SierpinskiGasket.cpp

#include<stdio.h>
#include<gl/glut.h>
int c;
float v[4][3] = { {0,0,1},{-1,-0.5,0},{0,1,0},{1,-0.5,0} };
void myinit()
{
	glMatrixMode(GL_PROJECTION_MATRIX);
	glLoadIdentity();
	glOrtho(-2, 2, -2, 2, -2, 2);
	glMatrixMode(GL_MODELVIEW);
}
void disp_tri(float a[3], float b[3], float c[3])
{
	glBegin(GL_POLYGON);
	glVertex3fv(a);
	glVertex3fv(b);
	glVertex3fv(c);
	glEnd();
}
void div_tri(float* a, float* b, float* c, int n)
{
	float v1[3], v2[3], v3[3];
	int i;

	if (n > 0)
	{
		for (i = 0; i < 3; i++)
		{
			v1[i] = (a[i] + b[i]) / 2;
			v2[i] = (a[i] + c[i]) / 2;
			v3[i] = (b[i] + c[i]) / 2;
		}
		div_tri(a, v1, v2, n - 1);
		div_tri(v1, b, v3, n - 1);
		div_tri(v2, v3, c, n - 1);

	}
	else
		disp_tri(a, b, c);
}

void display()
{
	glClearColor(0, 0, 0, 1);
	glClear(GL_COLOR_BUFFER_BIT);

	glColor3f(1, 1, 1);
	div_tri(v[1], v[2], v[3], c);

	glColor3f(1, 0, 0);
	div_tri(v[0], v[1], v[2], c);

	glColor3f(0, 1, 0);
	div_tri(v[0], v[2], v[3], c);

	glColor3f(0, 0, 1);
	div_tri(v[0], v[1], v[3], c);

	glFlush();
}

int main(int argc, char **argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(600, 600);
	glutInitWindowPosition(300, 150);
	printf("Enter the number of subdivisions:\n");
	scanf_s("%d", &c);
	glutCreateWindow("3D Recursive Sierpinski Gasket");
	myinit();
	glutDisplayFunc(display);
	glutMainLoop();
}