#include <math.h>
#include <stdio.h>
#include <stdlib.h>


#include "glut.h"


float point[2];
int points = 10000000;

void f1(){
	point[0] = point[0]*0.5;
	point[1] = point[1]*0.5;
}
void f2(){
	point[0] = point[0]*0.5+0.5;
	point[1] = point[1]*0.5;
}

void f3(){
	point[0] = point[0]*0.5;
	point[1] = point[1]*0.5+0.5;
}


void p1(){
	point[0] = 0;
	point[1] = 0.16*point[1];
}
void p2(){
	point[0] = 0.85*point[0]+0.04*point[1];
	point[1] = -0.04*point[0]+0.85*point[1] + 1.6;
}
void p3(){
	point[0] = 0.2*point[0] - 0.26*point[1];
	point[1] = 0.23*point[0] + 0.22*point[1] + 1.6;
}
void p4(){
	point[0] = -0.15*point[0] + 0.28*point[1];
	point[1] = 0.26*point[0] + 0.24*point[1] + 0.44;
}


void set_rand_point(){
	//point[0] = (rand() % 1000) /1000.0;
	//point[1] = (rand() % 1000) /1000.0;
	point[0] = 0;
	point[1] = 0;
}

int probability(){
	int r = rand() % 100;
	if(r < 1)
		return 0;
	if(r < 86)
		return 1;
	if(r < 93)
		return 2;
	return 3;

}

void render_scene(void) {
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glPointSize(1);
	glBegin(GL_POINTS);
		set_rand_point();

		for(int i = 0; i < points; i++)
		{
			switch(probability()){
				case 0:
					p1();
					break;

				case 1:
					p2();
					break;

				case 2:
					p3();
					break;

				case 3:
					p4();
					break;
			}
			glVertex2f(point[0],point[1]);
		}
	glEnd();



	glFlush();
}

void my_keyboard(unsigned char key, int x, int y){
	switch(key){
		case '+':
			if(points * 2 > 1000000)
				points = 1000000;
			else{
				points *= 2;
			}
			points *= 2;
			break;
		case '-':
			if(points > 1)points /= 2;;
			break;
	}
	render_scene();

}
int main(int argc, char **argv) {

	// init GLUT and create window

	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DEPTH | GLUT_RGBA);
	glutInitWindowSize(600,600);
	glutCreateWindow("Lighthouse3D - GLUT Tutorial");
// register callbacks
	glutDisplayFunc(render_scene);

	glutKeyboardFunc(my_keyboard);

	// OpenGL init
	glEnable(GL_DEPTH_TEST);
	glMatrixMode(GL_MODELVIEW);
	glTranslated(-0.5,-1.0,0);
	glScalef(0.18,0.18,0.18);
	// enter GLUT event processing cycle
	glutMainLoop();

	return 1;
}