializare ecran de vizualizare
{
	glClearColor (1.0, 1.0, 1.0, 0.0); // culoarea de fond a ecranului
	//glMatrixMode (GL_PROJECTION); // reprezentare 2D; proiectie ortogonala
	gluOrtho2D (0.0, 120.0, 70.0, 0.0);
}

// Aici modific realitatea sa se supuna la realitatea mea.
void fixer(void)
{
	int it;
	for(it=0; it<=nr; it++)
	{
		xs[it] = x[it];
		ys[it] = y[it];
	}
	xs[nr+1] = x[0];
	ys[nr+1] = y[0];
	len = nr + 2;
}

int comparator(const void *a, const void *b)
{
	double long rez;
	rez = *(double long *) a - *(double long *) b;
	if(rez > 0)
		return 1;
	if(rez < 0)
		return -1;
	return 0;
}

void draw_line_even_odd(double long line)
{
	int params[4];
	int toggle = 0, it;
	double long temp_x, temp_y;
	glGetIntegerv(GL_VIEWPORT, params);

	h_nodes[0] = 0;
	h_nodes_len++;

	for(it=0; it<len-1; it++)
		if(my_intersection(0, line, params[2], line, xs[it], ys[it], xs[it+1], ys[it+1], &temp_x, &temp_y))
		{
			h_nodes[h_nodes_len] = temp_x;
			h_nodes_len++;
		}

	qsort(h_nodes, h_nodes_len, sizeof(double long), comparator);

	glBegin(GL_LINES);
	for(it=0; it<h_nodes_len-1; it++)
	{
		if (toggle)
			glColor3f(0.2, 0.3, 0);
		else
			glColor3f(0, 0.2, 0.3);
        glVertex2f(h_nodes[it]+0.4, line);
		glVertex2f(h_nodes[it+1]-0.4, line);
        toggle = 1 - toggle;
	}
	glColor3f(0, 0.2, 0.3);
	glVertex2f(h_nodes[h_nodes_len-1], line);
	glVertex2f(120, line);
	glEnd();

	h_nodes_len = 0;
	glColor3f(0, 0.2, 0.3);
}

void desen (void) // procedura desenare
{
	//gradient background
	glPushMatrix();
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	glBegin(GL_QUADS);
	//black color
	glColor3f(0.0,0.0,0.0);
	glVertex2f(-1.0, 1.0);
	glVertex2f(-1.0,-1.0);
	//white color
	glColor3f(1.0,1.0,1.0);
	glVertex2f(1.0,-1.0);
	glVertex2f(1.0, 1.0);
	glEnd();
	glPopMatrix();

	int params[4];
	glGetIntegerv(GL_VIEWPORT, params);
	//int width = params[2];
	//int height = params[3];

	glDisable(GL_LINE_STIPPLE);
	glLineWidth(1);
	//glShadeModel(GL_FLAT);
	glColor3f(1, 0, 0);

	fixer();
	float it;
	for(it = 0; it < 70; it += 0.1)
		draw_line_even_odd(it);
	//points
	glPointSize(5.0);
	glColor3f (0.0, 0.0, 0.0); //negru
	glBegin (GL_POINTS); //marcam punctele initiale
	for(i=0;i<=nr;i++) {
		glVertex2i(x[i],y[i]);
	}
	glEnd();

	int k=0;
	for(i=0; i<nr; i++)
		for(j=i+1; j<nr; j++) 
			if (intersectie(x[i], y[i], x[i+1], y[i+1],
						x[j], y[j], x[j+1], y[j+1])==1)
			{
				aux[i] = 1;
				aux[j] = 1;
				a=coordXpunctintersectie(x[i], y[i], x[i+1], y[i+1],
						x[j], y[j], x[j+1], y[j+1]);
				b=coordYpunctintersectie(x[i], y[i], x[i+1], y[i+1],
						x[j], y[j], x[j+1], y[j+1]);

				punctex[k]=a;
				punctey[k]=b;
				k++;
				glColor3f(0.0,1.0,0.0);  //marcheaza punctu de intersectie
				glBegin(GL_POINTS);
				glVertex2d(a,b);
				glEnd();
			}
	glEnable(GL_LINE_STIPPLE);
	glLineWidth(4.0);
	for(i=0;i<nr;i++)
	{  
		if (aux[i]) {
			glColor3f (1.0, 0.0, 0.0); //red
			// Set the stippling pattern
			glLineStipple(3, 0xAAAA);
		} 
		else { 
			glColor3f (0.0, 0.0, 1.0);  //blue
			//Set a different stippling pattern
			glLineStipple(2, 0x0C0F);
		}
		glBegin(GL_LINE_STRIP);
		glVertex2i(x[i],y[i]);
		glVertex2i(x[i+1],y[i+1]);
		glEnd();
	} 

	//caz special pt segmentul ce inchide linia poligonala
	for (i=0;i<nr;i++)
		if (intersectie(x[i],y[i],x[i+1],y[i+1],x[0],y[0],x[nr],y[nr]) ==1) 
			status++;
	if (status>0) {
		glColor3f (1.0, 0.0, 0.0); //rosu
		glLineStipple(3, 0xAAAA);
	}
	else  {
		glColor3f (0.0, 0.0, 1.0);  //albastru
		glLineStipple(2, 0x0C0F);
	}
	glBegin(GL_LINES);
	glVertex2i(x[0],y[0]);
	glVertex2i(x[nr],y[nr]);
	glEnd();
	glFlush ( );

}

int main (int argc, char** argv)
{
	glutInit (&argc, argv);
	glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);

	glutInitWindowPosition (100, 20); // pozitia initiala a ferestrei de vizualizare
	glutInitWindowSize (1200, 700); // dimensiunile ferestrei
	glutCreateWindow ("Puncte & Segmente"); // titlul ferestrei
	init ( );
	glClear (GL_COLOR_BUFFER_BIT);
	glutDisplayFunc (desen);
	glutMainLoop ( );
    return 0;
}

Makefile

PROG = main
OBJ = $(PROG).o
FLAGS = -Wall -lglut -lGL -lGLU

all : $(PROG)

$(PROG) : $(OBJ)
	gcc $(OBJ) $(FLAGS) -o $(PROG)

%.o : %.c
	gcc $(FLAGS) -c $^

clean:
	$(RM) $(OBJ) $(PROG)